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• 201. [Article] Non-random biodiversity loss underlies predictable increases in viral disease prevalence

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The article is copyrighted by the author(s) and published by The Royal Society. It can be found at: http://rsif.royals...

  Citation × Citation Citation Abstract Copy Title: Non-random biodiversity loss underlies predictable increases in viral disease prevalence Author: Mitchell, Charles E., Power, Alison G., Lacroix, Christelle, Borer, Elizabeth T., Seabloom, Eric W., Jolles, Anna This is an author's peer-reviewed final manuscript, as accepted by the publisher. The article is copyrighted by the author(s) and published by The Royal Society. It can be found at: http://rsif.royalsocietypublishing.org/. Title: Non-random biodiversity loss underlies predictable increases in viral disease prevalence Author: Mitchell, Charles E., Power, Alison G., Lacroix, Christelle, Borer, Elizabeth T., Seabloom, Eric W., Jolles, Anna This is an author's peer-reviewed final manuscript, as accepted by the publisher. The article is copyrighted by the author(s) and published by The Royal Society. It can be found at: http://rsif.royalsocietypublishing.org/. Close

• 202. [Article] Climate-Suitable Planting as a Strategy for Maintaining Forest Productivity and Functional Diversity

  Within the time frame of the longevity of tree species, climate change will change faster than the ability of natural tree migration. Migration lags may result in reduced productivity and reduced diversity ...

  Citation × Citation Citation Abstract Copy Title: Climate-Suitable Planting as a Strategy for Maintaining Forest Productivity and Functional Diversity Author: Duveneck, Matthew Joshua, Scheller, Robert M. Year: 2015 Within the time frame of the longevity of tree species, climate change will change faster than the ability of natural tree migration. Migration lags may result in reduced productivity and reduced diversity in forests under current management and climate change. We evaluated the efficacy of planting climate-suitable tree species (CSP), those tree species with current or historic distributions immediately south of a focal landscape, to maintain or increase aboveground biomass, productivity, and species and functional diversity. We modeled forest change with the LANDIS-II forest simulation model for 100 years (2000–2100) at a 2-ha cell resolution and five-year time steps within two landscapes in the Great Lakes region (northeastern Minnesota and northern lower Michigan, USA). We compared current climate to low- and high-emission futures. We simulated a low-emission climate future with the Intergovernmental Panel on Climate Change (IPCC) 2007 B1 emission scenario and the Parallel Climate Model Global Circulation Model (GCM). We simulated a high-emission climate future with the IPCC A1FI emission scenario and the Geophysical Fluid Dynamics Laboratory (GFDL) GCM. We compared current forest management practices (business-asusual) to CSP management. In the CSP scenario, we simulated a target planting of 5.28% and 4.97% of forested area per five-year time step in the Minnesota and Michigan landscapes, respectively. We found that simulated CSP species successfully established in both landscapes under all climate scenarios. The presence of CSP species generally increased simulated aboveground biomass. Species diversity increased due to CSP; however, the effect on functional diversity was variable. Because the planted species were functionally similar to many native species, CSP did not result in a consistent increase nor decrease in functional diversity. These results provide an assessment of the potential efficacy and limitations of CSP management. These results have management implications for sites where diversity and productivity are expected to decline. Future efforts to restore a specific species or forest type may not be possible, but CSP may sustain a more general ecosystem service (e.g., aboveground biomass). Title: Climate-Suitable Planting as a Strategy for Maintaining Forest Productivity and Functional Diversity Author: Duveneck, Matthew Joshua, Scheller, Robert M. Year: 2015 Within the time frame of the longevity of tree species, climate change will change faster than the ability of natural tree migration. Migration lags may result in reduced productivity and reduced diversity in forests under current management and climate change. We evaluated the efficacy of planting climate-suitable tree species (CSP), those tree species with current or historic distributions immediately south of a focal landscape, to maintain or increase aboveground biomass, productivity, and species and functional diversity. We modeled forest change with the LANDIS-II forest simulation model for 100 years (2000–2100) at a 2-ha cell resolution and five-year time steps within two landscapes in the Great Lakes region (northeastern Minnesota and northern lower Michigan, USA). We compared current climate to low- and high-emission futures. We simulated a low-emission climate future with the Intergovernmental Panel on Climate Change (IPCC) 2007 B1 emission scenario and the Parallel Climate Model Global Circulation Model (GCM). We simulated a high-emission climate future with the IPCC A1FI emission scenario and the Geophysical Fluid Dynamics Laboratory (GFDL) GCM. We compared current forest management practices (business-asusual) to CSP management. In the CSP scenario, we simulated a target planting of 5.28% and 4.97% of forested area per five-year time step in the Minnesota and Michigan landscapes, respectively. We found that simulated CSP species successfully established in both landscapes under all climate scenarios. The presence of CSP species generally increased simulated aboveground biomass. Species diversity increased due to CSP; however, the effect on functional diversity was variable. Because the planted species were functionally similar to many native species, CSP did not result in a consistent increase nor decrease in functional diversity. These results provide an assessment of the potential efficacy and limitations of CSP management. These results have management implications for sites where diversity and productivity are expected to decline. Future efforts to restore a specific species or forest type may not be possible, but CSP may sustain a more general ecosystem service (e.g., aboveground biomass). Close

• 203. [Article] Conserving avian diversity in agricultural systems : the role of isolated Oregon white oak legacy trees

  Over one third of the earth’s land surface has been modified to some extent for agricultural purposes. The large global footprint of agriculture, combined with the knowledge that existing reserve networks ...

  Citation × Citation Citation Abstract Copy Title: Conserving avian diversity in agricultural systems : the role of isolated Oregon white oak legacy trees Author: DeMars, Craig A. Over one third of the earth’s land surface has been modified to some extent for agricultural purposes. The large global footprint of agriculture, combined with the knowledge that existing reserve networks are likely insufficient for long-term conservation of native biodiversity, has necessitated that agricultural systems contribute to conservation of native biota. Current research paradigms have taken a landscape-level view of conservation in agricultural systems, assessing the relative contribution that various habitat elements make in conserving biodiversity in the agricultural matrix. Within this context, I investigated the potential role that individual Oregon white oak (Quercus garryana) trees play in conserving avian diversity in the agricultural systems of the Willamette Valley, Oregon, U.S.A. Retained by landowners primarily for cultural reasons, many of these trees pre-date Euro-American settlement of the Willamette Valley and thus are biological legacies from historic white oak habitats. I compared avian use of isolated white oak trees in three different site contexts - croplands, pastures, and oak savanna reserves - and used an information-theoretic model selection approach to determine the relative importance of site-specific and landscape-level factors thought to influence avian use of these individual trees. Specifically, I tested whether avian species presence on Oregon white oak legacy trees could best be explained by: (i) tree architecture; (ii) the distance of the tree to the nearest tree or patch; (iii) the density of trees in the surrounding landscape; or (iv) the matrix in which the tree was embedded. I evaluated species-specific responses as well as four community-level responses: (i) total bird species richness; (ii) species richness of native birds associated with oak savanna; (iii) species richness of tree foraging birds; and (iv) the combined species richness of aerial- and ground-foraging birds. I sampled 35 individual white oak trees and recorded 47 avian species using these individual trees, including a high number of oak savanna-associated species such White-breasted Nuthatch (Sitta carolinensis) and Chipping Sparrow (Spizella passerina). For the majority of these species, the frequency of use of individual oak trees was similar among crop, pasture and reserve sites. The most important factors for predicting avian use were tree size and tree density in the surrounding landscape. In general, avian use increased with increasing tree size and decreasing tree density. My findings suggest that individual white oak legacy trees have the potential to positively contribute to landscape-level conservation of a wide range of avian species within the Willamette Valley. Due to the declining abundance of white oak legacy trees on the landscape, the conservation of existing legacy trees and the recruitment of younger replacement trees should be a management priority. Title: Conserving avian diversity in agricultural systems : the role of isolated Oregon white oak legacy trees Author: DeMars, Craig A. Over one third of the earth’s land surface has been modified to some extent for agricultural purposes. The large global footprint of agriculture, combined with the knowledge that existing reserve networks are likely insufficient for long-term conservation of native biodiversity, has necessitated that agricultural systems contribute to conservation of native biota. Current research paradigms have taken a landscape-level view of conservation in agricultural systems, assessing the relative contribution that various habitat elements make in conserving biodiversity in the agricultural matrix. Within this context, I investigated the potential role that individual Oregon white oak (Quercus garryana) trees play in conserving avian diversity in the agricultural systems of the Willamette Valley, Oregon, U.S.A. Retained by landowners primarily for cultural reasons, many of these trees pre-date Euro-American settlement of the Willamette Valley and thus are biological legacies from historic white oak habitats. I compared avian use of isolated white oak trees in three different site contexts - croplands, pastures, and oak savanna reserves - and used an information-theoretic model selection approach to determine the relative importance of site-specific and landscape-level factors thought to influence avian use of these individual trees. Specifically, I tested whether avian species presence on Oregon white oak legacy trees could best be explained by: (i) tree architecture; (ii) the distance of the tree to the nearest tree or patch; (iii) the density of trees in the surrounding landscape; or (iv) the matrix in which the tree was embedded. I evaluated species-specific responses as well as four community-level responses: (i) total bird species richness; (ii) species richness of native birds associated with oak savanna; (iii) species richness of tree foraging birds; and (iv) the combined species richness of aerial- and ground-foraging birds. I sampled 35 individual white oak trees and recorded 47 avian species using these individual trees, including a high number of oak savanna-associated species such White-breasted Nuthatch (Sitta carolinensis) and Chipping Sparrow (Spizella passerina). For the majority of these species, the frequency of use of individual oak trees was similar among crop, pasture and reserve sites. The most important factors for predicting avian use were tree size and tree density in the surrounding landscape. In general, avian use increased with increasing tree size and decreasing tree density. My findings suggest that individual white oak legacy trees have the potential to positively contribute to landscape-level conservation of a wide range of avian species within the Willamette Valley. Due to the declining abundance of white oak legacy trees on the landscape, the conservation of existing legacy trees and the recruitment of younger replacement trees should be a management priority. Close

• 204. [Article] Conservation and spatial use analyses for the recovery of bighorn sheep in the Peninsular Ranges

  The status of wild sheep in North America typifies the plight of many wildlife species in modern times: wild sheep have declined to 10-40% of their numbers during pristine times and on a global scale approximately ...

  Citation × Citation Citation Abstract Copy Title: Conservation and spatial use analyses for the recovery of bighorn sheep in the Peninsular Ranges Author: Ostermann, Stacey D. The status of wild sheep in North America typifies the plight of many wildlife species in modern times: wild sheep have declined to 10-40% of their numbers during pristine times and on a global scale approximately 31% of Caprine are considered threatened or critical. As human populations and the number of threatened and endangered wildlife species increase, research into the causes of wildlife population declines and tools to aid recovery are urgently needed. We conducted two studies of endangered desert bighorn sheep (Ovis canadensis nelsoni) in the Peninsular Ranges of Southern California with the primary goal of furthering recovery efforts for this species. First, in order to evaluate a captive breeding program for Peninsular bighorn, we developed the following criteria to provide a standard means of evaluating ongoing captive breeding and reintroduction programs: (1) survival and recruitment rates in the captive population, (2) survival of released animals, (3) recruitment of released animals, (4) growth rate of the reintroduced or augmented population, and (5) establishment of a viable wild population. In assessing the Peninsular bighorn sheep program, we found that while reintroduction did not result in population growth or establishment of a viable population, it helped prevent extirpation of the reinforced deme, preserved metapopulation linkage, and aided habitat preservation. Chronic low recruitment and low adult survivorship precluded achievement of criteria 3-5. Environmental conditions in the release area also appeared to hinder program success. We suggest that periodic evaluations are useful for improving the success of individual captive breeding and reintroduction programs, as well as for meta-analyses needed to refine reintroduction science as a recovery tool for threatened or endangered populations. Wildlife habituated to the presence of humans have been recognized as a new dilemma facing wildlife managers. Our second study involved examining the habitat use, home range size, and nutritional levels of Peninsular desert bighorn sheep along an urbanwildland interface during two time periods (1981-82 and 1995-98). We found that bighorn sheep monitored during 1995-98 used habitat within (P <0.001) and closer to (P < 0.001) urban environments than bighorn sheep monitored in 1981-82. Females monitored in the 1990s had smaller home ranges (P = 0.03), and selected habitat farther from escape terrain, natural water sources, and hiking trails (P <0.05) than females monitored in the 1980s. Habitat selection patterns were similar among captive-reared and wild-reared bighorn, as well as males and females within the 1990s. Bighorn use of urban areas increased 5-fold between our study periods; however, this population has declined precipitously in recent times and urbanization appears to be contributing directly and indirectly to adult and juvenile mortality. We recommend excluding bighorn from urban areas in order to encourage more natural resource use patterns. Understanding the implications of wildlife-human interactions may require long-term studies because the results of these interactions are often not obvious or intuitive. Title: Conservation and spatial use analyses for the recovery of bighorn sheep in the Peninsular Ranges Author: Ostermann, Stacey D. The status of wild sheep in North America typifies the plight of many wildlife species in modern times: wild sheep have declined to 10-40% of their numbers during pristine times and on a global scale approximately 31% of Caprine are considered threatened or critical. As human populations and the number of threatened and endangered wildlife species increase, research into the causes of wildlife population declines and tools to aid recovery are urgently needed. We conducted two studies of endangered desert bighorn sheep (Ovis canadensis nelsoni) in the Peninsular Ranges of Southern California with the primary goal of furthering recovery efforts for this species. First, in order to evaluate a captive breeding program for Peninsular bighorn, we developed the following criteria to provide a standard means of evaluating ongoing captive breeding and reintroduction programs: (1) survival and recruitment rates in the captive population, (2) survival of released animals, (3) recruitment of released animals, (4) growth rate of the reintroduced or augmented population, and (5) establishment of a viable wild population. In assessing the Peninsular bighorn sheep program, we found that while reintroduction did not result in population growth or establishment of a viable population, it helped prevent extirpation of the reinforced deme, preserved metapopulation linkage, and aided habitat preservation. Chronic low recruitment and low adult survivorship precluded achievement of criteria 3-5. Environmental conditions in the release area also appeared to hinder program success. We suggest that periodic evaluations are useful for improving the success of individual captive breeding and reintroduction programs, as well as for meta-analyses needed to refine reintroduction science as a recovery tool for threatened or endangered populations. Wildlife habituated to the presence of humans have been recognized as a new dilemma facing wildlife managers. Our second study involved examining the habitat use, home range size, and nutritional levels of Peninsular desert bighorn sheep along an urbanwildland interface during two time periods (1981-82 and 1995-98). We found that bighorn sheep monitored during 1995-98 used habitat within (P <0.001) and closer to (P < 0.001) urban environments than bighorn sheep monitored in 1981-82. Females monitored in the 1990s had smaller home ranges (P = 0.03), and selected habitat farther from escape terrain, natural water sources, and hiking trails (P <0.05) than females monitored in the 1980s. Habitat selection patterns were similar among captive-reared and wild-reared bighorn, as well as males and females within the 1990s. Bighorn use of urban areas increased 5-fold between our study periods; however, this population has declined precipitously in recent times and urbanization appears to be contributing directly and indirectly to adult and juvenile mortality. We recommend excluding bighorn from urban areas in order to encourage more natural resource use patterns. Understanding the implications of wildlife-human interactions may require long-term studies because the results of these interactions are often not obvious or intuitive. Close

• 205. [Image] Macroecology, paleoecology, and ecological integrity of terrestrial species and communities of the interior Columbia River basin and northern portions of the Klamath and Great Basins

  	This report presents information on biogeography and broad-scale ecology (macroecology) of selected fungi, lichens, bryophytes, vascular plants, invertebrates, and vertebrates of the interior Columbia ...
  	Citation × Citation Citation Abstract Copy Title: Macroecology, paleoecology, and ecological integrity of terrestrial species and communities of the interior Columbia River basin and northern portions of the Klamath and Great Basins Author: U.S. Department of Agriculture. Forest Service. Pacific Northwest Research Station; U.S.Department of the Interior. Bureau of Land Management. Year: 1998, 2006, 2005 This report presents information on biogeography and broad-scale ecology (macroecology) of selected fungi, lichens, bryophytes, vascular plants, invertebrates, and vertebrates of the interior Columbia River basin and adjacent areas. Rare plants include many endemics associated with local conditions. Potential plant and invertebrate bioindicators are identified. Species ecological functions differ among communities and variously affect ecosystem diversity and productivity. Species of alpine and subalpine communities are identified that may be at risk from climate change. Maps of terrestrial ecological integrity are presented. Keywords: Macroecology, paleoecology, ecological integrity, terrestrial communities, ecosystems, wildlife, fungi, lichens, bryophytes, vascular plants, invertebrates, arthropods, mollusks, amphibians, reptiles, birds, mammals, endemism, interior Columbia River basin, Klamath Basin, Great Basin. Title: Macroecology, paleoecology, and ecological integrity of terrestrial species and communities of the interior Columbia River basin and northern portions of the Klamath and Great Basins Author: U.S. Department of Agriculture. Forest Service. Pacific Northwest Research Station; U.S.Department of the Interior. Bureau of Land Management. Year: 1998, 2006, 2005 This report presents information on biogeography and broad-scale ecology (macroecology) of selected fungi, lichens, bryophytes, vascular plants, invertebrates, and vertebrates of the interior Columbia River basin and adjacent areas. Rare plants include many endemics associated with local conditions. Potential plant and invertebrate bioindicators are identified. Species ecological functions differ among communities and variously affect ecosystem diversity and productivity. Species of alpine and subalpine communities are identified that may be at risk from climate change. Maps of terrestrial ecological integrity are presented. Keywords: Macroecology, paleoecology, ecological integrity, terrestrial communities, ecosystems, wildlife, fungi, lichens, bryophytes, vascular plants, invertebrates, arthropods, mollusks, amphibians, reptiles, birds, mammals, endemism, interior Columbia River basin, Klamath Basin, Great Basin. Close

• 206. [Article] Ultraviolet radiation as an environmental stressor of amphibians

  My thesis explored the effects of and potential mediating mechanisms for an important environmental stressor, ultraviolet-B (UVB) radiation. UVB radiation has negative effects on organisms in both terrestrial ...

  Citation × Citation Citation Abstract Copy Title: Ultraviolet radiation as an environmental stressor of amphibians Author: Bancroft, Betsy A. My thesis explored the effects of and potential mediating mechanisms for an important environmental stressor, ultraviolet-B (UVB) radiation. UVB radiation has negative effects on organisms in both terrestrial and aquatic systems. I used meta-analysis to quantify the effects of UVB radiation on a diversity of aquatic organisms (Chapter 2). UVB negatively affects aquatic organisms by reducing both survival and growth. In particular, UVB reduces growth of embryos more than any other life history stage. Some taxonomic groups may be more affected by UVB radiation than others. In our analysis, the growth of members of the kingdom Protozoa was suppressed by UVB radiation to a greater degree than any other kingdom. These analyses suggest that UVB is an important stressor in both freshwater and marine systems. Amphibians are a common component of freshwater systems and are experiencing world-wide population declines. These declines may be due to a number of causes including habitat loss, introduced species, global climate change, disease, toxic chemicals and UVB radiation. I used meta-analytic techniques to quantify the effects of UVB radiation on amphibians. By synthesizing the results of 41 articles on the effects of UVB radiation on amphibians (Chapter 3), I found a nearly 2-fold reduction in survival of amphibians exposed to UVB radiation. Salamanders (caudates) appear to be more susceptible to damage from UVB than frogs or toads (anurans). Moreover, survival of larvae was much lower than survival of embryos or metamorphic individuals under UVB radiation. In addition, I used factorial meta-analytic techniques to explore the interaction between UVB radiation and other stressors in amphibian habitats. UVB radiation acted synergistically with other stressors to reduce survival of amphibians. Behavioral avoidance of UVB radiation may help mediate the negative effects of UVB radiation on amphibians. In aquatic systems, behavioral avoidance usually requires movement out of shallow water, where UVB levels can be high, into deeper waters with lower UVB transmittance. However, these two microhabitats have very different thermal profiles, creating a trade-off between exploiting warm waters with high UVB levels and avoiding UVB by seeking cooler, deeper regions of ponds. I explored the microhabitat use of larvae of four species through a series of laboratory experiments, field experiments, and observational field transects at three different amphibian habitats (Chapter 4). Larvae did not avoid UVB radiation in either the laboratory or field experiments. Larvae in thermal gradients selected relatively high temperatures regardless of the UVB exposure at these temperatures. In field transects, salamander larvae were most common in deeper, cooler waters where UVB levels were lower. In contrast, anuran larvae were frequently observed in the warmer and shallower regions of each habitat. These regions also had the highest UVB levels, suggesting that anuran larvae are exposed to high levels of UVB due to thermoregulatory behavior. Behavioral avoidance of UVB radiation is not the only mechanism amphibians may use to prevent damage from UVB. Pigments such as melanin may allow larvae to exploit warm shallow waters by absorbing harmful UVB radiation before it causes cellular damage. I tested the efficacy of melanin as a photoprotective pigment in the larvae of two species, Rana cascadae and Pseudacris regilla (Chapter 5). I found no evidence of a photoprotective function for melanin in these larvae. In contrast, lighter colored tadpoles grew more under UVB radiation compared to darker colored tadpoles. Overall, exposure to UVB reduced survival of P. regilla larvae and reduced growth of R. cascadae larvae. Larvae of both of these species were frequently observed in very shallow water with intense solar radiation. This thesis emphasizes the importance of UVB radiation as an environmental stressor in aquatic habitats. Many aquatic organisms are negatively affected by UVB exposure. My thesis work quantitatively demonstrated that UVB radiation is one factor that reduces survival of amphibians and suggests that some species are exposed to high levels of UVB radiation in natural habitats. While UVB radiation is not the sole cause of amphibian population declines, my work suggests that UVB radiation is an important stressor for amphibians that should not be overlooked. In addition, UVB radiation is clearly an important stressor for many other aquatic organisms. Future work should consider the effects of UVB in aquatic systems, particularly the effects of UVB radiation on community structure and ecosystem function. Title: Ultraviolet radiation as an environmental stressor of amphibians Author: Bancroft, Betsy A. My thesis explored the effects of and potential mediating mechanisms for an important environmental stressor, ultraviolet-B (UVB) radiation. UVB radiation has negative effects on organisms in both terrestrial and aquatic systems. I used meta-analysis to quantify the effects of UVB radiation on a diversity of aquatic organisms (Chapter 2). UVB negatively affects aquatic organisms by reducing both survival and growth. In particular, UVB reduces growth of embryos more than any other life history stage. Some taxonomic groups may be more affected by UVB radiation than others. In our analysis, the growth of members of the kingdom Protozoa was suppressed by UVB radiation to a greater degree than any other kingdom. These analyses suggest that UVB is an important stressor in both freshwater and marine systems. Amphibians are a common component of freshwater systems and are experiencing world-wide population declines. These declines may be due to a number of causes including habitat loss, introduced species, global climate change, disease, toxic chemicals and UVB radiation. I used meta-analytic techniques to quantify the effects of UVB radiation on amphibians. By synthesizing the results of 41 articles on the effects of UVB radiation on amphibians (Chapter 3), I found a nearly 2-fold reduction in survival of amphibians exposed to UVB radiation. Salamanders (caudates) appear to be more susceptible to damage from UVB than frogs or toads (anurans). Moreover, survival of larvae was much lower than survival of embryos or metamorphic individuals under UVB radiation. In addition, I used factorial meta-analytic techniques to explore the interaction between UVB radiation and other stressors in amphibian habitats. UVB radiation acted synergistically with other stressors to reduce survival of amphibians. Behavioral avoidance of UVB radiation may help mediate the negative effects of UVB radiation on amphibians. In aquatic systems, behavioral avoidance usually requires movement out of shallow water, where UVB levels can be high, into deeper waters with lower UVB transmittance. However, these two microhabitats have very different thermal profiles, creating a trade-off between exploiting warm waters with high UVB levels and avoiding UVB by seeking cooler, deeper regions of ponds. I explored the microhabitat use of larvae of four species through a series of laboratory experiments, field experiments, and observational field transects at three different amphibian habitats (Chapter 4). Larvae did not avoid UVB radiation in either the laboratory or field experiments. Larvae in thermal gradients selected relatively high temperatures regardless of the UVB exposure at these temperatures. In field transects, salamander larvae were most common in deeper, cooler waters where UVB levels were lower. In contrast, anuran larvae were frequently observed in the warmer and shallower regions of each habitat. These regions also had the highest UVB levels, suggesting that anuran larvae are exposed to high levels of UVB due to thermoregulatory behavior. Behavioral avoidance of UVB radiation is not the only mechanism amphibians may use to prevent damage from UVB. Pigments such as melanin may allow larvae to exploit warm shallow waters by absorbing harmful UVB radiation before it causes cellular damage. I tested the efficacy of melanin as a photoprotective pigment in the larvae of two species, Rana cascadae and Pseudacris regilla (Chapter 5). I found no evidence of a photoprotective function for melanin in these larvae. In contrast, lighter colored tadpoles grew more under UVB radiation compared to darker colored tadpoles. Overall, exposure to UVB reduced survival of P. regilla larvae and reduced growth of R. cascadae larvae. Larvae of both of these species were frequently observed in very shallow water with intense solar radiation. This thesis emphasizes the importance of UVB radiation as an environmental stressor in aquatic habitats. Many aquatic organisms are negatively affected by UVB exposure. My thesis work quantitatively demonstrated that UVB radiation is one factor that reduces survival of amphibians and suggests that some species are exposed to high levels of UVB radiation in natural habitats. While UVB radiation is not the sole cause of amphibian population declines, my work suggests that UVB radiation is an important stressor for amphibians that should not be overlooked. In addition, UVB radiation is clearly an important stressor for many other aquatic organisms. Future work should consider the effects of UVB in aquatic systems, particularly the effects of UVB radiation on community structure and ecosystem function. Close

• 207. [Article] Relationships of green-tree retention following timber harvest to forest growth and species composition in the western Cascade Mountains

  National Forest management in the Pacific Northwest is shifting from a focus on commodity production to ecosystem management, in which the health of the entire forest ecosystem is considered, rather than ...

  Citation × Citation Citation Abstract Copy Title: Relationships of green-tree retention following timber harvest to forest growth and species composition in the western Cascade Mountains Author: Rose, Coulter R. National Forest management in the Pacific Northwest is shifting from a focus on commodity production to ecosystem management, in which the health of the entire forest ecosystem is considered, rather than that of a few key species. Ecosystem management includes retention of some live trees following timber harvest (green-tree retention) to preserve biodiversity, imitating the natural fire regime of large, but patchy fires that leave many live trees. How ecosystem management will affect growth and species composition of future forests is an important question. This study takes a retrospective approach to this question by using past disturbance as an analogue to green-tree retention following timber harvest. Using USDA Forest Service timber inventory plot data from the Cascade Mountains of Oregon and SW Washington, 132 unmanaged stands were identified with a tree cohort of 70-110 years old (regeneration) or a tree cohort of 70-110 years old with an overstory of large trees 200+ years old (remnants). All stands were in the Tsuga heterophylla (Raf.) Sarg. zone (Franklin and Dyrness 1973). Single-aged stands represented clearcuts, while two-aged stands served as analogues to stands harvested with green-tree retention. Regeneration basal area/hectare (ba/ha) declined when remnant-tree densities exceeded about 15 remnant trees/ha (R²=0.51) in a relationship roughly described by a sigmoidal curve. Conceptually removing remnant-tree space occupancy effects decreased remnant-tree density's value as a predictor of regeneration ba/ha by about 50% at management-level remnant densities (≤45 remnant trees/ha). Thus, it appears that remnant "effects" were a result of both remnant-tree space occupancy and remnant resource use. Douglas-fir ba/ha in the regeneration also declined when remnant-tree densities exceeded about 15 remnant trees/ha (R²=0.60). Western hemlock ba/ha in the regeneration increased slightly with increasing remnant-tree densities (R²=0.19). Western redcedar ba/ha in the regeneration was apparently not related to remnant-tree density (R²=0.02). The degree of aggregation in remnant trees did not appear to affect regeneration ba/ha, but few stands contained the isolated clumps of remnant trees likely under a management scenario. Neither measured site characteristics nor regeneration density was related to regeneration ba/ha across species. Remnant-tree density was apparently unrelated to tree-species diversity in the regeneration. Total-stand ba/ha remained relatively constant across remnant densities. Title: Relationships of green-tree retention following timber harvest to forest growth and species composition in the western Cascade Mountains Author: Rose, Coulter R. National Forest management in the Pacific Northwest is shifting from a focus on commodity production to ecosystem management, in which the health of the entire forest ecosystem is considered, rather than that of a few key species. Ecosystem management includes retention of some live trees following timber harvest (green-tree retention) to preserve biodiversity, imitating the natural fire regime of large, but patchy fires that leave many live trees. How ecosystem management will affect growth and species composition of future forests is an important question. This study takes a retrospective approach to this question by using past disturbance as an analogue to green-tree retention following timber harvest. Using USDA Forest Service timber inventory plot data from the Cascade Mountains of Oregon and SW Washington, 132 unmanaged stands were identified with a tree cohort of 70-110 years old (regeneration) or a tree cohort of 70-110 years old with an overstory of large trees 200+ years old (remnants). All stands were in the Tsuga heterophylla (Raf.) Sarg. zone (Franklin and Dyrness 1973). Single-aged stands represented clearcuts, while two-aged stands served as analogues to stands harvested with green-tree retention. Regeneration basal area/hectare (ba/ha) declined when remnant-tree densities exceeded about 15 remnant trees/ha (R²=0.51) in a relationship roughly described by a sigmoidal curve. Conceptually removing remnant-tree space occupancy effects decreased remnant-tree density's value as a predictor of regeneration ba/ha by about 50% at management-level remnant densities (≤45 remnant trees/ha). Thus, it appears that remnant "effects" were a result of both remnant-tree space occupancy and remnant resource use. Douglas-fir ba/ha in the regeneration also declined when remnant-tree densities exceeded about 15 remnant trees/ha (R²=0.60). Western hemlock ba/ha in the regeneration increased slightly with increasing remnant-tree densities (R²=0.19). Western redcedar ba/ha in the regeneration was apparently not related to remnant-tree density (R²=0.02). The degree of aggregation in remnant trees did not appear to affect regeneration ba/ha, but few stands contained the isolated clumps of remnant trees likely under a management scenario. Neither measured site characteristics nor regeneration density was related to regeneration ba/ha across species. Remnant-tree density was apparently unrelated to tree-species diversity in the regeneration. Total-stand ba/ha remained relatively constant across remnant densities. Close

• 208. [Article] Do Douglas-fir branches and roots have juvenile wood?

  We sampled boles, branches, and roots of four Douglas-fir (Pseudotsuga menziesii var. menziesii) trees to learn a) whether branches and roots have a zone of juvenile wood, defined as a zone with progressive ...

  Citation × Citation Citation Abstract Copy Title: Do Douglas-fir branches and roots have juvenile wood? Author: Peterson, M. G., Lachenbruch, B., Dietterich, H. R. We sampled boles, branches, and roots of four Douglas-fir (Pseudotsuga menziesii var. menziesii) trees to learn a) whether branches and roots have a zone of juvenile wood, defined as a zone with progressive changes in wood density and/or tracheid length from the pith outward at successively greater cambial ages, and if so, b) whether the radial patterns in branches and roots are similar to those in boles. Samples came from the following positions: bole, 30 cm aboveground; branch, 30 cm outward on the lowest live branch, and root, 1–3 m from the bole. Average sample cambial ages were bole, 60 years; branch, 30 years; and root, 48 years. Roots and branches had higher density wood than did the bole at the positions studied, and roots had the longest tracheids followed by the bole and then the branches. All three positions exhibited juvenile wood but with different radial patterns. All positions had their highest density near the pith, which was followed by a steep decline in the boles and a more gradual decline in the roots and branches. Boles and roots, but not branches, then showed an increase in density after this decline. Boles and branches had short tracheids near the pith followed by a gradual increase to an asymptotic value. In contrast, tracheid length in roots was relatively constant from pith to bark, although there was a dip of about 20% from about cambial ages 14 to 24. This study shows that the vascular cambium of this species is not constrained to produce one sole radial pattern of wood properties as it matures. The presence of different radial patterns in boles, branches, and roots supports the hypothesis that juvenile wood in the bole is an adaptive feature rather than an unavoidable developmental consequence. Further work should investigate more fully the different physiological or mechanical roles of the various wood types within the context of the position in the tree at which they occur. Title: Do Douglas-fir branches and roots have juvenile wood? Author: Peterson, M. G., Lachenbruch, B., Dietterich, H. R. We sampled boles, branches, and roots of four Douglas-fir (Pseudotsuga menziesii var. menziesii) trees to learn a) whether branches and roots have a zone of juvenile wood, defined as a zone with progressive changes in wood density and/or tracheid length from the pith outward at successively greater cambial ages, and if so, b) whether the radial patterns in branches and roots are similar to those in boles. Samples came from the following positions: bole, 30 cm aboveground; branch, 30 cm outward on the lowest live branch, and root, 1–3 m from the bole. Average sample cambial ages were bole, 60 years; branch, 30 years; and root, 48 years. Roots and branches had higher density wood than did the bole at the positions studied, and roots had the longest tracheids followed by the bole and then the branches. All three positions exhibited juvenile wood but with different radial patterns. All positions had their highest density near the pith, which was followed by a steep decline in the boles and a more gradual decline in the roots and branches. Boles and roots, but not branches, then showed an increase in density after this decline. Boles and branches had short tracheids near the pith followed by a gradual increase to an asymptotic value. In contrast, tracheid length in roots was relatively constant from pith to bark, although there was a dip of about 20% from about cambial ages 14 to 24. This study shows that the vascular cambium of this species is not constrained to produce one sole radial pattern of wood properties as it matures. The presence of different radial patterns in boles, branches, and roots supports the hypothesis that juvenile wood in the bole is an adaptive feature rather than an unavoidable developmental consequence. Further work should investigate more fully the different physiological or mechanical roles of the various wood types within the context of the position in the tree at which they occur. Close

• 209. [Article] Value Chain Analysis of the Sea Cucumber Fishing Industry in Sri Lanka

  Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, ...

  Citation × Citation Citation Abstract Copy Title: Value Chain Analysis of the Sea Cucumber Fishing Industry in Sri Lanka Author: Dayarathne, Kelum, Dissanayake, Chamari Year: 2016 Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, July 11-15, 2016. Compiled by Stefani J. Evers and Ann L. Shriver. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016. Title: Value Chain Analysis of the Sea Cucumber Fishing Industry in Sri Lanka Author: Dayarathne, Kelum, Dissanayake, Chamari Year: 2016 Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, July 11-15, 2016. Compiled by Stefani J. Evers and Ann L. Shriver. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016. Close

• 210. [Article] From Fishing Capacity to Diversity: Changing Fishery Management Priorities in the New England Groundfish Fishery

  Research paper and Powerpoint Presentation

  Citation × Citation Citation Abstract Copy Title: From Fishing Capacity to Diversity: Changing Fishery Management Priorities in the New England Groundfish Fishery Author: Thunberg, Eric, Correia, Steven Research paper and Powerpoint Presentation Title: From Fishing Capacity to Diversity: Changing Fishery Management Priorities in the New England Groundfish Fishery Author: Thunberg, Eric, Correia, Steven Research paper and Powerpoint Presentation Close

• 211. [Article] From Fishing Capacity to Diversity; Changing Fishery Management Priorities in the US New England Groundfish Fishery

  presentation

  Citation × Citation Citation Abstract Copy Title: From Fishing Capacity to Diversity; Changing Fishery Management Priorities in the US New England Groundfish Fishery Author: Thunberg, Eric presentation Title: From Fishing Capacity to Diversity; Changing Fishery Management Priorities in the US New England Groundfish Fishery Author: Thunberg, Eric presentation Close

• 212. [Article] Whole system perspective: steelhead, Onchorhynchus mykiss, glutathione s-transferase as a biomarker of chlorpyrifos exposure

  2001

  Citation × Citation Citation Abstract Copy Title: Whole system perspective: steelhead, Onchorhynchus mykiss, glutathione s-transferase as a biomarker of chlorpyrifos exposure Author: Pecore, Rachael G. 2001 Title: Whole system perspective: steelhead, Onchorhynchus mykiss, glutathione s-transferase as a biomarker of chlorpyrifos exposure Author: Pecore, Rachael G. 2001 Close

• 213. [Article] Nutritional value of several Opuntia species

  Little is known about cactus nutrients, their proportions in different species and the variability of these proportions with season. In the scant literature available on Opuntia species, no systematic ...

  Citation × Citation Citation Abstract Copy Title: Nutritional value of several Opuntia species Author: Ben-Thlija, Abdellaziz Little is known about cactus nutrients, their proportions in different species and the variability of these proportions with season. In the scant literature available on Opuntia species, no systematic survey has been published to document and compare the nutritional qualities of different species. Also, no studies have been done to determine the seasonal variability of these nutrients. Past work on cactus has been mostly concentrated on Opuntia ficus-indica. This study was designed to determine and compare major pad nutrient content in five Opuntia species, and assess the seasonal variability in one of them: Opuntia fragilis (from John Day Fossil Beds, Central Oregon). The other species included in the analyses were: 0. engelmannii, 0. polyacantha, 0. filipendula and 0. versicolor, and were collected from different regions in the South western United States. Differences in nutrient content were detected between the species included in the analyses, but no single or group of species was consistently low or high in all the components analyzed. 0. engelmannii was the lowest in crude fiber components: 31.18% cell wall constituents, 7.9% cellulose and 2.89% lignin. Consequently, this species had the highest In vivo crude protein (51.80%), In vivo and In vitro dry matter digestibility (57.22% and 59.22%, respectively). The energy measurements indicated that, this species, 0. engelmannii had the highest digest ible energy (2098.54 kcal/kg). Conversely, 0. versicolor, the unique cylindropuntia included in the study, had the highest crude fiber content: 39.85% as Neutral Detergent Fiber residue, 13,73% as cellulose and 3.86% as lignin (second highest). With regard to dry matter digestibility, this species was among the group of lowest rates: 48.30% and 53.62 % respectively as In vivo and In vitro levels. This species, CK versicolor, had the highest crude protein content (6.83%), and the second highest in digestible energy (1927.15 kcal/kg) but it was the lowest in phosphorus concentration (0.08%). O. polyacantha had the highest lignin content (4.79%) and the lowest In vivo dry matter and crude protein degradability rates: 44.61% and 36.61%, respectively. The mineral analyses resulted in a highest calcium level for O. filipendula (6.83%) and a highest phosphorus content in the case of O. fragilis (0.29%). With regard to the seasonal variability, the analyses indicated a general trend of increase in fiber and calcium content from spring to summer. Nearly, these nutrients maintained constant proportions from summer to fall. This was primarily due to the fact that spring growth has reached maturity during this period. A slight decline of fiber content occurred from fall to winter: More soluble components have been synthesized during this period. Phosphorus content was not significantly different between seasons. Spring samples had highest crude protein (3.73%) and digestible energy (1922.33 kcal/kg) content. This was mainly due to rapid growth of the plant, considerable quantity of young pads was included in the spring collection. The seasonal variability was not highly significant. Moreover, content differences between seasons were not very high and a large part of these statistical variability could be inherent to the sampling procedure used. From a nutritional stand point, these small differences should not be taken into consideration in feeding CK fragilis to livestock through the year. All the five Opuntia species analyzed resulted in lower crude fiber content and higher dry matter and crude protein digestibility than grass hay samples (Agropyron cristatum and Bromus spp.) analyzed under the same conditions. When compared to alfalfa (Medicago satiya), cactus pads appeared to be intermediate in forage quality. All the cactus samples had higher calcium levels than the samples reference. In addition, 0. engelmannii had dry matter and crude protein digestibility rates close to those of alfalfa samples. Its digestible energy was only 20% lower than that of alfalfa. From this it could be concluded that the Opuntia species analyzed can fit in livestock rations with attention given to their low phosphorus and protein content. These Opuntias could be fed during any season but are needed, the most, as a late summer and fall supplement and during droughts when other forages are scarce or expensive to feed. Title: Nutritional value of several Opuntia species Author: Ben-Thlija, Abdellaziz Little is known about cactus nutrients, their proportions in different species and the variability of these proportions with season. In the scant literature available on Opuntia species, no systematic survey has been published to document and compare the nutritional qualities of different species. Also, no studies have been done to determine the seasonal variability of these nutrients. Past work on cactus has been mostly concentrated on Opuntia ficus-indica. This study was designed to determine and compare major pad nutrient content in five Opuntia species, and assess the seasonal variability in one of them: Opuntia fragilis (from John Day Fossil Beds, Central Oregon). The other species included in the analyses were: 0. engelmannii, 0. polyacantha, 0. filipendula and 0. versicolor, and were collected from different regions in the South western United States. Differences in nutrient content were detected between the species included in the analyses, but no single or group of species was consistently low or high in all the components analyzed. 0. engelmannii was the lowest in crude fiber components: 31.18% cell wall constituents, 7.9% cellulose and 2.89% lignin. Consequently, this species had the highest In vivo crude protein (51.80%), In vivo and In vitro dry matter digestibility (57.22% and 59.22%, respectively). The energy measurements indicated that, this species, 0. engelmannii had the highest digest ible energy (2098.54 kcal/kg). Conversely, 0. versicolor, the unique cylindropuntia included in the study, had the highest crude fiber content: 39.85% as Neutral Detergent Fiber residue, 13,73% as cellulose and 3.86% as lignin (second highest). With regard to dry matter digestibility, this species was among the group of lowest rates: 48.30% and 53.62 % respectively as In vivo and In vitro levels. This species, CK versicolor, had the highest crude protein content (6.83%), and the second highest in digestible energy (1927.15 kcal/kg) but it was the lowest in phosphorus concentration (0.08%). O. polyacantha had the highest lignin content (4.79%) and the lowest In vivo dry matter and crude protein degradability rates: 44.61% and 36.61%, respectively. The mineral analyses resulted in a highest calcium level for O. filipendula (6.83%) and a highest phosphorus content in the case of O. fragilis (0.29%). With regard to the seasonal variability, the analyses indicated a general trend of increase in fiber and calcium content from spring to summer. Nearly, these nutrients maintained constant proportions from summer to fall. This was primarily due to the fact that spring growth has reached maturity during this period. A slight decline of fiber content occurred from fall to winter: More soluble components have been synthesized during this period. Phosphorus content was not significantly different between seasons. Spring samples had highest crude protein (3.73%) and digestible energy (1922.33 kcal/kg) content. This was mainly due to rapid growth of the plant, considerable quantity of young pads was included in the spring collection. The seasonal variability was not highly significant. Moreover, content differences between seasons were not very high and a large part of these statistical variability could be inherent to the sampling procedure used. From a nutritional stand point, these small differences should not be taken into consideration in feeding CK fragilis to livestock through the year. All the five Opuntia species analyzed resulted in lower crude fiber content and higher dry matter and crude protein digestibility than grass hay samples (Agropyron cristatum and Bromus spp.) analyzed under the same conditions. When compared to alfalfa (Medicago satiya), cactus pads appeared to be intermediate in forage quality. All the cactus samples had higher calcium levels than the samples reference. In addition, 0. engelmannii had dry matter and crude protein digestibility rates close to those of alfalfa samples. Its digestible energy was only 20% lower than that of alfalfa. From this it could be concluded that the Opuntia species analyzed can fit in livestock rations with attention given to their low phosphorus and protein content. These Opuntias could be fed during any season but are needed, the most, as a late summer and fall supplement and during droughts when other forages are scarce or expensive to feed. Close

• 214. [Article] Emerging infectious disease in lentic environments : the ecology and biogeography of the amphibian chytrid fungus Batrachochytrium dendrobatidis, with perspectives on water quality, limnology, and chemical contaminants

  Biodiversity losses in terrestrial, freshwater, and marine systems are accelerating at a global scale and the most threatened vertebrate taxa are those associated with freshwater habitats. The causes of ...

  Citation × Citation Citation Abstract Copy Title: Emerging infectious disease in lentic environments : the ecology and biogeography of the amphibian chytrid fungus Batrachochytrium dendrobatidis, with perspectives on water quality, limnology, and chemical contaminants Author: Chestnut, Tara Biodiversity losses in terrestrial, freshwater, and marine systems are accelerating at a global scale and the most threatened vertebrate taxa are those associated with freshwater habitats. The causes of biodiversity losses are often complex and include synergistic effects of natural and human-induced stressors, such as habitat loss and fragmentation, urbanization, invasive species, contaminants, global climate change, and emerging infectious diseases. In the last 35 years, the amphibian extinction rate has been estimated to exceed 105 times the baseline expected rate for all species and in the USA, the number of occupied amphibian sites has been reported to be declining by 3.7% per year. Among the many threats to amphibians, the role of disease in population declines has been recognized increasingly over the last two decades. Numerous amphibian diseases have been identified and attributed to mass mortality events. Chytridiomycosis, the emerging infectious disease caused by the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is implicated as a causal agent in many recent global amphibian population declines and extinctions. To understand the pathology and conservation implications of Bd, a greater understanding of its ecology, life history, and distribution in the wild is of paramount importance. Although it has an impact on the persistence of selected amphibian populations around the world, the full scope of the effects of chytridiomycosis on global amphibian population declines are not well understood. Most Bd research efforts have focused on Bd in amphibian hosts per se, with little attention to understand the environmental associations and dynamics of free-living Bd outside of the amphibian host. In particular, information on Bd responses to climatic variation outside of hosts is a research gap. Furthermore, as a microorganism within an aquatic environment, studies are lacking of potential water quality associations, how Bd may interact with other members of their biological communities, and how Bd responses to chemical contaminants found in aquatic environments. My research begins to fill these gaps by studying the basic ecology of free-living Bd in field settings, and investigating factors that may influence its distribution at a landscape scale, occurrence at a regional scale, and detection at a site scale. Herein, I describe spatial and temporal patterns in the detection and density of free-living Bd in aquatic habitats in two different geographic regions of the United States, Alaska (Chapter 2) and Oregon (Chapter 3). The Alaska work examines Bd ecology at the northernmost extent of amphibian occurrence in North America, where climate associations may be particularly relevant and where Bd occurrence may be representative of one of the most novel pathogen-host systems in the world. I also describe (Chapter 2) experimental results of Bd and amphibian response to extreme cold temperatures they may experience in continental settings, at high elevations, and at high latitudes. My Oregon studies (Chapter 3) focus on multivariate associations of free-living Bd occurrences with a suite of aquatic environmental factors, both abiotic and biotic in nature. In Chapter 4, I describe how amphibians and Bd respond to agricultural chemicals (fungicides) that they may be exposed to in field settings. These results are specific to Bd, but might also warrant consideration as fungicidal treatments for a newly described chytrid affecting salamanders; both of these amphibian chytrids have been detected in captive animals and solutions to treat trade animals for the pathogen are gaining relevancy. Finally, in Chapter 5, I reflect upon the journey of conservation biologists and herpetologists for 25 years of amphibian decline research, with global losses becoming widely recognized in 1989. In this context, my research significantly advances understanding of the geographic distribution and ecology of one potential threat factor to amphibian populations on Earth, Batrachochytrium dendrobatidis. The factors that I report to both promote or limit free-living Bd distribution and abundance will further inform pathogen dynamics research. Title: Emerging infectious disease in lentic environments : the ecology and biogeography of the amphibian chytrid fungus Batrachochytrium dendrobatidis, with perspectives on water quality, limnology, and chemical contaminants Author: Chestnut, Tara Biodiversity losses in terrestrial, freshwater, and marine systems are accelerating at a global scale and the most threatened vertebrate taxa are those associated with freshwater habitats. The causes of biodiversity losses are often complex and include synergistic effects of natural and human-induced stressors, such as habitat loss and fragmentation, urbanization, invasive species, contaminants, global climate change, and emerging infectious diseases. In the last 35 years, the amphibian extinction rate has been estimated to exceed 105 times the baseline expected rate for all species and in the USA, the number of occupied amphibian sites has been reported to be declining by 3.7% per year. Among the many threats to amphibians, the role of disease in population declines has been recognized increasingly over the last two decades. Numerous amphibian diseases have been identified and attributed to mass mortality events. Chytridiomycosis, the emerging infectious disease caused by the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is implicated as a causal agent in many recent global amphibian population declines and extinctions. To understand the pathology and conservation implications of Bd, a greater understanding of its ecology, life history, and distribution in the wild is of paramount importance. Although it has an impact on the persistence of selected amphibian populations around the world, the full scope of the effects of chytridiomycosis on global amphibian population declines are not well understood. Most Bd research efforts have focused on Bd in amphibian hosts per se, with little attention to understand the environmental associations and dynamics of free-living Bd outside of the amphibian host. In particular, information on Bd responses to climatic variation outside of hosts is a research gap. Furthermore, as a microorganism within an aquatic environment, studies are lacking of potential water quality associations, how Bd may interact with other members of their biological communities, and how Bd responses to chemical contaminants found in aquatic environments. My research begins to fill these gaps by studying the basic ecology of free-living Bd in field settings, and investigating factors that may influence its distribution at a landscape scale, occurrence at a regional scale, and detection at a site scale. Herein, I describe spatial and temporal patterns in the detection and density of free-living Bd in aquatic habitats in two different geographic regions of the United States, Alaska (Chapter 2) and Oregon (Chapter 3). The Alaska work examines Bd ecology at the northernmost extent of amphibian occurrence in North America, where climate associations may be particularly relevant and where Bd occurrence may be representative of one of the most novel pathogen-host systems in the world. I also describe (Chapter 2) experimental results of Bd and amphibian response to extreme cold temperatures they may experience in continental settings, at high elevations, and at high latitudes. My Oregon studies (Chapter 3) focus on multivariate associations of free-living Bd occurrences with a suite of aquatic environmental factors, both abiotic and biotic in nature. In Chapter 4, I describe how amphibians and Bd respond to agricultural chemicals (fungicides) that they may be exposed to in field settings. These results are specific to Bd, but might also warrant consideration as fungicidal treatments for a newly described chytrid affecting salamanders; both of these amphibian chytrids have been detected in captive animals and solutions to treat trade animals for the pathogen are gaining relevancy. Finally, in Chapter 5, I reflect upon the journey of conservation biologists and herpetologists for 25 years of amphibian decline research, with global losses becoming widely recognized in 1989. In this context, my research significantly advances understanding of the geographic distribution and ecology of one potential threat factor to amphibian populations on Earth, Batrachochytrium dendrobatidis. The factors that I report to both promote or limit free-living Bd distribution and abundance will further inform pathogen dynamics research. Close

• 215. [Image] Questions and answers : five-year review of Klamath sucker populations

  	Fact sheet summarizing the reasons behind the five-year review of the issues surrounding the Klamath sucker fish
  	Citation × Citation Citation Abstract Copy Title: Questions and answers : five-year review of Klamath sucker populations Author: U.S. Fish and Wildlife Service Year: 2004, 2005 Fact sheet summarizing the reasons behind the five-year review of the issues surrounding the Klamath sucker fish Title: Questions and answers : five-year review of Klamath sucker populations Author: U.S. Fish and Wildlife Service Year: 2004, 2005 Fact sheet summarizing the reasons behind the five-year review of the issues surrounding the Klamath sucker fish Close

• 216. [Article] Indirect effects of fishing on predators and their prey

  Predators are fundamentally important for regulating and driving prey population dynamics as well as structuring ecological communities. Over-exploitation of marine resources has caused dramatic depletions ...

  Citation × Citation Citation Abstract Copy Title: Indirect effects of fishing on predators and their prey Author: Stallings, Christopher Derek Predators are fundamentally important for regulating and driving prey population dynamics as well as structuring ecological communities. Over-exploitation of marine resources has caused dramatic depletions of predatory fish species and shifts in marine community composition, with attendant declines in productivity and diversity of marine ecosystems. Despite the important ramifications of these patterns for humankind, the specific ecological mechanisms and potential indirect effects underlying these trends have been largely unexplored. I combined small-scale experiments and broad-scale observations to investigate how fishing can affect interactions among predators and subsequently be transferred to interactions between predators and their prey. Previous observations had indicated that small, unfished predators increase in abundance on reefs where large, fished predators are removed. To test the effects of such shifts in relative abundance of different predatory fishes on community structure of lower trophic-level species, I manipulated the presence of fished and unfished predatory species on coral patch reefs in the Bahamas. This controlled field experiment demonstrated that different predatory fishes, which are often assumed to have similar effects on prey species, in fact had remarkably different effects on prey diversity and abundance. In a second field experiment, I found that increased abundance of a large, fished predatory species on coral reefs decreased the activity and growth of smaller, unfished predators. Although small, unfished predators had strong, negative effects on lower trophic-level prey on reefs with low abundances of larger, fished predators, these effects were reduced with increasing abundance of the fished species. Lastly, I used observational data from volunteer SCUBA-diver surveys to investigate how the structure of predatory fish communities on coral reefs across the greater Caribbean region has been affected by fishing. I used density of human populations as a proxy for fishing intensity. I found that, as human density increases, overall predator abundance and diversity decreases, and reef communities became dominated by only a few, small species. This research indicates that the effects of fishing on larger predatory species can permeate throughout ecological communities, well beyond simple reductions in the abundance of fished species. In light of these community-wide effects, ecosystem-based approaches are necessary for successful management of fisheries and conservation of coral reefs. Title: Indirect effects of fishing on predators and their prey Author: Stallings, Christopher Derek Predators are fundamentally important for regulating and driving prey population dynamics as well as structuring ecological communities. Over-exploitation of marine resources has caused dramatic depletions of predatory fish species and shifts in marine community composition, with attendant declines in productivity and diversity of marine ecosystems. Despite the important ramifications of these patterns for humankind, the specific ecological mechanisms and potential indirect effects underlying these trends have been largely unexplored. I combined small-scale experiments and broad-scale observations to investigate how fishing can affect interactions among predators and subsequently be transferred to interactions between predators and their prey. Previous observations had indicated that small, unfished predators increase in abundance on reefs where large, fished predators are removed. To test the effects of such shifts in relative abundance of different predatory fishes on community structure of lower trophic-level species, I manipulated the presence of fished and unfished predatory species on coral patch reefs in the Bahamas. This controlled field experiment demonstrated that different predatory fishes, which are often assumed to have similar effects on prey species, in fact had remarkably different effects on prey diversity and abundance. In a second field experiment, I found that increased abundance of a large, fished predatory species on coral reefs decreased the activity and growth of smaller, unfished predators. Although small, unfished predators had strong, negative effects on lower trophic-level prey on reefs with low abundances of larger, fished predators, these effects were reduced with increasing abundance of the fished species. Lastly, I used observational data from volunteer SCUBA-diver surveys to investigate how the structure of predatory fish communities on coral reefs across the greater Caribbean region has been affected by fishing. I used density of human populations as a proxy for fishing intensity. I found that, as human density increases, overall predator abundance and diversity decreases, and reef communities became dominated by only a few, small species. This research indicates that the effects of fishing on larger predatory species can permeate throughout ecological communities, well beyond simple reductions in the abundance of fished species. In light of these community-wide effects, ecosystem-based approaches are necessary for successful management of fisheries and conservation of coral reefs. Close

• 217. [Article] The effects of an emerging pathogen on amphibian host behaviors and interactions

  Contemporary environmental change encompasses massive biodiversity loss and increasing numbers of emerging diseases worldwide. As part of a global biodiversity crisis, amphibians are disappearing at unprecedented ...

  Citation × Citation Citation Abstract Copy Title: The effects of an emerging pathogen on amphibian host behaviors and interactions Author: Han, Barbara A. Contemporary environmental change encompasses massive biodiversity loss and increasing numbers of emerging diseases worldwide. As part of a global biodiversity crisis, amphibians are disappearing at unprecedented rates. Batrachochytrium dendrobatidis is an emerging infectious pathogen prominently associated with many declines. Chapter 1 reviews the past decade of research on this system and highlights areas where knowledge is notably lacking. Host behavior remains a crucial determinant of host-pathogen dynamics yet studies addressing the effects of Batrachochytrium on amphibian behaviors are virtually nonexistent. Remaining chapters examine behavioral responses of host species to Batrachochytrium. Chapter 2 examines how ancient behaviors that have persisted in amphibians for millions of years change with exposure to Batrachochytrium. I examined thermoregulatory behavior in tadpoles of four species (Pseudacris regilla, Rana aurora, Bufo boreas, Rana cascadae), and aggregation behavior in two species that school as tadpoles (B. boreas, R. cascadae). Results suggest that some amphibians will continue seeking optimal temperatures and continue aggregating regardless of infection risk. I discuss the importance of behavioral plasticity and evolutionary inertia in interpreting host behavioral responses to infection. Chapter 3 examines Batrachochytrium dynamics when multiple host species interact. I manipulated infection status in tadpoles of three naturally co-occurring hosts (P. regilla, B. boreas, R. cascadae) in various combinations and measured growth, survival and infection severity. There were strong interactions between species combinations and infection leading to pathogen-mediated mutualism and competition. Results also suggest that both species richness and species identity may be important factors moderating a dilution effect in this system. Coexisting, interacting hosts must also contend with predators in a community. Chapter 4 explores Batrachochytrium-induced changes in antipredator behaviors in four species (P. regilla, R. aurora, B. boreas, R. cascadae). I also examined whether antipredator behaviors increased survivorship in the presence of lethal predators in R. cascadae, R. aurora. Exposure to Batrachochytrium changed activity rate and refuge use in Bufo, but not in the other species. Nonselective predation of Batrachochytriumexposed prey by susceptible predators adds an unexplored dimension of complexity to this system. Chapter 5 summarizes the ecological implications of studies presented in this dissertation. Title: The effects of an emerging pathogen on amphibian host behaviors and interactions Author: Han, Barbara A. Contemporary environmental change encompasses massive biodiversity loss and increasing numbers of emerging diseases worldwide. As part of a global biodiversity crisis, amphibians are disappearing at unprecedented rates. Batrachochytrium dendrobatidis is an emerging infectious pathogen prominently associated with many declines. Chapter 1 reviews the past decade of research on this system and highlights areas where knowledge is notably lacking. Host behavior remains a crucial determinant of host-pathogen dynamics yet studies addressing the effects of Batrachochytrium on amphibian behaviors are virtually nonexistent. Remaining chapters examine behavioral responses of host species to Batrachochytrium. Chapter 2 examines how ancient behaviors that have persisted in amphibians for millions of years change with exposure to Batrachochytrium. I examined thermoregulatory behavior in tadpoles of four species (Pseudacris regilla, Rana aurora, Bufo boreas, Rana cascadae), and aggregation behavior in two species that school as tadpoles (B. boreas, R. cascadae). Results suggest that some amphibians will continue seeking optimal temperatures and continue aggregating regardless of infection risk. I discuss the importance of behavioral plasticity and evolutionary inertia in interpreting host behavioral responses to infection. Chapter 3 examines Batrachochytrium dynamics when multiple host species interact. I manipulated infection status in tadpoles of three naturally co-occurring hosts (P. regilla, B. boreas, R. cascadae) in various combinations and measured growth, survival and infection severity. There were strong interactions between species combinations and infection leading to pathogen-mediated mutualism and competition. Results also suggest that both species richness and species identity may be important factors moderating a dilution effect in this system. Coexisting, interacting hosts must also contend with predators in a community. Chapter 4 explores Batrachochytrium-induced changes in antipredator behaviors in four species (P. regilla, R. aurora, B. boreas, R. cascadae). I also examined whether antipredator behaviors increased survivorship in the presence of lethal predators in R. cascadae, R. aurora. Exposure to Batrachochytrium changed activity rate and refuge use in Bufo, but not in the other species. Nonselective predation of Batrachochytriumexposed prey by susceptible predators adds an unexplored dimension of complexity to this system. Chapter 5 summarizes the ecological implications of studies presented in this dissertation. Close

• 218. [Article] Understory response to tree harvesting in pinyon-juniper woodlands

  Understory species associations and their association with tree species were examined on three intensively studied stands. We studied the chronosequence of understory species associated with different ...

  Citation × Citation Citation Abstract Copy Title: Understory response to tree harvesting in pinyon-juniper woodlands Author: Everett, Richard L. Understory species associations and their association with tree species were examined on three intensively studied stands. We studied the chronosequence of understory species associated with different aged singleleaf pinyon (Pinus monophylla Torr. and Frem.) trees. Mid- to late pinyon-juniper understory succession was found to be more spatial than floristic in nature. Plants of the same species but occurring on different soil microsites responded differently to increasing tree competition. Succession was a plant by plant process rather than a linear replacement series of species at the population level. Phytosociological changes were documented following tree harvesting on 15 widely separated singleleaf pinyon-Utah juniper (Juniperous osteosperma [Torr.] Little) stands. Pre- and post harvest plant assemblages from the same site appeared in the same phytosociological groupings 80% of the time as defined by discriminate analysis. We suggest initial post harvest response was short term cyclic rather than successional and therefore more predictable. Post harvest seed rain suggested understory species have increased reproductive potential following tree harvest and can rapidly reoccupy disturbed sites. Survival strategies of individual species determined the quantitative character of seed rain Seed rain and subsequent seedling establishment were not the primary causes of increased understory cover following tree harvest. Remnant plants provided the initial cover increase. Post harvest cover rapidly increased for two years on the three intensively studied sites, but rate of increase declined during the following two year period. Soil microsites associated with the tree canopy produced greater grass yields than soils in the interspace between trees. Percent nitrogen and phosphorus increased in most grass species following tree harvest. Because of increased soil nutrient concentrations under the tree canopy we anticipated higher nutrient level in associated grass plants, but were unable to demonstrate this difference because of the dilution effects from increased yields. Soil nutrients were concentrated under the tree crown but were not distributed similarly with depth. Mineralizable-N, PO₄, Zn, Mn, Cu, and Fe, accumulated in surface horizons. Total soluble salts, Ca, Mg, Na, and K accumulated in subsurface horizons. Nutrient enrichment in soils under the canopy was suggested to confer a competitive advantage to the tree species. Title: Understory response to tree harvesting in pinyon-juniper woodlands Author: Everett, Richard L. Understory species associations and their association with tree species were examined on three intensively studied stands. We studied the chronosequence of understory species associated with different aged singleleaf pinyon (Pinus monophylla Torr. and Frem.) trees. Mid- to late pinyon-juniper understory succession was found to be more spatial than floristic in nature. Plants of the same species but occurring on different soil microsites responded differently to increasing tree competition. Succession was a plant by plant process rather than a linear replacement series of species at the population level. Phytosociological changes were documented following tree harvesting on 15 widely separated singleleaf pinyon-Utah juniper (Juniperous osteosperma [Torr.] Little) stands. Pre- and post harvest plant assemblages from the same site appeared in the same phytosociological groupings 80% of the time as defined by discriminate analysis. We suggest initial post harvest response was short term cyclic rather than successional and therefore more predictable. Post harvest seed rain suggested understory species have increased reproductive potential following tree harvest and can rapidly reoccupy disturbed sites. Survival strategies of individual species determined the quantitative character of seed rain Seed rain and subsequent seedling establishment were not the primary causes of increased understory cover following tree harvest. Remnant plants provided the initial cover increase. Post harvest cover rapidly increased for two years on the three intensively studied sites, but rate of increase declined during the following two year period. Soil microsites associated with the tree canopy produced greater grass yields than soils in the interspace between trees. Percent nitrogen and phosphorus increased in most grass species following tree harvest. Because of increased soil nutrient concentrations under the tree canopy we anticipated higher nutrient level in associated grass plants, but were unable to demonstrate this difference because of the dilution effects from increased yields. Soil nutrients were concentrated under the tree crown but were not distributed similarly with depth. Mineralizable-N, PO₄, Zn, Mn, Cu, and Fe, accumulated in surface horizons. Total soluble salts, Ca, Mg, Na, and K accumulated in subsurface horizons. Nutrient enrichment in soils under the canopy was suggested to confer a competitive advantage to the tree species. Close

• 219. [Article] Foraminiferal trends of the central Oregon shelf

  Sediments of a portion of the central Oregon shelf between 17 and 339 m have been examined for modern foraminifera. Eighty-three samples were collected from 33 stations along three traverses located between ...

  Citation × Citation Citation Abstract Copy Title: Foraminiferal trends of the central Oregon shelf Author: Boettcher, Richard Scott Sediments of a portion of the central Oregon shelf between 17 and 339 m have been examined for modern foraminifera. Eighty-three samples were collected from 33 stations along three traverses located between 43° 16'N and 43° 50'N. One hundred fifty-five benthic and nine planktonic species are recognized. Fifty-six benthic species occur with a frequency of more than two percent in at least one sample. Benthic species are grouped into four distinct bathymetric faunas. Elphidiella hannai and Buccella spp. are indicative of Fauna A (17-50 m). Fauna B (50-100 m) is characterized by Buliminella elegantissima and Elphidium magellanicum. In the rocky area off Cape Arago Cassidulina californica, C. limbata, Cibicides fletcheri, and C. lobatulus become dominant. Spiroplectammina biformis, Textularia earlandi, and Trifarina angulosa are important species of Fauna C (100-175 m). Abundant species of Fauna D (175-339 m) include Eggerella advena, Epistominella exigua, and Uvigerina juncea. Species diversity increases offshore to a maximum of about 35 benthic species near 100 m and then decreases slightly with depth. Standing crop is low nearshore, rises to a maximum of approximately 300 specimens per 20 cm³ between 125 and 150 m, and then declines. Total benthic population reaches a maximum of approximately 6000 specimens per sample between 150 and 175 m. Values then decrease to about 2000 specimens at 339 m. A maximum of 15 to 20 percent live benthic specimens occurs near 50 m. Planktonic foraminifera constitute less than ten percent of the total population. Maximum percentages generally occur shoaler than 100 m, while maximum specimens per sample occur at the deepest stations. Porcelaneous specimens do not exceed six percent of the benthic population. Agglutinated foraminifera are more abundant than calcareous specimens deeper than 100 m. The frequency of occurrence of a species may vary by as much as 25 percentage points from samples collected approximately 15 cm apart. Statistical analysis of selected species indicates that sampling density was not too close along any one traverse, although the traverses possibly could have been spaced farther apart. Miscellaneous biofacies trends indicate that: thecamoebians are most abundant between 50 and 125 m; statoliths and otoliths occur most frequently between 75 and 2OO m; highest ostracod values are found between 25 and 150 m; and radiolarians generally exceed foraminifera deeper than 250 m. Title: Foraminiferal trends of the central Oregon shelf Author: Boettcher, Richard Scott Sediments of a portion of the central Oregon shelf between 17 and 339 m have been examined for modern foraminifera. Eighty-three samples were collected from 33 stations along three traverses located between 43° 16'N and 43° 50'N. One hundred fifty-five benthic and nine planktonic species are recognized. Fifty-six benthic species occur with a frequency of more than two percent in at least one sample. Benthic species are grouped into four distinct bathymetric faunas. Elphidiella hannai and Buccella spp. are indicative of Fauna A (17-50 m). Fauna B (50-100 m) is characterized by Buliminella elegantissima and Elphidium magellanicum. In the rocky area off Cape Arago Cassidulina californica, C. limbata, Cibicides fletcheri, and C. lobatulus become dominant. Spiroplectammina biformis, Textularia earlandi, and Trifarina angulosa are important species of Fauna C (100-175 m). Abundant species of Fauna D (175-339 m) include Eggerella advena, Epistominella exigua, and Uvigerina juncea. Species diversity increases offshore to a maximum of about 35 benthic species near 100 m and then decreases slightly with depth. Standing crop is low nearshore, rises to a maximum of approximately 300 specimens per 20 cm³ between 125 and 150 m, and then declines. Total benthic population reaches a maximum of approximately 6000 specimens per sample between 150 and 175 m. Values then decrease to about 2000 specimens at 339 m. A maximum of 15 to 20 percent live benthic specimens occurs near 50 m. Planktonic foraminifera constitute less than ten percent of the total population. Maximum percentages generally occur shoaler than 100 m, while maximum specimens per sample occur at the deepest stations. Porcelaneous specimens do not exceed six percent of the benthic population. Agglutinated foraminifera are more abundant than calcareous specimens deeper than 100 m. The frequency of occurrence of a species may vary by as much as 25 percentage points from samples collected approximately 15 cm apart. Statistical analysis of selected species indicates that sampling density was not too close along any one traverse, although the traverses possibly could have been spaced farther apart. Miscellaneous biofacies trends indicate that: thecamoebians are most abundant between 50 and 125 m; statoliths and otoliths occur most frequently between 75 and 2OO m; highest ostracod values are found between 25 and 150 m; and radiolarians generally exceed foraminifera deeper than 250 m. Close

• 220. [Article] 2006 OPRD- Oregon Chub Population Monitoring on Oregon State Park Lands Progress Reports 2006

  Abstract -- Oregon chub Oregonichthys crameri, small minnows endemic to the Willamette River drainage of western Oregon (Markle et al. 1991), were federally listed as endangered under the Endangered Species ...

  Citation × Citation Citation Abstract Copy Title: 2006 OPRD- Oregon Chub Population Monitoring on Oregon State Park Lands Progress Reports 2006 Abstract -- Oregon chub Oregonichthys crameri, small minnows endemic to the Willamette River drainage of western Oregon (Markle et al. 1991), were federally listed as endangered under the Endangered Species Act in 1993 (Markle and Pearsons 1990; Rhew 1993). This species was formerly distributed throughout the Willamette River Valley (Snyder 1908) in off-channel habitats such as beaver ponds, oxbows, backwater sloughs, and flooded marshes. These habitats usually have little or no water flow, have silty and organic substrate, and have an abundance of aquatic vegetation and cover for hiding and spawning. In the last 100 years, off-channel habitats have disappeared because of changes in seasonal flows and habitat characteristics resulting from the construction of flood control dams, revetments, channelization, diking, and the drainage of wetlands for bottomland agriculture. This loss of habitat combined with the introduction of non-native species to the Willamette Valley resulted in a restricted distribution and sharp decline in Oregon chub abundance. The Oregon chub is further threatened by predation and competition by non-native species such as largemouth bass Micropterus salmoides, crappies Pomoxis sp., sunfishes Lepomis sp., bullheads Ameiurus sp., and western mosquitofish Gambusia affinis. To evaluate abundance and distribution of Oregon chub populations, the Oregon Department of Fish and Wildlife has conducted surveys since 1991. Information collected also included the presence of non-native and native species, the characteristics of Oregon chub habitats, the characteristics of potential introduction sites, evaluation of Oregon chub introductions, and life history characteristics (Scheerer 2002, Scheerer and McDonald 2003, Scheerer et al. 2006). The Oregon Chub Recovery Plan (U.S. Fish and Wildlife Service 1998) set recovery criteria for downlisting the species to “threatened” and for delisting the species. The criteria for downlisting the species are: 1) establish and manage 10 populations of at least 500 adult fish, 2) all of these populations must exhibit a stable or increasing trend for five years, and 3) at least three populations meeting criterion 1 and 2 must be located in each of the three recovery areas (Middle Fork Willamette River, Santiam River, and Mid-Willamette River tributaries). In 2006, there were 18 populations totaling 500 or more individuals. Thirteen of these populations met the above criteria. Eight were located in the Middle Fork Willamette drainage, three were located in the Mid-Willamette drainage, and two were located in the Santiam drainage (Scheerer et al. 2006). The status of this species has improved substantially over the past decade and with the addition of a single Santiam population, the downlisting criteria will be met (Scheerer et al. 2006). Title: 2006 OPRD- Oregon Chub Population Monitoring on Oregon State Park Lands Progress Reports 2006 Abstract -- Oregon chub Oregonichthys crameri, small minnows endemic to the Willamette River drainage of western Oregon (Markle et al. 1991), were federally listed as endangered under the Endangered Species Act in 1993 (Markle and Pearsons 1990; Rhew 1993). This species was formerly distributed throughout the Willamette River Valley (Snyder 1908) in off-channel habitats such as beaver ponds, oxbows, backwater sloughs, and flooded marshes. These habitats usually have little or no water flow, have silty and organic substrate, and have an abundance of aquatic vegetation and cover for hiding and spawning. In the last 100 years, off-channel habitats have disappeared because of changes in seasonal flows and habitat characteristics resulting from the construction of flood control dams, revetments, channelization, diking, and the drainage of wetlands for bottomland agriculture. This loss of habitat combined with the introduction of non-native species to the Willamette Valley resulted in a restricted distribution and sharp decline in Oregon chub abundance. The Oregon chub is further threatened by predation and competition by non-native species such as largemouth bass Micropterus salmoides, crappies Pomoxis sp., sunfishes Lepomis sp., bullheads Ameiurus sp., and western mosquitofish Gambusia affinis. To evaluate abundance and distribution of Oregon chub populations, the Oregon Department of Fish and Wildlife has conducted surveys since 1991. Information collected also included the presence of non-native and native species, the characteristics of Oregon chub habitats, the characteristics of potential introduction sites, evaluation of Oregon chub introductions, and life history characteristics (Scheerer 2002, Scheerer and McDonald 2003, Scheerer et al. 2006). The Oregon Chub Recovery Plan (U.S. Fish and Wildlife Service 1998) set recovery criteria for downlisting the species to “threatened” and for delisting the species. The criteria for downlisting the species are: 1) establish and manage 10 populations of at least 500 adult fish, 2) all of these populations must exhibit a stable or increasing trend for five years, and 3) at least three populations meeting criterion 1 and 2 must be located in each of the three recovery areas (Middle Fork Willamette River, Santiam River, and Mid-Willamette River tributaries). In 2006, there were 18 populations totaling 500 or more individuals. Thirteen of these populations met the above criteria. Eight were located in the Middle Fork Willamette drainage, three were located in the Mid-Willamette drainage, and two were located in the Santiam drainage (Scheerer et al. 2006). The status of this species has improved substantially over the past decade and with the addition of a single Santiam population, the downlisting criteria will be met (Scheerer et al. 2006). Close

• 221. [Article] Patterns of distribution, abundance, and change over time in the marine bird community of Prince William Sound, Alaska, 1989-2012

  Over recent decades, the marine ecosystems of Prince William Sound (PWS), Alaska have experienced the concurrent effects of a major anthropogenic disturbance, the 1989 Exxon Valdez oil spill (EVOS), and ...

  Citation × Citation Citation Abstract Copy Title: Patterns of distribution, abundance, and change over time in the marine bird community of Prince William Sound, Alaska, 1989-2012 Author: Cushing, Daniel A. (Daniel Arel) Over recent decades, the marine ecosystems of Prince William Sound (PWS), Alaska have experienced the concurrent effects of a major anthropogenic disturbance, the 1989 Exxon Valdez oil spill (EVOS), and a dynamic atmospheric-oceanic environment. Studies of top marine consumers can provide insights into processes of ecosystem change. Using data collected during boat-based marine bird surveys in PWS over the period 1989-2012, I used complimentary taxon- and community-centric approaches to investigate patterns of distribution and abundance of marine birds across space and time. In doing so, I sought to provide insight into processes that may have affected both the birds themselves and the ecosystems of which they are a part. I found that the marine bird community as a whole was spatially structured along a primary onshore-offshore environmental gradient, and secondarily structured along an estuarine-marine environmental gradient. I found two patterns of community variability across time. The first temporal community-level pattern was likely related to sustained rates of change in the abundance of some genera, likely caused by demographic processes. This pattern was correlated with climate variability at time-scales of several years to a decade. The second temporal community-level pattern was characterized by fluctuations that correlated with climate variability at an annual time-scale, likely caused by movements of birds between PWS and the adjacent Gulf of Alaska. I also evaluated changes in the abundance of 18 genera of marine birds, and found that seven had declined in abundance and three had increased over the study period; all genera that declined were piscivorous or planktivorous. Furthermore, the rates of population change of genera were related to their position in the onshore-offshore gradient, with the highest rates of decline occurring in offshore-associated genera. I also investigated spatial habitat associations and temporal changes in abundance of a focal taxon, the seabird genus Brachyramphus. Two species within this piscivorous, pursuit-diving genus occur in PWS, the marbled murrelet (B. marmoratus) and the Kittlitz’s murrelet (B. brevirostris). Both are species of conservation concern, and both experienced acute mortality in PWS caused by the EVOS. Using a statistical model that accounted for variables affecting observed abundance across space and time, I found that abundance decreased by more than two-thirds over the study period. I found no evidence that rates of change differed along environmental or geographic gradients. There was also no evidence that changes in seasonal patterns of abundance occurred. These results are indicative of a widespread decline in the abundance of Brachyramphus murrelets within PWS. Taken as a whole, the results of my thesis are consistent with the hypothesis that climate change has differentially affected nearshore and offshore components of PWS food webs. This in turn has likely contributed to the failure of some taxa, including Brachyramphus murrelets, to recover from population injury caused by the EVOS. Title: Patterns of distribution, abundance, and change over time in the marine bird community of Prince William Sound, Alaska, 1989-2012 Author: Cushing, Daniel A. (Daniel Arel) Over recent decades, the marine ecosystems of Prince William Sound (PWS), Alaska have experienced the concurrent effects of a major anthropogenic disturbance, the 1989 Exxon Valdez oil spill (EVOS), and a dynamic atmospheric-oceanic environment. Studies of top marine consumers can provide insights into processes of ecosystem change. Using data collected during boat-based marine bird surveys in PWS over the period 1989-2012, I used complimentary taxon- and community-centric approaches to investigate patterns of distribution and abundance of marine birds across space and time. In doing so, I sought to provide insight into processes that may have affected both the birds themselves and the ecosystems of which they are a part. I found that the marine bird community as a whole was spatially structured along a primary onshore-offshore environmental gradient, and secondarily structured along an estuarine-marine environmental gradient. I found two patterns of community variability across time. The first temporal community-level pattern was likely related to sustained rates of change in the abundance of some genera, likely caused by demographic processes. This pattern was correlated with climate variability at time-scales of several years to a decade. The second temporal community-level pattern was characterized by fluctuations that correlated with climate variability at an annual time-scale, likely caused by movements of birds between PWS and the adjacent Gulf of Alaska. I also evaluated changes in the abundance of 18 genera of marine birds, and found that seven had declined in abundance and three had increased over the study period; all genera that declined were piscivorous or planktivorous. Furthermore, the rates of population change of genera were related to their position in the onshore-offshore gradient, with the highest rates of decline occurring in offshore-associated genera. I also investigated spatial habitat associations and temporal changes in abundance of a focal taxon, the seabird genus Brachyramphus. Two species within this piscivorous, pursuit-diving genus occur in PWS, the marbled murrelet (B. marmoratus) and the Kittlitz’s murrelet (B. brevirostris). Both are species of conservation concern, and both experienced acute mortality in PWS caused by the EVOS. Using a statistical model that accounted for variables affecting observed abundance across space and time, I found that abundance decreased by more than two-thirds over the study period. I found no evidence that rates of change differed along environmental or geographic gradients. There was also no evidence that changes in seasonal patterns of abundance occurred. These results are indicative of a widespread decline in the abundance of Brachyramphus murrelets within PWS. Taken as a whole, the results of my thesis are consistent with the hypothesis that climate change has differentially affected nearshore and offshore components of PWS food webs. This in turn has likely contributed to the failure of some taxa, including Brachyramphus murrelets, to recover from population injury caused by the EVOS. Close

• 222. [Article] Water relations and associated morphology of conditioned Douglas-fir and jack pine seedlings subjected to periods of drought stress

  Significant post planting mortality of young conifer seedlings often occurs on drought prone sites because seedlings fail to either establish, or maintain favourable water relations. Survival is contingent ...

  Citation × Citation Citation Abstract Copy Title: Water relations and associated morphology of conditioned Douglas-fir and jack pine seedlings subjected to periods of drought stress Author: McClain, K. M. Significant post planting mortality of young conifer seedlings often occurs on drought prone sites because seedlings fail to either establish, or maintain favourable water relations. Survival is contingent upon growth which occurs when turgor pressure is above a threshold level. Since growth after planting is influenced by nursery cultural practices, it was hypothesized that survival may be enhanced by the effect of irrigation and nutrient conditioning on seedling water relations. Principal water relation parameters estimated by traditional and pressure-volume methods were evaluated in conditioned Douglas-fir and jack pine container seedlings during imposed drought stress in a growth room and outside in raised cold frames containing two soil types. Seedling morphology and ion concentrations in the roots were also determined. Initially, declines in plant water potential (psi) were paralleled by decreases in osmotic potential (psi pi), but as stress increased, differential declines resulted in turgor pressure (psi rho) being variously maintained depending upon irrigation and level of applied KCl. Estimates of tissue elasticity during drought stress suggested that turgor maintenance was the result of solute concentration through tissue dehydration, not osmotic adjustment. During a second drought stress, declines in (psi) and (psi pi) lead to marked increases in in some treatments. In jack pine, this continued to be the result of dehydration and concentration of solutes, but in Douglas-fir, osmotic adjustment was a factor in turgor maintenance. Variable water relations in either species could not he attributed to the accumulation of any particular ion. Only root area exhibited an increase during drought stress. Mortality during recovery was significantly higher in daily than weekly irrigated seedlings and was not influenced by the level of applied KCl. Post drought evaluation of growth potential of surviving seedlings revealed that neither conditioning treatment nor successive drought stress precluded growth. Under field conditions the progressions of water relation parameters were similar to those recorded in growth room conditions, but the rapidity of the responses were affected by soil type. Results suggested the occurrence of osmotic adjustment in Douglas-fir; restrained decline in turgor pressure in jack pine was clearly the result of concentration of salutes through dehydration. Mortality was confined entirely to Douglas-fir in the clay loam soil, but in the sandy soil both species, regardless of conditioning treatment, experienced mortality at low soil water availability. Title: Water relations and associated morphology of conditioned Douglas-fir and jack pine seedlings subjected to periods of drought stress Author: McClain, K. M. Significant post planting mortality of young conifer seedlings often occurs on drought prone sites because seedlings fail to either establish, or maintain favourable water relations. Survival is contingent upon growth which occurs when turgor pressure is above a threshold level. Since growth after planting is influenced by nursery cultural practices, it was hypothesized that survival may be enhanced by the effect of irrigation and nutrient conditioning on seedling water relations. Principal water relation parameters estimated by traditional and pressure-volume methods were evaluated in conditioned Douglas-fir and jack pine container seedlings during imposed drought stress in a growth room and outside in raised cold frames containing two soil types. Seedling morphology and ion concentrations in the roots were also determined. Initially, declines in plant water potential (psi) were paralleled by decreases in osmotic potential (psi pi), but as stress increased, differential declines resulted in turgor pressure (psi rho) being variously maintained depending upon irrigation and level of applied KCl. Estimates of tissue elasticity during drought stress suggested that turgor maintenance was the result of solute concentration through tissue dehydration, not osmotic adjustment. During a second drought stress, declines in (psi) and (psi pi) lead to marked increases in in some treatments. In jack pine, this continued to be the result of dehydration and concentration of solutes, but in Douglas-fir, osmotic adjustment was a factor in turgor maintenance. Variable water relations in either species could not he attributed to the accumulation of any particular ion. Only root area exhibited an increase during drought stress. Mortality during recovery was significantly higher in daily than weekly irrigated seedlings and was not influenced by the level of applied KCl. Post drought evaluation of growth potential of surviving seedlings revealed that neither conditioning treatment nor successive drought stress precluded growth. Under field conditions the progressions of water relation parameters were similar to those recorded in growth room conditions, but the rapidity of the responses were affected by soil type. Results suggested the occurrence of osmotic adjustment in Douglas-fir; restrained decline in turgor pressure in jack pine was clearly the result of concentration of salutes through dehydration. Mortality was confined entirely to Douglas-fir in the clay loam soil, but in the sandy soil both species, regardless of conditioning treatment, experienced mortality at low soil water availability. Close

• 223. [Article] Measuring and Managing Resistance and Resilience Under Climate Change in Northern Great Lake Forests (USA)

  Context: Climate change will have diverse and interacting effects on forests over the next century. One of the most pronounced effects may be a decline in resistance to chronic change and resilience to ...

  Citation × Citation Citation Abstract Copy Title: Measuring and Managing Resistance and Resilience Under Climate Change in Northern Great Lake Forests (USA) Author: Duveneck, Matthew Joshua, Scheller, Robert M. Year: 2016 Context: Climate change will have diverse and interacting effects on forests over the next century. One of the most pronounced effects may be a decline in resistance to chronic change and resilience to acute disturbances. The capacity for forests to persist and/or adapt to climate change remains largely unknown, in part because there is not broad agreement how to measure and apply resilience concepts. Objectives: We assessed the interactions of climate change, resistance, resilience, diversity, and alternative management of northern Great Lake forests. Methods: We simulated two landscapes (northern Minnesota and northern lower Michigan), three climate futures (current climate, a low emissions trajectory, and a high emissions trajectory), and four management regimes [business as usual, expanded forest reserves, modified silviculture, and climate suitable planting (CSP)]. We simulated each scenario with a forest landscape simulation model. We assessed resistance as the change in species composition over time. We assessed resilience and calculated an index of resilience that incorporated both recovery of pre-fire tree species composition and aboveground biomass within simulated burned areas. Results: Results indicate a positive relationship between diversity and resistance within low diversity areas. Simulations of the high emission climate future resulted in a decline in both resistance and resilience. Conclusions: Of the management regimes, the CSP regime resulted in some of the greatest resilience under climate change although our results suggest that differences in forest management are largely outweighed by the effects of climate change. Our results provide a framework for assessing resistance and resilience relevant and valuable to a broad array of ecological systems. Title: Measuring and Managing Resistance and Resilience Under Climate Change in Northern Great Lake Forests (USA) Author: Duveneck, Matthew Joshua, Scheller, Robert M. Year: 2016 Context: Climate change will have diverse and interacting effects on forests over the next century. One of the most pronounced effects may be a decline in resistance to chronic change and resilience to acute disturbances. The capacity for forests to persist and/or adapt to climate change remains largely unknown, in part because there is not broad agreement how to measure and apply resilience concepts. Objectives: We assessed the interactions of climate change, resistance, resilience, diversity, and alternative management of northern Great Lake forests. Methods: We simulated two landscapes (northern Minnesota and northern lower Michigan), three climate futures (current climate, a low emissions trajectory, and a high emissions trajectory), and four management regimes [business as usual, expanded forest reserves, modified silviculture, and climate suitable planting (CSP)]. We simulated each scenario with a forest landscape simulation model. We assessed resistance as the change in species composition over time. We assessed resilience and calculated an index of resilience that incorporated both recovery of pre-fire tree species composition and aboveground biomass within simulated burned areas. Results: Results indicate a positive relationship between diversity and resistance within low diversity areas. Simulations of the high emission climate future resulted in a decline in both resistance and resilience. Conclusions: Of the management regimes, the CSP regime resulted in some of the greatest resilience under climate change although our results suggest that differences in forest management are largely outweighed by the effects of climate change. Our results provide a framework for assessing resistance and resilience relevant and valuable to a broad array of ecological systems. Close

• 224. [Article] The Effects of Hypoxia and Temperature on Developing Embryos of the Annual Killifish Austrofundulus limnaeus

  Little is known about the physiology or biochemistry of hypoxia (reduced levels of oxygen) tolerance during development in vertebrate embryos. In most species, relatively brief bouts of severe hypoxia ...

  Citation × Citation Citation Abstract Copy Title: The Effects of Hypoxia and Temperature on Developing Embryos of the Annual Killifish Austrofundulus limnaeus Author: Anderson, Skye N. Year: 2012 Little is known about the physiology or biochemistry of hypoxia (reduced levels of oxygen) tolerance during development in vertebrate embryos. In most species, relatively brief bouts of severe hypoxia are lethal or teratogenic. An exception to such hypoxia intolerance is the annual killifish Austrofundulus limnaeus, in which populations persist in hypoxic environments. This species inhabits seasonal ponds in Venezuela, surviving through the dry season in the form of diapausing embryos. Embedded in the pond sediment, embryos of A. limnaeus are routinely exposed to hypoxia and anoxia (lack of oxygen) as part of their normal development. Here, we exposed embryos to various levels of PO2 (21.2, 15.6, 10.8, 8.4, 6.1, 3.6, and 2.2 kPa) at two different temperatures (25°C and 30°C) to study the effects on developmental rate and heart rate. We also measured enzyme activity and quantified DNA content of individual embryos to compare differences among the varying levels of hypoxia and temperature. Hypoxia caused a significant decline in developmental rate and caused a stage-specific decline in heart rate. Higher temperature caused an increase in the developmental rate for those embryos incubated at PO2 of 6.1 kPa and greater. Temperature had a negative effect by hindering development below a PO2 of 6.1 kPa. Total embryonic DNA content was reduced at low partial pressures (15.6, 10.8, 8.4, 6.1, 3.6, and 2.2 kPa) of oxygen. Citrate synthase, lactate dehydrogenase, and phosphoenolpyruvate carboxykinase were all down-regulated indicating a complete lack of enzymatic metabolic compensation to combat reduced oxygen levels. Title: The Effects of Hypoxia and Temperature on Developing Embryos of the Annual Killifish Austrofundulus limnaeus Author: Anderson, Skye N. Year: 2012 Little is known about the physiology or biochemistry of hypoxia (reduced levels of oxygen) tolerance during development in vertebrate embryos. In most species, relatively brief bouts of severe hypoxia are lethal or teratogenic. An exception to such hypoxia intolerance is the annual killifish Austrofundulus limnaeus, in which populations persist in hypoxic environments. This species inhabits seasonal ponds in Venezuela, surviving through the dry season in the form of diapausing embryos. Embedded in the pond sediment, embryos of A. limnaeus are routinely exposed to hypoxia and anoxia (lack of oxygen) as part of their normal development. Here, we exposed embryos to various levels of PO2 (21.2, 15.6, 10.8, 8.4, 6.1, 3.6, and 2.2 kPa) at two different temperatures (25°C and 30°C) to study the effects on developmental rate and heart rate. We also measured enzyme activity and quantified DNA content of individual embryos to compare differences among the varying levels of hypoxia and temperature. Hypoxia caused a significant decline in developmental rate and caused a stage-specific decline in heart rate. Higher temperature caused an increase in the developmental rate for those embryos incubated at PO2 of 6.1 kPa and greater. Temperature had a negative effect by hindering development below a PO2 of 6.1 kPa. Total embryonic DNA content was reduced at low partial pressures (15.6, 10.8, 8.4, 6.1, 3.6, and 2.2 kPa) of oxygen. Citrate synthase, lactate dehydrogenase, and phosphoenolpyruvate carboxykinase were all down-regulated indicating a complete lack of enzymatic metabolic compensation to combat reduced oxygen levels. Close

• 225. [Article] Demography of a Ground Nesting Bird in an Urban System: Are Populations Self-Sustaining?

  Urbanization poses threats to earth’s biota, and retention of remnant native habitat in protected areas within expanding urban boundaries may help alleviate threats to wildlife. However, it is unclear ...

  Citation × Citation Citation Abstract Copy Title: Demography of a Ground Nesting Bird in an Urban System: Are Populations Self-Sustaining? Author: Bartos Smith, Sarah, McKay, Jenny E., Richardson, Jennifer K., Shipley, Amy A., Murphy, Michael T. Year: 2016 Urbanization poses threats to earth’s biota, and retention of remnant native habitat in protected areas within expanding urban boundaries may help alleviate threats to wildlife. However, it is unclear for nearly all nonsynanthropic (i.e., not benefiting from an association with humans) species whether vital rates in urban habitats can sustain populations or if populations persist only through immigration from outside the urban boundary. We conducted a three-year study of spotted towhees (Aves: Pipilo maculatus) breeding in four undeveloped parks in Portland, OR, USA, to measure park-specific seasonal reproductive output (F) and annual adult survival (SA). We developed a stochastic model that combined F and SA with an estimate of first-year survival to measure population growth rate (λ) in all parks assumed to be closed to immigration. F differed among parks but SA did not. Relatively high F was possible because many pairs raised >1 brood/season. When combined with empirical estimates of survival through the 30-day period of post-fledging parental care (SD = 0.645), only 2 of 4 parks were self-sustaining (i.e., λ > 1.0). However, SD reflected substantial loss of fledglings to domestic cats (Felis catus). Assuming no loss to cats and either partial compensatory or additive mortality of fledglings substantially improved prospects of population persistence for declining (sink) populations. Moreover, allowing low levels of immigration to sinks reversed population declines in most parks even when vital rates were insufficient to maintain populations. Our results suggest that nonsynanthropic bird species can persist in urban landscapes, but also that offspring mortality in the post-fledging period may be a critical determinant of population viability. Title: Demography of a Ground Nesting Bird in an Urban System: Are Populations Self-Sustaining? Author: Bartos Smith, Sarah, McKay, Jenny E., Richardson, Jennifer K., Shipley, Amy A., Murphy, Michael T. Year: 2016 Urbanization poses threats to earth’s biota, and retention of remnant native habitat in protected areas within expanding urban boundaries may help alleviate threats to wildlife. However, it is unclear for nearly all nonsynanthropic (i.e., not benefiting from an association with humans) species whether vital rates in urban habitats can sustain populations or if populations persist only through immigration from outside the urban boundary. We conducted a three-year study of spotted towhees (Aves: Pipilo maculatus) breeding in four undeveloped parks in Portland, OR, USA, to measure park-specific seasonal reproductive output (F) and annual adult survival (SA). We developed a stochastic model that combined F and SA with an estimate of first-year survival to measure population growth rate (λ) in all parks assumed to be closed to immigration. F differed among parks but SA did not. Relatively high F was possible because many pairs raised >1 brood/season. When combined with empirical estimates of survival through the 30-day period of post-fledging parental care (SD = 0.645), only 2 of 4 parks were self-sustaining (i.e., λ > 1.0). However, SD reflected substantial loss of fledglings to domestic cats (Felis catus). Assuming no loss to cats and either partial compensatory or additive mortality of fledglings substantially improved prospects of population persistence for declining (sink) populations. Moreover, allowing low levels of immigration to sinks reversed population declines in most parks even when vital rates were insufficient to maintain populations. Our results suggest that nonsynanthropic bird species can persist in urban landscapes, but also that offspring mortality in the post-fledging period may be a critical determinant of population viability. Close

• 226. [Article] Stranding Mortality Patterns in California Sea Lions and Steller Sea Lions in Oregon and Southern Washington, 2006 to 2014

  As changing ocean conditions lead to declining fish stocks and movement of forage fish, sea lions on the Oregon coast are subject to the pressures of declining prey availability and increasing conflicts ...

  Citation × Citation Citation Abstract Copy Title: Stranding Mortality Patterns in California Sea Lions and Steller Sea Lions in Oregon and Southern Washington, 2006 to 2014 Author: Lee, Kessina Year: 2016 As changing ocean conditions lead to declining fish stocks and movement of forage fish, sea lions on the Oregon coast are subject to the pressures of declining prey availability and increasing conflicts with commercial and recreational fisheries. An analysis of strandings of California sea lions, Zalophus californianus, and Steller sea lions, Eumetopias jubatus, from 2006 to 2014, included cause of death, changing ocean conditions, and anthropogenic activity. Causes of death included disease, injury, and human interaction, such as gunshot wounds, fisheries net entanglements and boat strikes. Oregon and Washington strandings of California sea lions are primarily adult and subadult males that migrate north from California rookeries, while Steller sea lions are year-round residents and strandings are comprised of males and females of all ages. While the California sea lion population is currently at or near carrying capacity, the Eastern Pacific population of Steller sea lions was designated as Threatened under the Endangered Species Act until October 2013. Understanding impacts to these two pinniped species is vital to implementing effective management and conservation policies. Oregon and southern Washington strandings of California sea lions and Steller sea lions from 2006 to 2014 were analyzed spatially using the geographic information system (GIS), and temporally to identify possible correlations with prey availability and human interaction. Strandings were found to follow seasonal patterns from year to year: Steller sea lion strandings were highest from May to July, California sea lions peaked in September, October, and November. There was a correlation between significantly high numbers of strandings and the three largest commercial fisheries in Oregon: Chinook salmon, Coho salmon, and Dungeness crab. This analysis provides a format for continuing to monitor primary ecological and anthropogenic drivers of pinniped mortality in Oregon and southern Washington. Title: Stranding Mortality Patterns in California Sea Lions and Steller Sea Lions in Oregon and Southern Washington, 2006 to 2014 Author: Lee, Kessina Year: 2016 As changing ocean conditions lead to declining fish stocks and movement of forage fish, sea lions on the Oregon coast are subject to the pressures of declining prey availability and increasing conflicts with commercial and recreational fisheries. An analysis of strandings of California sea lions, Zalophus californianus, and Steller sea lions, Eumetopias jubatus, from 2006 to 2014, included cause of death, changing ocean conditions, and anthropogenic activity. Causes of death included disease, injury, and human interaction, such as gunshot wounds, fisheries net entanglements and boat strikes. Oregon and Washington strandings of California sea lions are primarily adult and subadult males that migrate north from California rookeries, while Steller sea lions are year-round residents and strandings are comprised of males and females of all ages. While the California sea lion population is currently at or near carrying capacity, the Eastern Pacific population of Steller sea lions was designated as Threatened under the Endangered Species Act until October 2013. Understanding impacts to these two pinniped species is vital to implementing effective management and conservation policies. Oregon and southern Washington strandings of California sea lions and Steller sea lions from 2006 to 2014 were analyzed spatially using the geographic information system (GIS), and temporally to identify possible correlations with prey availability and human interaction. Strandings were found to follow seasonal patterns from year to year: Steller sea lion strandings were highest from May to July, California sea lions peaked in September, October, and November. There was a correlation between significantly high numbers of strandings and the three largest commercial fisheries in Oregon: Chinook salmon, Coho salmon, and Dungeness crab. This analysis provides a format for continuing to monitor primary ecological and anthropogenic drivers of pinniped mortality in Oregon and southern Washington. Close

• 227. [Article] Experimental Evidence for Evolved Tolerance to Avian Malaria in a Wild Population of Low Elevation Hawai‘i ‘Amakihi (Hemignathus virens)

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the International ...

  Citation × Citation Citation Abstract Copy Title: Experimental Evidence for Evolved Tolerance to Avian Malaria in a Wild Population of Low Elevation Hawai‘i ‘Amakihi (Hemignathus virens) Author: Saili, Katerine S., Jarvi, Susan I., Atkinson, Carter T., Utzurrum, Ruth B. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the International Association for Ecology and Health and published by Springer. It can be found at: http://link.springer.com/journal/10393. Title: Experimental Evidence for Evolved Tolerance to Avian Malaria in a Wild Population of Low Elevation Hawai‘i ‘Amakihi (Hemignathus virens) Author: Saili, Katerine S., Jarvi, Susan I., Atkinson, Carter T., Utzurrum, Ruth B. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the International Association for Ecology and Health and published by Springer. It can be found at: http://link.springer.com/journal/10393. Close

• 228. [Article] Packaging Usable Climate Change Information for Sagebrush Country

  One of the largest ecosystems in the United States, sagebrush-steppe communities are currently in peril and threaten to impact at least 150 species of vertebrates (Hagen 2011). The decline of sagebrush ...

  Citation × Citation Citation Abstract Copy Title: Packaging Usable Climate Change Information for Sagebrush Country Author: Brown, Melanie One of the largest ecosystems in the United States, sagebrush-steppe communities are currently in peril and threaten to impact at least 150 species of vertebrates (Hagen 2011). The decline of sagebrush habitat is exacerbated through an interaction of threats and feedbacks, including fire and invasive species, making the management of sagebrush ecosystems a challenge (Connelly et al. 2004). Optimizing sagebrush management to reduce sagebrush decline includes understanding the role of climate (Dalgleish et al. 2011; Schrag et al. 2010; Compagnoni 2013). Current climate tools may be too coarse or may not include the specific variables useful for land management. Further complications may include communication barriers between land managers and climate scientists that can impede efficient information exchange, leaving climate scientists without necessary questions and land managers without necessary answers. There is a need for managers and climate scientist to work together to make current and future climate information more applicable to land management needs (Kocher et al. 2012). This research seeks to understand: Can collaboration between climate scientists and land managers lead to more useful and useable climate tools for land management? The main objectives of this project include the following: ➢ Understand current threats and their sensitivity to climate within Oregon and Idaho sagebrush habitat. ➢ Identify climate information that is needed by land managers to make sagebrush management decisions. ➢ Identify climate tools that would be most useful to land managers. ➢ Compile information to be used within a climate tool that is both useful and useable by land managers. ➢ Gather feedback from managers about the collaboration process and the climate tool created ➢ Assess the collaboration process and whether it was beneficial in adapting climate tools for land managers. ➢ Complete thesis and/or presentation on topic. Title: Packaging Usable Climate Change Information for Sagebrush Country Author: Brown, Melanie One of the largest ecosystems in the United States, sagebrush-steppe communities are currently in peril and threaten to impact at least 150 species of vertebrates (Hagen 2011). The decline of sagebrush habitat is exacerbated through an interaction of threats and feedbacks, including fire and invasive species, making the management of sagebrush ecosystems a challenge (Connelly et al. 2004). Optimizing sagebrush management to reduce sagebrush decline includes understanding the role of climate (Dalgleish et al. 2011; Schrag et al. 2010; Compagnoni 2013). Current climate tools may be too coarse or may not include the specific variables useful for land management. Further complications may include communication barriers between land managers and climate scientists that can impede efficient information exchange, leaving climate scientists without necessary questions and land managers without necessary answers. There is a need for managers and climate scientist to work together to make current and future climate information more applicable to land management needs (Kocher et al. 2012). This research seeks to understand: Can collaboration between climate scientists and land managers lead to more useful and useable climate tools for land management? The main objectives of this project include the following: ➢ Understand current threats and their sensitivity to climate within Oregon and Idaho sagebrush habitat. ➢ Identify climate information that is needed by land managers to make sagebrush management decisions. ➢ Identify climate tools that would be most useful to land managers. ➢ Compile information to be used within a climate tool that is both useful and useable by land managers. ➢ Gather feedback from managers about the collaboration process and the climate tool created ➢ Assess the collaboration process and whether it was beneficial in adapting climate tools for land managers. ➢ Complete thesis and/or presentation on topic. Close

• 229. [Article] Differences in sensitivity to the fungal pathogen Batrachochytrium dendrobatidis among amphibian populations

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by Society for Conservation ...

  Citation × Citation Citation Abstract Copy Title: Differences in sensitivity to the fungal pathogen Batrachochytrium dendrobatidis among amphibian populations Author: Blaustein, Andrew R., Gervasi, Stephanie S., Hua, Jessica, et al., Bradley, Paul W. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by Society for Conservation Biology and published by John Wiley & Sons, Inc. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291523-1739 Title: Differences in sensitivity to the fungal pathogen Batrachochytrium dendrobatidis among amphibian populations Author: Blaustein, Andrew R., Gervasi, Stephanie S., Hua, Jessica, et al., Bradley, Paul W. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by Society for Conservation Biology and published by John Wiley & Sons, Inc. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291523-1739 Close

• 230. [Article] Nutrient stores and dynamics of woody detritus in a boreal forest: modeling potential implications at the stand level

  Concentrations of 14 chemical elements (Al, B, C, Ca, Cu, Fe, K, N, Mg, Mn, Na, P, S, Zn) were measured in wood and bark of 126 sample trees representing different stages of decomposition in three major ...

  Citation × Citation Citation Abstract Copy Title: Nutrient stores and dynamics of woody detritus in a boreal forest: modeling potential implications at the stand level Author: Harmon, Mark E., Krankina, Olga N., Griazkin, Anatolii V. Concentrations of 14 chemical elements (Al, B, C, Ca, Cu, Fe, K, N, Mg, Mn, Na, P, S, Zn) were measured in wood and bark of 126 sample trees representing different stages of decomposition in three major tree species of northwestern Russia: Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.), and birch (Betula pendula Roth.). Changes in nutrient stores in decay classes were calculated with adjustments for the loss of density and volume by dead trees. Although the concentration of many nutrients increased relative to the estimated initial level, the total amount of most nutrients contained in dead trees declined with decay. For example, nitrogen stores declined from decay class 1 to 4 by 45% for birch, 39% for spruce, and by 60% for pine. The rate and pattern of these losses varied by nutrient and by species and were primarily related to the patterns of bark loss. Pine lost bark early in the process of decomposition and released many essential nutrients (i.e., N, P, Ca) at the early stages, while birch retained most of its bark throughout the decomposition process and lost nutrients more gradually. The temporal dynamics of N, Ca, and K loss in pine were examined using a chronosequence approach, and the results were used in stand-level modeling. The analysis of modeling results suggests that, in northwestern Russia, post-disturbance release of nutrients from woody detritus can potentially supply a large proportion of the net N, Ca, and K accumulation in live forest biomass. Title: Nutrient stores and dynamics of woody detritus in a boreal forest: modeling potential implications at the stand level Author: Harmon, Mark E., Krankina, Olga N., Griazkin, Anatolii V. Concentrations of 14 chemical elements (Al, B, C, Ca, Cu, Fe, K, N, Mg, Mn, Na, P, S, Zn) were measured in wood and bark of 126 sample trees representing different stages of decomposition in three major tree species of northwestern Russia: Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.), and birch (Betula pendula Roth.). Changes in nutrient stores in decay classes were calculated with adjustments for the loss of density and volume by dead trees. Although the concentration of many nutrients increased relative to the estimated initial level, the total amount of most nutrients contained in dead trees declined with decay. For example, nitrogen stores declined from decay class 1 to 4 by 45% for birch, 39% for spruce, and by 60% for pine. The rate and pattern of these losses varied by nutrient and by species and were primarily related to the patterns of bark loss. Pine lost bark early in the process of decomposition and released many essential nutrients (i.e., N, P, Ca) at the early stages, while birch retained most of its bark throughout the decomposition process and lost nutrients more gradually. The temporal dynamics of N, Ca, and K loss in pine were examined using a chronosequence approach, and the results were used in stand-level modeling. The analysis of modeling results suggests that, in northwestern Russia, post-disturbance release of nutrients from woody detritus can potentially supply a large proportion of the net N, Ca, and K accumulation in live forest biomass. Close

• 231. [Article] A study of Myxobolus cerebralis in the Lostine River, Oregon : epizootiology, distribution and implications for resident and anadromous salmonids

  Myxobolus cerebralis, a myxozoan parasite that infects almost all species of wild and cultured salmonids, was first identified in northeastern Oregon in the Lostine River in 1986. Fish that are heavily ...

  Citation × Citation Citation Abstract Copy Title: A study of Myxobolus cerebralis in the Lostine River, Oregon : epizootiology, distribution and implications for resident and anadromous salmonids Author: Sandell, Todd A. Myxobolus cerebralis, a myxozoan parasite that infects almost all species of wild and cultured salmonids, was first identified in northeastern Oregon in the Lostine River in 1986. Fish that are heavily infected with M. cerebralis develop whirling disease, which was determined to be the cause of catastrophic declines in rainbow trout populations in Montana and Colorado in 1996. There have been no reports of severe salmonid population declines attributed to whirling disease in Oregon, although many populations are at levels that warrant protective listing under the Endangered Species Act. This study was undertaken to I) establish the distribution and seasonal prevalence of M. cerebralis infection in the Lostine River, 2) investigate the epizootiological factors influencing the occurrence of whirling disease in this river, 3) determine the potential impact of the parasite on chinook salmon, and 4) evaluate the suitability of a non-lethal tissue sampling protocol for the detection of M. cerebralis in juvenile and adult salmonids for use in monitoring the effects and distribution of the parasite in protected salmonid populations. Results of this study indicate that the parasite is present throughout the main stem of the Lostine River during all seasons, and that rainbow and anadromous steelhead trout fry emerging in the lower river are most likely to become infected and develop whirling disease. Chinook salmon were shown to be relatively resistant to M. cerebralis at low levels of exposure, but this effect was less evident when the parasite exposure increased. The non-lethal sampling protocol was successful in detecting M. cerebralis in juvenile salmonids but not in adults, where it is most needed. The information gathered during these studies was then correlated with the life histories of resident and anadromous salmonids in the Lostine River to determine the potential impact of M. cerebralis On salmonid populations in this region. Title: A study of Myxobolus cerebralis in the Lostine River, Oregon : epizootiology, distribution and implications for resident and anadromous salmonids Author: Sandell, Todd A. Myxobolus cerebralis, a myxozoan parasite that infects almost all species of wild and cultured salmonids, was first identified in northeastern Oregon in the Lostine River in 1986. Fish that are heavily infected with M. cerebralis develop whirling disease, which was determined to be the cause of catastrophic declines in rainbow trout populations in Montana and Colorado in 1996. There have been no reports of severe salmonid population declines attributed to whirling disease in Oregon, although many populations are at levels that warrant protective listing under the Endangered Species Act. This study was undertaken to I) establish the distribution and seasonal prevalence of M. cerebralis infection in the Lostine River, 2) investigate the epizootiological factors influencing the occurrence of whirling disease in this river, 3) determine the potential impact of the parasite on chinook salmon, and 4) evaluate the suitability of a non-lethal tissue sampling protocol for the detection of M. cerebralis in juvenile and adult salmonids for use in monitoring the effects and distribution of the parasite in protected salmonid populations. Results of this study indicate that the parasite is present throughout the main stem of the Lostine River during all seasons, and that rainbow and anadromous steelhead trout fry emerging in the lower river are most likely to become infected and develop whirling disease. Chinook salmon were shown to be relatively resistant to M. cerebralis at low levels of exposure, but this effect was less evident when the parasite exposure increased. The non-lethal sampling protocol was successful in detecting M. cerebralis in juvenile salmonids but not in adults, where it is most needed. The information gathered during these studies was then correlated with the life histories of resident and anadromous salmonids in the Lostine River to determine the potential impact of M. cerebralis On salmonid populations in this region. Close

• 232. [Article] Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix) response to high intensity-short duration goat browsing

  The goal of this dissertation is to examine the effectiveness of high intensity-short duration goat browsing for the control of Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix), two ...

  Citation × Citation Citation Abstract Copy Title: Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix) response to high intensity-short duration goat browsing Author: Ingham, Claudia S. The goal of this dissertation is to examine the effectiveness of high intensity-short duration goat browsing for the control of Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix), two widespread noxious weeds in the Pacific Northwest. The effects of goat browsing on Himalayan blackberry vigor, as quantified by densities of different age class stems, are compared to mowing and goat browsing followed by mowing over a period of three years. Although total stem density and node density declined, primocane density increased after all types of treatment. This indicates that the population was still vigorous. Recruitment of new plants was reflected by an increase in seedling density. Changes in percent cover of vegetation functional groups were also examined. All three treatments produced a decline in Himalayan blackberry cover and an increase in perennial grass cover, though differences among treatment types were not significant. Perennial forb cover increased as a result of all treatment types. English ivy was successfully controlled by goat browsing as quantified by percent cover. Two years of browsing reduced percent cover more than one year of browsing. Both levels of browsing produced results that were significantly different when compared to the untreated control indicating that repeated high intensity-short duration browsing is justified for control of this invasive plant species. Differences in response of these two invasive, creeping perennials are attributed to differences in species growth rates, location of meristematic tissue in stolons vs. rhizomes and shade conditions at the research sites. Title: Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix) response to high intensity-short duration goat browsing Author: Ingham, Claudia S. The goal of this dissertation is to examine the effectiveness of high intensity-short duration goat browsing for the control of Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix), two widespread noxious weeds in the Pacific Northwest. The effects of goat browsing on Himalayan blackberry vigor, as quantified by densities of different age class stems, are compared to mowing and goat browsing followed by mowing over a period of three years. Although total stem density and node density declined, primocane density increased after all types of treatment. This indicates that the population was still vigorous. Recruitment of new plants was reflected by an increase in seedling density. Changes in percent cover of vegetation functional groups were also examined. All three treatments produced a decline in Himalayan blackberry cover and an increase in perennial grass cover, though differences among treatment types were not significant. Perennial forb cover increased as a result of all treatment types. English ivy was successfully controlled by goat browsing as quantified by percent cover. Two years of browsing reduced percent cover more than one year of browsing. Both levels of browsing produced results that were significantly different when compared to the untreated control indicating that repeated high intensity-short duration browsing is justified for control of this invasive plant species. Differences in response of these two invasive, creeping perennials are attributed to differences in species growth rates, location of meristematic tissue in stolons vs. rhizomes and shade conditions at the research sites. Close

• 233. [Article] Effects of diet on growth and development of nesting seabirds

  Recent declines in nesting success of some fish-eating seabirds in Alaska have been attributed to declines in availability of certain schooling forage fishes (e.g., capelin Mallotus villosus, Pacific sand ...

  Citation × Citation Citation Abstract Copy Title: Effects of diet on growth and development of nesting seabirds Author: Romano, Marc D. Recent declines in nesting success of some fish-eating seabirds in Alaska have been attributed to declines in availability of certain schooling forage fishes (e.g., capelin Mallotus villosus, Pacific sand lance Ammodytes hexapterus, and Pacific herring Clupea harengus pallasi). These fishes tend to have high lipid content compared with other species and, consequently, are assumed to have high nutritional value as food for young seabirds. I tested hypotheses that type of fish consumed by the nestling, and lipid:protein ratio of the diet constrain growth and development of piscivorous seabird nestlings. I raised seabird nestlings (Black-legged Kittiwakes, Rissa tridactyla and Tufted Puffins, Fratercula cirrhata) on controlled diets of either capelin, herring, or sand lance (high-lipid fish), or juvenile walleye pollock (Theragra chalcograma; a low-lipid fish). Seabird nestlings fed herring, sand lance, or capelin had higher growth rates (body mass and wing length) than nestlings fed equal biomass rations of pollock. Growth in body mass and wing length of kittiwake nestlings was not affected by lipid:protein ratio of the diet when on a high nutritional plane (i.e., high caloric intake), but growth was significantly affected by dietary lipid:protein ratio when on a low plane of nutrition. Growth in body mass and wing length of puffins was not significantly affected by the lipid:protein ratio of the diet. Diets with a higher lipid:protein ratio resulted in greater fat reserves in both seabird species, regardless of nutritional plane. Additionally, diets with a higher lipid:protein ratio resulted in higher apparent metabolizable energy coefficients. The increased growth rates, fat reserves, and energy utilization efficiencies of chicks fed high-lipid diets suggest that pre- and post-fledging survival are enhanced when parent seabirds have access to high-lipid forage fish. Title: Effects of diet on growth and development of nesting seabirds Author: Romano, Marc D. Recent declines in nesting success of some fish-eating seabirds in Alaska have been attributed to declines in availability of certain schooling forage fishes (e.g., capelin Mallotus villosus, Pacific sand lance Ammodytes hexapterus, and Pacific herring Clupea harengus pallasi). These fishes tend to have high lipid content compared with other species and, consequently, are assumed to have high nutritional value as food for young seabirds. I tested hypotheses that type of fish consumed by the nestling, and lipid:protein ratio of the diet constrain growth and development of piscivorous seabird nestlings. I raised seabird nestlings (Black-legged Kittiwakes, Rissa tridactyla and Tufted Puffins, Fratercula cirrhata) on controlled diets of either capelin, herring, or sand lance (high-lipid fish), or juvenile walleye pollock (Theragra chalcograma; a low-lipid fish). Seabird nestlings fed herring, sand lance, or capelin had higher growth rates (body mass and wing length) than nestlings fed equal biomass rations of pollock. Growth in body mass and wing length of kittiwake nestlings was not affected by lipid:protein ratio of the diet when on a high nutritional plane (i.e., high caloric intake), but growth was significantly affected by dietary lipid:protein ratio when on a low plane of nutrition. Growth in body mass and wing length of puffins was not significantly affected by the lipid:protein ratio of the diet. Diets with a higher lipid:protein ratio resulted in greater fat reserves in both seabird species, regardless of nutritional plane. Additionally, diets with a higher lipid:protein ratio resulted in higher apparent metabolizable energy coefficients. The increased growth rates, fat reserves, and energy utilization efficiencies of chicks fed high-lipid diets suggest that pre- and post-fledging survival are enhanced when parent seabirds have access to high-lipid forage fish. Close

• 234. [Article] Development of a Structured Adaptive Approach to Klamath Basin Sucker Recovery Planning

  Listed as endangered in 1988, the Lost River sucker (Deltistes luxatus) and Shortnose sucker (Chasmistes brevirostris) were once abundant and widely distributed in the Klamath Basin in Southern Oregon ...

  Citation × Citation Citation Abstract Copy Title: Development of a Structured Adaptive Approach to Klamath Basin Sucker Recovery Planning Author: Barajas, Miguel F. Listed as endangered in 1988, the Lost River sucker (Deltistes luxatus) and Shortnose sucker (Chasmistes brevirostris) were once abundant and widely distributed in the Klamath Basin in Southern Oregon and Northern California. Populations of both species have been declining since the late 1960’s. Factors thought responsible for declines include naturally occurring disturbances (e.g., periodic drought), water resource and land development activities, degradation of habitat and water quality, and interactions with introduced exotic species. Detection of any substantial adult recruitment for the last few decades has been minimal. We used a quantitative decision modeling approach to explore potential outcomes of alternative conservation strategies that include captive propagation and catch, grow, and release. Uncertainty about the factors responsible for the apparent lack of recruitment was represented using alternative models of system dynamics. Sensitivity analysis indicated that the model predictions were highly sensitive to population dynamics during early life stages and the alternative ideas of system dynamics. To address these uncertainties, I propose an adaptive approach to sucker recovery that integrates monitoring, research, and management. Title: Development of a Structured Adaptive Approach to Klamath Basin Sucker Recovery Planning Author: Barajas, Miguel F. Listed as endangered in 1988, the Lost River sucker (Deltistes luxatus) and Shortnose sucker (Chasmistes brevirostris) were once abundant and widely distributed in the Klamath Basin in Southern Oregon and Northern California. Populations of both species have been declining since the late 1960’s. Factors thought responsible for declines include naturally occurring disturbances (e.g., periodic drought), water resource and land development activities, degradation of habitat and water quality, and interactions with introduced exotic species. Detection of any substantial adult recruitment for the last few decades has been minimal. We used a quantitative decision modeling approach to explore potential outcomes of alternative conservation strategies that include captive propagation and catch, grow, and release. Uncertainty about the factors responsible for the apparent lack of recruitment was represented using alternative models of system dynamics. Sensitivity analysis indicated that the model predictions were highly sensitive to population dynamics during early life stages and the alternative ideas of system dynamics. To address these uncertainties, I propose an adaptive approach to sucker recovery that integrates monitoring, research, and management. Close

• 235. [Article] The effect of grazing interval on forage quality and production of meadow foxtail

  For the last fifty years, meadow foxtail (Alopecurus pratensis L.) has been invading native flood meadows throughout the Harney Basin in southeastern Oregon. The expansion of this grass species has been ...

  Citation × Citation Citation Abstract Copy Title: The effect of grazing interval on forage quality and production of meadow foxtail Author: Wenick, Jess J. For the last fifty years, meadow foxtail (Alopecurus pratensis L.) has been invading native flood meadows throughout the Harney Basin in southeastern Oregon. The expansion of this grass species has been the result of its broad climatic requirements and ability to withstand drought while thriving in saturated soil conditions for a large part of the growing season. Meadow foxtail starts growth as soon as adequate soil moisture exists. Managing this early maturing hay species can prove to be a challenge because soil saturation and elevated water tables make it difficult to harvest hay when forage quality and yield are maximized. The purpose of this study was to evaluate whether planned grazing would retard maturation and thus prolong forage quality. Treatments included a non-grazed control and grazing durations of 2, 4, 6, and 8 weeks. Grazing was initiated in May of 1998 and 1999 on six replications of each treatment arranged in a randomized block design. Within each treatment/replicate combination, ten 0.2 m² plots were clipped to ground level at about two week intervals from May to August. The samples were weighed and dried for standing crop estimation and 4 of the 10 samples were selected at random and analyzed for acid detergent fiber (ADF), neutral detergent fiber (NDF), and crude protein (CP). Analyses of variance, least significant differences, and regression analyses were calculated to determine whether or not there were statistical differences of P≤0.05. We found that early spring grazing decreased forage yield significantly. An increase in CP with duration of defoliation was expected and obtained. The results of grazing on the fiber components of forage, however, were inconclusive. Grazing had minimal effect on fiber fractions, but did delay the decline in CP. However, there was a fairly severe decline in hay production, even with the shortest duration of grazing. Title: The effect of grazing interval on forage quality and production of meadow foxtail Author: Wenick, Jess J. For the last fifty years, meadow foxtail (Alopecurus pratensis L.) has been invading native flood meadows throughout the Harney Basin in southeastern Oregon. The expansion of this grass species has been the result of its broad climatic requirements and ability to withstand drought while thriving in saturated soil conditions for a large part of the growing season. Meadow foxtail starts growth as soon as adequate soil moisture exists. Managing this early maturing hay species can prove to be a challenge because soil saturation and elevated water tables make it difficult to harvest hay when forage quality and yield are maximized. The purpose of this study was to evaluate whether planned grazing would retard maturation and thus prolong forage quality. Treatments included a non-grazed control and grazing durations of 2, 4, 6, and 8 weeks. Grazing was initiated in May of 1998 and 1999 on six replications of each treatment arranged in a randomized block design. Within each treatment/replicate combination, ten 0.2 m² plots were clipped to ground level at about two week intervals from May to August. The samples were weighed and dried for standing crop estimation and 4 of the 10 samples were selected at random and analyzed for acid detergent fiber (ADF), neutral detergent fiber (NDF), and crude protein (CP). Analyses of variance, least significant differences, and regression analyses were calculated to determine whether or not there were statistical differences of P≤0.05. We found that early spring grazing decreased forage yield significantly. An increase in CP with duration of defoliation was expected and obtained. The results of grazing on the fiber components of forage, however, were inconclusive. Grazing had minimal effect on fiber fractions, but did delay the decline in CP. However, there was a fairly severe decline in hay production, even with the shortest duration of grazing. Close

• 236. [Article] Live-tree carbon in the Pacific Northwest : estimates and uncertainties

  Concentration of carbon dioxide (CO₂) in the atmosphere has increased over the past 150 years. Because CO₂ is one of a number of radiatively active gases, there is concern that global temperatures will ...

  Citation × Citation Citation Abstract Copy Title: Live-tree carbon in the Pacific Northwest : estimates and uncertainties Author: Melson, Susanna L. Concentration of carbon dioxide (CO₂) in the atmosphere has increased over the past 150 years. Because CO₂ is one of a number of radiatively active gases, there is concern that global temperatures will rise and climatic conditions will change. Recent research indicates northern hemisphere forests may currently be accumulating carbon (C) from the atmosphere. Live trees hold a large proportion of forest C, however, live-tree C can only be measured indirectly and therefore estimates of live-tree C are subject to numerous uncertainties. The objectives of this research were to estimate how live-tree C stores changed in the Pacific Northwest (Oregon and Washington west of the Cascade crest) between 1963-91 and to assess the factors introducing uncertainty into the estimate of live-tree C storage. The first objective was accomplished by using data from the Forest Service Forest Inventory and Analysis Program (FIA), combined with western Oregon and western Washington annual timber harvest data. The study produced live-tree C estimates for all timberland by land-ownership group. Between 1963-91, C on all timberland in the Pacific Northwest decreased from 1636 to 1392 Tg, or by 15% of the 1963 total. National forest, other public (other federal, state, and local government), forest industry, and miscellaneous private land lost 15, 5 (non-significant), 24, and 18% of their 1963 total timberland live-tree C by 1991, respectively. All landowners except industry experienced significant declines in total timberland area. C density (live-tree C per area) on all timberland dropped by 13% on national forests and by 30% on forest industry, but rose by 1% (non-significant) on other public and 26% on miscellaneous private land. For the Pacific Northwest as a whole, C density on all timberland decreased by 8% over the 28-year study period. C density declined most dramatically between 1963 and 1974. Since 1974, increasing C density on other public and miscellaneous private land balanced declining C density on national forest and forest industry land, resulting a C density ranging between 135-136 Mg C ha⁻¹ on all timberland. The live-tree C estimate is subject to uncertainty arising from sampling, regression, measurement, and model error. We created and implemented a method for assessing uncertainty arising from model error. Volume equations, densities, biomass equations, and C:biomass ratios were compiled for the five major tree species in northwest Oregon: Picea sitchensis, Pseudotsuga menziesii, Tsuga heterophylla, Acer macrophyllum, and Alnus rubra. Volume equations were transformed into biomass by multiplying predicted volume with a range of species-specific measured densities. Biomass derived from volume equations multiplied by densities or from biomass equations was converted to C using a range of C:biomass ratios. For each tree component, species, and diameter at breast height, the maximum and minimum C predicted by equations was captured and stored as lookup tables. Component lookup tables were summed to create estimates of tree total C under three assumptions about within-dbh class correlation between components: perfect positive, zero, or perfect negative correlation. Application of lookup table bounds to individual tree data from the FIA program produced estimates of minimum and maximum C for the five target species in northwest Oregon. The above methods resulted in a base-case live-tree C estimate for northwest Oregon ranging from 28-210 Tg C (±76% uncertainty) assuming perfect positive correlation, and 67-1 54 Tg C (±40% uncertainty) for perfect negative correlation. When height variation was incorporated, C storage uncertainty rose to ±91% for positive and ±51% for negative correlation. A gain in precision was realized when species-specific equations were applied. Replacement of diameter-distribution data by quadratic mean diameter for each species reduced the absolute value of uncertainty, but created a bias when compared to the base case. Our attempt to incorporate regression standard error produced extremely large uncertainties for some equations and therefore was not pursued further. Results indicate that the most substantial reductions in uncertainty could be obtained by accurately assigning individual trees to suitable equations. The magnitude of model error produced by our methods currently precludes determination of significant differences between live-tree C stores of most landowners in the Pacific Northwest, and renders impossible the precise determination of the amount of live-tree C in a given forest area. Nevertheless, this does not necessarily preclude meaningful comparisons of C flux. Results of this study indicate uncertainty from model error in live-tree C could be extremely large. However, by accurately assigning appropriate volume or biomass prediction equations to trees, uncertainty could be greatly reduced. Title: Live-tree carbon in the Pacific Northwest : estimates and uncertainties Author: Melson, Susanna L. Concentration of carbon dioxide (CO₂) in the atmosphere has increased over the past 150 years. Because CO₂ is one of a number of radiatively active gases, there is concern that global temperatures will rise and climatic conditions will change. Recent research indicates northern hemisphere forests may currently be accumulating carbon (C) from the atmosphere. Live trees hold a large proportion of forest C, however, live-tree C can only be measured indirectly and therefore estimates of live-tree C are subject to numerous uncertainties. The objectives of this research were to estimate how live-tree C stores changed in the Pacific Northwest (Oregon and Washington west of the Cascade crest) between 1963-91 and to assess the factors introducing uncertainty into the estimate of live-tree C storage. The first objective was accomplished by using data from the Forest Service Forest Inventory and Analysis Program (FIA), combined with western Oregon and western Washington annual timber harvest data. The study produced live-tree C estimates for all timberland by land-ownership group. Between 1963-91, C on all timberland in the Pacific Northwest decreased from 1636 to 1392 Tg, or by 15% of the 1963 total. National forest, other public (other federal, state, and local government), forest industry, and miscellaneous private land lost 15, 5 (non-significant), 24, and 18% of their 1963 total timberland live-tree C by 1991, respectively. All landowners except industry experienced significant declines in total timberland area. C density (live-tree C per area) on all timberland dropped by 13% on national forests and by 30% on forest industry, but rose by 1% (non-significant) on other public and 26% on miscellaneous private land. For the Pacific Northwest as a whole, C density on all timberland decreased by 8% over the 28-year study period. C density declined most dramatically between 1963 and 1974. Since 1974, increasing C density on other public and miscellaneous private land balanced declining C density on national forest and forest industry land, resulting a C density ranging between 135-136 Mg C ha⁻¹ on all timberland. The live-tree C estimate is subject to uncertainty arising from sampling, regression, measurement, and model error. We created and implemented a method for assessing uncertainty arising from model error. Volume equations, densities, biomass equations, and C:biomass ratios were compiled for the five major tree species in northwest Oregon: Picea sitchensis, Pseudotsuga menziesii, Tsuga heterophylla, Acer macrophyllum, and Alnus rubra. Volume equations were transformed into biomass by multiplying predicted volume with a range of species-specific measured densities. Biomass derived from volume equations multiplied by densities or from biomass equations was converted to C using a range of C:biomass ratios. For each tree component, species, and diameter at breast height, the maximum and minimum C predicted by equations was captured and stored as lookup tables. Component lookup tables were summed to create estimates of tree total C under three assumptions about within-dbh class correlation between components: perfect positive, zero, or perfect negative correlation. Application of lookup table bounds to individual tree data from the FIA program produced estimates of minimum and maximum C for the five target species in northwest Oregon. The above methods resulted in a base-case live-tree C estimate for northwest Oregon ranging from 28-210 Tg C (±76% uncertainty) assuming perfect positive correlation, and 67-1 54 Tg C (±40% uncertainty) for perfect negative correlation. When height variation was incorporated, C storage uncertainty rose to ±91% for positive and ±51% for negative correlation. A gain in precision was realized when species-specific equations were applied. Replacement of diameter-distribution data by quadratic mean diameter for each species reduced the absolute value of uncertainty, but created a bias when compared to the base case. Our attempt to incorporate regression standard error produced extremely large uncertainties for some equations and therefore was not pursued further. Results indicate that the most substantial reductions in uncertainty could be obtained by accurately assigning individual trees to suitable equations. The magnitude of model error produced by our methods currently precludes determination of significant differences between live-tree C stores of most landowners in the Pacific Northwest, and renders impossible the precise determination of the amount of live-tree C in a given forest area. Nevertheless, this does not necessarily preclude meaningful comparisons of C flux. Results of this study indicate uncertainty from model error in live-tree C could be extremely large. However, by accurately assigning appropriate volume or biomass prediction equations to trees, uncertainty could be greatly reduced. Close

• 237. [Article] Demographic response of northern spotted owls to barred owl removal

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Wildlife Society ...

  Citation × Citation Citation Abstract Copy Title: Demographic response of northern spotted owls to barred owl removal Author: Diller, Lowell V., Schwarz, Carl J., Early, Desiree A., Lamphear, David W., McDonald, Trent L., Hamm, Keith A., Yackulic, Charles B., Dugger, Katie M., Carlson, Peter C. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Wildlife Society and published by John Wiley & Sons, Inc. It can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291937-2817 Title: Demographic response of northern spotted owls to barred owl removal Author: Diller, Lowell V., Schwarz, Carl J., Early, Desiree A., Lamphear, David W., McDonald, Trent L., Hamm, Keith A., Yackulic, Charles B., Dugger, Katie M., Carlson, Peter C. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Wildlife Society and published by John Wiley & Sons, Inc. It can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291937-2817 Close

• 238. [Article] Characterization, epidemiology, and ecology of a virus associated with black raspberry decline

  The objective of this study was to characterize an unknown agent associated with decline in black raspberry (Rubus occidentalis) in Oregon. A virus was found consistently associated with decline symptoms ...

  Citation × Citation Citation Abstract Copy Title: Characterization, epidemiology, and ecology of a virus associated with black raspberry decline Author: Halgren, Anne B. The objective of this study was to characterize an unknown agent associated with decline in black raspberry (Rubus occidentalis) in Oregon. A virus was found consistently associated with decline symptoms of black raspberries and was named Black raspberry decline associated virus (BRDaV). Double stranded RNA extraction from BRDaV-infected black raspberry revealed the presence of two bands of approximately 8.5 and 7 kilobase pairs, which were cloned and sequenced. The complete nucleotide sequences of RNA 1 and RNA 2 are 7581 nt and 6364 nt, respectively, excluding the 3' poly(A) tails. The genome structure was identical to that of Strawberry mottle virus (SMoV), with the putative polyproteins being less than 50% identical to that of SMoV and other related sequenced viruses. The final 189 amino acids of the RNA-dependent- RNA-polymerase (RdRp) reveal an unusual indel with homology to AlkB-like protein domains, suggesting a role in repair of alkylation damage. This is the first report of a virus outside the Flexiviridae and ampeloviruses of the Closteroviridae to contain these domains. An RT-PCR test was designed for the detection of BRDaV from Rubus tissue. BRDaV is vectored non-persistently by the large raspberry aphid Amphorophora agathonica, the green peach aphid Myzus persicae, and likely nonspecifically by other aphid species. Phylogenetic analysis of conserved motifs of the RdRp, helicase, and protease regions indicate that BRDaV belongs to the Sadwavirus genus. To assess the rate of spread BRDaV, four newly planted fields of black raspberries (Rubus occidentalis) in Oregon were studied for three years. In an effort to characterize the suspected complexity of synergistic interactions between BRDaV and other Rubus-infecting viruses, the prevalence of ten additional Rubus viruses was also monitored in the study fields. The timing of BRDaV infection as it relates to aphid populations and flights was also determined. Testing of nearby vegetation identified several symptomless Rubus hosts of BRDaV, as well as detection in multiple cultivars of black raspberry and several non-Rubus weeds. It was determined that BRDaV spreads rapidly with a low aphid threshold and consistently is associated with decline of black raspberries in Oregon. Title: Characterization, epidemiology, and ecology of a virus associated with black raspberry decline Author: Halgren, Anne B. The objective of this study was to characterize an unknown agent associated with decline in black raspberry (Rubus occidentalis) in Oregon. A virus was found consistently associated with decline symptoms of black raspberries and was named Black raspberry decline associated virus (BRDaV). Double stranded RNA extraction from BRDaV-infected black raspberry revealed the presence of two bands of approximately 8.5 and 7 kilobase pairs, which were cloned and sequenced. The complete nucleotide sequences of RNA 1 and RNA 2 are 7581 nt and 6364 nt, respectively, excluding the 3' poly(A) tails. The genome structure was identical to that of Strawberry mottle virus (SMoV), with the putative polyproteins being less than 50% identical to that of SMoV and other related sequenced viruses. The final 189 amino acids of the RNA-dependent- RNA-polymerase (RdRp) reveal an unusual indel with homology to AlkB-like protein domains, suggesting a role in repair of alkylation damage. This is the first report of a virus outside the Flexiviridae and ampeloviruses of the Closteroviridae to contain these domains. An RT-PCR test was designed for the detection of BRDaV from Rubus tissue. BRDaV is vectored non-persistently by the large raspberry aphid Amphorophora agathonica, the green peach aphid Myzus persicae, and likely nonspecifically by other aphid species. Phylogenetic analysis of conserved motifs of the RdRp, helicase, and protease regions indicate that BRDaV belongs to the Sadwavirus genus. To assess the rate of spread BRDaV, four newly planted fields of black raspberries (Rubus occidentalis) in Oregon were studied for three years. In an effort to characterize the suspected complexity of synergistic interactions between BRDaV and other Rubus-infecting viruses, the prevalence of ten additional Rubus viruses was also monitored in the study fields. The timing of BRDaV infection as it relates to aphid populations and flights was also determined. Testing of nearby vegetation identified several symptomless Rubus hosts of BRDaV, as well as detection in multiple cultivars of black raspberry and several non-Rubus weeds. It was determined that BRDaV spreads rapidly with a low aphid threshold and consistently is associated with decline of black raspberries in Oregon. Close

• 239. [Article] The Role of Emerging Pathogens in Amphibian Population Declines : Experimental Evidence

  Rapid rates of biodiversity loss have supported the notion that Earth is experiencing a sixth major extinction event. The causes of worldwide biodiversity loss are multifaceted and context dependent. One ...

  Citation × Citation Citation Abstract Copy Title: The Role of Emerging Pathogens in Amphibian Population Declines : Experimental Evidence Author: Hambalek, Natalie M. Rapid rates of biodiversity loss have supported the notion that Earth is experiencing a sixth major extinction event. The causes of worldwide biodiversity loss are multifaceted and context dependent. One of the most prominent groups experiencing population declines and extinctions are amphibians. Several pathogens and their associated diseases are especially significant contributors to amphibian population declines. These include the chytrid fungus, Batrachochytrium dendrobatidis, the related but highly divergent fungal pathogen, B. salamandrivorans, and ranaviruses. In Chapter 1, I summarize the life-history traits of these three amphibian pathogens. In Chapter 2, I present a synthesis of these three emerging infectious pathogens by assessing their broad effects on amphibian hosts as found in experimental studies. I also examined the interactive effects of these pathogens with other potential and known contributors of amphibian population declines that have been experimentally studied. Well-designed experimental studies are critical for understanding the impacts of disease. However, inconsistencies in experimental methodologies often hinder our ability to form valuable comparisons and conclusions. Chapter 2 highlights the importance of implementing standard experimental protocols and reporting. Furthermore, we emphasize the significance of investigating the roles of multiple environmental and anthropogenic stressors. The effects of B. dendrobatidis and ranaviruses on their hosts have been well documented but the effects of coinfection with these pathogens are poorly understood. In Chapter 3, I experimentally examined the effects of simultaneous and independent exposure of B. dendrobatidis and ranavirus on survival, growth, and activity levels in two amphibian host species, the Pacific treefrog (Pseudacris regilla) and the western toad (Anaxyrus boreas). I predicted that coinfection with Bd and Rv would have increased lethal and sublethal effects on hosts compared with hosts that were infected with one of the pathogens independently. The results showed antagonistic effects of concurrent exposure to B. dendrobatidis and ranavirus, with individuals exposed to only one pathogen exhibiting more lethal and sublethal effects compared to individuals exposed to both pathogens. These results support the proposition that the dynamics behind multiple pathogen exposure are complex and that one pathogen may mitigate the effects of another to induce response variation. Title: The Role of Emerging Pathogens in Amphibian Population Declines : Experimental Evidence Author: Hambalek, Natalie M. Rapid rates of biodiversity loss have supported the notion that Earth is experiencing a sixth major extinction event. The causes of worldwide biodiversity loss are multifaceted and context dependent. One of the most prominent groups experiencing population declines and extinctions are amphibians. Several pathogens and their associated diseases are especially significant contributors to amphibian population declines. These include the chytrid fungus, Batrachochytrium dendrobatidis, the related but highly divergent fungal pathogen, B. salamandrivorans, and ranaviruses. In Chapter 1, I summarize the life-history traits of these three amphibian pathogens. In Chapter 2, I present a synthesis of these three emerging infectious pathogens by assessing their broad effects on amphibian hosts as found in experimental studies. I also examined the interactive effects of these pathogens with other potential and known contributors of amphibian population declines that have been experimentally studied. Well-designed experimental studies are critical for understanding the impacts of disease. However, inconsistencies in experimental methodologies often hinder our ability to form valuable comparisons and conclusions. Chapter 2 highlights the importance of implementing standard experimental protocols and reporting. Furthermore, we emphasize the significance of investigating the roles of multiple environmental and anthropogenic stressors. The effects of B. dendrobatidis and ranaviruses on their hosts have been well documented but the effects of coinfection with these pathogens are poorly understood. In Chapter 3, I experimentally examined the effects of simultaneous and independent exposure of B. dendrobatidis and ranavirus on survival, growth, and activity levels in two amphibian host species, the Pacific treefrog (Pseudacris regilla) and the western toad (Anaxyrus boreas). I predicted that coinfection with Bd and Rv would have increased lethal and sublethal effects on hosts compared with hosts that were infected with one of the pathogens independently. The results showed antagonistic effects of concurrent exposure to B. dendrobatidis and ranavirus, with individuals exposed to only one pathogen exhibiting more lethal and sublethal effects compared to individuals exposed to both pathogens. These results support the proposition that the dynamics behind multiple pathogen exposure are complex and that one pathogen may mitigate the effects of another to induce response variation. Close

• 240. [Article] A study of public perceptions of energy issues and technology for the development of engineering education activities

  Human use of fossil fuels has caused a dramatic shift in the earth’s environment, with global temperatures rising and ecosystem health declining. The need for the human species to reduce our reliance on ...

  Citation × Citation Citation Abstract Copy Title: A study of public perceptions of energy issues and technology for the development of engineering education activities Author: Hinkle, Nathan Human use of fossil fuels has caused a dramatic shift in the earth’s environment, with global temperatures rising and ecosystem health declining. The need for the human species to reduce our reliance on fossil fuels is apparent. This will be achieved by replacing conventional energy resources with sustainable alternatives, and by reducing overall energy consumption on both a personal and global scale. Citizens must be engaged and informed on energy issues in order to achieve the drastic changes required. This project studied public perceptions and understandings of energy issues and technologies through survey research, and developed five new engineering education activities to address knowledge gaps identified in the survey. These activities have been conducted with groups of students at OSU, revised based on student feedback, and will be made available to educators online. Title: A study of public perceptions of energy issues and technology for the development of engineering education activities Author: Hinkle, Nathan Human use of fossil fuels has caused a dramatic shift in the earth’s environment, with global temperatures rising and ecosystem health declining. The need for the human species to reduce our reliance on fossil fuels is apparent. This will be achieved by replacing conventional energy resources with sustainable alternatives, and by reducing overall energy consumption on both a personal and global scale. Citizens must be engaged and informed on energy issues in order to achieve the drastic changes required. This project studied public perceptions and understandings of energy issues and technologies through survey research, and developed five new engineering education activities to address knowledge gaps identified in the survey. These activities have been conducted with groups of students at OSU, revised based on student feedback, and will be made available to educators online. Close

• 241. [Article] Japan's Declining Fish Catch Raises Trade Prospects

  Between 1988 and 1997, Japanese fish and shellfish catch dropped by 42 percent, falling to its lowest level in 31 years. Domestic prices sharply increased, but per capita fish and shellfish consumption ...

  Citation × Citation Citation Abstract Copy Title: Japan's Declining Fish Catch Raises Trade Prospects Author: Taha, Fawzi A. Year: 2001 Between 1988 and 1997, Japanese fish and shellfish catch dropped by 42 percent, falling to its lowest level in 31 years. Domestic prices sharply increased, but per capita fish and shellfish consumption is still higher than that of all meats. To meet rising demand, Japan became the world’s largest importer, absorbing one third of global fish and shellfish imports, and the United States became its largest supplier up to 1996, when the United States was superceded by China. Outlook for exporting to Japan is excellent because the U.S. catch contains most of the species prized highly in the Japanese market, such as salmon, crabs, and Alaska pollack. Title: Japan's Declining Fish Catch Raises Trade Prospects Author: Taha, Fawzi A. Year: 2001 Between 1988 and 1997, Japanese fish and shellfish catch dropped by 42 percent, falling to its lowest level in 31 years. Domestic prices sharply increased, but per capita fish and shellfish consumption is still higher than that of all meats. To meet rising demand, Japan became the world’s largest importer, absorbing one third of global fish and shellfish imports, and the United States became its largest supplier up to 1996, when the United States was superceded by China. Outlook for exporting to Japan is excellent because the U.S. catch contains most of the species prized highly in the Japanese market, such as salmon, crabs, and Alaska pollack. Close

• 242. [Article] An application of the control chart method to the analysis of fisheries data

  In a paper now in press as a Bulletin of the U. S. Fish and Wildlife Services the writer has discussed the downward trend of the catch of Columbia River Chinook salmon since 1920 and has stated that the ...

  Citation × Citation Citation Abstract Copy Title: An application of the control chart method to the analysis of fisheries data Author: Oregon. Fish Commission, Rich, Willis H. (Willis Horton), 1885-1972 In a paper now in press as a Bulletin of the U. S. Fish and Wildlife Services the writer has discussed the downward trend of the catch of Columbia River Chinook salmon since 1920 and has stated that the decline is doubtless an indication that the runs of this species are seriously depleted. Recently the same data have been studied by means of the control chart method and the results show so clearly that the productivity has dropped to a new and much lower level that it has seemed worth while to present a brief note amplifying the discussion in the bulletin. Title: An application of the control chart method to the analysis of fisheries data Author: Oregon. Fish Commission, Rich, Willis H. (Willis Horton), 1885-1972 In a paper now in press as a Bulletin of the U. S. Fish and Wildlife Services the writer has discussed the downward trend of the catch of Columbia River Chinook salmon since 1920 and has stated that the decline is doubtless an indication that the runs of this species are seriously depleted. Recently the same data have been studied by means of the control chart method and the results show so clearly that the productivity has dropped to a new and much lower level that it has seemed worth while to present a brief note amplifying the discussion in the bulletin. Close

• 243. [Article] Aquaculture as a Vehicle for Socio-Economic Development in Namibia

  Throughout the world the landings of capture fisheries are declining and this is not because the fishing nations are managing their resources better but because of the non-availability of the fish species. ...

  Citation × Citation Citation Abstract Copy Title: Aquaculture as a Vehicle for Socio-Economic Development in Namibia Author: Elago, Panduleni Throughout the world the landings of capture fisheries are declining and this is not because the fishing nations are managing their resources better but because of the non-availability of the fish species. The reduction in capture fisheries is a wakeup call for the nations to undertake Aquaculture development. Though Namibia is one of the driest countries in the world, aquaculture development is a necessity if fish is to remain part of our menu. The goal of aquaculture development in Namibia is to develop a sustainable industry aiming to promote food security and poverty reduction. Since the introduction of fish farming in 2003, the Government has been engaged in creating a conducive environment for the small and medium fish farmers. This paper focuses on the responses of small and medium farmers towards the government’s effort, for promoting Aquaculture as a vehicle for Socio-Economic Development in Namibia. Title: Aquaculture as a Vehicle for Socio-Economic Development in Namibia Author: Elago, Panduleni Throughout the world the landings of capture fisheries are declining and this is not because the fishing nations are managing their resources better but because of the non-availability of the fish species. The reduction in capture fisheries is a wakeup call for the nations to undertake Aquaculture development. Though Namibia is one of the driest countries in the world, aquaculture development is a necessity if fish is to remain part of our menu. The goal of aquaculture development in Namibia is to develop a sustainable industry aiming to promote food security and poverty reduction. Since the introduction of fish farming in 2003, the Government has been engaged in creating a conducive environment for the small and medium fish farmers. This paper focuses on the responses of small and medium farmers towards the government’s effort, for promoting Aquaculture as a vehicle for Socio-Economic Development in Namibia. Close

• 244. [Article] Where Have All the Native Fish Gone? The Fate of Fish that Lewis and Clark Encountered on the Lower Columbia River

  As part of a special issue of the 'Oregon Historical Quarterly,' discusses the native species of fish in the lower Columbia River described by Meriwether Lewis and William Clark in 1805-06. They identified ...

  Citation × Citation Citation Abstract Copy Title: Where Have All the Native Fish Gone? The Fate of Fish that Lewis and Clark Encountered on the Lower Columbia River Author: Butler, Virginia L. Year: 2004 As part of a special issue of the 'Oregon Historical Quarterly,' discusses the native species of fish in the lower Columbia River described by Meriwether Lewis and William Clark in 1805-06. They identified red charr, salmon trout, sturgeon, anchovy, skeet, and other fish that Indians caught and used as trade items with the Corps of Discovery. However, editors of the Lewis and Clark journals have often erred in identifying the fish Lewis and Clark described; the challenge in identifying anadromous fish lies in changing coloration, markings, and examination of habitat. There has been a drastic decline of native fish since 1805 and a growing dominance of exotic species. Title: Where Have All the Native Fish Gone? The Fate of Fish that Lewis and Clark Encountered on the Lower Columbia River Author: Butler, Virginia L. Year: 2004 As part of a special issue of the 'Oregon Historical Quarterly,' discusses the native species of fish in the lower Columbia River described by Meriwether Lewis and William Clark in 1805-06. They identified red charr, salmon trout, sturgeon, anchovy, skeet, and other fish that Indians caught and used as trade items with the Corps of Discovery. However, editors of the Lewis and Clark journals have often erred in identifying the fish Lewis and Clark described; the challenge in identifying anadromous fish lies in changing coloration, markings, and examination of habitat. There has been a drastic decline of native fish since 1805 and a growing dominance of exotic species. Close

• 245. [Article] Toad Populations Decreasing in South Korea.

  Massive die-offs of Bufo bufo gargarizans were observed in May 2008 in Mangwal Gee, Korea. To find out the causes for this disaster several different elements were examined: pH, total nitrogen, dissolved ...

  Citation × Citation Citation Abstract Copy Title: Toad Populations Decreasing in South Korea. Author: Chung, Yun Soo Massive die-offs of Bufo bufo gargarizans were observed in May 2008 in Mangwal Gee, Korea. To find out the causes for this disaster several different elements were examined: pH, total nitrogen, dissolved oxygen (DO), and dissolved heavy metal, suspension, introduced species, habitat change, disease, temperature changes, and precipitation and humidity. After checking pH, total nitrogen, dissolved oxygen, and heavy metal, the quality of water appeared to be acceptable for toads. No introduced species were found which could kill or compete with toads. Even though there were environment changes surrounding Mangwal Gee, thanks to government efforts the condition of the pond has not changed for years. The pathogenic chytrid fungus, Batrachochytrium dendrobatidis responsible for amphibian population declines worldwide was not found. The average temperature was little higher, and precipitation was lower compared to last 30 years, however there was no evidence found to indicate as a cause of mass die-off. Title: Toad Populations Decreasing in South Korea. Author: Chung, Yun Soo Massive die-offs of Bufo bufo gargarizans were observed in May 2008 in Mangwal Gee, Korea. To find out the causes for this disaster several different elements were examined: pH, total nitrogen, dissolved oxygen (DO), and dissolved heavy metal, suspension, introduced species, habitat change, disease, temperature changes, and precipitation and humidity. After checking pH, total nitrogen, dissolved oxygen, and heavy metal, the quality of water appeared to be acceptable for toads. No introduced species were found which could kill or compete with toads. Even though there were environment changes surrounding Mangwal Gee, thanks to government efforts the condition of the pond has not changed for years. The pathogenic chytrid fungus, Batrachochytrium dendrobatidis responsible for amphibian population declines worldwide was not found. The average temperature was little higher, and precipitation was lower compared to last 30 years, however there was no evidence found to indicate as a cause of mass die-off. Close

• 246. [Article] A study of the effects of exposure to air on the respiration of two intertidal snails

  Callistoma costatum and Tegula funebralis, marine intertidal snails from low and high littoral zones respectively, were exposed to air for two, six and twelve hour periods, during which time their oxygen ...

  Citation × Citation Citation Abstract Copy Title: A study of the effects of exposure to air on the respiration of two intertidal snails Author: Baker, Carol Dianne Callistoma costatum and Tegula funebralis, marine intertidal snails from low and high littoral zones respectively, were exposed to air for two, six and twelve hour periods, during which time their oxygen consumption rates were measured. The animals were then immersed in sea water and their respiration rates recorded for a period of four hours. The oxygen consumption rates were corrected to a standard 0.1 gram animal using plots of metabolic rate versus weight. Calliostoma has a higher respiration rate in water than Tegula. In air, Tegula has the higher rate. The respiration of the two species in water following varying durations of exposure to air follow different patterns. In Tegula there is in all cases an initial rise followed by a decline in respiration. In Calliostoma the recovery pattern is irregular but in all cases the trend indicates a gradual increase in oxygen consumption rate following immersion in water. The significance of these findings in relation to the position of the species in the intertidal is discussed. Some of the factors (size, tidal and circadian rhythms, sex, activity, nutritional state and oxygen tension) which could influence respiration rates are discussed. Title: A study of the effects of exposure to air on the respiration of two intertidal snails Author: Baker, Carol Dianne Callistoma costatum and Tegula funebralis, marine intertidal snails from low and high littoral zones respectively, were exposed to air for two, six and twelve hour periods, during which time their oxygen consumption rates were measured. The animals were then immersed in sea water and their respiration rates recorded for a period of four hours. The oxygen consumption rates were corrected to a standard 0.1 gram animal using plots of metabolic rate versus weight. Calliostoma has a higher respiration rate in water than Tegula. In air, Tegula has the higher rate. The respiration of the two species in water following varying durations of exposure to air follow different patterns. In Tegula there is in all cases an initial rise followed by a decline in respiration. In Calliostoma the recovery pattern is irregular but in all cases the trend indicates a gradual increase in oxygen consumption rate following immersion in water. The significance of these findings in relation to the position of the species in the intertidal is discussed. Some of the factors (size, tidal and circadian rhythms, sex, activity, nutritional state and oxygen tension) which could influence respiration rates are discussed. Close

• 247. [Article] Species Extinction and Cultural Arrogance: The Perils of Ignoring History

  For more than a century, politicians, newspaper editors, tate and federal fisheries managers, and their various constituencies with an interest in salmon have complained,lobbied and petitioned, sought ...

  Citation × Citation Citation Abstract Copy Title: Species Extinction and Cultural Arrogance: The Perils of Ignoring History Author: Robbins, William G. Year: 2001 For more than a century, politicians, newspaper editors, tate and federal fisheries managers, and their various constituencies with an interest in salmon have complained,lobbied and petitioned, sought legislative relief, and studied to near extinction the declining runs of the Pacific Northwest’s anadromous fish runs. All to no avail, of course. Management efforts have failed; the attempt to the establish reliable, predictive models has failed; massive federal expenditures to rescue crashing stocks have failed; and endeavors to achieve consensus about future policymaking have failed. And today one can add to the now familiar story of extinct and endangered salmon, similar tales about ocean groundfish, newly impoverished fishing communities, reductions in fleet size, and more federal bailouts. What is fascinating in the unveiling of this most recent story is the sense of history repeating itself as commercial fishers shift from one species to the next. Title: Species Extinction and Cultural Arrogance: The Perils of Ignoring History Author: Robbins, William G. Year: 2001 For more than a century, politicians, newspaper editors, tate and federal fisheries managers, and their various constituencies with an interest in salmon have complained,lobbied and petitioned, sought legislative relief, and studied to near extinction the declining runs of the Pacific Northwest’s anadromous fish runs. All to no avail, of course. Management efforts have failed; the attempt to the establish reliable, predictive models has failed; massive federal expenditures to rescue crashing stocks have failed; and endeavors to achieve consensus about future policymaking have failed. And today one can add to the now familiar story of extinct and endangered salmon, similar tales about ocean groundfish, newly impoverished fishing communities, reductions in fleet size, and more federal bailouts. What is fascinating in the unveiling of this most recent story is the sense of history repeating itself as commercial fishers shift from one species to the next. Close

• 248. [Article] Modeling the stochastic dynamics of the aggregate stock in collapsed fisheries: the case of the northern cod

  Abstract Only

  Citation × Citation Citation Abstract Copy Title: Modeling the stochastic dynamics of the aggregate stock in collapsed fisheries: the case of the northern cod Author: Maroto, Jose Abstract Only Title: Modeling the stochastic dynamics of the aggregate stock in collapsed fisheries: the case of the northern cod Author: Maroto, Jose Abstract Only Close

• 249. [Article] Increased Habitat Connectivity Homogenizes Freshwater Communities: Historical and Landscape Perspectives

  Increases in habitat connectivity can have consequences for taxonomic, functional, and genetic diversity of communities. Previously isolated aquatic habitats were connected with canals and pipelines in ...

  Citation × Citation Citation Abstract Copy Title: Increased Habitat Connectivity Homogenizes Freshwater Communities: Historical and Landscape Perspectives Author: Strecker, Angela L., Brittain, Jeffrey Thomas Year: 2017 Increases in habitat connectivity can have consequences for taxonomic, functional, and genetic diversity of communities. Previously isolated aquatic habitats were connected with canals and pipelines in the largest water development project in the US history, the Columbia Basin Project (CBP; eastern Washington, USA), which also altered environmental conditions; however, the ecological consequences are largely unknown. Using a historical dataset, we examined long-term patterns in zooplankton communities, water chemistry and clarity, testing the hypothesis that increased connectivity will result in taxonomic homogenization. Further, we tested contemporary drivers of communities using a comprehensive set of environmental and landscape variables. Waterbodies were sampled for zooplankton community composition as well as physical and chemical variables inside and outside the CBP using methods consistent with historical studies. We found significant declines in salinity inside the CBP, whereas changes in water clarity were prevalent across all waterbodies. Increased connectivity via canals homogenized zooplankton communities over time, as well as increasing regional richness. Other long-term changes in zooplankton communities may be related to climate change, invasive species, and land-use changes. Synthesis and applications. Though canals may offer species spatial refugia, homogenization may decrease resilience to environmental stressors. These new hybrid aquatic landscapes, or hydroscapes, should be considered carefully in future water development, including specific plans for monitoring of species and environmental conditions, as well as mitigation of undesirable conditions and/or non-native species. Title: Increased Habitat Connectivity Homogenizes Freshwater Communities: Historical and Landscape Perspectives Author: Strecker, Angela L., Brittain, Jeffrey Thomas Year: 2017 Increases in habitat connectivity can have consequences for taxonomic, functional, and genetic diversity of communities. Previously isolated aquatic habitats were connected with canals and pipelines in the largest water development project in the US history, the Columbia Basin Project (CBP; eastern Washington, USA), which also altered environmental conditions; however, the ecological consequences are largely unknown. Using a historical dataset, we examined long-term patterns in zooplankton communities, water chemistry and clarity, testing the hypothesis that increased connectivity will result in taxonomic homogenization. Further, we tested contemporary drivers of communities using a comprehensive set of environmental and landscape variables. Waterbodies were sampled for zooplankton community composition as well as physical and chemical variables inside and outside the CBP using methods consistent with historical studies. We found significant declines in salinity inside the CBP, whereas changes in water clarity were prevalent across all waterbodies. Increased connectivity via canals homogenized zooplankton communities over time, as well as increasing regional richness. Other long-term changes in zooplankton communities may be related to climate change, invasive species, and land-use changes. Synthesis and applications. Though canals may offer species spatial refugia, homogenization may decrease resilience to environmental stressors. These new hybrid aquatic landscapes, or hydroscapes, should be considered carefully in future water development, including specific plans for monitoring of species and environmental conditions, as well as mitigation of undesirable conditions and/or non-native species. Close

• 250. [Article] Foliar Nutrient Concentrations Related to Soil Sources Across a Range of Sites in the Northeastern United States

  Understanding the supply of nutrients from various soil sources and the sensitivity of tree species to soil nutrient availability is critical for predicting the effects of declines in base cations due ...

  Citation × Citation Citation Abstract Copy Title: Foliar Nutrient Concentrations Related to Soil Sources Across a Range of Sites in the Northeastern United States Author: Lucash, Melissa S., Yanai, Ruth D., Blum, Joel D., Park, B. B. Year: 2011 Understanding the supply of nutrients from various soil sources and the sensitivity of tree species to soil nutrient availability is critical for predicting the effects of declines in base cations due to acid rain and forest harvesting on forest health and productivity. We collected soil samples from 19 sites in the northeastern United States, chemically analyzed them using a sequential extraction procedure, and compared them to the chemical composition of foliage of the dominant tree species. Concentrations of Ca and Mg in foliage were correlated with exchangeable Ca and Mg concentrations in the upper mineral soil; for most tree species they were also correlated to acid-extractable Ca and Mg in the parent material (C horizon). Foliar P was better correlated with soil P in the upper mineral soil than in the C horizon, while foliar AI was insensitive to soil AI concentrations. In five sites in New Hampshire, the Ca/Sr of foliage was consistent with that of the Oie horizon, after taking the reported discrimination of Ca over Sr into account. In sites in New York, without an Oie horizon, the Ca/Sr of foliage was too high to be explained by any of the soil pools. A comparison of Ca/Sr ratios of foliage among species at common sites showed oak (Quercus spp.) to have higher Ca/Sr ratios than sugar maple (Acer saccharum Marsh.), birch (Betula spp.), red maple (A. rubrum L.) and beech (Fagus spp.). The interpretation of soil Ca sources from Ca/Sr ratios is complicated at sites where a single horizon does not dominate the source. Title: Foliar Nutrient Concentrations Related to Soil Sources Across a Range of Sites in the Northeastern United States Author: Lucash, Melissa S., Yanai, Ruth D., Blum, Joel D., Park, B. B. Year: 2011 Understanding the supply of nutrients from various soil sources and the sensitivity of tree species to soil nutrient availability is critical for predicting the effects of declines in base cations due to acid rain and forest harvesting on forest health and productivity. We collected soil samples from 19 sites in the northeastern United States, chemically analyzed them using a sequential extraction procedure, and compared them to the chemical composition of foliage of the dominant tree species. Concentrations of Ca and Mg in foliage were correlated with exchangeable Ca and Mg concentrations in the upper mineral soil; for most tree species they were also correlated to acid-extractable Ca and Mg in the parent material (C horizon). Foliar P was better correlated with soil P in the upper mineral soil than in the C horizon, while foliar AI was insensitive to soil AI concentrations. In five sites in New Hampshire, the Ca/Sr of foliage was consistent with that of the Oie horizon, after taking the reported discrimination of Ca over Sr into account. In sites in New York, without an Oie horizon, the Ca/Sr of foliage was too high to be explained by any of the soil pools. A comparison of Ca/Sr ratios of foliage among species at common sites showed oak (Quercus spp.) to have higher Ca/Sr ratios than sugar maple (Acer saccharum Marsh.), birch (Betula spp.), red maple (A. rubrum L.) and beech (Fagus spp.). The interpretation of soil Ca sources from Ca/Sr ratios is complicated at sites where a single horizon does not dominate the source. Close

• 251. [Article] Abundances of Coplanted Native Bunchgrasses and Crested Wheatgrass after 13 Years

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Society for Range ...

  Citation × Citation Citation Abstract Copy Title: Abundances of Coplanted Native Bunchgrasses and Crested Wheatgrass after 13 Years Author: Ganskopp, David C., Nafus, Aleta M., Svejcar, Tony J., Davies, Kirk W. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Society for Range Management and published by Elsevier. It can be found at: http://www.journals.elsevier.com/rangeland-ecology-and-management. Title: Abundances of Coplanted Native Bunchgrasses and Crested Wheatgrass after 13 Years Author: Ganskopp, David C., Nafus, Aleta M., Svejcar, Tony J., Davies, Kirk W. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Society for Range Management and published by Elsevier. It can be found at: http://www.journals.elsevier.com/rangeland-ecology-and-management. Close

• 252. [Article] Emerging Jellyfish and its Significance in Local Fisheries - a Periphylla Story in the Trondheimsfjord

  presentation

  Citation × Citation Citation Abstract Copy Title: Emerging Jellyfish and its Significance in Local Fisheries - a Periphylla Story in the Trondheimsfjord Author: Liu, Yajie, Mork, Jarle presentation Title: Emerging Jellyfish and its Significance in Local Fisheries - a Periphylla Story in the Trondheimsfjord Author: Liu, Yajie, Mork, Jarle presentation Close

• 253. [Article] Host selection and wood channelization by beetles in conifer logs in western Oregon

  The host preferences and wood channelization rates of scolytid and cerambycid beetles were studied at the H. J. Andrews Experimental Forest (Lane County, Oregon) during 1986 and 1987. Attack density and ...

  Citation × Citation Citation Abstract Copy Title: Host selection and wood channelization by beetles in conifer logs in western Oregon Author: Zhong, He The host preferences and wood channelization rates of scolytid and cerambycid beetles were studied at the H. J. Andrews Experimental Forest (Lane County, Oregon) during 1986 and 1987. Attack density and gallery volumes were measured in fall-felled experimental logs of four major conifer species: Douglas-fir (Pseudotsuga mensiesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.)Sarg.), Pacific silver fir (Abies amabalis (Dougl.)Forbes), and western redcedar (Thu'a plicata Donn). The ambrosia beetles (Coleoptera: Scolytidae), Trypodendron lineatum (Olivier) and Gnathotrichus spp., were significantly more abundant in Douglas-fir and western hemlock than in silver fir or western redcedar, but Xyleborinus saxeseni (Ratzeburg) showed no discrimination among the four tree species. The average emergence of ambrosia beetle brood per gallery was 1.8 in spring-felled Douglas-fir logs and 2.2 in western hemlock. The data indicate a declining ambrosia beetle population emerging from these logs. About 0.16% of the sapwood volume of Douglas-fir and about 0.18% of the sapwood volume of western hemlock were removed by Trypodendron. About 0.01% of the sapwood volume of Douglas-fir and about 0.06% of the sapwood volume of western hemlock were removed by Gnathotrichus. The bark beetles (Coleoptera: Scolytidae) Dendroctonus pseudotsugae Hopkins and Dryocoetes autographus Ratzeburg excavated about 7.6% of Douglas-fir phloem surface area. Pseudohylesinus sericeus (Mannerheim) removed 6.8% of Pacific silver fir phloem surface area. Long-horned beetles (Coleoptera: Cerambycidae) excavated an additional 2.3% of Pacific silver fir phloem surface area. These data indicate that each tree species has a distinct boring insect species pool with differences in channelization rates through time. Colonization and fragmentation of fallen trees by beetles are important to the initiation of the decomposition process in forest ecosystems. Title: Host selection and wood channelization by beetles in conifer logs in western Oregon Author: Zhong, He The host preferences and wood channelization rates of scolytid and cerambycid beetles were studied at the H. J. Andrews Experimental Forest (Lane County, Oregon) during 1986 and 1987. Attack density and gallery volumes were measured in fall-felled experimental logs of four major conifer species: Douglas-fir (Pseudotsuga mensiesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.)Sarg.), Pacific silver fir (Abies amabalis (Dougl.)Forbes), and western redcedar (Thu'a plicata Donn). The ambrosia beetles (Coleoptera: Scolytidae), Trypodendron lineatum (Olivier) and Gnathotrichus spp., were significantly more abundant in Douglas-fir and western hemlock than in silver fir or western redcedar, but Xyleborinus saxeseni (Ratzeburg) showed no discrimination among the four tree species. The average emergence of ambrosia beetle brood per gallery was 1.8 in spring-felled Douglas-fir logs and 2.2 in western hemlock. The data indicate a declining ambrosia beetle population emerging from these logs. About 0.16% of the sapwood volume of Douglas-fir and about 0.18% of the sapwood volume of western hemlock were removed by Trypodendron. About 0.01% of the sapwood volume of Douglas-fir and about 0.06% of the sapwood volume of western hemlock were removed by Gnathotrichus. The bark beetles (Coleoptera: Scolytidae) Dendroctonus pseudotsugae Hopkins and Dryocoetes autographus Ratzeburg excavated about 7.6% of Douglas-fir phloem surface area. Pseudohylesinus sericeus (Mannerheim) removed 6.8% of Pacific silver fir phloem surface area. Long-horned beetles (Coleoptera: Cerambycidae) excavated an additional 2.3% of Pacific silver fir phloem surface area. These data indicate that each tree species has a distinct boring insect species pool with differences in channelization rates through time. Colonization and fragmentation of fallen trees by beetles are important to the initiation of the decomposition process in forest ecosystems. Close

• 254. [Article] Progress Reports 2004: 2004 Oregon Chub Investigations

  Abstract -- Oregon chub are endemic to the Willamette River drainage of western Oregon (Markle et al. 1991). This species was formerly distributed throughout the Willamette River Valley (Snyder 1908) in ...

  Citation × Citation Citation Abstract Copy Title: Progress Reports 2004: 2004 Oregon Chub Investigations Abstract -- Oregon chub are endemic to the Willamette River drainage of western Oregon (Markle et al. 1991). This species was formerly distributed throughout the Willamette River Valley (Snyder 1908) in off-channel habitats such as beaver ponds, oxbows, stable backwater sloughs, and flooded marshes. These habitats usually have little or no water flow, have silty and organic substrate, and have an abundance of aquatic vegetation and cover for hiding and spawning. In the last 100 years, off-channel habitats have disappeared because of changes in seasonal flows resulting from the construction of dams throughout the basin, channelization of the Willamette River and its tributaries, and agricultural practices. This loss of habitat combined with the introduction of non-native species to the Willamette Valley resulted in a sharp decline in Oregon chub abundance. The reduction of habitat and the restricted distribution of the Oregon chub resulted in a determination of "endangered" status under the federal endangered species act (Markle and Pearsons 1990; Rhew 1993). To evaluate Oregon chub population abundance and distribution, the Oregon Department of Fish and Wildlife conducted surveys in April-October 2004. We conducted similar surveys in 1991-2003 (Scheerer et. al. 1992; 1993; 1994; 1995; 1996; 1998; 1999; 2000; 2001; 2002; 2003; 2004; Scheerer and Jones 1997). The survey objectives were to collect information on the status, distribution, and abundance of Oregon chub, the presence of non-native and native species, the characteristics of Oregon chub habitats, the characteristics of potential introduction sites, and to evaluate the success of Oregon chub introductions. In addition, we reviewed and evaluated projects and activities with the potential to impact Oregon chub and their habitats and provided summaries to the U.S. Fish and Wildlife Service. Title: Progress Reports 2004: 2004 Oregon Chub Investigations Abstract -- Oregon chub are endemic to the Willamette River drainage of western Oregon (Markle et al. 1991). This species was formerly distributed throughout the Willamette River Valley (Snyder 1908) in off-channel habitats such as beaver ponds, oxbows, stable backwater sloughs, and flooded marshes. These habitats usually have little or no water flow, have silty and organic substrate, and have an abundance of aquatic vegetation and cover for hiding and spawning. In the last 100 years, off-channel habitats have disappeared because of changes in seasonal flows resulting from the construction of dams throughout the basin, channelization of the Willamette River and its tributaries, and agricultural practices. This loss of habitat combined with the introduction of non-native species to the Willamette Valley resulted in a sharp decline in Oregon chub abundance. The reduction of habitat and the restricted distribution of the Oregon chub resulted in a determination of "endangered" status under the federal endangered species act (Markle and Pearsons 1990; Rhew 1993). To evaluate Oregon chub population abundance and distribution, the Oregon Department of Fish and Wildlife conducted surveys in April-October 2004. We conducted similar surveys in 1991-2003 (Scheerer et. al. 1992; 1993; 1994; 1995; 1996; 1998; 1999; 2000; 2001; 2002; 2003; 2004; Scheerer and Jones 1997). The survey objectives were to collect information on the status, distribution, and abundance of Oregon chub, the presence of non-native and native species, the characteristics of Oregon chub habitats, the characteristics of potential introduction sites, and to evaluate the success of Oregon chub introductions. In addition, we reviewed and evaluated projects and activities with the potential to impact Oregon chub and their habitats and provided summaries to the U.S. Fish and Wildlife Service. Close

• 255. [Article] Molecular characterization of criniviruses and ilarviruses infecting strawberry

  Pallidosis is a disease of strawberry identified in 1957 with an unknown etiology. Two previously uncharacterized viruses in strawberry, Strawberry pallidosis associated virus (SPaV) and Beet pseudo-yellows ...

  Citation × Citation Citation Abstract Copy Title: Molecular characterization of criniviruses and ilarviruses infecting strawberry Author: Tzanetakis, Ioannis E. Pallidosis is a disease of strawberry identified in 1957 with an unknown etiology. Two previously uncharacterized viruses in strawberry, Strawberry pallidosis associated virus (SPaV) and Beet pseudo-yellows virus (BPYV), have been found associated with disease symptoms. The complete nucleotide sequence of both viruses was determined and molecular detection protocols developed. In addition, an immunological tissue blot assay was developed for SPaV. Phylogenetic analysis of SPaV placed it in the genus Crinivirus, family Closteroviridae, along with BPYV. Transmission studies identified Trialeuroides vaporariorum, the greenhouse whitefly, as a vector of SPaV, while the virus was not transmitted by pollen or seed. The geographic distribution of both SPaY and BPYV in the United States was examined. Two ilarviruses of strawberry were investigated. Tobacco streak virus (TSV) is the type member of the genus Ilarvirus, family Bromoviridae, and can cause severe yield losses in small fruit crops. Sequence and phylogenetic analysis of 15 "TSV" isolates from Fragaria and Rubus revealed that they are homogeneous and represent a new virus species designated as Strawberry necrotic shock virus (SNSV). Nucleic acid-based protocols failed to identify any plants of the study infected with TSV an indication that the virus may not be a pathogen of Fragaria and Rubus. Fragaria chiloensis latent virus (FC1LV) is the second member of the genus Ilarvirus that infects strawberry. Previously, the virus had been found only in Chile and although many plants have been tested in North America using a serological test, none was found infected with the virus. A molecular test has been developed and used to confirm the presence of the virus in strawberries along the west coast of North America. Phylogenetic analysis of the coat protein gene of the virus place it in subgroup 4 of the genus along Prune dwarf virus, while it was previously thought to be related most closely to Lilac ring mottle virus and Asparagus virus-2. The role of the newly identified viruses and other viruses infecting strawberry is discussed in association with the strawberry decline disease found to cause severe symptoms and yield losses in both California and British Columbia, Canada. The significance of the work presented in this publication includes: the identification of two viruses associated with strawberry pallidosis disease; the complete nucleotide sequence of two criniviruses, an emerging group of plant viruses adds to the limited knowledge we have about this diverse virus genus; the identification of FC1LV in North America; the identification of SNSV as a distinct virus species which demonstrates the need of further studies on TSV, a virus species that infect a wide range of plant species and may actually be a cluster of diverse species. The high incidence of the pallidosis associated viruses points to the significance of the disease and their role in strawberry decline. The development of fast, sensitive and reliable tests for four strawberry viruses will have an impact to the strawberry industry, since the need for high quality, virus-free plants is essential for a crop that is asexually propagated. Title: Molecular characterization of criniviruses and ilarviruses infecting strawberry Author: Tzanetakis, Ioannis E. Pallidosis is a disease of strawberry identified in 1957 with an unknown etiology. Two previously uncharacterized viruses in strawberry, Strawberry pallidosis associated virus (SPaV) and Beet pseudo-yellows virus (BPYV), have been found associated with disease symptoms. The complete nucleotide sequence of both viruses was determined and molecular detection protocols developed. In addition, an immunological tissue blot assay was developed for SPaV. Phylogenetic analysis of SPaV placed it in the genus Crinivirus, family Closteroviridae, along with BPYV. Transmission studies identified Trialeuroides vaporariorum, the greenhouse whitefly, as a vector of SPaV, while the virus was not transmitted by pollen or seed. The geographic distribution of both SPaY and BPYV in the United States was examined. Two ilarviruses of strawberry were investigated. Tobacco streak virus (TSV) is the type member of the genus Ilarvirus, family Bromoviridae, and can cause severe yield losses in small fruit crops. Sequence and phylogenetic analysis of 15 "TSV" isolates from Fragaria and Rubus revealed that they are homogeneous and represent a new virus species designated as Strawberry necrotic shock virus (SNSV). Nucleic acid-based protocols failed to identify any plants of the study infected with TSV an indication that the virus may not be a pathogen of Fragaria and Rubus. Fragaria chiloensis latent virus (FC1LV) is the second member of the genus Ilarvirus that infects strawberry. Previously, the virus had been found only in Chile and although many plants have been tested in North America using a serological test, none was found infected with the virus. A molecular test has been developed and used to confirm the presence of the virus in strawberries along the west coast of North America. Phylogenetic analysis of the coat protein gene of the virus place it in subgroup 4 of the genus along Prune dwarf virus, while it was previously thought to be related most closely to Lilac ring mottle virus and Asparagus virus-2. The role of the newly identified viruses and other viruses infecting strawberry is discussed in association with the strawberry decline disease found to cause severe symptoms and yield losses in both California and British Columbia, Canada. The significance of the work presented in this publication includes: the identification of two viruses associated with strawberry pallidosis disease; the complete nucleotide sequence of two criniviruses, an emerging group of plant viruses adds to the limited knowledge we have about this diverse virus genus; the identification of FC1LV in North America; the identification of SNSV as a distinct virus species which demonstrates the need of further studies on TSV, a virus species that infect a wide range of plant species and may actually be a cluster of diverse species. The high incidence of the pallidosis associated viruses points to the significance of the disease and their role in strawberry decline. The development of fast, sensitive and reliable tests for four strawberry viruses will have an impact to the strawberry industry, since the need for high quality, virus-free plants is essential for a crop that is asexually propagated. Close

• 256. [Article] Elevational differences in UV-B response by the long-toed salamander (Ambystoma macrodactylum)

  Global amphibian declines have been attributed to numerous and often synergistic causes, such as invasive species, pathogens, and ultraviolet-B (UV-B) radiation. The effects of these stressors are context ...

  Citation × Citation Citation Abstract Copy Title: Elevational differences in UV-B response by the long-toed salamander (Ambystoma macrodactylum) Author: Thurman, Lindsey L. Global amphibian declines have been attributed to numerous and often synergistic causes, such as invasive species, pathogens, and ultraviolet-B (UV-B) radiation. The effects of these stressors are context dependent and can vary with location, species, and populations. As sensitivity to UV-B has shown inconsistencies across amphibian taxa, it can be expected that variation also occurs between populations of a single species. High elevation populations of the long-toed salamander (Ambystoma macrodactylum) face exponentially higher UV-B radiation levels relative to low elevation populations and these levels are predicted to increase in conjunction with continued ozone depletion. We hypothesized that breeding long-toed salamander females at high elevations have modified oviposition behavior to better protect embryos from UV-B induced damage. In addition, we hypothesized that long-toed salamander embryos at high elevation would exhibit elevated photolyase activity, a photo-reactivating enzyme that repairs UV-B radiation-induced damage to DNA. We predicted that this behavioral defense strategy would be employed together with an elevated physiological response as a correlated defense response to increased levels of UV-B radiation in high elevation populations. We surveyed high and low elevation long-toed salamander breeding sites throughout Oregon to quantify oviposition site characteristics and associated UV-B profiles. We simultaneously collected embryos for quantification of photolyase activity in a bacterial transformation assay. We found significant differences in oviposition behavior across elevations, with high elevation breeding females ovipositing in deeper water and using UV-B protective refugia. Oviposition sites at low elevations, however, were most often found in UV-B exposed microhabitats located at the surface of the water. This population difference in oviposition behavior resulted in a standardization of UV-B and temperature conditions for long-toed salamander embryos across elevation. In contrast, we found no population differentiation in photolyase activity between high and low elevation breeding sites. This indicates that behavioral selection for UV-B protected oviposition substrates may either be negating the need for increased photolyase activity in long-toed salamander embryos, or that populations lack the capacity to adapt a heightened physiological response to UV-B at high elevations. Together, these results show how trade-offs in physiology and behavior are a unique adaptation to a significant environmental stressor. Further research into the susceptibility of amphibian species to changing environmental conditions may help to demonstrate the effectiveness of correlated trait responses and plasticity in behavior, and species persistence under changing climate regimes. Title: Elevational differences in UV-B response by the long-toed salamander (Ambystoma macrodactylum) Author: Thurman, Lindsey L. Global amphibian declines have been attributed to numerous and often synergistic causes, such as invasive species, pathogens, and ultraviolet-B (UV-B) radiation. The effects of these stressors are context dependent and can vary with location, species, and populations. As sensitivity to UV-B has shown inconsistencies across amphibian taxa, it can be expected that variation also occurs between populations of a single species. High elevation populations of the long-toed salamander (Ambystoma macrodactylum) face exponentially higher UV-B radiation levels relative to low elevation populations and these levels are predicted to increase in conjunction with continued ozone depletion. We hypothesized that breeding long-toed salamander females at high elevations have modified oviposition behavior to better protect embryos from UV-B induced damage. In addition, we hypothesized that long-toed salamander embryos at high elevation would exhibit elevated photolyase activity, a photo-reactivating enzyme that repairs UV-B radiation-induced damage to DNA. We predicted that this behavioral defense strategy would be employed together with an elevated physiological response as a correlated defense response to increased levels of UV-B radiation in high elevation populations. We surveyed high and low elevation long-toed salamander breeding sites throughout Oregon to quantify oviposition site characteristics and associated UV-B profiles. We simultaneously collected embryos for quantification of photolyase activity in a bacterial transformation assay. We found significant differences in oviposition behavior across elevations, with high elevation breeding females ovipositing in deeper water and using UV-B protective refugia. Oviposition sites at low elevations, however, were most often found in UV-B exposed microhabitats located at the surface of the water. This population difference in oviposition behavior resulted in a standardization of UV-B and temperature conditions for long-toed salamander embryos across elevation. In contrast, we found no population differentiation in photolyase activity between high and low elevation breeding sites. This indicates that behavioral selection for UV-B protected oviposition substrates may either be negating the need for increased photolyase activity in long-toed salamander embryos, or that populations lack the capacity to adapt a heightened physiological response to UV-B at high elevations. Together, these results show how trade-offs in physiology and behavior are a unique adaptation to a significant environmental stressor. Further research into the susceptibility of amphibian species to changing environmental conditions may help to demonstrate the effectiveness of correlated trait responses and plasticity in behavior, and species persistence under changing climate regimes. Close

• 257. [Article] Ectomycorrhizal inoculation of Douglas-fir nursery stock with commercially produced inoculum

  Nine species of ectomycorrhizal fungi were grown in liquid media over a pH range of 2-7. Species fell into five major groups: (1) growth significantly best only at the optimal pH, (2) growth increased ...

  Citation × Citation Citation Abstract Copy Title: Ectomycorrhizal inoculation of Douglas-fir nursery stock with commercially produced inoculum Author: Hung, Ling-ling L. Nine species of ectomycorrhizal fungi were grown in liquid media over a pH range of 2-7. Species fell into five major groups: (1) growth significantly best only at the optimal pH, (2) growth increased with increase of pH, (3) significantly best growth spans three pH units, (4) spans four pH units, and (5) spans five pH units. A comparison of four isolates each of Cenococcum geophilum and Laccaria laccata revealed striking infraspecific differences in response to pH. Species also differed in their effect on pH of the medium over the duration of the experiment. Isolates that grow well over a broad pH range would be preferred for inoculation in tree nurseries. Ectomycorrhizal inoculation of Douglas-fir container-grown seedlings succeeded with coninercially produced Laccaria laccata and Hebeloma crustuliniforme in an research greenhouse and/or commercial nurseries. However, Pisolithus tinctorius inoculum was less effective and the most sensitive to inoculum storage. Inoculated seedlings with abundant mycorrhizae generally had significantly more feeder roots than those with poor or no mycorrhizae. Fresh inoculum was the most effective, and this effectiveness declined as storage period increased. In the case of L. laccata, mycorrhiza formation increased with increased inoculation rate; the lower the inoculation rate, the sooner the effectiveness declined. The best inoculation rate for seedling growth and mycorrhiza formation differed between nurseries. Storage of inoculum at 2°C prolonged inoculum viability for at least two months over that of room-temperature storage. Inoculum from different species or isolates within species responded to storage temperature differently. Results from ectomycorrhizal inoculation of plug+l seedlings indicated that inoculated seedlings had significantly higher foliage Zn concentration, and all but L. laccata-inoculated seedlings had significantly lower foliage Mn levels as compared to noninoculated controls. After being transplanted from containers to nursery beds and grown there for 17 months, all seedlings had 80% mycorrhizal. H. crustuliniforme persisted as a mycorrhizal dominant on seedlings previously inoculated with this fungus. L. laccata-inoculated seedlings had 40% of their feeder roots colonized by Laccaria and other 40% by native fungi (Rhizopogon and Thelephora spp.). All newly formed mycorrhizae of P. tinctorius-inoculated and noninoculated seedlings were with fungi native to the nursery bed, not by P. tinctorius. Title: Ectomycorrhizal inoculation of Douglas-fir nursery stock with commercially produced inoculum Author: Hung, Ling-ling L. Nine species of ectomycorrhizal fungi were grown in liquid media over a pH range of 2-7. Species fell into five major groups: (1) growth significantly best only at the optimal pH, (2) growth increased with increase of pH, (3) significantly best growth spans three pH units, (4) spans four pH units, and (5) spans five pH units. A comparison of four isolates each of Cenococcum geophilum and Laccaria laccata revealed striking infraspecific differences in response to pH. Species also differed in their effect on pH of the medium over the duration of the experiment. Isolates that grow well over a broad pH range would be preferred for inoculation in tree nurseries. Ectomycorrhizal inoculation of Douglas-fir container-grown seedlings succeeded with coninercially produced Laccaria laccata and Hebeloma crustuliniforme in an research greenhouse and/or commercial nurseries. However, Pisolithus tinctorius inoculum was less effective and the most sensitive to inoculum storage. Inoculated seedlings with abundant mycorrhizae generally had significantly more feeder roots than those with poor or no mycorrhizae. Fresh inoculum was the most effective, and this effectiveness declined as storage period increased. In the case of L. laccata, mycorrhiza formation increased with increased inoculation rate; the lower the inoculation rate, the sooner the effectiveness declined. The best inoculation rate for seedling growth and mycorrhiza formation differed between nurseries. Storage of inoculum at 2°C prolonged inoculum viability for at least two months over that of room-temperature storage. Inoculum from different species or isolates within species responded to storage temperature differently. Results from ectomycorrhizal inoculation of plug+l seedlings indicated that inoculated seedlings had significantly higher foliage Zn concentration, and all but L. laccata-inoculated seedlings had significantly lower foliage Mn levels as compared to noninoculated controls. After being transplanted from containers to nursery beds and grown there for 17 months, all seedlings had 80% mycorrhizal. H. crustuliniforme persisted as a mycorrhizal dominant on seedlings previously inoculated with this fungus. L. laccata-inoculated seedlings had 40% of their feeder roots colonized by Laccaria and other 40% by native fungi (Rhizopogon and Thelephora spp.). All newly formed mycorrhizae of P. tinctorius-inoculated and noninoculated seedlings were with fungi native to the nursery bed, not by P. tinctorius. Close

• 258. [Article] Stable occupancy by breeding hawks (Buteo spp.) over 25 years on a privately managed bunchgrass prairie in northeastern Oregon, USA

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Cooper ...

  Citation × Citation Citation Abstract Copy Title: Stable occupancy by breeding hawks (Buteo spp.) over 25 years on a privately managed bunchgrass prairie in northeastern Oregon, USA Author: Bartuszevige, Anne M., Humphrey, Ann B., Houle, Marcy, Kennedy, Patricia L., Dugger, Katie M., Williams, John To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Cooper Ornithological Society and can be found at: http://www.bioone.org/loi/cond. Title: Stable occupancy by breeding hawks (Buteo spp.) over 25 years on a privately managed bunchgrass prairie in northeastern Oregon, USA Author: Bartuszevige, Anne M., Humphrey, Ann B., Houle, Marcy, Kennedy, Patricia L., Dugger, Katie M., Williams, John To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Cooper Ornithological Society and can be found at: http://www.bioone.org/loi/cond. Close

• 259. [Article] Linking removal targets to the ecological effects of invaders: a predictive model and field test

  Species invasions have a range of negative effects on recipient ecosystems, and many occur at a scale and magnitude that preclude complete eradication. When complete extirpation is unlikely with available ...

  Citation × Citation Citation Abstract Copy Title: Linking removal targets to the ecological effects of invaders: a predictive model and field test Author: Brooks, Annabelle L. M., Côté, Isabelle M., Miller, Skylar, Green, Stephanie J., Dulvy, Nicholas K., Cooper, Andrew B., Akins, John L. Species invasions have a range of negative effects on recipient ecosystems, and many occur at a scale and magnitude that preclude complete eradication. When complete extirpation is unlikely with available management resources, an effective strategy may be to suppress invasive populations below levels predicted to cause undesirable ecological change. We illustrate this approach by developing and testing targets for the control of invasive Indo-Pacific lionfish (Pterois volitans and P. miles) on Western Atlantic coral reefs. We first developed a size structured simulation model of predation by lionfish on native fish communities, which we used to predict threshold densities of lionfish beyond which native fish biomass should decline. We then tested our predictions by experimentally manipulating lionfish densities above or below reef-specific thresholds, and monitoring the consequences for native fish populations on 24 Bahamian patch reefs over 18 months. We found that reducing lionfish below predicted threshold densities effectively protected native fish community biomass from predation-induced declines. Reductions in density of 75- 95%, depending on the reef, were required to suppress lionfish below levels predicted to over-consume prey. On reefs where lionfish were kept threshold densities, native prey fish biomass increased by 50-70%. Gains in small (<6cm) size classes of native fishes translated into lagged increases in larger size classes over time. The biomass of larger individuals (>15cm total length), including ecologically important grazers and economically important fisheries species, had increased by 10-65% by the end of the experiment. Crucially, similar gains in prey fish biomass were realized on reefs subjected to partial and full removal of lionfish, but partial removals took 30% less time to implement. By contrast, the biomass of small native fishes declined by more than 50% on all reefs with lionfish densities exceeding reef-specific thresholds. Large inter-reef variation in the biomass of prey fishes at the outset of the study, which influences the threshold density of lionfish, means that we identify a single rule-of-thumb for guiding control efforts. However, our model provides a method for setting reef-specific targets for population control using local monitoring data. Our work is the first to demonstrate that for ongoing invasions, suppressing invaders below densitiesterms of protecting the native ecosystem on a local scale, to achieving complete eradication Title: Linking removal targets to the ecological effects of invaders: a predictive model and field test Author: Brooks, Annabelle L. M., Côté, Isabelle M., Miller, Skylar, Green, Stephanie J., Dulvy, Nicholas K., Cooper, Andrew B., Akins, John L. Species invasions have a range of negative effects on recipient ecosystems, and many occur at a scale and magnitude that preclude complete eradication. When complete extirpation is unlikely with available management resources, an effective strategy may be to suppress invasive populations below levels predicted to cause undesirable ecological change. We illustrate this approach by developing and testing targets for the control of invasive Indo-Pacific lionfish (Pterois volitans and P. miles) on Western Atlantic coral reefs. We first developed a size structured simulation model of predation by lionfish on native fish communities, which we used to predict threshold densities of lionfish beyond which native fish biomass should decline. We then tested our predictions by experimentally manipulating lionfish densities above or below reef-specific thresholds, and monitoring the consequences for native fish populations on 24 Bahamian patch reefs over 18 months. We found that reducing lionfish below predicted threshold densities effectively protected native fish community biomass from predation-induced declines. Reductions in density of 75- 95%, depending on the reef, were required to suppress lionfish below levels predicted to over-consume prey. On reefs where lionfish were kept threshold densities, native prey fish biomass increased by 50-70%. Gains in small (<6cm) size classes of native fishes translated into lagged increases in larger size classes over time. The biomass of larger individuals (>15cm total length), including ecologically important grazers and economically important fisheries species, had increased by 10-65% by the end of the experiment. Crucially, similar gains in prey fish biomass were realized on reefs subjected to partial and full removal of lionfish, but partial removals took 30% less time to implement. By contrast, the biomass of small native fishes declined by more than 50% on all reefs with lionfish densities exceeding reef-specific thresholds. Large inter-reef variation in the biomass of prey fishes at the outset of the study, which influences the threshold density of lionfish, means that we identify a single rule-of-thumb for guiding control efforts. However, our model provides a method for setting reef-specific targets for population control using local monitoring data. Our work is the first to demonstrate that for ongoing invasions, suppressing invaders below densitiesterms of protecting the native ecosystem on a local scale, to achieving complete eradication Close

• 260. [Article] 2005 Diamond Lake Submersed Aquatic Vegetation Survey

  Diamond Lake is a large natural lake having a surface area of some 3214 acres (1300.7 hectares) and a maximum depth of 52 feet (15.8 meters). It is located within the Umpqua National Forest in the Southern ...

  Citation × Citation Citation Abstract Copy Title: 2005 Diamond Lake Submersed Aquatic Vegetation Survey Author: Sytsma, Mark D., Pfauth, Mary Year: 2006 Diamond Lake is a large natural lake having a surface area of some 3214 acres (1300.7 hectares) and a maximum depth of 52 feet (15.8 meters). It is located within the Umpqua National Forest in the Southern Cascade Mountains of Oregon, at an elevation of over 5000 feet (>1524 meters). Diamond Lake is a high-use waterbody that supports angling, public campgrounds, recreational boating, swimming, and water skiing. The human activity associated with the lake has been a significant contributor to the economy of southern Oregon since the early part of the twentieth century. Historically Diamond Lake was fishless but since 1910 the lake has been managed as a popular trophy trout fishery. The unauthorized introduction of the tui chub (Gila bicolor) into the lake in the 1930s caused disruption of the food web and a decline in the fishery. In 1954, the Oregon Game Commission constructed a canal near the Lake Creek outlet, lowered the lake level, and treated Diamond Lake with rotenone, to eradicate tui chub. The lake was restocked with trout following the successful rotenone treatment and a fishery was maintained for several decades. In 1992, tui chub were reintroduced, through accidental introduction or intentional illegal stocking, and again caused a decline in the trout fishery. Originally mesotrophic, Diamond Lake Diamond Lake productivity increased over the last century to a eutrophic state, and is currently included on the Oregon Department of Environmental Quality (ODEQ) 303(d) list of water quality limited water bodies for pH and algae. The lake had severe blooms of the cyanobacteria (blue-green algae) Anabaena flos-aquae, which produce neurotoxins, in the summers of 2001, 2002, and 2003. Microcystis aeruginosa, another toxin producing cyanobacterium species, was also present in the 2003 bloom. Diamond Lake was closed to some public uses (wading, swimming, water skiing, and boating) during portions of all three summers due to public health and safety concerns. Algae blooms and declining trout fishery have been attributed to alteration of the food web by the tui chubs. The chubs spawn early and consume the zooplankton in the lake, which reduces grazing pressure on phytoplankton. Since the lake is nitrogen limited, nitrogen-fixing cyanobacteria dominate the phytoplankton community. Therefore, the chubs reduce the quality of the trout fishery by reducing food available for trout and impact water quality by facilitating cyanobacteria blooms, which can be toxic. In response to the impact of the tui chub on Diamond Lake the US Forest Service and Oregon Department of Fish and Wildlife are collaborating in a tui chub eradication effort. The eradication plan includes a 2.4-m (8 ft) drawdown of the lake in the winter and spring of 2006 and a rotenone treatment of remaining lake volume in 2006 to kill any remaining fish. The US Forest Service prepared an EIS for the drawdown and rotenone treatment. Potential impacts of the drawdown on littoral aquatic plant communities were identified in the EIS. The US Forest Service conducted a qualitative survey to develop a species list for the lake. The survey described here provides a quantitative, pretreatment measure of cover and biomass of aquatic plants in Diamond Lake. Follow-up sampling, using similar methods, will permit assessment of changes in the plant community following drawdown and refilling of the lake. Title: 2005 Diamond Lake Submersed Aquatic Vegetation Survey Author: Sytsma, Mark D., Pfauth, Mary Year: 2006 Diamond Lake is a large natural lake having a surface area of some 3214 acres (1300.7 hectares) and a maximum depth of 52 feet (15.8 meters). It is located within the Umpqua National Forest in the Southern Cascade Mountains of Oregon, at an elevation of over 5000 feet (>1524 meters). Diamond Lake is a high-use waterbody that supports angling, public campgrounds, recreational boating, swimming, and water skiing. The human activity associated with the lake has been a significant contributor to the economy of southern Oregon since the early part of the twentieth century. Historically Diamond Lake was fishless but since 1910 the lake has been managed as a popular trophy trout fishery. The unauthorized introduction of the tui chub (Gila bicolor) into the lake in the 1930s caused disruption of the food web and a decline in the fishery. In 1954, the Oregon Game Commission constructed a canal near the Lake Creek outlet, lowered the lake level, and treated Diamond Lake with rotenone, to eradicate tui chub. The lake was restocked with trout following the successful rotenone treatment and a fishery was maintained for several decades. In 1992, tui chub were reintroduced, through accidental introduction or intentional illegal stocking, and again caused a decline in the trout fishery. Originally mesotrophic, Diamond Lake Diamond Lake productivity increased over the last century to a eutrophic state, and is currently included on the Oregon Department of Environmental Quality (ODEQ) 303(d) list of water quality limited water bodies for pH and algae. The lake had severe blooms of the cyanobacteria (blue-green algae) Anabaena flos-aquae, which produce neurotoxins, in the summers of 2001, 2002, and 2003. Microcystis aeruginosa, another toxin producing cyanobacterium species, was also present in the 2003 bloom. Diamond Lake was closed to some public uses (wading, swimming, water skiing, and boating) during portions of all three summers due to public health and safety concerns. Algae blooms and declining trout fishery have been attributed to alteration of the food web by the tui chubs. The chubs spawn early and consume the zooplankton in the lake, which reduces grazing pressure on phytoplankton. Since the lake is nitrogen limited, nitrogen-fixing cyanobacteria dominate the phytoplankton community. Therefore, the chubs reduce the quality of the trout fishery by reducing food available for trout and impact water quality by facilitating cyanobacteria blooms, which can be toxic. In response to the impact of the tui chub on Diamond Lake the US Forest Service and Oregon Department of Fish and Wildlife are collaborating in a tui chub eradication effort. The eradication plan includes a 2.4-m (8 ft) drawdown of the lake in the winter and spring of 2006 and a rotenone treatment of remaining lake volume in 2006 to kill any remaining fish. The US Forest Service prepared an EIS for the drawdown and rotenone treatment. Potential impacts of the drawdown on littoral aquatic plant communities were identified in the EIS. The US Forest Service conducted a qualitative survey to develop a species list for the lake. The survey described here provides a quantitative, pretreatment measure of cover and biomass of aquatic plants in Diamond Lake. Follow-up sampling, using similar methods, will permit assessment of changes in the plant community following drawdown and refilling of the lake. Close

• 261. [Image] Oregon lampreys : natural history, status, and analysis of management issues

  	Executive Summary The jawless lampreys are remnants of the oldest vertebrates in the world. Oregon has somewhere between eight and a dozen species of these primitive fishes. Their taxonomy is obscure ...
  	Citation × Citation Citation Abstract Copy Title: Oregon lampreys : natural history, status, and analysis of management issues Author: Kostow, Kathryn Year: 2002, 2008, 2005 Executive Summary The jawless lampreys are remnants of the oldest vertebrates in the world. Oregon has somewhere between eight and a dozen species of these primitive fishes. Their taxonomy is obscure because different species tend to look very similar through most of their life cycle, and they have not been well-studied in Oregon. Lampreys occur in the Columbia Basin, including the lower Snake River, along the Oregon coast, in the upper Klamath Basin, and in Goose Lake Basin in southeastern Oregon. They all begin life in fresh water where juveniles burrow into silt and filter feed on algae. As some species approach adulthood they migrate to the ocean or to lakes where they briefly become ecto-parasites, feeding on other live fishes by attaching to them with sucker disc mouths. Other species remain non-parasitic. In addition to some enigmatic species identities, we generally have very little information about the detailed distributions, life histories and basic biology of lampreys. Lampreys became a conservation concern in the early 1990s when tribal co-managers and some Oregon Department of Fish and Wildlife (ODFW) staff noted that populations of Pacific Lampreys, Lampetra tridentata, were apparently declining to perilously low numbers. Pacific Lampreys were listed as an Oregon State sensitive species in 1993 and were given further legal protected status by the state in 1997 (OAR 635-044-0130). Lamprey status is difficult to assess for several reasons: 1) Most observations of lampreys in fresh water are of juveniles and it is difficult to tell the various species apart, even to the extent that the various species are currently clearly designated; 2) Data on lamprey is only collected incidental to monitoring of salmonids. The design and efficiency of the data collection effort is not always adequate for lampreys; and 3) We have very few historic data sets for lampreys. Therefore we often cannot determine how the abundances and distributions we see now compare with those in the past. The limited data that we have suggests that lampreys have declined through many parts of their ranges. The most precipitous declines appear to be in the upper Columbia and Snake basins where we have some historic data from mainstem dam counts. Pacific Lampreys have declined to only about 200 adults annually passing the Snake River dams. We also have evidence of declines of Pacific Lampreys in the lower Columbia and on the Oregon coast, although our data is quite limited. We have little to no information about any of the other species of lampreys. We are not even sure whether some of the recognized species, like the River Lamprey (L. ayresi), is still present in Oregon. This paper concludes with a Problem Analysis for Oregon lampreys. Our biggest problem is poor information, ranging from not knowing basic species identity to having inefficient or no systematic monitoring of lamprey abundance and distribution. ODFW continued an annual harvest on Pacific Lamprey in the Willamette Basin in 2001, but we lack the necessary information to assess the affects of the harvest on the population. Major habitat problems that affect lampreys include upstream passage over artificial barriers, a need for lamprey-friendly screening of water diversions, and urban and agricultural development of low-gradient flood plain habitats. Title: Oregon lampreys : natural history, status, and analysis of management issues Author: Kostow, Kathryn Year: 2002, 2008, 2005 Executive Summary The jawless lampreys are remnants of the oldest vertebrates in the world. Oregon has somewhere between eight and a dozen species of these primitive fishes. Their taxonomy is obscure because different species tend to look very similar through most of their life cycle, and they have not been well-studied in Oregon. Lampreys occur in the Columbia Basin, including the lower Snake River, along the Oregon coast, in the upper Klamath Basin, and in Goose Lake Basin in southeastern Oregon. They all begin life in fresh water where juveniles burrow into silt and filter feed on algae. As some species approach adulthood they migrate to the ocean or to lakes where they briefly become ecto-parasites, feeding on other live fishes by attaching to them with sucker disc mouths. Other species remain non-parasitic. In addition to some enigmatic species identities, we generally have very little information about the detailed distributions, life histories and basic biology of lampreys. Lampreys became a conservation concern in the early 1990s when tribal co-managers and some Oregon Department of Fish and Wildlife (ODFW) staff noted that populations of Pacific Lampreys, Lampetra tridentata, were apparently declining to perilously low numbers. Pacific Lampreys were listed as an Oregon State sensitive species in 1993 and were given further legal protected status by the state in 1997 (OAR 635-044-0130). Lamprey status is difficult to assess for several reasons: 1) Most observations of lampreys in fresh water are of juveniles and it is difficult to tell the various species apart, even to the extent that the various species are currently clearly designated; 2) Data on lamprey is only collected incidental to monitoring of salmonids. The design and efficiency of the data collection effort is not always adequate for lampreys; and 3) We have very few historic data sets for lampreys. Therefore we often cannot determine how the abundances and distributions we see now compare with those in the past. The limited data that we have suggests that lampreys have declined through many parts of their ranges. The most precipitous declines appear to be in the upper Columbia and Snake basins where we have some historic data from mainstem dam counts. Pacific Lampreys have declined to only about 200 adults annually passing the Snake River dams. We also have evidence of declines of Pacific Lampreys in the lower Columbia and on the Oregon coast, although our data is quite limited. We have little to no information about any of the other species of lampreys. We are not even sure whether some of the recognized species, like the River Lamprey (L. ayresi), is still present in Oregon. This paper concludes with a Problem Analysis for Oregon lampreys. Our biggest problem is poor information, ranging from not knowing basic species identity to having inefficient or no systematic monitoring of lamprey abundance and distribution. ODFW continued an annual harvest on Pacific Lamprey in the Willamette Basin in 2001, but we lack the necessary information to assess the affects of the harvest on the population. Major habitat problems that affect lampreys include upstream passage over artificial barriers, a need for lamprey-friendly screening of water diversions, and urban and agricultural development of low-gradient flood plain habitats. Close

• 262. [Article] Planktivorous Auklets (Aethia pusilla and A. cristatella) nesting on St. Lawrence Island, Alaska as indicators of marine conditions in the northern Bering Sea

  Monitoring reproductive success, prey species composition, and colony size of marine birds has been proposed as a method of assessing changes in marine systems that are otherwise difficult to sample (Cairns ...

  Citation × Citation Citation Abstract Copy Title: Planktivorous Auklets (Aethia pusilla and A. cristatella) nesting on St. Lawrence Island, Alaska as indicators of marine conditions in the northern Bering Sea Author: Gall, Adrian Monitoring reproductive success, prey species composition, and colony size of marine birds has been proposed as a method of assessing changes in marine systems that are otherwise difficult to sample (Cairns 1987). I measured inter-annual and intra-seasonal variability in reproductive parameters, taxonomic composition of the diet, and adult body condition of Crested Auklets (Aethia cristatella) and Least Auklets (A. pusilla) at 2 colonies near the village of Savoonga, St. Lawrence Island, Alaska during the 2000-2002 breeding seasons to evaluate how reproductive success of planktivorous seabirds is related to diet. I also assessed the utility of two methods of population monitoring (surface counts and mark-resighting) for detecting annual changes in breeding populations of Crested and Least auklets during the 2001 and 2002 breeding seasons on the Kitnik colony. Average reproductive success was generally high (>60% of nests) for both auklet species during the 3 years of the study, but differed among years. Median hatching dates for both species were 2 weeks earlier in the year of highest reproductive success (2002), compared to the previous 2 years. In all 3 years, the diet of Crested Auklets was predominantly euphausiids, while the diet of Least Auklets consisted primarily of calanoid copepods, but species composition of the diet differed among years for both species. Crested and Least auklets consumed more of the large, lipid-rich copepod Neocalanus cristatus in 2002 than in the other 2 years of the study. The year of lowest reproductive success (2001) was associated with low prevalence of euphausiids in Crested Auklet diets late in the chick-rearing period and high prevalence of the small, low-lipid copepod Calanus marshallae in Least Auklet diets. I observed an increase in total body mass of Crested Auklets during the 2002 breeding season, whereas total body mass declined through the breeding season in the other 2 years. Seasonal changes in adult body mass of Crested Auklets may, therefore, be a useful indicator of food availability. Average body mass of Least Auklets declined in all 3 years, but was lowest in 2001, suggesting that low adult body mass of Least Auklets may reflect poor foraging conditions. Fat reserves of breeding auklets during egg-laying were not highly variable among or within breeding seasons and therefore were not a sensitive predictor of subsequent breeding success. Counts of Crested Auklets in plots on the colony surface were highest in areas of large average boulder size; Least Auklet surface counts were not as variable among plots. Maximum counts of both species of auklets in plots did not differ between years. Patterns of colony surface attendance during the breeding season, however, did differ between years. The colony surface attendance of both auklet species after hatching was higher in the year of high reproductive success. Preventing nest initiation by covering plots with tarps did not reduce subsequent colony surface attendance during chick-rearing (after the tarps were removed) for either species, suggesting that reproductive success, independent of differences in food availability, did not cause a difference in colony surface attendance. I estimated abundance of Least Auklets nesting in two 100-m² plots using mark-resight methods. I concluded that surface counts may provide an indication of among-year differences in colony attendance, but underestimate the number of breeding individuals by a factor of 10. Mark-resighting techniques show more promise for detecting changes in the number of breeding pairs. Reproductive success, adult body mass, and post-hatch colony attendance of Crested and Least auklets appear positively associated with zooplankton availability, particularly the prevalence of N. cristatus in the diet. Annual monitoring of these 3 parameters, together with diet composition, are important for understanding how both natural and anthropogenic climate change may affect trophic structure of the northern Bering Sea ecosystem. Title: Planktivorous Auklets (Aethia pusilla and A. cristatella) nesting on St. Lawrence Island, Alaska as indicators of marine conditions in the northern Bering Sea Author: Gall, Adrian Monitoring reproductive success, prey species composition, and colony size of marine birds has been proposed as a method of assessing changes in marine systems that are otherwise difficult to sample (Cairns 1987). I measured inter-annual and intra-seasonal variability in reproductive parameters, taxonomic composition of the diet, and adult body condition of Crested Auklets (Aethia cristatella) and Least Auklets (A. pusilla) at 2 colonies near the village of Savoonga, St. Lawrence Island, Alaska during the 2000-2002 breeding seasons to evaluate how reproductive success of planktivorous seabirds is related to diet. I also assessed the utility of two methods of population monitoring (surface counts and mark-resighting) for detecting annual changes in breeding populations of Crested and Least auklets during the 2001 and 2002 breeding seasons on the Kitnik colony. Average reproductive success was generally high (>60% of nests) for both auklet species during the 3 years of the study, but differed among years. Median hatching dates for both species were 2 weeks earlier in the year of highest reproductive success (2002), compared to the previous 2 years. In all 3 years, the diet of Crested Auklets was predominantly euphausiids, while the diet of Least Auklets consisted primarily of calanoid copepods, but species composition of the diet differed among years for both species. Crested and Least auklets consumed more of the large, lipid-rich copepod Neocalanus cristatus in 2002 than in the other 2 years of the study. The year of lowest reproductive success (2001) was associated with low prevalence of euphausiids in Crested Auklet diets late in the chick-rearing period and high prevalence of the small, low-lipid copepod Calanus marshallae in Least Auklet diets. I observed an increase in total body mass of Crested Auklets during the 2002 breeding season, whereas total body mass declined through the breeding season in the other 2 years. Seasonal changes in adult body mass of Crested Auklets may, therefore, be a useful indicator of food availability. Average body mass of Least Auklets declined in all 3 years, but was lowest in 2001, suggesting that low adult body mass of Least Auklets may reflect poor foraging conditions. Fat reserves of breeding auklets during egg-laying were not highly variable among or within breeding seasons and therefore were not a sensitive predictor of subsequent breeding success. Counts of Crested Auklets in plots on the colony surface were highest in areas of large average boulder size; Least Auklet surface counts were not as variable among plots. Maximum counts of both species of auklets in plots did not differ between years. Patterns of colony surface attendance during the breeding season, however, did differ between years. The colony surface attendance of both auklet species after hatching was higher in the year of high reproductive success. Preventing nest initiation by covering plots with tarps did not reduce subsequent colony surface attendance during chick-rearing (after the tarps were removed) for either species, suggesting that reproductive success, independent of differences in food availability, did not cause a difference in colony surface attendance. I estimated abundance of Least Auklets nesting in two 100-m² plots using mark-resight methods. I concluded that surface counts may provide an indication of among-year differences in colony attendance, but underestimate the number of breeding individuals by a factor of 10. Mark-resighting techniques show more promise for detecting changes in the number of breeding pairs. Reproductive success, adult body mass, and post-hatch colony attendance of Crested and Least auklets appear positively associated with zooplankton availability, particularly the prevalence of N. cristatus in the diet. Annual monitoring of these 3 parameters, together with diet composition, are important for understanding how both natural and anthropogenic climate change may affect trophic structure of the northern Bering Sea ecosystem. Close

• 263. [Article] Patterns of interactive segregation in three species of sculpins (Cottus) in western Oregon

  Species interactions and their effect on the use of habitat by benthic fishes were examined in a guild composed of Cottus perplexus, C. rhotheus, and C. beldingi in the Marys River above Philomath, Oregon, ...

  Citation × Citation Citation Abstract Copy Title: Patterns of interactive segregation in three species of sculpins (Cottus) in western Oregon Author: Finger, Terry Richard Species interactions and their effect on the use of habitat by benthic fishes were examined in a guild composed of Cottus perplexus, C. rhotheus, and C. beldingi in the Marys River above Philomath, Oregon, and in a constant environment provided by an artificial stream. In the Marys River system, the pattern of longitudinal succession in this guild was one of species additions downstream rather than sequential longitudinal replacement. Cottus perplexus occurred throughout the river system, C. rhotheus was found only in the middle and lower reaches, and C. beldingi was restricted to the lower reaches within the study area. Longitudinal distributions appeared to be most strongly related to substrate characteristics in riffles. Cottus perplexus occurred on all substrates, C. rhotheus was found only where rock was present, and C. beldingi was captured only in riffles dominated by loose, cobble-sized rock with many interstitial spaces. Local use of habitat was strongly related to the breadth of environmental tolerance of each species arid the presence or absence of other cottus species. The species broadly overlapped in their use of different substrates, depths, and distances from shore, but segregated in an orderly manner with respect to current velocity. Where it existed alone, C. perplexus utilized both pools and riffles and was found in greatest densities near cover. Where it coexisted with C. rhotheus, C. perplexus was primarily confined to pools and declined significantly in abundance. The degree to which C. perplexus was excluded from riffles varied in relation to seasons and the size composition of the C. rhotheus population. In areas where there were low densities of large C. rhotheus, the exclusion of C. perplexus was not as pronounced as in areas where there were many large C. rhotheus, and was apparently due mainly to competition. In these areas overlap between the species was also greater in spring, the time of peak food abundance, than in summer or winter. In areas where there were greater numbers of large C. rhotheus, the exclusion of C. perplexus from riffles was more pronounced and did not vary seasonally. In these areas predation was apparently the most important mechanism causing the interactive segregation. Cottus rhotheus was generally confined to riffles, although some large individuals did wander into pools during times of food scarcity. Cottus beldingi was exclusively found in riffles and had a greater maximum current velocity tolerance than C. rhotheus. In summer, all riffle areas in the Marys River flowed slowly enough for C. rhotheus, and C. beldingi apparently was forced, by predation and competition exerted by C. rhotheus, to burrow into the substrate. In winter and spring, C. rhotheus was excluded from areas of some riffles by the faster currents. tn these areas C. beldingi had a refuge from competition and predation and was found atop the substrate to a greater degree. Experiments with the three species in the artificial stream supported the field data and suggested that the competition contributing to the habitat shifts was interference competition for space. Cottus perplexus selected riffle areas when alone, but was displaced partially to pools by C. beldingi through interference competition. The addition of C. rhotheus caused C. perplexus to be more rigidly confined to pools, but C. beldingi was able to coexist in riffles with C. rhotheus apparently by utilizing the interstitial spaces in the substrate. Comparison of these results with those of other studies suggests that segregation in stream fishes should be more commonly based on habitat than on food or time. A model was constructed that could be used to predict patterns of habitat utilization in other guilds of benthic fishes. Species interactions were also suggested as having a major influence on the evolutionary patterns of Cottus in western North America. Large, dominant species will obtain their preferred habitat throughout their geographical range. They will therefore not need to adapt to a wide range of conditions and thus may exhibit low morphological variability. Contrastingly, less dominant species may be forced into many different habitats, depending on which dominant species are also present, and may thus exhibit greater morphological variability. Title: Patterns of interactive segregation in three species of sculpins (Cottus) in western Oregon Author: Finger, Terry Richard Species interactions and their effect on the use of habitat by benthic fishes were examined in a guild composed of Cottus perplexus, C. rhotheus, and C. beldingi in the Marys River above Philomath, Oregon, and in a constant environment provided by an artificial stream. In the Marys River system, the pattern of longitudinal succession in this guild was one of species additions downstream rather than sequential longitudinal replacement. Cottus perplexus occurred throughout the river system, C. rhotheus was found only in the middle and lower reaches, and C. beldingi was restricted to the lower reaches within the study area. Longitudinal distributions appeared to be most strongly related to substrate characteristics in riffles. Cottus perplexus occurred on all substrates, C. rhotheus was found only where rock was present, and C. beldingi was captured only in riffles dominated by loose, cobble-sized rock with many interstitial spaces. Local use of habitat was strongly related to the breadth of environmental tolerance of each species arid the presence or absence of other cottus species. The species broadly overlapped in their use of different substrates, depths, and distances from shore, but segregated in an orderly manner with respect to current velocity. Where it existed alone, C. perplexus utilized both pools and riffles and was found in greatest densities near cover. Where it coexisted with C. rhotheus, C. perplexus was primarily confined to pools and declined significantly in abundance. The degree to which C. perplexus was excluded from riffles varied in relation to seasons and the size composition of the C. rhotheus population. In areas where there were low densities of large C. rhotheus, the exclusion of C. perplexus was not as pronounced as in areas where there were many large C. rhotheus, and was apparently due mainly to competition. In these areas overlap between the species was also greater in spring, the time of peak food abundance, than in summer or winter. In areas where there were greater numbers of large C. rhotheus, the exclusion of C. perplexus from riffles was more pronounced and did not vary seasonally. In these areas predation was apparently the most important mechanism causing the interactive segregation. Cottus rhotheus was generally confined to riffles, although some large individuals did wander into pools during times of food scarcity. Cottus beldingi was exclusively found in riffles and had a greater maximum current velocity tolerance than C. rhotheus. In summer, all riffle areas in the Marys River flowed slowly enough for C. rhotheus, and C. beldingi apparently was forced, by predation and competition exerted by C. rhotheus, to burrow into the substrate. In winter and spring, C. rhotheus was excluded from areas of some riffles by the faster currents. tn these areas C. beldingi had a refuge from competition and predation and was found atop the substrate to a greater degree. Experiments with the three species in the artificial stream supported the field data and suggested that the competition contributing to the habitat shifts was interference competition for space. Cottus perplexus selected riffle areas when alone, but was displaced partially to pools by C. beldingi through interference competition. The addition of C. rhotheus caused C. perplexus to be more rigidly confined to pools, but C. beldingi was able to coexist in riffles with C. rhotheus apparently by utilizing the interstitial spaces in the substrate. Comparison of these results with those of other studies suggests that segregation in stream fishes should be more commonly based on habitat than on food or time. A model was constructed that could be used to predict patterns of habitat utilization in other guilds of benthic fishes. Species interactions were also suggested as having a major influence on the evolutionary patterns of Cottus in western North America. Large, dominant species will obtain their preferred habitat throughout their geographical range. They will therefore not need to adapt to a wide range of conditions and thus may exhibit low morphological variability. Contrastingly, less dominant species may be forced into many different habitats, depending on which dominant species are also present, and may thus exhibit greater morphological variability. Close

• 264. [Article] Foraging ecology of migrant waterbirds, Lake Abert, Oregon

  Seven species of water-dependent birds (northern phalarope, Phalaropus lobatus; American avocet, Recurvirostra americana; Wilson's phalarope, P. tricolor; eared grebe, Podiceps nigricollis; ring-billed ...

  Citation × Citation Citation Abstract Copy Title: Foraging ecology of migrant waterbirds, Lake Abert, Oregon Author: Boula, Kathryn Marcile Seven species of water-dependent birds (northern phalarope, Phalaropus lobatus; American avocet, Recurvirostra americana; Wilson's phalarope, P. tricolor; eared grebe, Podiceps nigricollis; ring-billed gull Larus delawarensis; California gull, L. californicus; and northern shoveler, Anas clypeata) were studied during the fall migrations of 1982 and 1983 to determine the diets and foraging strategies of mixed-species feeding assemblages at an alkaline lake in southcentral Oregon. Information on density and distribution of birds and their prey resources was collected at permanent sampling points along the eastern shore of Lake Abert, Lake Co., OR. Determination of diet composition was based on analysis of stomach samples from collected specimens. Between-species comparisons of diet composition were made using classification analyses. Diet samples were compared to prey availability samples to discern whether birds fed preferentially on particular prey types. Timed observations were used to develop time budgets. Multivariate ordination procedures were used to determine the extent of niche overlap and resource partitioning. Structural measurements were taken from collected specimens to aid in assessment of physiological condition of migrants. Total numbers of migrants using Lake Abert varied from year to year. Numbers of all species except eared grebes and gulls were lower in 1983 than in 1982. Total sample biomass of prey also declined between 1982 and 1983. Fifteen potential prey types were identified within the lake and along the lakeshore. Of these, the alkali fly (Ephydra hians) was the principal prey of all birds except the northern shoveler, whose diet included large percentages of brine shrimp (Artemia salina) and water fleas (Moina sp.). Bivariate correlation analysis revealed no significant relationships between concentrations of birds and aggregations of prey organisms. Foraging was the predominant activity of all bird species. Northern shovelers foraged for a larger percentage of the day than did other species (71%) while eared grebes foraged least (14% of daylight hours). Morning and afternoon foraging peaks were noted for shovelers and avocets. Classification and preference analyses indicated substantial overlap in diets of migrant birds, particularly among shorebirds and between gulls. When other dimensions of resource use (i.e. time allocation, foraging substrate, and technique) were examined along with diet, using a reciprocal averaging technique, some partitioning was evident in the foraging time allocation and techniques of shorebirds. Time allocation, diets and foraging techniques of the two gull species were strikingly similar. Mean weights and/or mean fat scores of all species tended to be lower in 1983 than in 1982. Changes in relative abundance of prey types, and availability of foraging macrohabitats, resulting from rising water levels, may have affected foraging patterns and condition of migrants. Title: Foraging ecology of migrant waterbirds, Lake Abert, Oregon Author: Boula, Kathryn Marcile Seven species of water-dependent birds (northern phalarope, Phalaropus lobatus; American avocet, Recurvirostra americana; Wilson's phalarope, P. tricolor; eared grebe, Podiceps nigricollis; ring-billed gull Larus delawarensis; California gull, L. californicus; and northern shoveler, Anas clypeata) were studied during the fall migrations of 1982 and 1983 to determine the diets and foraging strategies of mixed-species feeding assemblages at an alkaline lake in southcentral Oregon. Information on density and distribution of birds and their prey resources was collected at permanent sampling points along the eastern shore of Lake Abert, Lake Co., OR. Determination of diet composition was based on analysis of stomach samples from collected specimens. Between-species comparisons of diet composition were made using classification analyses. Diet samples were compared to prey availability samples to discern whether birds fed preferentially on particular prey types. Timed observations were used to develop time budgets. Multivariate ordination procedures were used to determine the extent of niche overlap and resource partitioning. Structural measurements were taken from collected specimens to aid in assessment of physiological condition of migrants. Total numbers of migrants using Lake Abert varied from year to year. Numbers of all species except eared grebes and gulls were lower in 1983 than in 1982. Total sample biomass of prey also declined between 1982 and 1983. Fifteen potential prey types were identified within the lake and along the lakeshore. Of these, the alkali fly (Ephydra hians) was the principal prey of all birds except the northern shoveler, whose diet included large percentages of brine shrimp (Artemia salina) and water fleas (Moina sp.). Bivariate correlation analysis revealed no significant relationships between concentrations of birds and aggregations of prey organisms. Foraging was the predominant activity of all bird species. Northern shovelers foraged for a larger percentage of the day than did other species (71%) while eared grebes foraged least (14% of daylight hours). Morning and afternoon foraging peaks were noted for shovelers and avocets. Classification and preference analyses indicated substantial overlap in diets of migrant birds, particularly among shorebirds and between gulls. When other dimensions of resource use (i.e. time allocation, foraging substrate, and technique) were examined along with diet, using a reciprocal averaging technique, some partitioning was evident in the foraging time allocation and techniques of shorebirds. Time allocation, diets and foraging techniques of the two gull species were strikingly similar. Mean weights and/or mean fat scores of all species tended to be lower in 1983 than in 1982. Changes in relative abundance of prey types, and availability of foraging macrohabitats, resulting from rising water levels, may have affected foraging patterns and condition of migrants. Close

• 265. [Article] Negative effect of purple loosestrife and reed canary grass on the diversity of wetland plant and moth communities

  Invasive plants have the potential to reduce the diversity of species in plant and animal communities. I examined the negative effect of two invasive wetland plants, purple loosestrife and reed canary ...

  Citation × Citation Citation Abstract Copy Title: Negative effect of purple loosestrife and reed canary grass on the diversity of wetland plant and moth communities Author: Schooler, Shon Invasive plants have the potential to reduce the diversity of species in plant and animal communities. I examined the negative effect of two invasive wetland plants, purple loosestrife and reed canary grass, on the species richness and diversity of plant and moth communities within 24 wetland study sites in the Pacific Northwest. I hypothesized that as the cover of the invasive species increased, the diversity of the local plant and moth community would decrease. Increasing cover of purple loosestrife and reed canary grass was associated with reduction in the diversity of wetland plant communities irrespective of the diversity measure examined. Moth species richness was positively correlated with plant species richness, but I found no detectable direct negative association between loosestrife and canary grass cover and moth community diversity. Wetland hydrology, soil characteristics, and topography were measured to control for potentially covarying and confounding influences on plant diversity. Temperature, ambient light, and surrounding land-use were measured to control for potentially covarying and confounding influences on moth sampling and diversity. None of these variables was significantly associated with invasive species abundance. This strengthens the conclusion that the invasive species are the cause of the decline in biotic diversity. Understanding the mechanisms that influence plant invasions will lead to more effective management strategies. I examined the role of soil nutrients in the invasive potential of purple loosestrife. I hypothesized that nitrogen was the primary nutrient limiting plant growth and that higher soil nitrogen concentrations would increase the growth of purple loosestrife within 13 wetland sites in the Willamette Valley, Oregon. Using greenhouse experiments and field studies I found that nitrogen was the primary resource limiting both plant community biomass and purple loosestrife growth. Purple loosestrife grew well in soils taken from nine wetlands currently not colonized by loosestrife. Given their similar hydroperiods, this suggests that these wetlands will be susceptible to invasion should loosestrife colonize. Plant species richness was negatively associated with soil nitrate and ammonium concentrations, This trend included invaded and non-invaded sites. Therefore, to prevent repeated invasions, management strategies should consider methods for reducing soil nutrient concentrations, particularly nitrogen. Title: Negative effect of purple loosestrife and reed canary grass on the diversity of wetland plant and moth communities Author: Schooler, Shon Invasive plants have the potential to reduce the diversity of species in plant and animal communities. I examined the negative effect of two invasive wetland plants, purple loosestrife and reed canary grass, on the species richness and diversity of plant and moth communities within 24 wetland study sites in the Pacific Northwest. I hypothesized that as the cover of the invasive species increased, the diversity of the local plant and moth community would decrease. Increasing cover of purple loosestrife and reed canary grass was associated with reduction in the diversity of wetland plant communities irrespective of the diversity measure examined. Moth species richness was positively correlated with plant species richness, but I found no detectable direct negative association between loosestrife and canary grass cover and moth community diversity. Wetland hydrology, soil characteristics, and topography were measured to control for potentially covarying and confounding influences on plant diversity. Temperature, ambient light, and surrounding land-use were measured to control for potentially covarying and confounding influences on moth sampling and diversity. None of these variables was significantly associated with invasive species abundance. This strengthens the conclusion that the invasive species are the cause of the decline in biotic diversity. Understanding the mechanisms that influence plant invasions will lead to more effective management strategies. I examined the role of soil nutrients in the invasive potential of purple loosestrife. I hypothesized that nitrogen was the primary nutrient limiting plant growth and that higher soil nitrogen concentrations would increase the growth of purple loosestrife within 13 wetland sites in the Willamette Valley, Oregon. Using greenhouse experiments and field studies I found that nitrogen was the primary resource limiting both plant community biomass and purple loosestrife growth. Purple loosestrife grew well in soils taken from nine wetlands currently not colonized by loosestrife. Given their similar hydroperiods, this suggests that these wetlands will be susceptible to invasion should loosestrife colonize. Plant species richness was negatively associated with soil nitrate and ammonium concentrations, This trend included invaded and non-invaded sites. Therefore, to prevent repeated invasions, management strategies should consider methods for reducing soil nutrient concentrations, particularly nitrogen. Close

• 266. [Article] Fish assemblage organization in the Amazon River floodplain : species richness, spatial distribution and recruitment processes

  The composition and distribution of fish assemblages was examined in a floodplain lake system in the Amazon basin. Quantitative samples were collected during the 1992-1993 flooding season at Marchantaria ...

  Citation × Citation Citation Abstract Copy Title: Fish assemblage organization in the Amazon River floodplain : species richness, spatial distribution and recruitment processes Author: Petry, Paulo The composition and distribution of fish assemblages was examined in a floodplain lake system in the Amazon basin. Quantitative samples were collected during the 1992-1993 flooding season at Marchantaria Island, Solimoes River. A total of 25,819 specimens representing 8 orders, 30 families, 101 genera and 139 species of fish were collected. Analysis of species richness distribution among 7 vegetation strata showed that vegetated sites had higher species richness than unvegetated sites. Stands of Paspalum repens had the most diverse fish fauna. Canonical correspondence analysis (CCA) was used to investigate relationship between fish assemblages and 16 environmental variables. CCA revealed that dissolved oxygen, water transparency, water depth and aquatic vegetation structure were significantly related to fish assemblage organization. The results suggest that physiological adaptations to hypoxia and habitat complexity play a major role in the organization of these assemblages. The morphology, ontogenetic development, shape variability and deposition of otolith microincrements are described for floodplain serrasalmin fishes. Serrasalmin otoliths were similar to other ostariophysan, nevertheless their shape was species-specific. Elliptical Fourier analysis showed that Mylossoma aureum lapilli were highly variable in shape when compared to closely related species. PCA and discriminant function analysis indicated that two distinct forms of lapillus can be recognized for M. aureum, and intra-species variation was higher than inter-species variation. Otolith microincrement analysis was tested for these fishes, and microincrement deposition validation showed that Piaractus brachipomus deposits otolith increments on a daily basis. Patterns of spatial distribution, growth and mortality characteristics of larvae and juvenile were examined for M. aureum inhabiting the Marchantaria Island floodplain. Otolith-derived birth date reconstruction showed that M. aureum spawning season extended from late November to March, and peak larvae recruitment to the island occurred in mid-December. Larvae and juveniles had different spatial distributions in relation to habitat usage. Instantaneous growth coefficients (g) varied from 0.0197(d⁻¹) to 0.265(d⁻¹) among cohorts. Early-season cohorts had wider otolith microincrements and higher instantaneous growth coefficients than late-season cohorts. Mortality estimated by the decline of loge (abundance) regressed on age indicated that cohort-specific instantaneous mortality varied significantly among cohorts, ranging from 0.027(d⁻¹) (2.6%/d) to 0.103(d⁻¹) (9.7%/d). Title: Fish assemblage organization in the Amazon River floodplain : species richness, spatial distribution and recruitment processes Author: Petry, Paulo The composition and distribution of fish assemblages was examined in a floodplain lake system in the Amazon basin. Quantitative samples were collected during the 1992-1993 flooding season at Marchantaria Island, Solimoes River. A total of 25,819 specimens representing 8 orders, 30 families, 101 genera and 139 species of fish were collected. Analysis of species richness distribution among 7 vegetation strata showed that vegetated sites had higher species richness than unvegetated sites. Stands of Paspalum repens had the most diverse fish fauna. Canonical correspondence analysis (CCA) was used to investigate relationship between fish assemblages and 16 environmental variables. CCA revealed that dissolved oxygen, water transparency, water depth and aquatic vegetation structure were significantly related to fish assemblage organization. The results suggest that physiological adaptations to hypoxia and habitat complexity play a major role in the organization of these assemblages. The morphology, ontogenetic development, shape variability and deposition of otolith microincrements are described for floodplain serrasalmin fishes. Serrasalmin otoliths were similar to other ostariophysan, nevertheless their shape was species-specific. Elliptical Fourier analysis showed that Mylossoma aureum lapilli were highly variable in shape when compared to closely related species. PCA and discriminant function analysis indicated that two distinct forms of lapillus can be recognized for M. aureum, and intra-species variation was higher than inter-species variation. Otolith microincrement analysis was tested for these fishes, and microincrement deposition validation showed that Piaractus brachipomus deposits otolith increments on a daily basis. Patterns of spatial distribution, growth and mortality characteristics of larvae and juvenile were examined for M. aureum inhabiting the Marchantaria Island floodplain. Otolith-derived birth date reconstruction showed that M. aureum spawning season extended from late November to March, and peak larvae recruitment to the island occurred in mid-December. Larvae and juveniles had different spatial distributions in relation to habitat usage. Instantaneous growth coefficients (g) varied from 0.0197(d⁻¹) to 0.265(d⁻¹) among cohorts. Early-season cohorts had wider otolith microincrements and higher instantaneous growth coefficients than late-season cohorts. Mortality estimated by the decline of loge (abundance) regressed on age indicated that cohort-specific instantaneous mortality varied significantly among cohorts, ranging from 0.027(d⁻¹) (2.6%/d) to 0.103(d⁻¹) (9.7%/d). Close

• 267. [Article] Spatio-Temporal Analysis and Modeling in the Marine Environment : Humpback Whale Genetic Variability and Seabird Distributions in the Northeastern Pacific Ocean

  The rapid decline of marine ecosystems worldwide and the failure of traditional single species management pushed for the development of ecosystem-based conservation measures such as marine protected areas ...

  Citation × Citation Citation Abstract Copy Title: Spatio-Temporal Analysis and Modeling in the Marine Environment : Humpback Whale Genetic Variability and Seabird Distributions in the Northeastern Pacific Ocean Author: Dick, Dorothy Marie The rapid decline of marine ecosystems worldwide and the failure of traditional single species management pushed for the development of ecosystem-based conservation measures such as marine protected areas (MPA) to slow the loss of marine biodiversity. One approach to MPA creation advocates targeting marine megafauna (e.g., marine mammals, seabirds, sharks, etc.) and assumes protective measures for megafauna will extend safeguards to areas of ocean productivity and other species dependent on that productivity. The marine spatial planning (MSP) process requires spatially-explicit information resulting in the development of map products used in planning and decision making. The crux of map creation is georeferenced species occurrence data. This three-part study takes a multidisciplinary approach, combining geography, marine conservation, molecular ecology, and spatial ecology to explore species occurrence data and development of novel geoanalytical tools, spatial analyses, and predictive modeling to inform the MSP process and help design more effective MPA networks for North Pacific marine megafauna (humpback whales and seabirds). Chapter 2 includes the development of geneGIS, a customized Arc Marine data model and suite of computational GIS tools to explore, analyze, and visualize spatially-explicit, individual-based records from North Pacific humpback whale photo-identification and genetic data. Unlike most occurrence data, this presence-only dataset is enriched by the addition of genetic information enabling mangers to factor in population structure and genetic diversity, and thus maximize species resilience, when designing MPAs. Chapters 3 and 4 focus on using presence-absence data to develop spatially-explicit ecological models to identify multispecies seabird foraging aggregations (hotspots) and assess how these locations may shift with climate change within the California Current System. Key to both components is an improved understanding of what factors influence the presence of a species and/or its genetic variability to enable present day planning and design of MPA networks to ensure adequate protection will be in place now and as climate change progresses. This information can also be used to inform policy decisions by adapting strategies to reduce non-climate stressors such as fishery pressures and coastal development in areas predicted to be important to marine species in the future. Title: Spatio-Temporal Analysis and Modeling in the Marine Environment : Humpback Whale Genetic Variability and Seabird Distributions in the Northeastern Pacific Ocean Author: Dick, Dorothy Marie The rapid decline of marine ecosystems worldwide and the failure of traditional single species management pushed for the development of ecosystem-based conservation measures such as marine protected areas (MPA) to slow the loss of marine biodiversity. One approach to MPA creation advocates targeting marine megafauna (e.g., marine mammals, seabirds, sharks, etc.) and assumes protective measures for megafauna will extend safeguards to areas of ocean productivity and other species dependent on that productivity. The marine spatial planning (MSP) process requires spatially-explicit information resulting in the development of map products used in planning and decision making. The crux of map creation is georeferenced species occurrence data. This three-part study takes a multidisciplinary approach, combining geography, marine conservation, molecular ecology, and spatial ecology to explore species occurrence data and development of novel geoanalytical tools, spatial analyses, and predictive modeling to inform the MSP process and help design more effective MPA networks for North Pacific marine megafauna (humpback whales and seabirds). Chapter 2 includes the development of geneGIS, a customized Arc Marine data model and suite of computational GIS tools to explore, analyze, and visualize spatially-explicit, individual-based records from North Pacific humpback whale photo-identification and genetic data. Unlike most occurrence data, this presence-only dataset is enriched by the addition of genetic information enabling mangers to factor in population structure and genetic diversity, and thus maximize species resilience, when designing MPAs. Chapters 3 and 4 focus on using presence-absence data to develop spatially-explicit ecological models to identify multispecies seabird foraging aggregations (hotspots) and assess how these locations may shift with climate change within the California Current System. Key to both components is an improved understanding of what factors influence the presence of a species and/or its genetic variability to enable present day planning and design of MPA networks to ensure adequate protection will be in place now and as climate change progresses. This information can also be used to inform policy decisions by adapting strategies to reduce non-climate stressors such as fishery pressures and coastal development in areas predicted to be important to marine species in the future. Close

• 268. [Article] Population and conservation genetic structure of the Cascades frog, Rana cascadae throughout the species' range

  A major goal of conservation biology is to elucidate the population genetic structure in threatened species and assess the relative importance of the evolutionary forces that shape that population genetic ...

  Citation × Citation Citation Abstract Copy Title: Population and conservation genetic structure of the Cascades frog, Rana cascadae throughout the species' range Author: Monsen, Kirsten J. A major goal of conservation biology is to elucidate the population genetic structure in threatened species and assess the relative importance of the evolutionary forces that shape that population genetic structure. I conducted three studies in the declining amphibian Rana cascadae to assess levels of population genetic differentiation and the relative importance of gene flow versus random genetic drift throughout the species' range. In the first study, 1 examined phylogeographic structure on a species-wide geographic scale with both mitochondrial and nuclear molecular markers. I found three mitochondrial groups within R. cascadae that are as divergent at the mitochondrial DNA as sister species. However, I only found two nuclear groups within R. cascadae, suggesting there are two Distinct Population Segments and three Management Units within the species' range. In the second study, I compared sequence data from mtDNA and nuclear DNA of the three R. cascadae mtl)NA groups to several closely related Pacific Northwestern ranid species. I found the surprising result that the mtDNA of R. aurora aurora is more closely related to the mtDNA of' R. cascadae than to the mtDNA of its own subspecies R. aurora drayloni. The nuclear data support the sub-specific relationship between R. aurora aurora and R. aurora draytoni. This result is most likely due to incomplete lineage sorting of ancestral mtDNA alleles. Finally, in the third study, I examined the relative importance of gene flow versus random genetic drift on a fine geographic scale using microsatellite loci. Additionally, I estimated the long-term effective population sizes and genetic neighborhood size for 11 R. cascadae populations. Rana cascadae shows extreme isolation by distance with very little gene flow occurring past a distance of 10 km. Long-term effective population sizes were unrealistically large for current effective population sizes, but the estimates oF genetic neighborhood size are consistent with those expected based on current census population size and genetic neighborhood size in other amphibians. My research suggests Rana cascadae should be managed as three separate groups corresponding to the Olympic Peninsula, the Cascades of Washington and Oregon, and Northern California. Additionally, R. cascadae exhibits extreme isolation by distance with reduced gene flow at distances greater than 10 km, suggesting metapopulation structure is weak, and populations that go extinct are unlikely to be re-colonized quickly despite the presence of nearby R. cascadae populations. Title: Population and conservation genetic structure of the Cascades frog, Rana cascadae throughout the species' range Author: Monsen, Kirsten J. A major goal of conservation biology is to elucidate the population genetic structure in threatened species and assess the relative importance of the evolutionary forces that shape that population genetic structure. I conducted three studies in the declining amphibian Rana cascadae to assess levels of population genetic differentiation and the relative importance of gene flow versus random genetic drift throughout the species' range. In the first study, 1 examined phylogeographic structure on a species-wide geographic scale with both mitochondrial and nuclear molecular markers. I found three mitochondrial groups within R. cascadae that are as divergent at the mitochondrial DNA as sister species. However, I only found two nuclear groups within R. cascadae, suggesting there are two Distinct Population Segments and three Management Units within the species' range. In the second study, I compared sequence data from mtDNA and nuclear DNA of the three R. cascadae mtl)NA groups to several closely related Pacific Northwestern ranid species. I found the surprising result that the mtDNA of R. aurora aurora is more closely related to the mtDNA of' R. cascadae than to the mtDNA of its own subspecies R. aurora drayloni. The nuclear data support the sub-specific relationship between R. aurora aurora and R. aurora draytoni. This result is most likely due to incomplete lineage sorting of ancestral mtDNA alleles. Finally, in the third study, I examined the relative importance of gene flow versus random genetic drift on a fine geographic scale using microsatellite loci. Additionally, I estimated the long-term effective population sizes and genetic neighborhood size for 11 R. cascadae populations. Rana cascadae shows extreme isolation by distance with very little gene flow occurring past a distance of 10 km. Long-term effective population sizes were unrealistically large for current effective population sizes, but the estimates oF genetic neighborhood size are consistent with those expected based on current census population size and genetic neighborhood size in other amphibians. My research suggests Rana cascadae should be managed as three separate groups corresponding to the Olympic Peninsula, the Cascades of Washington and Oregon, and Northern California. Additionally, R. cascadae exhibits extreme isolation by distance with reduced gene flow at distances greater than 10 km, suggesting metapopulation structure is weak, and populations that go extinct are unlikely to be re-colonized quickly despite the presence of nearby R. cascadae populations. Close

• 269. [Article] Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations

  In grasslands, grazing by large ungulates can influence vegetation structure, composition, primary productivity, and ultimately, ecosystem functioning. While grazing represents a complex disturbance, grazing ...

  Citation × Citation Citation Abstract Copy Title: Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations Author: Johnson, Tracey N. In grasslands, grazing by large ungulates can influence vegetation structure, composition, primary productivity, and ultimately, ecosystem functioning. While grazing represents a complex disturbance, grazing intensity largely determines the effects of grazing on vegetation. Structural and compositional changes in the plant community caused by grazing could have bottom-up effects on species and interactions at higher trophic levels. Thus, particular management strategies for domestic livestock in rangeland systems could exert a strong affect on grassland wildlife. Grassland-dependent songbirds may be particularly susceptible to the effects of domestic grazers because they depend on grassland vegetation for foraging and nesting. Domestic livestock may influence grassland-breeding bird populations by affecting settlement decisions, resource availability, or reproductive success. We investigated the effects of grazing intensity on grassland vegetation structure and songbird demography in a northwestern bunchgrass prairie using paddocks with experimentally-manipulated cattle stocking rates. We compared effects of four stocking rates (0, 14.4, 28.8, and 43.2 animal unit months) on songbirds using a randomized complete block design with four replicates of each stocking rate to address hypotheses regarding demography of grassland songbirds. Overall paddock-level vegetation structure decreased and structural heterogeneity of vegetation increased with higher stocking rates, and those effects carried over one-year post-grazing. However, most bird species were able to locate nesting sites with similar vegetation structure regardless of paddock-level effects of stocking rate. The exceptions were western meadowlarks and vesper sparrows; nests of these species in paddocks with higher stocking rates had less vegetative cover. Apparent nest density for grasshopper sparrows was negatively affected by higher stocking rates. Grazing treatment effects on songbird population density were restricted to negative effects of higher stocking rates on savannah sparrows, but this relationship was not observed until the post-treatment year. Songbird community composition differed between control and heavily-grazed paddocks, but diversity was not affected by stocking rate. Nest fates were evaluated to determine whether stocking rate influenced nest survival or cause-specific nest failure. Other variables such as vegetation structure and predator community, date, year, and nest age were included to help clarify which mechanisms might be responsible for differences in nest survival or failure rates among treatments. For our analysis, we introduce the use of a novel software package, McNestimate, to estimate the daily probability of nest survival and failure from specific causes. McNestimate estimates the probability of nest failure from competing causes when the exact dates of failure are unknown using a Markov Chain framework, and incorporates a model selection approach which allows the use of covariates to help identify variables important in explaining variation in the daily probability of nest failure. Nest predation rates increased with the age of the nest and throughout the breeding season, but were not affected by stocking rate. The probability of nest failure from adverse weather declined throughout the season, but the rate of decline depended on year. Nest failure rates due to trampling were higher in paddocks with higher stocking rates, but also depended on the number of days cattle were present during the nesting period. Patterns of overall probability of nest success were driven by predation patterns in the first year, but in the second year were strongly influenced by the chances of weather-related nest failure. Although starvation was not identified as a significant source of nest failure, grazing-induced changes to vegetation structure and composition could influence food availability for breeding songbirds, ultimately affecting the composition of nestling diets and nestling condition. To better understand the relationship between grazing intensity, nestling diet composition, and subsequent effects on nestling condition, we examined the invertebrate composition of nestling fecal samples. All species showed strong preferences for Lepidoptera (moths and butterflies) larvae, and partial preferences for Coleoptera (beetles) and Araneae (spiders). The proportion of preferred prey items was not affected by stocking rate. There were effects of bird species on the proportion of Araneae and Coleoptera and the proportion of Acrididae (short-horned grasshoppers) in the diet of western meadowlark nestlings decreased with high stocking rates. Growth rates for western meadowlarks and vesper sparrows were negatively affected by higher stocking rates. These results suggest that stocking rates can have variable effects on grassland songbird population and nest density depending on each species' habitat requirements. However, negative effects of high stocking rates on nest survival and nestling condition could have consequences for juvenile survival and recruitment. Overall, low-to-moderate stocking rates are likely compatible with many grassland bird species in northwest bunchgrass prairie, and although heavier livestock grazing may help create suitable vegetation structure for some songbird species, high stocking rates may influence grassland songbird diet quality, or have negative effects on nestling condition. We hypothesized that grazing intensity could influence the grassland songbird community through "bottom-up" effects on vegetation, but effects of grazing at different intensities did not translate directly through the food web to influence songbird populations as strongly as lower trophic levels. Processes responsible for changes in community composition such as immigration or emigration may not have had time to ensue during our short-term experiment; alternatively, sufficient spatial or temporal heterogeneity remained in the system, even at the highest grazing intensity, such that grazing-induced changes in lower trophic levels were irrelevant for most songbird species. Our results contribute to understanding grassland songbird demographic responses to different grazing intensities and identify specific mechanisms by which conservation measures for declining grassland bird populations can be improved. Title: Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations Author: Johnson, Tracey N. In grasslands, grazing by large ungulates can influence vegetation structure, composition, primary productivity, and ultimately, ecosystem functioning. While grazing represents a complex disturbance, grazing intensity largely determines the effects of grazing on vegetation. Structural and compositional changes in the plant community caused by grazing could have bottom-up effects on species and interactions at higher trophic levels. Thus, particular management strategies for domestic livestock in rangeland systems could exert a strong affect on grassland wildlife. Grassland-dependent songbirds may be particularly susceptible to the effects of domestic grazers because they depend on grassland vegetation for foraging and nesting. Domestic livestock may influence grassland-breeding bird populations by affecting settlement decisions, resource availability, or reproductive success. We investigated the effects of grazing intensity on grassland vegetation structure and songbird demography in a northwestern bunchgrass prairie using paddocks with experimentally-manipulated cattle stocking rates. We compared effects of four stocking rates (0, 14.4, 28.8, and 43.2 animal unit months) on songbirds using a randomized complete block design with four replicates of each stocking rate to address hypotheses regarding demography of grassland songbirds. Overall paddock-level vegetation structure decreased and structural heterogeneity of vegetation increased with higher stocking rates, and those effects carried over one-year post-grazing. However, most bird species were able to locate nesting sites with similar vegetation structure regardless of paddock-level effects of stocking rate. The exceptions were western meadowlarks and vesper sparrows; nests of these species in paddocks with higher stocking rates had less vegetative cover. Apparent nest density for grasshopper sparrows was negatively affected by higher stocking rates. Grazing treatment effects on songbird population density were restricted to negative effects of higher stocking rates on savannah sparrows, but this relationship was not observed until the post-treatment year. Songbird community composition differed between control and heavily-grazed paddocks, but diversity was not affected by stocking rate. Nest fates were evaluated to determine whether stocking rate influenced nest survival or cause-specific nest failure. Other variables such as vegetation structure and predator community, date, year, and nest age were included to help clarify which mechanisms might be responsible for differences in nest survival or failure rates among treatments. For our analysis, we introduce the use of a novel software package, McNestimate, to estimate the daily probability of nest survival and failure from specific causes. McNestimate estimates the probability of nest failure from competing causes when the exact dates of failure are unknown using a Markov Chain framework, and incorporates a model selection approach which allows the use of covariates to help identify variables important in explaining variation in the daily probability of nest failure. Nest predation rates increased with the age of the nest and throughout the breeding season, but were not affected by stocking rate. The probability of nest failure from adverse weather declined throughout the season, but the rate of decline depended on year. Nest failure rates due to trampling were higher in paddocks with higher stocking rates, but also depended on the number of days cattle were present during the nesting period. Patterns of overall probability of nest success were driven by predation patterns in the first year, but in the second year were strongly influenced by the chances of weather-related nest failure. Although starvation was not identified as a significant source of nest failure, grazing-induced changes to vegetation structure and composition could influence food availability for breeding songbirds, ultimately affecting the composition of nestling diets and nestling condition. To better understand the relationship between grazing intensity, nestling diet composition, and subsequent effects on nestling condition, we examined the invertebrate composition of nestling fecal samples. All species showed strong preferences for Lepidoptera (moths and butterflies) larvae, and partial preferences for Coleoptera (beetles) and Araneae (spiders). The proportion of preferred prey items was not affected by stocking rate. There were effects of bird species on the proportion of Araneae and Coleoptera and the proportion of Acrididae (short-horned grasshoppers) in the diet of western meadowlark nestlings decreased with high stocking rates. Growth rates for western meadowlarks and vesper sparrows were negatively affected by higher stocking rates. These results suggest that stocking rates can have variable effects on grassland songbird population and nest density depending on each species' habitat requirements. However, negative effects of high stocking rates on nest survival and nestling condition could have consequences for juvenile survival and recruitment. Overall, low-to-moderate stocking rates are likely compatible with many grassland bird species in northwest bunchgrass prairie, and although heavier livestock grazing may help create suitable vegetation structure for some songbird species, high stocking rates may influence grassland songbird diet quality, or have negative effects on nestling condition. We hypothesized that grazing intensity could influence the grassland songbird community through "bottom-up" effects on vegetation, but effects of grazing at different intensities did not translate directly through the food web to influence songbird populations as strongly as lower trophic levels. Processes responsible for changes in community composition such as immigration or emigration may not have had time to ensue during our short-term experiment; alternatively, sufficient spatial or temporal heterogeneity remained in the system, even at the highest grazing intensity, such that grazing-induced changes in lower trophic levels were irrelevant for most songbird species. Our results contribute to understanding grassland songbird demographic responses to different grazing intensities and identify specific mechanisms by which conservation measures for declining grassland bird populations can be improved. Close

• 270. [Image] Breeding-site characteristics of pond breeding amphibians at White-horse ponds, Crater Lake National Park

  	ill., maps; Thesis (B.A.)-Oregon State University, 1997; Includes bibliographical referenes (leaves 20-22)
  	Citation × Citation Citation Abstract Copy Title: Breeding-site characteristics of pond breeding amphibians at White-horse ponds, Crater Lake National Park Author: Bergmann, Stefan A. Year: 1997, 2009 ill., maps; Thesis (B.A.)-Oregon State University, 1997; Includes bibliographical referenes (leaves 20-22) Title: Breeding-site characteristics of pond breeding amphibians at White-horse ponds, Crater Lake National Park Author: Bergmann, Stefan A. Year: 1997, 2009 ill., maps; Thesis (B.A.)-Oregon State University, 1997; Includes bibliographical referenes (leaves 20-22) Close

• 271. [Article] Patterns of tree establishment and vegetation composition in relation to climate and topography of a subalpine meadow landscape, Jefferson Park, Oregon, USA

  The forest alpine tundra ecotone (FTE, also known as alpine treeline or subalpine parkland), is a conspicuous feature of mountain landscapes throughout the world. Climate change-driven increases in temperature ...

  Citation × Citation Citation Abstract Copy Title: Patterns of tree establishment and vegetation composition in relation to climate and topography of a subalpine meadow landscape, Jefferson Park, Oregon, USA Author: Zald, Harold Samuel James The forest alpine tundra ecotone (FTE, also known as alpine treeline or subalpine parkland), is a conspicuous feature of mountain landscapes throughout the world. Climate change-driven increases in temperature are believed to result in FTE movement and tree invasion of subalpine meadows, which have been documented throughout the Northern Hemisphere across a wide range of geographic locations, climatic regimes, forest types, land use histories, and disturbance regimes. Climate-driven FTE movement may have numerous ecological effects such as: positive temperature feedbacks, increased net primary productivity and carbon storage, and declines of plant populations and species. The magnitude of these ecological effects is highly uncertain, but will be largely determined by the rates and spatial extent of FTE movement and meadow invasion. FTE movement and meadow invasion are often considered at global or regional spatial scales in relation to climate, yet they are fundamentally driven by tree regeneration processes that are influenced by a variety of climatic and biophysical factors at micro site, landscape, and regional scales. Much of the research on the FTE has not taken a landscape approach incorporating multi-scale processes. For example, species distribution models used to project climate change effects on future species distributions and plant biodiversity in mountainous landscapes rely on species distribution data that is often sparse and incomplete across FTE landscapes. This dissertation attempts to overcome many of the limitations in FTE research by taking a landscape approach to develop a greater understanding of past spatiotemporal patterns of tree invasion, current spatial patterns of vegetation composition and structure, and potential future patterns of climate-driven tree invasion in the FTE. The setting for this research is Jefferson Park, a 260 ha subalpine parkland landscape in the Oregon High Cascades, USA. This study uses field plots, remotely sensed imagery, airborne Light Detection and Ranging (LiDAR), and simulation modeling to: 1) predictively map current fine-scale species distributions, vegetation structure, and tree ages; 2) reconstruct patterns of tree invasion over the last fifty years in subalpine meadows in relation to climatic conditions, landforms, microtopography, and seed dispersal limitations; and 3) develop a statistical model that projects future patterns of tree invasion into subalpine meadows under different climate scenarios in Jefferson Park. In chapter two, I generated fine-scale spatially-explicit predictions of current vegetation composition, structure, and tree ages in the Jefferson Park study area. Objectives of this chapter were threefold: 1) to characterize spatial patterns of tree ages, vegetation composition, and vegetation structure in a FTE landscape in the Oregon Cascades using predictive mapping; 2) determine how vegetation composition and structure were associated with gradients of environmental factors derived from multispectral satellite imagery and Light Detection and Ranging (LiDAR) data; and 3) determine if predictive mapping characterizations of tree age, vegetation composition, and vegetation structure were improved by the inclusion of LiDAR data. Predictive mapping of vegetation attributes was accomplished using gradient analysis with nearest neighbor imputation; integrating field plots, multispectral SPOT 5 satellite imagery, and LiDAR data. Vegetation composition was best described by SPOT 5 imagery and LiDAR-derived topography, while vegetation structure was best described by LiDAR-derived vegetation heights. Predictions of species occurrence were most accurate for tree species, moderate for shrub species and vegetation groups, and highly variable for graminoid species. Tree age, which was the most accurately predicted vegetation structure variable, indicates the study area was largely un-forested in 1600, gradually invaded by trees from 1600 to the 1920's, and rapidly invaded from the 1920's to 1980. Predictive mapping of vegetation structure variables such as basal area and stand density were subject to large amounts of error, possibly resulting from scale incompatibilities between vegetation patterns and plot size, and/or heterogeneous FTE landscapes where forest structure does not develop along consistent trajectories with stand age. This study suggests integrating multispectral satellite imagery, LiDAR data, and field plots can accurately predict fine-scale spatial characterizations of species distributions and tree invasion in the FTE. This study also indicates that sample design can influence spatial patterns of model uncertainty, which needs to be considered if predictive mapping of vegetation and sensitive ecosystems is a component of inventory and monitoring programs. In chapter three, I focused on quantifying spatiotemporal patterns of subalpine parkland tree invasion in Jefferson Park over the past five decades in relation multi-scale climatic and biophysical controls. LiDAR data provided previously unavailable fine-scale spatial characterizations of microtopography and vegetation structure. I utilized LiDAR, georeferenced field plots, and tree establishment reconstructions to quantify spatiotemporal patterns of tree invasion in relation to late season snow persistence, landform types, fine-scale topographic variability, distances from potential seed sources, and climate variation within 130 ha of the subalpine parkland landscape of Jefferson Park. Tree occurrence (i.e. tree presence in 2 m plots and grid cells) occurred in 7.75% of study area meadows in 1950 and increased to 34.7% in 2007. Landform types and finer-scale patterns of topography and vegetation structure influenced summer snow depth, which influenced temporal and spatial patterns of tree establishment. Tree invasion rates were higher on debris flow landforms, which had lower summer snow depth than glacial landforms, suggesting potentially rapid treeline responses to disturbance events. Tree invasion rates were strongly associated with reduced annual snow fall on glacial landforms, but not on debris flows. Tree establishment was spatially constrained to micro sites with high topographic positions and close proximity to overstory canopy, site conditions associated with low summer snow depth. Seed source limitations placed an additional species-specific spatial constraint on where trees invaded meadows. Climate and topography had an interactive effect, with trees establishing on higher topographic positions during both high snow/low temperature and low snow/high temperature periods, but had greater than expected establishment on lower topographic positions during low snow/high temperature periods. Within the context of larger landform types, topography and proximity to overstory trees constrained where trees established in the meadows, even during climate periods with higher temperatures and lower snowfall. Results of this study suggest large scale climate-driven models of vegetation change may overestimate treeline movement and meadow invasion, because they do not account for biophysical controls limiting tree establishment at multiple spatial scales. In chapter four, I used field data and analyses from chapter 3 to parameterize a spatially and temporally explicit statistical model of fine-scale tree invasion within 130 ha of the Jefferson Park study area. The model incorporated both the climatic and biophysical controls found in chapter 3 to influence tree invasion. The model was used in two ways: (1) to spatially project patterns of tree invasion from 1950 to 2007 in response to historical climate; and (2) to project future tree invasion of the study area from 2007 to 2064 under six different annual snowfall scenarios. Modeling addressed the following questions: (1) Can fine-scale (2 m pixel size) patterns of historical tree invasion be accurately predicted? (2) How sensitive is future tree invasion (and therefore meadow persistence) to different future snowfall scenarios? (3) Are non-climatic factors such as landforms and biotic interactions associated with different spatial patterns of tree invasion? From 1950 to 2007, simulated historical meadow area declined from 82% to 65% of the study area. Model outputs of historical area, spatial distributions, and spatial clustering of tree invasion generally agreed with independent validation, and suggest biotic interactions due to young tree establishment facilitation are important on glacial landforms but not debris flows. Simulations of future scenarios indicated meadow declined to 36 to 43% of the study area by 2064. Projected meadow area declined with reduced annual snow fall, but not under prolonged high and low snow fall periods. Meadows persisted under all future scenarios in 2064. This model suggests subalpine meadows may significantly decline under climate warming, but will still persist in 2064. Micro sites and recruitment limitation may be equally or more important factors than climate change in influencing subalpine landscape change, suggesting local high-elevation persistence of subalpine meadows under future climate warming. Title: Patterns of tree establishment and vegetation composition in relation to climate and topography of a subalpine meadow landscape, Jefferson Park, Oregon, USA Author: Zald, Harold Samuel James The forest alpine tundra ecotone (FTE, also known as alpine treeline or subalpine parkland), is a conspicuous feature of mountain landscapes throughout the world. Climate change-driven increases in temperature are believed to result in FTE movement and tree invasion of subalpine meadows, which have been documented throughout the Northern Hemisphere across a wide range of geographic locations, climatic regimes, forest types, land use histories, and disturbance regimes. Climate-driven FTE movement may have numerous ecological effects such as: positive temperature feedbacks, increased net primary productivity and carbon storage, and declines of plant populations and species. The magnitude of these ecological effects is highly uncertain, but will be largely determined by the rates and spatial extent of FTE movement and meadow invasion. FTE movement and meadow invasion are often considered at global or regional spatial scales in relation to climate, yet they are fundamentally driven by tree regeneration processes that are influenced by a variety of climatic and biophysical factors at micro site, landscape, and regional scales. Much of the research on the FTE has not taken a landscape approach incorporating multi-scale processes. For example, species distribution models used to project climate change effects on future species distributions and plant biodiversity in mountainous landscapes rely on species distribution data that is often sparse and incomplete across FTE landscapes. This dissertation attempts to overcome many of the limitations in FTE research by taking a landscape approach to develop a greater understanding of past spatiotemporal patterns of tree invasion, current spatial patterns of vegetation composition and structure, and potential future patterns of climate-driven tree invasion in the FTE. The setting for this research is Jefferson Park, a 260 ha subalpine parkland landscape in the Oregon High Cascades, USA. This study uses field plots, remotely sensed imagery, airborne Light Detection and Ranging (LiDAR), and simulation modeling to: 1) predictively map current fine-scale species distributions, vegetation structure, and tree ages; 2) reconstruct patterns of tree invasion over the last fifty years in subalpine meadows in relation to climatic conditions, landforms, microtopography, and seed dispersal limitations; and 3) develop a statistical model that projects future patterns of tree invasion into subalpine meadows under different climate scenarios in Jefferson Park. In chapter two, I generated fine-scale spatially-explicit predictions of current vegetation composition, structure, and tree ages in the Jefferson Park study area. Objectives of this chapter were threefold: 1) to characterize spatial patterns of tree ages, vegetation composition, and vegetation structure in a FTE landscape in the Oregon Cascades using predictive mapping; 2) determine how vegetation composition and structure were associated with gradients of environmental factors derived from multispectral satellite imagery and Light Detection and Ranging (LiDAR) data; and 3) determine if predictive mapping characterizations of tree age, vegetation composition, and vegetation structure were improved by the inclusion of LiDAR data. Predictive mapping of vegetation attributes was accomplished using gradient analysis with nearest neighbor imputation; integrating field plots, multispectral SPOT 5 satellite imagery, and LiDAR data. Vegetation composition was best described by SPOT 5 imagery and LiDAR-derived topography, while vegetation structure was best described by LiDAR-derived vegetation heights. Predictions of species occurrence were most accurate for tree species, moderate for shrub species and vegetation groups, and highly variable for graminoid species. Tree age, which was the most accurately predicted vegetation structure variable, indicates the study area was largely un-forested in 1600, gradually invaded by trees from 1600 to the 1920's, and rapidly invaded from the 1920's to 1980. Predictive mapping of vegetation structure variables such as basal area and stand density were subject to large amounts of error, possibly resulting from scale incompatibilities between vegetation patterns and plot size, and/or heterogeneous FTE landscapes where forest structure does not develop along consistent trajectories with stand age. This study suggests integrating multispectral satellite imagery, LiDAR data, and field plots can accurately predict fine-scale spatial characterizations of species distributions and tree invasion in the FTE. This study also indicates that sample design can influence spatial patterns of model uncertainty, which needs to be considered if predictive mapping of vegetation and sensitive ecosystems is a component of inventory and monitoring programs. In chapter three, I focused on quantifying spatiotemporal patterns of subalpine parkland tree invasion in Jefferson Park over the past five decades in relation multi-scale climatic and biophysical controls. LiDAR data provided previously unavailable fine-scale spatial characterizations of microtopography and vegetation structure. I utilized LiDAR, georeferenced field plots, and tree establishment reconstructions to quantify spatiotemporal patterns of tree invasion in relation to late season snow persistence, landform types, fine-scale topographic variability, distances from potential seed sources, and climate variation within 130 ha of the subalpine parkland landscape of Jefferson Park. Tree occurrence (i.e. tree presence in 2 m plots and grid cells) occurred in 7.75% of study area meadows in 1950 and increased to 34.7% in 2007. Landform types and finer-scale patterns of topography and vegetation structure influenced summer snow depth, which influenced temporal and spatial patterns of tree establishment. Tree invasion rates were higher on debris flow landforms, which had lower summer snow depth than glacial landforms, suggesting potentially rapid treeline responses to disturbance events. Tree invasion rates were strongly associated with reduced annual snow fall on glacial landforms, but not on debris flows. Tree establishment was spatially constrained to micro sites with high topographic positions and close proximity to overstory canopy, site conditions associated with low summer snow depth. Seed source limitations placed an additional species-specific spatial constraint on where trees invaded meadows. Climate and topography had an interactive effect, with trees establishing on higher topographic positions during both high snow/low temperature and low snow/high temperature periods, but had greater than expected establishment on lower topographic positions during low snow/high temperature periods. Within the context of larger landform types, topography and proximity to overstory trees constrained where trees established in the meadows, even during climate periods with higher temperatures and lower snowfall. Results of this study suggest large scale climate-driven models of vegetation change may overestimate treeline movement and meadow invasion, because they do not account for biophysical controls limiting tree establishment at multiple spatial scales. In chapter four, I used field data and analyses from chapter 3 to parameterize a spatially and temporally explicit statistical model of fine-scale tree invasion within 130 ha of the Jefferson Park study area. The model incorporated both the climatic and biophysical controls found in chapter 3 to influence tree invasion. The model was used in two ways: (1) to spatially project patterns of tree invasion from 1950 to 2007 in response to historical climate; and (2) to project future tree invasion of the study area from 2007 to 2064 under six different annual snowfall scenarios. Modeling addressed the following questions: (1) Can fine-scale (2 m pixel size) patterns of historical tree invasion be accurately predicted? (2) How sensitive is future tree invasion (and therefore meadow persistence) to different future snowfall scenarios? (3) Are non-climatic factors such as landforms and biotic interactions associated with different spatial patterns of tree invasion? From 1950 to 2007, simulated historical meadow area declined from 82% to 65% of the study area. Model outputs of historical area, spatial distributions, and spatial clustering of tree invasion generally agreed with independent validation, and suggest biotic interactions due to young tree establishment facilitation are important on glacial landforms but not debris flows. Simulations of future scenarios indicated meadow declined to 36 to 43% of the study area by 2064. Projected meadow area declined with reduced annual snow fall, but not under prolonged high and low snow fall periods. Meadows persisted under all future scenarios in 2064. This model suggests subalpine meadows may significantly decline under climate warming, but will still persist in 2064. Micro sites and recruitment limitation may be equally or more important factors than climate change in influencing subalpine landscape change, suggesting local high-elevation persistence of subalpine meadows under future climate warming. Close

• 272. [Article] Ecophysiological interpretation of oxygen consumption rates and enzymatic activities of deep-sea copepods

  We measured oxygen consumption rates, the activities of citrate synthase (CS) and lactate dehydrogenase (LDH) and protein contents for over 30 species of deep-sea pelagic Copepoda. The lowest oxygen consumption ...

  Citation × Citation Citation Abstract Copy Title: Ecophysiological interpretation of oxygen consumption rates and enzymatic activities of deep-sea copepods Author: Childress, James J., Thuesen, Erik V., Miller, Charles B. We measured oxygen consumption rates, the activities of citrate synthase (CS) and lactate dehydrogenase (LDH) and protein contents for over 30 species of deep-sea pelagic Copepoda. The lowest oxygen consumption rates were measured in Euaugaptilus magnus and the highest rates were measured in Paraeuchaeta tonsa. Weight-specific oxygen consumption rates declined significantly with increasing size of the organism. None of the biochemical parameters were particularly good predictors of metabolic rate. Although linear regressions of LDH activity and protein content against oxygen consumption were statistically significant, R2 values for the relationships were very low. CS activity was not significantly correlated with metabolic rate. The highest CS activities were measured in Pleurontarnrna abdominalis and Calanus pacificus, which were the 2 smallest and shallowest-living species in our investigation. The lowest CS activities were measured in Euaugaptilus antarcticus and Pachyptilus pacificus. Disseta scopularis had the highest LDH activities and Onchocalanus rnagnus had the lowest LDH activities. Over all specimens, there were statistically significant increases in weight-specific activities of CS and LDH as a function of body mass. There was much greater variation in glycolytic potential as indicated by LDH activity than in CS activities. Epipelagic copepods apparently rely less on glycolytic energy sources than do mesopelagic and bathypelagic copepods. Higher LDH activities of larger Copepoda may indicate a greater dependence on LDH for burst swimming in large species compared with smaller ones or a reliance on glycolytic abilities for sustained swimming during vertical migrations. Our enzyme data do not support the suggestion that high LDH activities are adaptations to the very low oxygen concentrations found in the oxygen minimum layer. Enzymatic ratios were used to interpret lifestyle, and deep-sea copepods fell into 3 metabolic groups, 'muscular sinkers', 'thin-muscled floaters' and 'giants', that were related to morphological pattern and behaviour. The effect of hydrostatic pressure on the metabolic rate of an undescribed, but very common, species of Megacalanus was investigated and found to be non-significant. Copepods do not display the depth-related declines in metabolic rates that are found in shrimps, fishes and cephalopods. Title: Ecophysiological interpretation of oxygen consumption rates and enzymatic activities of deep-sea copepods Author: Childress, James J., Thuesen, Erik V., Miller, Charles B. We measured oxygen consumption rates, the activities of citrate synthase (CS) and lactate dehydrogenase (LDH) and protein contents for over 30 species of deep-sea pelagic Copepoda. The lowest oxygen consumption rates were measured in Euaugaptilus magnus and the highest rates were measured in Paraeuchaeta tonsa. Weight-specific oxygen consumption rates declined significantly with increasing size of the organism. None of the biochemical parameters were particularly good predictors of metabolic rate. Although linear regressions of LDH activity and protein content against oxygen consumption were statistically significant, R2 values for the relationships were very low. CS activity was not significantly correlated with metabolic rate. The highest CS activities were measured in Pleurontarnrna abdominalis and Calanus pacificus, which were the 2 smallest and shallowest-living species in our investigation. The lowest CS activities were measured in Euaugaptilus antarcticus and Pachyptilus pacificus. Disseta scopularis had the highest LDH activities and Onchocalanus rnagnus had the lowest LDH activities. Over all specimens, there were statistically significant increases in weight-specific activities of CS and LDH as a function of body mass. There was much greater variation in glycolytic potential as indicated by LDH activity than in CS activities. Epipelagic copepods apparently rely less on glycolytic energy sources than do mesopelagic and bathypelagic copepods. Higher LDH activities of larger Copepoda may indicate a greater dependence on LDH for burst swimming in large species compared with smaller ones or a reliance on glycolytic abilities for sustained swimming during vertical migrations. Our enzyme data do not support the suggestion that high LDH activities are adaptations to the very low oxygen concentrations found in the oxygen minimum layer. Enzymatic ratios were used to interpret lifestyle, and deep-sea copepods fell into 3 metabolic groups, 'muscular sinkers', 'thin-muscled floaters' and 'giants', that were related to morphological pattern and behaviour. The effect of hydrostatic pressure on the metabolic rate of an undescribed, but very common, species of Megacalanus was investigated and found to be non-significant. Copepods do not display the depth-related declines in metabolic rates that are found in shrimps, fishes and cephalopods. Close

• 273. [Article] Production and behavioral interactions of salmonids in an experimental stream

  The behavior of two species of stream salmonids, juvenile coho salmon, Oncorhynchus kisutch (Walbaurn) and cutthroat trout, Salmo clarki clarki Richardson, was studied in terms of the time spent by individual ...

  Citation × Citation Citation Abstract Copy Title: Production and behavioral interactions of salmonids in an experimental stream Author: McIntyre, John D. The behavior of two species of stream salmonids, juvenile coho salmon, Oncorhynchus kisutch (Walbaurn) and cutthroat trout, Salmo clarki clarki Richardson, was studied in terms of the time spent by individual fish in carrying out various activities. Studies were conducted from June 1968, through May 1969, at Berry Creek, a small woodland stream located approximately ten miles north of Corvallis, Oregon. A 1500 foot section of the stream was brought under complete flow control for experimental purposes by a concrete diversion dam and a bypass channel. Water flow into the experimental section was controlled by a large gate valve at the dam. The lower part of the controlled section was divided into experimental sections that were separated by inclined-screen fish traps. The Berry Creek Experimental Stream Laboratory is maintained as a field research station by the Department of Fisheries and Wildlife, Oregon State University. Behavioral observations were made from an observation booth located in an experimental section of Berry Creek. Time-budget analyses derived from observational data were used to evaluate the effects on production of the interaction between individual salmon stocked at different densities in separate stream sections and the interaction among populations comprising both species stocked separately and together at similar densities in different sections of the stream. The growth rates of juvenile coho salmon stocked during June and July 1968, at different biomasses in five of the experimental sections generally declined with increases of salmon biomass. Downstream movement and mean percentages of time spent in agonistic behavior by individual salmon increased with increases in biomass. Higher values of production and mean biomass were generally recorded for an experimental group comprising salmon and trout than for single species groups. Several of the trout on occasion occupied the riffle area of the observation section, whereas, coho salmon remained in the pool throughout the experiment. The use of the riffle area by the trout may have resulted in more efficient utilization of space and food and may explain, in part, the differences in production between the trout-salmon group and the single species group. The growth and location in the stream section of an individual trout or salmon appeared to depend on the fish's position in the integrated social structure. Fish of high social position benefitted in terms of increased amounts of feeding time, decreased activity and decreased agonistic behavior as compared with fish of lower social position. The effect of intraspecific interaction among salmon appeared to be greatest at those stocking densities which resulted in a decline of growth rate from the growth rates that were associated with the highest values of production. This interaction appeared to lead to a compromise between energy expenditures for agonistic behavior and efficient metabolism that resulted in stock densities between two and three grams/meter2 of section area. Title: Production and behavioral interactions of salmonids in an experimental stream Author: McIntyre, John D. The behavior of two species of stream salmonids, juvenile coho salmon, Oncorhynchus kisutch (Walbaurn) and cutthroat trout, Salmo clarki clarki Richardson, was studied in terms of the time spent by individual fish in carrying out various activities. Studies were conducted from June 1968, through May 1969, at Berry Creek, a small woodland stream located approximately ten miles north of Corvallis, Oregon. A 1500 foot section of the stream was brought under complete flow control for experimental purposes by a concrete diversion dam and a bypass channel. Water flow into the experimental section was controlled by a large gate valve at the dam. The lower part of the controlled section was divided into experimental sections that were separated by inclined-screen fish traps. The Berry Creek Experimental Stream Laboratory is maintained as a field research station by the Department of Fisheries and Wildlife, Oregon State University. Behavioral observations were made from an observation booth located in an experimental section of Berry Creek. Time-budget analyses derived from observational data were used to evaluate the effects on production of the interaction between individual salmon stocked at different densities in separate stream sections and the interaction among populations comprising both species stocked separately and together at similar densities in different sections of the stream. The growth rates of juvenile coho salmon stocked during June and July 1968, at different biomasses in five of the experimental sections generally declined with increases of salmon biomass. Downstream movement and mean percentages of time spent in agonistic behavior by individual salmon increased with increases in biomass. Higher values of production and mean biomass were generally recorded for an experimental group comprising salmon and trout than for single species groups. Several of the trout on occasion occupied the riffle area of the observation section, whereas, coho salmon remained in the pool throughout the experiment. The use of the riffle area by the trout may have resulted in more efficient utilization of space and food and may explain, in part, the differences in production between the trout-salmon group and the single species group. The growth and location in the stream section of an individual trout or salmon appeared to depend on the fish's position in the integrated social structure. Fish of high social position benefitted in terms of increased amounts of feeding time, decreased activity and decreased agonistic behavior as compared with fish of lower social position. The effect of intraspecific interaction among salmon appeared to be greatest at those stocking densities which resulted in a decline of growth rate from the growth rates that were associated with the highest values of production. This interaction appeared to lead to a compromise between energy expenditures for agonistic behavior and efficient metabolism that resulted in stock densities between two and three grams/meter2 of section area. Close

• 274. [Article] North or south? Niche separation of endemic red-legged kittiwakes and sympatric black-legged kittiwakes during their non-breeding migrations

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by John Wiley ...

  Citation × Citation Citation Abstract Copy Title: North or south? Niche separation of endemic red-legged kittiwakes and sympatric black-legged kittiwakes during their non-breeding migrations Author: Paredes, Rosana, Irons, David B., Shaffer, Scott A., Orben, Rachael A., Phillips, Richard A., Roby, Daniel D. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by John Wiley & Sons Ltd. and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2699. Title: North or south? Niche separation of endemic red-legged kittiwakes and sympatric black-legged kittiwakes during their non-breeding migrations Author: Paredes, Rosana, Irons, David B., Shaffer, Scott A., Orben, Rachael A., Phillips, Richard A., Roby, Daniel D. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by John Wiley & Sons Ltd. and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2699. Close

• 275. [Article] Multiscale controls on woody riparian vegetation : distribution, diversity, and tree regeneration in four western Oregon watersheds

  I studied riparian forests of four western Oregon watersheds (dry south to wet north) to determine the multiscale controls on woody riparian vegetation. I conducted separate analyses of controls on plant ...

  Citation × Citation Citation Abstract Copy Title: Multiscale controls on woody riparian vegetation : distribution, diversity, and tree regeneration in four western Oregon watersheds Author: Sarr, Daniel Allen I studied riparian forests of four western Oregon watersheds (dry south to wet north) to determine the multiscale controls on woody riparian vegetation. I conducted separate analyses of controls on plant distribution, diversity, and tree regeneration using vegetation and environmental data collected in two related field studies: (1) a multiscale riparian forest inventory; (2) a comparative study of natural forest gaps and interiors. Climatic moisture, indexed by vapor pressure deficit in summer, was the primary correlate of compositional change between riparian sites at all scales analyzed, demonstrating that the majority of riparian species responded directly or indirectly to the landscape scale climate gradient. Additional variation in composition was explained by measures of local topography and disturbance. Climate, as indexed by modeled gross primary productivity (GPP), explained the majority of the variation in multiple regression models of plant diversity that included local and landscape scale variables. As GPP increased from dry to wet climates, understory light and moisture heterogeneity decreased, coincident with declines in alpha, beta, and hectare scale diversity, suggesting that climate controls diversity indirectly through its effects on local conditions. Tree regeneration varied sharply across the climate gradient; seedling frequency and diversity declined and nurse log use increased from the driest to wettest climates. Life history attributes of riparian tree species provided important clues to their regeneration success in different environments. These relationships were explored in a model that linked species shade and drought tolerance with expected variation in the environment caused by climate and disturbance. The model accurately predicted regeneration patterns for four of five functional groups of tree species. The studies in this dissertation provided compelling evidence of regional variation in riparian vegetation composition, diversity, and dynamics, illustrating that these communities are strongly shaped by landscape scale as well as local scale factors. Moreover, climate-related differences among riparian sites were at least as important as the local variation within them in explaining spatial vegetation patterns. These findings argue for a multiscale perspective of riparian forest ecology that closely integrates larger scale controls, such as climate, with local hydrologic processes. Title: Multiscale controls on woody riparian vegetation : distribution, diversity, and tree regeneration in four western Oregon watersheds Author: Sarr, Daniel Allen I studied riparian forests of four western Oregon watersheds (dry south to wet north) to determine the multiscale controls on woody riparian vegetation. I conducted separate analyses of controls on plant distribution, diversity, and tree regeneration using vegetation and environmental data collected in two related field studies: (1) a multiscale riparian forest inventory; (2) a comparative study of natural forest gaps and interiors. Climatic moisture, indexed by vapor pressure deficit in summer, was the primary correlate of compositional change between riparian sites at all scales analyzed, demonstrating that the majority of riparian species responded directly or indirectly to the landscape scale climate gradient. Additional variation in composition was explained by measures of local topography and disturbance. Climate, as indexed by modeled gross primary productivity (GPP), explained the majority of the variation in multiple regression models of plant diversity that included local and landscape scale variables. As GPP increased from dry to wet climates, understory light and moisture heterogeneity decreased, coincident with declines in alpha, beta, and hectare scale diversity, suggesting that climate controls diversity indirectly through its effects on local conditions. Tree regeneration varied sharply across the climate gradient; seedling frequency and diversity declined and nurse log use increased from the driest to wettest climates. Life history attributes of riparian tree species provided important clues to their regeneration success in different environments. These relationships were explored in a model that linked species shade and drought tolerance with expected variation in the environment caused by climate and disturbance. The model accurately predicted regeneration patterns for four of five functional groups of tree species. The studies in this dissertation provided compelling evidence of regional variation in riparian vegetation composition, diversity, and dynamics, illustrating that these communities are strongly shaped by landscape scale as well as local scale factors. Moreover, climate-related differences among riparian sites were at least as important as the local variation within them in explaining spatial vegetation patterns. These findings argue for a multiscale perspective of riparian forest ecology that closely integrates larger scale controls, such as climate, with local hydrologic processes. Close

• 276. [Article] Direct effects and tradeoffs affect vegetative growth and sexual reproduction in an invasive seagrass experiencing different disturbance regimes

  Disturbance has both direct and indirect ramifications that can influence species abundance, distribution, and ultimately the diversity found within a community. As a result, we might expect disturbance ...

  Citation × Citation Citation Abstract Copy Title: Direct effects and tradeoffs affect vegetative growth and sexual reproduction in an invasive seagrass experiencing different disturbance regimes Author: Henderson, Jeremy Scott Disturbance has both direct and indirect ramifications that can influence species abundance, distribution, and ultimately the diversity found within a community. As a result, we might expect disturbance to play a particularly important role in the ability of non-native species to proliferate outside of their native range. In practice, disturbance has been shown to facilitate invasions indirectly by reducing competition with established species, but less is known about the direct effects of disturbance on potential invaders. It is generally assumed that the direct effects of disturbance will be negative, but an exemption to this exists if disturbance results in tradeoffs that favor the allocation of resources to sexual reproduction. To examine this possibility, I considered the direct effects of disturbance and the relative importance of tradeoffs on the invasion dynamics of the dwarf eelgrass, Zostera japonica Aschers. & Graebn., across different sediment disturbance regimes in Yaquina Bay, a North American Pacific coast estuary near Newport, Oregon. The basis of my thesis work is a conceptual model in which tradeoffs in resource allocation between reproduction and vegetative growth in plants results in increased sexual reproduction at intermediate levels of disturbance. My hypothesis is that as disturbance severity increases, vegetative biomass declines until there is complete mortality of the population. Moreover, I suggest that flowering biomass will increase with disturbance to some intermediate level but then decline as disturbance severity increases. This increase in flowering biomass is the result of a tradeoff in which individuals reallocate resources from asexual to sexual reproduction as disturbance increases the mortality risk and reduces the fitness of clonal progeny. To test this model, I conducted two years of monthly monitoring at six sites representing the potential for different sediment disturbance regimes, and also conducted a field experiment at three sites representative of low, moderate, and high sediment disturbance. The observational study showed sediment disturbance was strongly site dependent, with three sites having high sedimentation, one site having moderate sedimentation, and two sites having low sedimentation. In the observational and experimental study, there was a negative linear relationship between the abundance (percent cover and biomass) of Z. japonica and sedimentation among the sites. Vegetative growth showed a negative linear response to increased sedimentation, with approximately 50% mortality seen at sediment deposition rates of 1 cm per month, and nearly 100% mortality seen at rates above 3.5 cm per month. The experiment also showed that flowering and seed production responded unimodally to increased sedimentation, and they were greatest at sediment deposition rates of roughly 0.75 cm per month, and effectively inhibited at rates above 1.5 cm per month. My results suggest that the unimodal response of this non-native eelgrass to disturbance is the result of tradeoffs in resource allocation favoring sexual reproduction and the production of seeds, which is potentially an escape from increasing disturbance severity. This type of tradeoff might result in an increased likelihood that Z. japonica could reach new sites, and, as has been shown in other invasive grasses, could possibly result in an increase in genetic diversity that would allow this species to successfully proliferate across a wider range of environmental conditions. As disturbance regimes change due to anthropogenic causes, it is important to document these tradeoffs and determine whether they could contribute to making communities more susceptible to invasion and thus of greater management concern. Title: Direct effects and tradeoffs affect vegetative growth and sexual reproduction in an invasive seagrass experiencing different disturbance regimes Author: Henderson, Jeremy Scott Disturbance has both direct and indirect ramifications that can influence species abundance, distribution, and ultimately the diversity found within a community. As a result, we might expect disturbance to play a particularly important role in the ability of non-native species to proliferate outside of their native range. In practice, disturbance has been shown to facilitate invasions indirectly by reducing competition with established species, but less is known about the direct effects of disturbance on potential invaders. It is generally assumed that the direct effects of disturbance will be negative, but an exemption to this exists if disturbance results in tradeoffs that favor the allocation of resources to sexual reproduction. To examine this possibility, I considered the direct effects of disturbance and the relative importance of tradeoffs on the invasion dynamics of the dwarf eelgrass, Zostera japonica Aschers. & Graebn., across different sediment disturbance regimes in Yaquina Bay, a North American Pacific coast estuary near Newport, Oregon. The basis of my thesis work is a conceptual model in which tradeoffs in resource allocation between reproduction and vegetative growth in plants results in increased sexual reproduction at intermediate levels of disturbance. My hypothesis is that as disturbance severity increases, vegetative biomass declines until there is complete mortality of the population. Moreover, I suggest that flowering biomass will increase with disturbance to some intermediate level but then decline as disturbance severity increases. This increase in flowering biomass is the result of a tradeoff in which individuals reallocate resources from asexual to sexual reproduction as disturbance increases the mortality risk and reduces the fitness of clonal progeny. To test this model, I conducted two years of monthly monitoring at six sites representing the potential for different sediment disturbance regimes, and also conducted a field experiment at three sites representative of low, moderate, and high sediment disturbance. The observational study showed sediment disturbance was strongly site dependent, with three sites having high sedimentation, one site having moderate sedimentation, and two sites having low sedimentation. In the observational and experimental study, there was a negative linear relationship between the abundance (percent cover and biomass) of Z. japonica and sedimentation among the sites. Vegetative growth showed a negative linear response to increased sedimentation, with approximately 50% mortality seen at sediment deposition rates of 1 cm per month, and nearly 100% mortality seen at rates above 3.5 cm per month. The experiment also showed that flowering and seed production responded unimodally to increased sedimentation, and they were greatest at sediment deposition rates of roughly 0.75 cm per month, and effectively inhibited at rates above 1.5 cm per month. My results suggest that the unimodal response of this non-native eelgrass to disturbance is the result of tradeoffs in resource allocation favoring sexual reproduction and the production of seeds, which is potentially an escape from increasing disturbance severity. This type of tradeoff might result in an increased likelihood that Z. japonica could reach new sites, and, as has been shown in other invasive grasses, could possibly result in an increase in genetic diversity that would allow this species to successfully proliferate across a wider range of environmental conditions. As disturbance regimes change due to anthropogenic causes, it is important to document these tradeoffs and determine whether they could contribute to making communities more susceptible to invasion and thus of greater management concern. Close

• 277. [Article] Benthic biological invasions in two temperate estuaries and their effects on trophic relations of native fish and community stability

  The extent of biological invasions, their role on the feeding of native fishes and their impact on community stability were investigated in Alsea Bay and Yaquina Bay, two estuaries on the central Oregon ...

  Citation × Citation Citation Abstract Copy Title: Benthic biological invasions in two temperate estuaries and their effects on trophic relations of native fish and community stability Author: Castillo, Gonzalo C. The extent of biological invasions, their role on the feeding of native fishes and their impact on community stability were investigated in Alsea Bay and Yaquina Bay, two estuaries on the central Oregon coast, USA. Most nonindigenous species (NIS) introduced in these intermediately invaded estuaries are considered byproducts of culturing introduced Atlantic and Pacific oysters. Secondary potential vectors of NIS in Yaquina Bay are external fouling of ship hulls and ballast water. Native benthic invertebrates and native fishes dominate in density, catch per unit effort (CPUE) and richness in both estuaries. Three of the 11 benthic NIS of invertebrates in Yaquina Bay and one of the eight NIS in Alsea Bay are among the 10 most dominant benthic invertebrate species. The NIS of invertebrates are concentrated in habitats with above average water temperature, salinity, and macrophyte density at high-tide. The CPUE of fishes and decapod crustaceans are associated with above average water temperature, salinity and macrophyte density but are not consistently correlated with invertebrate density in sediments. Biological invasions have caused significant prey shifts in intertidal food webs of Yaquina Bay. Diets of two species of native juvenile flatfishes (Pleuronectes vetulus and Platichthys stellatus) included mainly polychaetes, crustaceans and bivalves and each of these taxa are represented in the diet by native species and NIS in each estuary. Both flatfish species are generalist predators and had no consistently higher selection for either native species or MIS. Prey selection experiments indicated that two native and two introduced amphipod prey (Corophium spp.) are acceptable prey for juvenile English sole. Thus, predator-prey coevolution plays no significant role on prey selection. Interspecific prey selection may depend on prey exposure, water visibility, substratum type, and species diversity of available prey. Modeling of functional-group interactions for the intertidal benthic community of Yaquina Bay suggested reduced community response to invasions or removal of fish predators as indicated by the community tendency to zero overall-feedback. However, the increased risk of stability decline of invaded community models implies that further human-mediated biological invasions should be avoided. Title: Benthic biological invasions in two temperate estuaries and their effects on trophic relations of native fish and community stability Author: Castillo, Gonzalo C. The extent of biological invasions, their role on the feeding of native fishes and their impact on community stability were investigated in Alsea Bay and Yaquina Bay, two estuaries on the central Oregon coast, USA. Most nonindigenous species (NIS) introduced in these intermediately invaded estuaries are considered byproducts of culturing introduced Atlantic and Pacific oysters. Secondary potential vectors of NIS in Yaquina Bay are external fouling of ship hulls and ballast water. Native benthic invertebrates and native fishes dominate in density, catch per unit effort (CPUE) and richness in both estuaries. Three of the 11 benthic NIS of invertebrates in Yaquina Bay and one of the eight NIS in Alsea Bay are among the 10 most dominant benthic invertebrate species. The NIS of invertebrates are concentrated in habitats with above average water temperature, salinity, and macrophyte density at high-tide. The CPUE of fishes and decapod crustaceans are associated with above average water temperature, salinity and macrophyte density but are not consistently correlated with invertebrate density in sediments. Biological invasions have caused significant prey shifts in intertidal food webs of Yaquina Bay. Diets of two species of native juvenile flatfishes (Pleuronectes vetulus and Platichthys stellatus) included mainly polychaetes, crustaceans and bivalves and each of these taxa are represented in the diet by native species and NIS in each estuary. Both flatfish species are generalist predators and had no consistently higher selection for either native species or MIS. Prey selection experiments indicated that two native and two introduced amphipod prey (Corophium spp.) are acceptable prey for juvenile English sole. Thus, predator-prey coevolution plays no significant role on prey selection. Interspecific prey selection may depend on prey exposure, water visibility, substratum type, and species diversity of available prey. Modeling of functional-group interactions for the intertidal benthic community of Yaquina Bay suggested reduced community response to invasions or removal of fish predators as indicated by the community tendency to zero overall-feedback. However, the increased risk of stability decline of invaded community models implies that further human-mediated biological invasions should be avoided. Close

• 278. [Article] The development and maintenance of stream community structure and organization

  The goal of this study was to better understand stream communities through a perspective that might make their structure, organization, and development more understandable. This goal was approached through ...

  Citation × Citation Citation Abstract Copy Title: The development and maintenance of stream community structure and organization Author: Wevers, Mary Jo The goal of this study was to better understand stream communities through a perspective that might make their structure, organization, and development more understandable. This goal was approached through the following objectives: 1. To determine the assemblages of stream organisms and define subsystems within a stream community. 2. To explain the structure and organization of the subsystems by means of habitat, life history, trophic, and environmental relationships. 3. To explain how the community as a whole and the subsystems develop and persist through immigration, colonization, and subsystem interactions. An organismic perspective of stream communities is utilized in addressing the development and maintenance of stream community structure and organization. The conceptual framework of Warren et al. (1979) provides a perspective which emphasizes the importance of species interrelationships and interdspendencies within a community. This perspective is organismic in that it takes the view that communities exhibit organismic properties. It is hot organismic in the Clementsian sense that communities are metaphorical organisms. A hierarchical scheme of stream community subsystems is presented. Habitat organization is used to define 2° and 3° subsystems. Trophic organization defines 4° subsystems, and other aspects of life history organization define 5° subsystems. Two model streams were employed in this study of stream community structure and organization. The 2° subsystems, shallow riffles, deep riffles, and pools, were sampled for one year following initiation of the experiment. Community organization and development are described in terms of biomass and taxa numbers. Macroinvertebrate biomass and taxa number tended to be greater in riffle habitats than in pool habitats. Biomass in 2° and 3° subsystems generally in creased with time. Taxa number increased until early winter when it declined slightly. Changes in biomass and taxa number in 4° trophic subsystems and 5° species population subsystems are also discussed. Species pool, life history, and colonization determination of stream community structure and organization are addressed. The potential capacity of the stream community resides in the species pool. The pattern of kinds and abundances of species in space and time is partially determined by the life history patterns of the species. Colonizing ability of species populations affects the development and organization of stream communities. Downstream drift and aerial sources of colonists contributed to the colonization of the experimental streams in this study, although the relative importance of the two sources changed through time. Stream habitat and environment play important roles in stream community development and organization by providing shelter or cover and supplying needed resources. As the environment provided by a stream system impinges upon the stream community, there must be concordance between the community and its environment. The climatic parameters light and temperature and autochthonous and allochthonous inputs such as litter fall are discussed as environmental parameters that impinge on the model stream communities. Title: The development and maintenance of stream community structure and organization Author: Wevers, Mary Jo The goal of this study was to better understand stream communities through a perspective that might make their structure, organization, and development more understandable. This goal was approached through the following objectives: 1. To determine the assemblages of stream organisms and define subsystems within a stream community. 2. To explain the structure and organization of the subsystems by means of habitat, life history, trophic, and environmental relationships. 3. To explain how the community as a whole and the subsystems develop and persist through immigration, colonization, and subsystem interactions. An organismic perspective of stream communities is utilized in addressing the development and maintenance of stream community structure and organization. The conceptual framework of Warren et al. (1979) provides a perspective which emphasizes the importance of species interrelationships and interdspendencies within a community. This perspective is organismic in that it takes the view that communities exhibit organismic properties. It is hot organismic in the Clementsian sense that communities are metaphorical organisms. A hierarchical scheme of stream community subsystems is presented. Habitat organization is used to define 2° and 3° subsystems. Trophic organization defines 4° subsystems, and other aspects of life history organization define 5° subsystems. Two model streams were employed in this study of stream community structure and organization. The 2° subsystems, shallow riffles, deep riffles, and pools, were sampled for one year following initiation of the experiment. Community organization and development are described in terms of biomass and taxa numbers. Macroinvertebrate biomass and taxa number tended to be greater in riffle habitats than in pool habitats. Biomass in 2° and 3° subsystems generally in creased with time. Taxa number increased until early winter when it declined slightly. Changes in biomass and taxa number in 4° trophic subsystems and 5° species population subsystems are also discussed. Species pool, life history, and colonization determination of stream community structure and organization are addressed. The potential capacity of the stream community resides in the species pool. The pattern of kinds and abundances of species in space and time is partially determined by the life history patterns of the species. Colonizing ability of species populations affects the development and organization of stream communities. Downstream drift and aerial sources of colonists contributed to the colonization of the experimental streams in this study, although the relative importance of the two sources changed through time. Stream habitat and environment play important roles in stream community development and organization by providing shelter or cover and supplying needed resources. As the environment provided by a stream system impinges upon the stream community, there must be concordance between the community and its environment. The climatic parameters light and temperature and autochthonous and allochthonous inputs such as litter fall are discussed as environmental parameters that impinge on the model stream communities. Close

• 279. [Article] Impacts of fuel reduction thinning treatments on oak and chaparral communities of southwestern Oregon

  In response to concerns about excessive stand densities and high-severity wildfires, land managers in the western United States are carrying out extensive programs of fuel reduction thinning. How will ...

  Citation × Citation Citation Abstract Copy Title: Impacts of fuel reduction thinning treatments on oak and chaparral communities of southwestern Oregon Author: Perchemlides, Keith A. In response to concerns about excessive stand densities and high-severity wildfires, land managers in the western United States are carrying out extensive programs of fuel reduction thinning. How will these sudden reductions in canopy cover and associated changes in habitat affect native and exotic herbaceous vegetation and canopy species regeneration? Where thinning treatments have both fuel-reduction and ecological restoration objectives, to what extent are these goals compatible? I compared vegetation and abiotic site characteristics between thinned and unthinned chaparral and oak communities of southwestern Oregon where landscape-scale fuel-reduction thinning is occurring. I sampled paired thinned and unthinned transects, established four to seven years post-treatment. I also contrasted impacts of manual vs. mechanical thinning methods, and examined differences in herbaceous composition and responses among canopy community types. Thinning treatments had significant impacts on site conditions and herbaceous cover and composition. Herbaceous cover increased on thinned sites, but species richness and diversity did not change. The strongest differences were decreases in perennial species cover and a near doubling of cover by annual species on thinned sites. While overall proportions of natives and exotics did not change, there were changes at the functional group level. Exotic annual grass cover and the proportion of herbaceous community cover composed of these species increased, while cover by native perennial grasses and regeneration of oaks did not. Cover and proportion of native annual forbs increased more than all other functional groups, while exotic annual forbs and native perennial forbs declined. Herbaceous communities at thinned sites had an early-post-disturbance type of composition dominated by native annual forbs and exotic annual grasses four to seven years after treatments. Re-establishment of native shrubs was sparse in thinned areas, likely due to a lack of fire-stimulated germination. Sites that varied in canopy species composition also supported different herbaceous communities in the absence of thinning, and appeared to respond differently to fuel reduction treatments. Manual and mechanical treatment impacts on abiotic site conditions differed, but their overall impacts on vegetation across canopy community types did not. Treatment type differences in herbaceous responses to thinning were found within some canopy vegetation groups, but sample sizes were small. Results suggest that fuel-reduction thinning may have some unintended negative impacts on oak and chaparral communities of southwestern Oregon. Although treatments have altered fuel conditions, thinning does not appear to have achieved restoration goals and may have substantially changed the composition and regeneration of native perennial communities including canopy species. Continued research and expanded monitoring that account for differences between canopy vegetation communities and treatment types are needed to inform adaptive management in these ecosystems. Title: Impacts of fuel reduction thinning treatments on oak and chaparral communities of southwestern Oregon Author: Perchemlides, Keith A. In response to concerns about excessive stand densities and high-severity wildfires, land managers in the western United States are carrying out extensive programs of fuel reduction thinning. How will these sudden reductions in canopy cover and associated changes in habitat affect native and exotic herbaceous vegetation and canopy species regeneration? Where thinning treatments have both fuel-reduction and ecological restoration objectives, to what extent are these goals compatible? I compared vegetation and abiotic site characteristics between thinned and unthinned chaparral and oak communities of southwestern Oregon where landscape-scale fuel-reduction thinning is occurring. I sampled paired thinned and unthinned transects, established four to seven years post-treatment. I also contrasted impacts of manual vs. mechanical thinning methods, and examined differences in herbaceous composition and responses among canopy community types. Thinning treatments had significant impacts on site conditions and herbaceous cover and composition. Herbaceous cover increased on thinned sites, but species richness and diversity did not change. The strongest differences were decreases in perennial species cover and a near doubling of cover by annual species on thinned sites. While overall proportions of natives and exotics did not change, there were changes at the functional group level. Exotic annual grass cover and the proportion of herbaceous community cover composed of these species increased, while cover by native perennial grasses and regeneration of oaks did not. Cover and proportion of native annual forbs increased more than all other functional groups, while exotic annual forbs and native perennial forbs declined. Herbaceous communities at thinned sites had an early-post-disturbance type of composition dominated by native annual forbs and exotic annual grasses four to seven years after treatments. Re-establishment of native shrubs was sparse in thinned areas, likely due to a lack of fire-stimulated germination. Sites that varied in canopy species composition also supported different herbaceous communities in the absence of thinning, and appeared to respond differently to fuel reduction treatments. Manual and mechanical treatment impacts on abiotic site conditions differed, but their overall impacts on vegetation across canopy community types did not. Treatment type differences in herbaceous responses to thinning were found within some canopy vegetation groups, but sample sizes were small. Results suggest that fuel-reduction thinning may have some unintended negative impacts on oak and chaparral communities of southwestern Oregon. Although treatments have altered fuel conditions, thinning does not appear to have achieved restoration goals and may have substantially changed the composition and regeneration of native perennial communities including canopy species. Continued research and expanded monitoring that account for differences between canopy vegetation communities and treatment types are needed to inform adaptive management in these ecosystems. Close

• 280. [Article] Greater Sage-Grouse Umbrella CCAA for Wyoming Ranch Management: a Candidate Conservation Agreement with Assurances for Greater Sage-Grouse Centrocercus urophasianus

  Prior to settlement in the 19th century, greater sage-grouse (Centrocercus urophasianus; hereafter referred to as ‘sage-grouse’) inhabited 13 western States and three Canadian provinces, and their potential ...

  Citation × Citation Citation Abstract Copy Title: Greater Sage-Grouse Umbrella CCAA for Wyoming Ranch Management: a Candidate Conservation Agreement with Assurances for Greater Sage-Grouse Centrocercus urophasianus Author: Wyoming Association of Conservation Districts, Wyoming Game and Fish Department, Natural Resources Conservation Service, Wyoming Bureau of Land Management, Wyoming Department of Agriculture, U. S. Fish and Wildlife Service, U. S. Forest Service, Wyoming Governor’s Office Prior to settlement in the 19th century, greater sage-grouse (Centrocercus urophasianus; hereafter referred to as ‘sage-grouse’) inhabited 13 western States and three Canadian provinces, and their potential habitat covered over 1,200,483 square kilometers (km) (463,509 square miles (mi)). Sage-grouse have declined across their range due to a variety of causes and now occur in 11 States and two Canadian provinces. Many factors played a role in reducing sage-grouse from a once abundant, broadly distributed species, but the primary threat is loss of habitat due to increased surface disturbance and general fragmentation of the landscape. These concerns were identified in the 2005 Endangered Species Act (ESA) listing finding and remain so, but with more intensity and on a larger scale today. In the 2010 listing finding, additional concerns were identified as threats, including an increase in the use of sagebrush habitat for renewable energy such as wind power, and the spread of West Nile Virus (WNv). In anticipation of a final listing decision by the U.S. Fish and Wildlife Service (FWS), the Wyoming Governor’s Office (WGO) requested assistance from the FWS in developing a sage-grouse strategy for ranch management activities that could offer private landowners assurances their livestock operations could continue in the event the species was listed under the ESA. The WGO and FWS in conjunction with the Bureau of Land Management (BLM), the Natural Resources Conservation Service (NRCS), the U.S Forest Service (USFS), the Wyoming Department of Agriculture (WDA), Wyoming Game and Fish Department (WGFD), and the Wyoming Association of Conservation Districts have developed this umbrella Candidate Conservation Agreement with Assurances (CCAA). A CCAA is a voluntary agreement whereby private landowners agree to manage their lands to remove or reduce threats to species at risk of being listed under the ESA. In return for managing their lands to the benefit of species at risk, these landowners receive assurances against additional regulatory requirements should that species ever be listed under the ESA. Under a CCAA, the FWS will issue enrolled landowners Enhancement of Survival (EOS) permits pursuant to section 10(a)(1)(A) of the ESA for a period of 20 years. Since the agreement is voluntary, the landowner can end it at any point, although in doing so they would give up any assurances, and the EOS permit would terminate. FWS will issue EOS permits to participating landowners contingent on development of a site-specific individual sage-grouse conservation plan consistent with this umbrella CCAA. This umbrella CCAA includes:  A general description of responsibilities of all involved participating agencies and landowners, and the area covered under the umbrella CCAA;  Background, status and general threats to sage-grouse, and conservation measures needed to remove or reduce those identified threats;  Expected benefits of prescribed actions in relation to the five threat factors the FWS is required to evaluate when considering a species for listing; and  Level of take likely to occur from activities on enrolled lands, assurances, monitoring, and annual reporting. Title: Greater Sage-Grouse Umbrella CCAA for Wyoming Ranch Management: a Candidate Conservation Agreement with Assurances for Greater Sage-Grouse Centrocercus urophasianus Author: Wyoming Association of Conservation Districts, Wyoming Game and Fish Department, Natural Resources Conservation Service, Wyoming Bureau of Land Management, Wyoming Department of Agriculture, U. S. Fish and Wildlife Service, U. S. Forest Service, Wyoming Governor’s Office Prior to settlement in the 19th century, greater sage-grouse (Centrocercus urophasianus; hereafter referred to as ‘sage-grouse’) inhabited 13 western States and three Canadian provinces, and their potential habitat covered over 1,200,483 square kilometers (km) (463,509 square miles (mi)). Sage-grouse have declined across their range due to a variety of causes and now occur in 11 States and two Canadian provinces. Many factors played a role in reducing sage-grouse from a once abundant, broadly distributed species, but the primary threat is loss of habitat due to increased surface disturbance and general fragmentation of the landscape. These concerns were identified in the 2005 Endangered Species Act (ESA) listing finding and remain so, but with more intensity and on a larger scale today. In the 2010 listing finding, additional concerns were identified as threats, including an increase in the use of sagebrush habitat for renewable energy such as wind power, and the spread of West Nile Virus (WNv). In anticipation of a final listing decision by the U.S. Fish and Wildlife Service (FWS), the Wyoming Governor’s Office (WGO) requested assistance from the FWS in developing a sage-grouse strategy for ranch management activities that could offer private landowners assurances their livestock operations could continue in the event the species was listed under the ESA. The WGO and FWS in conjunction with the Bureau of Land Management (BLM), the Natural Resources Conservation Service (NRCS), the U.S Forest Service (USFS), the Wyoming Department of Agriculture (WDA), Wyoming Game and Fish Department (WGFD), and the Wyoming Association of Conservation Districts have developed this umbrella Candidate Conservation Agreement with Assurances (CCAA). A CCAA is a voluntary agreement whereby private landowners agree to manage their lands to remove or reduce threats to species at risk of being listed under the ESA. In return for managing their lands to the benefit of species at risk, these landowners receive assurances against additional regulatory requirements should that species ever be listed under the ESA. Under a CCAA, the FWS will issue enrolled landowners Enhancement of Survival (EOS) permits pursuant to section 10(a)(1)(A) of the ESA for a period of 20 years. Since the agreement is voluntary, the landowner can end it at any point, although in doing so they would give up any assurances, and the EOS permit would terminate. FWS will issue EOS permits to participating landowners contingent on development of a site-specific individual sage-grouse conservation plan consistent with this umbrella CCAA. This umbrella CCAA includes:  A general description of responsibilities of all involved participating agencies and landowners, and the area covered under the umbrella CCAA;  Background, status and general threats to sage-grouse, and conservation measures needed to remove or reduce those identified threats;  Expected benefits of prescribed actions in relation to the five threat factors the FWS is required to evaluate when considering a species for listing; and  Level of take likely to occur from activities on enrolled lands, assurances, monitoring, and annual reporting. Close

• 281. [Article] Indirect effects of ultraviolet-B radiation on larval amphibians as mediated by food quality and trophic interactions

  Ultraviolet-B radiation (UVB) is an abiotic stressor in both terrestrial and aquatic systems. The stratospheric ozone layer, depleted due to anthropogenic activities and the cause of elevated UVB at earth's ...

  Citation × Citation Citation Abstract Copy Title: Indirect effects of ultraviolet-B radiation on larval amphibians as mediated by food quality and trophic interactions Author: Scheessele, Erin A. Ultraviolet-B radiation (UVB) is an abiotic stressor in both terrestrial and aquatic systems. The stratospheric ozone layer, depleted due to anthropogenic activities and the cause of elevated UVB at earth's surface over the last four decades, is predicted to recover by 2065. However, UVB levels in aquatic systems may continue to increase as UVB penetration of the water column increases due to acidification, warming and changing precipitation patterns. Subsequent to the 1974 prediction and 1985 discovery of the "ozone hole", much work was done investigating the direct effects of UVB on organisms. Much less work has been done examining the role of UVB as a stressor in the context of communities and food webs. Amphibian population declines are one facet of the current crisis of loss in biodiversity, and some population declines may be linked to exposure to UVB radiation. When some amphibian embryos, larvae and juveniles are exposed to UVB, they can experience increased mortality, slowed growth and development, increased malformations, as well as increased susceptibility to other biotic and abiotic stressors including pathogens and competitors. My research moves beyond direct effects of UVB on amphibians and asks what indirect effects may be transmitted via trophic interactions when examined in the context of aquatic communities and food webs. I first focused on how a UVB-exposed natural diet affects early larval growth and development in two anuran species, Pseudacris regilla and Rana cascadae. Growth and development of R. cascadae did not differ between a UVB-exposed and UVB-shielded diet, but P. regilla grew less on the UVB-exposed diet. Previous work has shown that P. regilla is less vulnerable when exposed directly to UVB. My research emphasizes that the main effect of UVB on an organism may not be a direct effect. I next investigated whether P. regilla and Bufo boreas would distinguish between diets when offered both a UVB-exposed and UVB-shielded diet consisting of natural algal assemblage reared in the field. Bufo boreas demonstrated no selectivity, while P. regilla spent more time near the UVB-shielded algae. An ability to discern UVB-stressed food may allow larvae to avoid indirect UVB effects. Analyses in these two experiments indicate that there were no direct effects of UVB at the producer trophic level. Bioassays, however, did indicate a UVB-induced change in the producer trophic level with implications for growth of consumers. My findings imply that effects of UVB on adjacent trophic levels may not be predicted from analysis at one level. In the final study, I investigated the direct and indirect effects of ambient UVB on salamander larvae and a tritrophic freshwater community. Both UVB and predation were forces that structured the community, and there is potential for a direct effect of UVB on the salamanders to mitigate their role as predator. The field of UVB-research must continue to mature in its investigations of effects, both direct and indirect, in evermore real and complex contexts. Title: Indirect effects of ultraviolet-B radiation on larval amphibians as mediated by food quality and trophic interactions Author: Scheessele, Erin A. Ultraviolet-B radiation (UVB) is an abiotic stressor in both terrestrial and aquatic systems. The stratospheric ozone layer, depleted due to anthropogenic activities and the cause of elevated UVB at earth's surface over the last four decades, is predicted to recover by 2065. However, UVB levels in aquatic systems may continue to increase as UVB penetration of the water column increases due to acidification, warming and changing precipitation patterns. Subsequent to the 1974 prediction and 1985 discovery of the "ozone hole", much work was done investigating the direct effects of UVB on organisms. Much less work has been done examining the role of UVB as a stressor in the context of communities and food webs. Amphibian population declines are one facet of the current crisis of loss in biodiversity, and some population declines may be linked to exposure to UVB radiation. When some amphibian embryos, larvae and juveniles are exposed to UVB, they can experience increased mortality, slowed growth and development, increased malformations, as well as increased susceptibility to other biotic and abiotic stressors including pathogens and competitors. My research moves beyond direct effects of UVB on amphibians and asks what indirect effects may be transmitted via trophic interactions when examined in the context of aquatic communities and food webs. I first focused on how a UVB-exposed natural diet affects early larval growth and development in two anuran species, Pseudacris regilla and Rana cascadae. Growth and development of R. cascadae did not differ between a UVB-exposed and UVB-shielded diet, but P. regilla grew less on the UVB-exposed diet. Previous work has shown that P. regilla is less vulnerable when exposed directly to UVB. My research emphasizes that the main effect of UVB on an organism may not be a direct effect. I next investigated whether P. regilla and Bufo boreas would distinguish between diets when offered both a UVB-exposed and UVB-shielded diet consisting of natural algal assemblage reared in the field. Bufo boreas demonstrated no selectivity, while P. regilla spent more time near the UVB-shielded algae. An ability to discern UVB-stressed food may allow larvae to avoid indirect UVB effects. Analyses in these two experiments indicate that there were no direct effects of UVB at the producer trophic level. Bioassays, however, did indicate a UVB-induced change in the producer trophic level with implications for growth of consumers. My findings imply that effects of UVB on adjacent trophic levels may not be predicted from analysis at one level. In the final study, I investigated the direct and indirect effects of ambient UVB on salamander larvae and a tritrophic freshwater community. Both UVB and predation were forces that structured the community, and there is potential for a direct effect of UVB on the salamanders to mitigate their role as predator. The field of UVB-research must continue to mature in its investigations of effects, both direct and indirect, in evermore real and complex contexts. Close

• 282. [Article] Local weather, regional climate, and population dynamics of northern spotted owls in Washington and Oregon

  Since the early 1990s, declines in northern spotted owl (Strix occidentalis caurina) populations have been documented through extensive field surveys and range-wide demographic analyses. Although loss ...

  Citation × Citation Citation Abstract Copy Title: Local weather, regional climate, and population dynamics of northern spotted owls in Washington and Oregon Author: Glenn, Elizabeth M. Since the early 1990s, declines in northern spotted owl (Strix occidentalis caurina) populations have been documented through extensive field surveys and range-wide demographic analyses. Although loss of late-successional forest has been credited as the primary cause for spotted owl population declines, environmental variation has also been shown to influence vital rates of many avian species, including spotted owls. Weather and climate are often the most important sources of environmental variation for many species, and population processes can be affected by both large-scale climate fluctuations as well as by local variation in weather. My objectives were to identify associations between weather and climate and demographic rates of northern spotted owls using data collected from marked spotted owls on 6 long-term study areas in Washington and Oregon. I used an information-theoretic approach to rank statistical models representing a priori hypotheses regarding effects of weather and climate on annual survival, reproduction, and realized rate of population change. Annual survival was negatively associated with drier-than-normal conditions on a regional scale at 3 areas, but was also associated with local weather conditions at 3 areas. Number of young fledged per pair per year was negatively associated with cold, wet nesting seasons at 3 areas, although larger-scale weather patterns were associated with reproduction as well. Climate accounted for moderate to high amounts of temporal variation for both survival and reproduction, but little of the spatial variation. My analyses of realized rates of population change indicated continued declines in populations at the 6 study areas, with climate accounting for 3-85% of the temporal variation in lambda. My results suggest that spotted owl populations may face additional challenges if climate in the Pacific Northwest follows the current predictions of year-round warming with warmer, wetter winters and hotter, drier summers in the 21st century. Title: Local weather, regional climate, and population dynamics of northern spotted owls in Washington and Oregon Author: Glenn, Elizabeth M. Since the early 1990s, declines in northern spotted owl (Strix occidentalis caurina) populations have been documented through extensive field surveys and range-wide demographic analyses. Although loss of late-successional forest has been credited as the primary cause for spotted owl population declines, environmental variation has also been shown to influence vital rates of many avian species, including spotted owls. Weather and climate are often the most important sources of environmental variation for many species, and population processes can be affected by both large-scale climate fluctuations as well as by local variation in weather. My objectives were to identify associations between weather and climate and demographic rates of northern spotted owls using data collected from marked spotted owls on 6 long-term study areas in Washington and Oregon. I used an information-theoretic approach to rank statistical models representing a priori hypotheses regarding effects of weather and climate on annual survival, reproduction, and realized rate of population change. Annual survival was negatively associated with drier-than-normal conditions on a regional scale at 3 areas, but was also associated with local weather conditions at 3 areas. Number of young fledged per pair per year was negatively associated with cold, wet nesting seasons at 3 areas, although larger-scale weather patterns were associated with reproduction as well. Climate accounted for moderate to high amounts of temporal variation for both survival and reproduction, but little of the spatial variation. My analyses of realized rates of population change indicated continued declines in populations at the 6 study areas, with climate accounting for 3-85% of the temporal variation in lambda. My results suggest that spotted owl populations may face additional challenges if climate in the Pacific Northwest follows the current predictions of year-round warming with warmer, wetter winters and hotter, drier summers in the 21st century. Close

• 283. [Article] The effect of plant moisture stress on the physiology and establishment of planted Douglas-fir and ponderosa pine seedlings

  The role of moisture stress in seedling physiology and establishment was studied in both the field environment and laboratory experiments. Plant moisture stress was measured using the pressure chamber ...

  Citation × Citation Citation Abstract Copy Title: The effect of plant moisture stress on the physiology and establishment of planted Douglas-fir and ponderosa pine seedlings Author: Cleary, Brian D. The role of moisture stress in seedling physiology and establishment was studied in both the field environment and laboratory experiments. Plant moisture stress was measured using the pressure chamber technique. This technique was modified and tested using a fascicle of pine needles as a sample, an improvement which allows the technique to be used repeatedly in the same seedling and is equivalent to measurements on twigs. Using the pressure chamber, ponderosa pine and Douglas-fir seedlings which were planted in early spring were monitored for both seasonal and diurnal changes in moisture stress throughout the first growing season until the fall rains recharged the soil. Differences in seedling growth and-survival during the three years of measurement were related to moisture stress levels experienced by the seedlings. Needle length of ponderosa pine was a good indicator of seasonal moisture stress levels. The photosynthetic response of seedlings to different levels of moisture stress with light at saturation levels was evaluated in a series of laboratory experiments using an infra-red gas analyzer in a closed system. The relative net photosynthetic response of ponderosa pine and Douglas-fir to moisture stress showed distinct differences between the two species. Douglas-fir showed an almost linear decline in photosynthesis from a maximum when plant moisture stress (PMS) was less than 8 atm to 20% of maximum at 22 atm. In contrast, ponderosa pine showed little decline in photosynthesis until about 15 atm PMS. There the decline, probably associated with stomatal closure, occurred abruptly with no measurable photosynthesis occurring after 20 atm PMS. Seedlings which had experienced 50 atm PMS showed reduced photosynthetic rates even two weeks after the moisture stress was relieved. PMS levels of 80 atm were lethal to the needle tissue of both species. There was more variability in response within the population of pine seedlings compared to the population of Douglas-fir. The photosynthetic response of ponderosa pine seedlings to temperature and moisture stress varying independently was also evaluated. The resulting response surface showed the proportion of a given response attributable to temperature and the proportion attributable to moisture stress. A partial differential equation is suggested for use in examining how the environmental factors contribute to a given plant response. An equation to describe how the plant occupies a predominant regulatory position in the soil-plant-atmosphere continuum is proposed. Title: The effect of plant moisture stress on the physiology and establishment of planted Douglas-fir and ponderosa pine seedlings Author: Cleary, Brian D. The role of moisture stress in seedling physiology and establishment was studied in both the field environment and laboratory experiments. Plant moisture stress was measured using the pressure chamber technique. This technique was modified and tested using a fascicle of pine needles as a sample, an improvement which allows the technique to be used repeatedly in the same seedling and is equivalent to measurements on twigs. Using the pressure chamber, ponderosa pine and Douglas-fir seedlings which were planted in early spring were monitored for both seasonal and diurnal changes in moisture stress throughout the first growing season until the fall rains recharged the soil. Differences in seedling growth and-survival during the three years of measurement were related to moisture stress levels experienced by the seedlings. Needle length of ponderosa pine was a good indicator of seasonal moisture stress levels. The photosynthetic response of seedlings to different levels of moisture stress with light at saturation levels was evaluated in a series of laboratory experiments using an infra-red gas analyzer in a closed system. The relative net photosynthetic response of ponderosa pine and Douglas-fir to moisture stress showed distinct differences between the two species. Douglas-fir showed an almost linear decline in photosynthesis from a maximum when plant moisture stress (PMS) was less than 8 atm to 20% of maximum at 22 atm. In contrast, ponderosa pine showed little decline in photosynthesis until about 15 atm PMS. There the decline, probably associated with stomatal closure, occurred abruptly with no measurable photosynthesis occurring after 20 atm PMS. Seedlings which had experienced 50 atm PMS showed reduced photosynthetic rates even two weeks after the moisture stress was relieved. PMS levels of 80 atm were lethal to the needle tissue of both species. There was more variability in response within the population of pine seedlings compared to the population of Douglas-fir. The photosynthetic response of ponderosa pine seedlings to temperature and moisture stress varying independently was also evaluated. The resulting response surface showed the proportion of a given response attributable to temperature and the proportion attributable to moisture stress. A partial differential equation is suggested for use in examining how the environmental factors contribute to a given plant response. An equation to describe how the plant occupies a predominant regulatory position in the soil-plant-atmosphere continuum is proposed. Close

• 284. [Article] Breeding season habitat use and response to management activities by greater sage-grouse on Sheldon National Wildlife Refuge, Nevada

  Greater Sage-Grouse (Centrocercus urophasianus) have experienced declines throughout their range over the last 50 years. Long-term declines in sage-grouse abundance in Nevada and Oregon have been attributed ...

  Citation × Citation Citation Abstract Copy Title: Breeding season habitat use and response to management activities by greater sage-grouse on Sheldon National Wildlife Refuge, Nevada Author: Davis, Dawn M. Greater Sage-Grouse (Centrocercus urophasianus) have experienced declines throughout their range over the last 50 years. Long-term declines in sage-grouse abundance in Nevada and Oregon have been attributed to reduced productivity. From 1995-1997, sage-grouse production on Sheldon National Wildlife Refuge (SNWR), Nevada was greater compared to Hart Mountain National Antelope Refuge (HMNAR), Oregon. Specific causes for the difference were unknown. Thus, the objectives were to: 1) Determine sage-grouse breeding season habitat use (especially with regard to wildfire) on SNWR; 2) Evaluate reproductive parameters to discern differences between SNWR and HMNAR; 3) Compare habitat components which may relate to differences in sage-grouse reproductive success on SNWR and HMNAR; and 4) Establish hematological and serum chemistry reference ranges for sage-grouse hens to assess physiological condition. Cover type was important in selection of nest sites at SNWR; however, nest cover did not affect nesting success and nest-site selection was not related to experience. Vegetative characteristics at successful nest sites were similar to unsuccessful nests but nest sites had greater amounts of tall residual grass (≥18 cm) and medium height shrub cover (40-80 cm) than at random sites. Broods used areas with greater forb cover than random sites, indicating use was influenced by availability of forbs. Plant communities in wildfire and associated control sites did not differ appreciably in species composition. Although burning had little stimulatory effect on total forb cover 10-12 years post-burn, alteration of the sagebrush community did not limit sage-grouse use for successful nesting and brood-rearing. Fire did not negatively impact arthropod abundance. Differences in habitat use and sage-grouse productivity between SNWR and HMNAR may be related to differences in forb availability. Forb cover was greater at HMNAR than at SNWR for all cover types. Correspondingly, home range size for sage-grouse broods was greater on SNWR than at HMNAR. Nutrient analysis of forbs indicated higher crude protein, potassium, and magnesium levels at HMNAR than at SNWR; however, these nutrients are not likely to be deficient in most sage-grouse diets. Thus sagebrush-steppe communities supporting these forbs likely meet the dietary nutritional requirements of sage-grouse. Although blood calcium and uric acid levels were greater in sage-grouse hens on HMNAR than at SNWR, differences were attributed to capture date. Furthermore, physiological condition did not affect a hen's ability to nest successfully, nor was condition related to a hen's ability to recruit chicks to 1 August. Causes of sage-grouse decline are varied, but ultimately they are habitat based. Comparisons of reproductive parameters and habitat evaluations, combined with sage-grouse physiology data, may provide insight into habitat differences between study areas not previously recognized. Land management practices (e.g., prescribed fire) which recast the balance of native herbaceous species in degraded big sagebrush communities, may be necessary in the restoration of sagebrush-steppe ecosystems, and ultimately, the recovery of sage-grouse populations. Title: Breeding season habitat use and response to management activities by greater sage-grouse on Sheldon National Wildlife Refuge, Nevada Author: Davis, Dawn M. Greater Sage-Grouse (Centrocercus urophasianus) have experienced declines throughout their range over the last 50 years. Long-term declines in sage-grouse abundance in Nevada and Oregon have been attributed to reduced productivity. From 1995-1997, sage-grouse production on Sheldon National Wildlife Refuge (SNWR), Nevada was greater compared to Hart Mountain National Antelope Refuge (HMNAR), Oregon. Specific causes for the difference were unknown. Thus, the objectives were to: 1) Determine sage-grouse breeding season habitat use (especially with regard to wildfire) on SNWR; 2) Evaluate reproductive parameters to discern differences between SNWR and HMNAR; 3) Compare habitat components which may relate to differences in sage-grouse reproductive success on SNWR and HMNAR; and 4) Establish hematological and serum chemistry reference ranges for sage-grouse hens to assess physiological condition. Cover type was important in selection of nest sites at SNWR; however, nest cover did not affect nesting success and nest-site selection was not related to experience. Vegetative characteristics at successful nest sites were similar to unsuccessful nests but nest sites had greater amounts of tall residual grass (≥18 cm) and medium height shrub cover (40-80 cm) than at random sites. Broods used areas with greater forb cover than random sites, indicating use was influenced by availability of forbs. Plant communities in wildfire and associated control sites did not differ appreciably in species composition. Although burning had little stimulatory effect on total forb cover 10-12 years post-burn, alteration of the sagebrush community did not limit sage-grouse use for successful nesting and brood-rearing. Fire did not negatively impact arthropod abundance. Differences in habitat use and sage-grouse productivity between SNWR and HMNAR may be related to differences in forb availability. Forb cover was greater at HMNAR than at SNWR for all cover types. Correspondingly, home range size for sage-grouse broods was greater on SNWR than at HMNAR. Nutrient analysis of forbs indicated higher crude protein, potassium, and magnesium levels at HMNAR than at SNWR; however, these nutrients are not likely to be deficient in most sage-grouse diets. Thus sagebrush-steppe communities supporting these forbs likely meet the dietary nutritional requirements of sage-grouse. Although blood calcium and uric acid levels were greater in sage-grouse hens on HMNAR than at SNWR, differences were attributed to capture date. Furthermore, physiological condition did not affect a hen's ability to nest successfully, nor was condition related to a hen's ability to recruit chicks to 1 August. Causes of sage-grouse decline are varied, but ultimately they are habitat based. Comparisons of reproductive parameters and habitat evaluations, combined with sage-grouse physiology data, may provide insight into habitat differences between study areas not previously recognized. Land management practices (e.g., prescribed fire) which recast the balance of native herbaceous species in degraded big sagebrush communities, may be necessary in the restoration of sagebrush-steppe ecosystems, and ultimately, the recovery of sage-grouse populations. Close

• 285. [Article] Reproductive success and foraging ecology of the rusty blackbird on the Copper River Delta, Alaska

  The Rusty Blackbird (Euphagus carolinus) has suffered significant population declines across its entire geographic range and the mechanisms associated with this decline are poorly understood. Although ...

  Citation × Citation Citation Abstract Copy Title: Reproductive success and foraging ecology of the rusty blackbird on the Copper River Delta, Alaska Author: Loomis, David (David Michael) The Rusty Blackbird (Euphagus carolinus) has suffered significant population declines across its entire geographic range and the mechanisms associated with this decline are poorly understood. Although much of the Rusty Blackbird breeding habitat in Alaska has remained relatively unaltered by anthropogenic activities, this species continues to decline by an estimated 5% annually. As part of a collaborative effort to obtain data on the reproductive ecology, breeding success, and habitat requirements of this species throughout their range, a total of 42 nests were found and monitored for two consecutive breeding seasons (2009 – 2010) on the Copper River Delta in south-central Alaska. Nests were monitored every 2-4 days to calculate nest success, survival rates, clutch initiation date, clutch size, egg viability, and fledging rates. In 2010, chick provisioning rates, chick diet, and aquatic invertebrate availability in Rusty Blackbird foraging habitats were also investigated. Mean clutch size ranged from 5 to 7 eggs both years (2009 = 5.41 ± 0.15, 2010 = 5.67 ± 0.13). Daily nest survival rate averaged over both seasons was high, at 0.9913 ± 0.0043 (95% CI 0.9772-0.9967) and most eggs were viable (N = 31 nests), with 0.8922 ± 0.0275 of eggs over both seasons hatching. Approximately 85% of clutches were initiated within a two week period for both years of the study. Clutch-initiation date (CID) was significantly different between years (p-value < 0.0001), with mean CID of 10 May (x̅ = 10.476 ± 0.95) in 2010 and May 18 (x̅ = 18.421 ± 1.13) in 2009. The mean provisioning rate was 0.84 (± 0.06; 95% CI: 0.72 to 0.95) invertebrate food items per chick per hour. Large odonate nymphs, specifically dragonflies, made up the bulk (97.2%) of the observed food items provisioned to chicks. Weekly pond sampling revealed four taxonomic groups of invertebrates that were of the size observed provisioned to chicks (Coleoptera, Hirudinea, Zygoptera, Anisoptera) and Anisoptera were among the rarest collected (16.2%) of this size. Although the least common large invertebrate collected, Anisoptera nymphs were present in all weekly samples. The week with the most abundant Anisoptera collection coincided with the week of peak hatching during 2010 of the study. Thus, availability of dragonfly nymphs appear to be important to Rusty Blackbird reproductive success on the Copper River Delta and may have contributed to the high nest success observed in this study. Title: Reproductive success and foraging ecology of the rusty blackbird on the Copper River Delta, Alaska Author: Loomis, David (David Michael) The Rusty Blackbird (Euphagus carolinus) has suffered significant population declines across its entire geographic range and the mechanisms associated with this decline are poorly understood. Although much of the Rusty Blackbird breeding habitat in Alaska has remained relatively unaltered by anthropogenic activities, this species continues to decline by an estimated 5% annually. As part of a collaborative effort to obtain data on the reproductive ecology, breeding success, and habitat requirements of this species throughout their range, a total of 42 nests were found and monitored for two consecutive breeding seasons (2009 – 2010) on the Copper River Delta in south-central Alaska. Nests were monitored every 2-4 days to calculate nest success, survival rates, clutch initiation date, clutch size, egg viability, and fledging rates. In 2010, chick provisioning rates, chick diet, and aquatic invertebrate availability in Rusty Blackbird foraging habitats were also investigated. Mean clutch size ranged from 5 to 7 eggs both years (2009 = 5.41 ± 0.15, 2010 = 5.67 ± 0.13). Daily nest survival rate averaged over both seasons was high, at 0.9913 ± 0.0043 (95% CI 0.9772-0.9967) and most eggs were viable (N = 31 nests), with 0.8922 ± 0.0275 of eggs over both seasons hatching. Approximately 85% of clutches were initiated within a two week period for both years of the study. Clutch-initiation date (CID) was significantly different between years (p-value < 0.0001), with mean CID of 10 May (x̅ = 10.476 ± 0.95) in 2010 and May 18 (x̅ = 18.421 ± 1.13) in 2009. The mean provisioning rate was 0.84 (± 0.06; 95% CI: 0.72 to 0.95) invertebrate food items per chick per hour. Large odonate nymphs, specifically dragonflies, made up the bulk (97.2%) of the observed food items provisioned to chicks. Weekly pond sampling revealed four taxonomic groups of invertebrates that were of the size observed provisioned to chicks (Coleoptera, Hirudinea, Zygoptera, Anisoptera) and Anisoptera were among the rarest collected (16.2%) of this size. Although the least common large invertebrate collected, Anisoptera nymphs were present in all weekly samples. The week with the most abundant Anisoptera collection coincided with the week of peak hatching during 2010 of the study. Thus, availability of dragonfly nymphs appear to be important to Rusty Blackbird reproductive success on the Copper River Delta and may have contributed to the high nest success observed in this study. Close

• 286. [Article] Performance of Progeny From Steelhead and Rainbow Trout Crosses - Final Report 2009

  Abstract -- Many salmonids exhibit partial migration: the phenomenon of populations partitioned into migratory and non-migratory individuals (Jonsson and Jonsson 1993). Oncorhynchus mykiss exhibit a complex ...

  Citation × Citation Citation Abstract Copy Title: Performance of Progeny From Steelhead and Rainbow Trout Crosses - Final Report 2009 Abstract -- Many salmonids exhibit partial migration: the phenomenon of populations partitioned into migratory and non-migratory individuals (Jonsson and Jonsson 1993). Oncorhynchus mykiss exhibit a complex of life-history strategies ranging from residency in small headwater streams to anadromy involving migrations of hundreds of kilometers. In the Grande Ronde River basin of northeast Oregon, both resident and anadromous life-history forms coexist, and thus populations found there likely exhibit partial migration. Partial migration may have important consequences for anadromous species listed under the Endangered Species Act (ESA). The recent decline of summer steelhead (Oncorhynchus mykiss) populations in the lower Snake River has prompted their listing under the ESA. Declines in steelhead are potentially due to elevated mortality rates associated with anadromous migrations. If resident and anadromous life-history characteristics result from a phenotypically plastic trait (i.e. a genetic trait that is highly variable due to influences from environmental factors), then elevated mortality associated with the anadromous type may be shifting the populations towards residency. Further, although the anadromous expression of the trait may be declining, the trait would not necessarily be lost. Identification of the plasticity of these traits would then be important for the management of these populations. We investigated life history traits of O. mykiss with studies in both the hatchery and natural environment. We anticipated that these complimentary approaches would allow us to evaluate the relationship between the two life-history forms. They should further allow us to explore the feasibility of using hatcheries to produce anadromous progeny from resident parents if the number of anadromous life-history forms becomes severely depressed. The overall goal of this study was to determine the plasticity of life history forms, specifically the ability of resident adults to produce anadromous progeny. Lower Snake River Compensation Plan (LSRCP) ODFW- Eastern Oregon Fish Research (EOFR) Title: Performance of Progeny From Steelhead and Rainbow Trout Crosses - Final Report 2009 Abstract -- Many salmonids exhibit partial migration: the phenomenon of populations partitioned into migratory and non-migratory individuals (Jonsson and Jonsson 1993). Oncorhynchus mykiss exhibit a complex of life-history strategies ranging from residency in small headwater streams to anadromy involving migrations of hundreds of kilometers. In the Grande Ronde River basin of northeast Oregon, both resident and anadromous life-history forms coexist, and thus populations found there likely exhibit partial migration. Partial migration may have important consequences for anadromous species listed under the Endangered Species Act (ESA). The recent decline of summer steelhead (Oncorhynchus mykiss) populations in the lower Snake River has prompted their listing under the ESA. Declines in steelhead are potentially due to elevated mortality rates associated with anadromous migrations. If resident and anadromous life-history characteristics result from a phenotypically plastic trait (i.e. a genetic trait that is highly variable due to influences from environmental factors), then elevated mortality associated with the anadromous type may be shifting the populations towards residency. Further, although the anadromous expression of the trait may be declining, the trait would not necessarily be lost. Identification of the plasticity of these traits would then be important for the management of these populations. We investigated life history traits of O. mykiss with studies in both the hatchery and natural environment. We anticipated that these complimentary approaches would allow us to evaluate the relationship between the two life-history forms. They should further allow us to explore the feasibility of using hatcheries to produce anadromous progeny from resident parents if the number of anadromous life-history forms becomes severely depressed. The overall goal of this study was to determine the plasticity of life history forms, specifically the ability of resident adults to produce anadromous progeny. Lower Snake River Compensation Plan (LSRCP) ODFW- Eastern Oregon Fish Research (EOFR) Close

• 287. [Article] Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire

  Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as ...

  Citation × Citation Citation Abstract Copy Title: Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire Author: Foster, Lee (Lee Jacob) Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as well as for determining the appropriate conservation actions needed to maintain those populations. Greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern in western North America. The distribution of the species has been reduced by approximately half since European settlement, with concurrent and continuing population declines across its occupied range. The primary threats to the species are habitat alteration and loss, caused by multiple factors. In the western portion of its distribution, increasing wildfire activity is a primary cause of habitat loss and degradation. Single wildfires in this area may now reach extremely large sizes (>100,000 ha), and wildfires have been linked to local population declines. However, no published studies, to date, have examined the immediate effects of large-scale wildfire on sage-grouse habitat selection and demographic rates, using modern telemetry methods. I studied the habitat selection patterns, nest success, and survival of adult, and yearling female sage-grouse, captured within or near the Holloway fire, using state-of-the-art GPS-PTT telemetry methods. The Holloway fire burned ~187,000 ha of highly productive sage-grouse habitat in August, 2012. My study began during the first spring post-fire (March, 2013), and continued through February, 2015. I monitored seasonal habitat use patterns, and site-fidelity of sage-grouse, and modeled third-order seasonal resource selection, using mixed effects resource selection functions, in relation to characteristics of the post-fire habitat mosaic, terrain, mesic habitat availability, and herbaceous vegetation regeneration. I described sage-grouse nesting habitat use, nesting effort, and modeled daily nest survival in relation to temporal patterns, patch scale vegetation, biological factors, and landscape-scale habitat composition. I modeled adult and yearling female sage-grouse survival in relation to temporal patterns, biological factors, and landscape-scale habitat composition. Female sage-grouse primarily exhibited a three range seasonal movement pattern, with differentiation between breeding-nesting-early brood-rearing habitat (mean use dates: 8 Mar - 12 Jun), late brood-rearing-summer habitat (13 Jun - 20 Oct), and winter habitat (21 Oct - 7 Mar). However there was variation in seasonal range behavior among individuals. Sage-grouse exhibited considerable fidelity to all seasonal ranges, for individuals which survived >1 yr, mean distance between seasonal range centroids of the same type were 1.80 km, 1.65 km, and 3.96 km, for breeding ranges, summer ranges, and winter ranges, respectively. Within seasonal ranges, sage-grouse exhibited third-order resource selection patterns similar to those observed for populations in undisturbed habitats. Sage-grouse, at the population level, selected for level terrain throughout the year. During the breeding season sage-grouse selected for areas with increased amounts of intact sagebrush land-cover within a 1-km² area around used locations, areas of increased NDVI values within a 6.25-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and mid-level elevations. During summer, sage-grouse, at the population level, selected for an areas with an intermediate density of burned-intact habitat edge within a 1 km² area, areas of increased NDVI values within a 6.25-km² area, intermediate distances to mesic habitat, and high elevations. During winter, sage-grouse, at the population level, selected for increased amounts of intact sagebrush land-cover within a 0.089-km² area, areas with decreased variation in NDVI within a 0.089-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and intermediate elevations. There was considerable variation in third-order resource selection patterns among individuals during all seasons. Sage-grouse nest success was consistently low during the study (2013: 19.3%, 2014: 30.1%), and nest initiation rates were average to high (2013: 1st nest initiation = 90.5%, 2nd nest initiation = 23.1%; 2014: 1st nest initiation = 100%, 2nd nest initiation = 57.1%). Daily nest survival rates were influenced by an interaction between year and nesting attempt, and by forb cover within 5 m of the nest. Nest survival over the incubation period was consistently low for 1st and 2nd nests during 2013, and for 1st nests during 2014 (range: 0.131 - 0.212), but increased to 0.744 for 2nd nests during 2014. Forb cover within 5 m of the nest had a positive effect on daily nest survival rates, with a 1% increase in forb cover increasing the probability of a nest surviving a given day by 1.02 times. We did not detect strong direct effects of habitat or biological characteristics on survival of adult and yearling female sage-grouse. Rather, survival varied by month with lowest survival occurring in April and August of each year, and highest survival occurring during the winter. While patterns of monthly survival were similar between years, there was a strong, negative additive effect on survival which extended from the beginning of the study (March, 2013), through the end of the first post fire growing season (July, 2013). Although monthly survival increased following the end of the 1st post-fire growing season, yearly survival over both the 1st and 2nd biological years post-fire was low (March 2013 - February 2014: 24.0%; March 2014 - February 2015: 37.9%). These results indicate that female greater-sage grouse do not respond to wildfire related habitat disturbance through emigration, and rather continue to attempt to exist and reproduce in habitats disturbed by wildfire during the immediate years following a fire. While, due to site-fidelity, sage-grouse are not able to leave wildfire affected seasonal ranges, within those seasonal ranges they still attempt to utilize habitat components which most closely match their life-history requirements. However, this behavior appears to have an acute fitness cost to individuals, with reduced nesting success and survival of individuals utilizing fire-affected habitats during the first two years post-fire. This reduction in demographic rates likely explains observed sage-grouse population declines following wildfire, and indicates that these population declines are not the result of sage-grouse emigration away from fire-affected leks, but rather a true decline in the number of individual sage-grouse on the landscape following large-scale wildfire. Title: Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire Author: Foster, Lee (Lee Jacob) Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as well as for determining the appropriate conservation actions needed to maintain those populations. Greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern in western North America. The distribution of the species has been reduced by approximately half since European settlement, with concurrent and continuing population declines across its occupied range. The primary threats to the species are habitat alteration and loss, caused by multiple factors. In the western portion of its distribution, increasing wildfire activity is a primary cause of habitat loss and degradation. Single wildfires in this area may now reach extremely large sizes (>100,000 ha), and wildfires have been linked to local population declines. However, no published studies, to date, have examined the immediate effects of large-scale wildfire on sage-grouse habitat selection and demographic rates, using modern telemetry methods. I studied the habitat selection patterns, nest success, and survival of adult, and yearling female sage-grouse, captured within or near the Holloway fire, using state-of-the-art GPS-PTT telemetry methods. The Holloway fire burned ~187,000 ha of highly productive sage-grouse habitat in August, 2012. My study began during the first spring post-fire (March, 2013), and continued through February, 2015. I monitored seasonal habitat use patterns, and site-fidelity of sage-grouse, and modeled third-order seasonal resource selection, using mixed effects resource selection functions, in relation to characteristics of the post-fire habitat mosaic, terrain, mesic habitat availability, and herbaceous vegetation regeneration. I described sage-grouse nesting habitat use, nesting effort, and modeled daily nest survival in relation to temporal patterns, patch scale vegetation, biological factors, and landscape-scale habitat composition. I modeled adult and yearling female sage-grouse survival in relation to temporal patterns, biological factors, and landscape-scale habitat composition. Female sage-grouse primarily exhibited a three range seasonal movement pattern, with differentiation between breeding-nesting-early brood-rearing habitat (mean use dates: 8 Mar - 12 Jun), late brood-rearing-summer habitat (13 Jun - 20 Oct), and winter habitat (21 Oct - 7 Mar). However there was variation in seasonal range behavior among individuals. Sage-grouse exhibited considerable fidelity to all seasonal ranges, for individuals which survived >1 yr, mean distance between seasonal range centroids of the same type were 1.80 km, 1.65 km, and 3.96 km, for breeding ranges, summer ranges, and winter ranges, respectively. Within seasonal ranges, sage-grouse exhibited third-order resource selection patterns similar to those observed for populations in undisturbed habitats. Sage-grouse, at the population level, selected for level terrain throughout the year. During the breeding season sage-grouse selected for areas with increased amounts of intact sagebrush land-cover within a 1-km² area around used locations, areas of increased NDVI values within a 6.25-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and mid-level elevations. During summer, sage-grouse, at the population level, selected for an areas with an intermediate density of burned-intact habitat edge within a 1 km² area, areas of increased NDVI values within a 6.25-km² area, intermediate distances to mesic habitat, and high elevations. During winter, sage-grouse, at the population level, selected for increased amounts of intact sagebrush land-cover within a 0.089-km² area, areas with decreased variation in NDVI within a 0.089-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and intermediate elevations. There was considerable variation in third-order resource selection patterns among individuals during all seasons. Sage-grouse nest success was consistently low during the study (2013: 19.3%, 2014: 30.1%), and nest initiation rates were average to high (2013: 1st nest initiation = 90.5%, 2nd nest initiation = 23.1%; 2014: 1st nest initiation = 100%, 2nd nest initiation = 57.1%). Daily nest survival rates were influenced by an interaction between year and nesting attempt, and by forb cover within 5 m of the nest. Nest survival over the incubation period was consistently low for 1st and 2nd nests during 2013, and for 1st nests during 2014 (range: 0.131 - 0.212), but increased to 0.744 for 2nd nests during 2014. Forb cover within 5 m of the nest had a positive effect on daily nest survival rates, with a 1% increase in forb cover increasing the probability of a nest surviving a given day by 1.02 times. We did not detect strong direct effects of habitat or biological characteristics on survival of adult and yearling female sage-grouse. Rather, survival varied by month with lowest survival occurring in April and August of each year, and highest survival occurring during the winter. While patterns of monthly survival were similar between years, there was a strong, negative additive effect on survival which extended from the beginning of the study (March, 2013), through the end of the first post fire growing season (July, 2013). Although monthly survival increased following the end of the 1st post-fire growing season, yearly survival over both the 1st and 2nd biological years post-fire was low (March 2013 - February 2014: 24.0%; March 2014 - February 2015: 37.9%). These results indicate that female greater-sage grouse do not respond to wildfire related habitat disturbance through emigration, and rather continue to attempt to exist and reproduce in habitats disturbed by wildfire during the immediate years following a fire. While, due to site-fidelity, sage-grouse are not able to leave wildfire affected seasonal ranges, within those seasonal ranges they still attempt to utilize habitat components which most closely match their life-history requirements. However, this behavior appears to have an acute fitness cost to individuals, with reduced nesting success and survival of individuals utilizing fire-affected habitats during the first two years post-fire. This reduction in demographic rates likely explains observed sage-grouse population declines following wildfire, and indicates that these population declines are not the result of sage-grouse emigration away from fire-affected leks, but rather a true decline in the number of individual sage-grouse on the landscape following large-scale wildfire. Close

• 288. [Article] Associations Between Crested Wheatgrass and Native Vegetation in Southeastern Oregon : An Investigation of Co-establishment, Environment, Seeding History, and Livestock management

  Crested wheatgrass (Agropyron cristatum [L] Gaertm), an introduced bunchgrass, has been seeded on over 5 million hectares of degraded rangeland in western North America because it establishes more readily ...

  Citation × Citation Citation Abstract Copy Title: Associations Between Crested Wheatgrass and Native Vegetation in Southeastern Oregon : An Investigation of Co-establishment, Environment, Seeding History, and Livestock management Author: Nafus, Aleta M. Crested wheatgrass (Agropyron cristatum [L] Gaertm), an introduced bunchgrass, has been seeded on over 5 million hectares of degraded rangeland in western North America because it establishes more readily than native bunchgrasses. Because crested wheatgrass stands are associated with native species displacement and low biological diversity, there is substantial interest in re-establishing native species within seeded stands. However, efforts to reintroduce native grasses into crested wheatgrass stands have been largely unsuccessful, and little is known about the long-term dynamics of crested wheatgrass/native species mixes. This project was composed of two studies evaluating interactions between crested wheatgrass and associated native vegetation. In the first study, I examined the abundance of crested wheatgrass and seven native sagebrush steppe bunchgrasses which had been planted concurrently 13 years prior at equal densities. Thirteen years after planting, crested wheatgrass was the dominant bunchgrass with a ten-fold increase from its original planted density. Of the seven native bunchgrasses, four species: Idaho fescue (Festuca idahoensis Elmer); Thurber's needlegrass (Achnatherum thurberianum (Piper) Barkworth); basin wildrye (Leymus cinereus (Scribn. & Merr.) A. Löve) and Sandberg bluegrass (Poa secunda J. Presl) maintained their low planting density while three species: bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) A. Löve), needle-and-thread (Hesperostipa comata (Trin. & Rupr.) Barkworth), and squirreltail (Elymus elymoides (Raf.) Swezey), declined in density over the 13-year period. Results suggested that densities of native bunchgrasses planted concurrently with crested wheatgrass were unlikely to increase and that some species only persisted at low levels. However, the continued persistence of native bunchgrasses, even at low densities, suggests that co-planting of some native bunchgrasses may be a viable way of avoiding crested wheatgrass monocultures when this species is necessary for rehabilitation or restoration. In the second study, I sought to identify environmental, historic and livestock management factors associated with native vegetation occasionally found in seeded crested wheatgrass stands. Basal cover, density, species richness and diversity were measured in 2012 and 2013 on 121 sites previously seeded to crested wheatgrass in southeastern Oregon. Plant community composition of crested wheatgrass stands was variable; some of the seedings were monocultures of crested wheatgrass while others contained diverse native species. Functional group variability explained by environmental factors ranged from 0% of annual grass density to 56% of large native perennial bunchgrass density. Soil texture was significant and appeared to be an important environmental characteristic explaining functional group cover and density 10-50 years post seeding. Native vegetation was, for all functional groups, positively correlated with soils lower in sand content. Precipitation in the year following seeding of crested wheatgrass has long-term effects on plant community dynamics, especially for Wyoming big sagebrush. Higher precipitation in the year following crested wheatgrass seeding was associated with decreased shrubs, likely because crested wheatgrass seedlings were more successful and therefore sagebrush seedlings experience greater competition. Moderate grazing was associated with reduced crested wheatgrass monoculture characteristics relative to ungrazed sites. However, within spring grazed and spring-summer grazed sites, there was a negative relationship between increased stocking rate and native species cover and abundance. I speculate that was largely the effect of higher stocking rates being allotted to more productive crested wheatgrass seedings. Overall, my research suggested that pre-seeding treatment/disturbance on a site appears to have long-term implications for plant community dynamics. However, functional groups varied in response to different pre-seeding treatments. Results support the notion that crested wheatgrass is very competitive with native bunchgrasses in particular; and that introducing natives into crested wheatgrass stands may require high levels of disturbance and may be most successful in more finely-textured soils. The results of this study also suggest that management actions, both at the time of seeding and after seeding, can influence plant community characteristics. Title: Associations Between Crested Wheatgrass and Native Vegetation in Southeastern Oregon : An Investigation of Co-establishment, Environment, Seeding History, and Livestock management Author: Nafus, Aleta M. Crested wheatgrass (Agropyron cristatum [L] Gaertm), an introduced bunchgrass, has been seeded on over 5 million hectares of degraded rangeland in western North America because it establishes more readily than native bunchgrasses. Because crested wheatgrass stands are associated with native species displacement and low biological diversity, there is substantial interest in re-establishing native species within seeded stands. However, efforts to reintroduce native grasses into crested wheatgrass stands have been largely unsuccessful, and little is known about the long-term dynamics of crested wheatgrass/native species mixes. This project was composed of two studies evaluating interactions between crested wheatgrass and associated native vegetation. In the first study, I examined the abundance of crested wheatgrass and seven native sagebrush steppe bunchgrasses which had been planted concurrently 13 years prior at equal densities. Thirteen years after planting, crested wheatgrass was the dominant bunchgrass with a ten-fold increase from its original planted density. Of the seven native bunchgrasses, four species: Idaho fescue (Festuca idahoensis Elmer); Thurber's needlegrass (Achnatherum thurberianum (Piper) Barkworth); basin wildrye (Leymus cinereus (Scribn. & Merr.) A. Löve) and Sandberg bluegrass (Poa secunda J. Presl) maintained their low planting density while three species: bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) A. Löve), needle-and-thread (Hesperostipa comata (Trin. & Rupr.) Barkworth), and squirreltail (Elymus elymoides (Raf.) Swezey), declined in density over the 13-year period. Results suggested that densities of native bunchgrasses planted concurrently with crested wheatgrass were unlikely to increase and that some species only persisted at low levels. However, the continued persistence of native bunchgrasses, even at low densities, suggests that co-planting of some native bunchgrasses may be a viable way of avoiding crested wheatgrass monocultures when this species is necessary for rehabilitation or restoration. In the second study, I sought to identify environmental, historic and livestock management factors associated with native vegetation occasionally found in seeded crested wheatgrass stands. Basal cover, density, species richness and diversity were measured in 2012 and 2013 on 121 sites previously seeded to crested wheatgrass in southeastern Oregon. Plant community composition of crested wheatgrass stands was variable; some of the seedings were monocultures of crested wheatgrass while others contained diverse native species. Functional group variability explained by environmental factors ranged from 0% of annual grass density to 56% of large native perennial bunchgrass density. Soil texture was significant and appeared to be an important environmental characteristic explaining functional group cover and density 10-50 years post seeding. Native vegetation was, for all functional groups, positively correlated with soils lower in sand content. Precipitation in the year following seeding of crested wheatgrass has long-term effects on plant community dynamics, especially for Wyoming big sagebrush. Higher precipitation in the year following crested wheatgrass seeding was associated with decreased shrubs, likely because crested wheatgrass seedlings were more successful and therefore sagebrush seedlings experience greater competition. Moderate grazing was associated with reduced crested wheatgrass monoculture characteristics relative to ungrazed sites. However, within spring grazed and spring-summer grazed sites, there was a negative relationship between increased stocking rate and native species cover and abundance. I speculate that was largely the effect of higher stocking rates being allotted to more productive crested wheatgrass seedings. Overall, my research suggested that pre-seeding treatment/disturbance on a site appears to have long-term implications for plant community dynamics. However, functional groups varied in response to different pre-seeding treatments. Results support the notion that crested wheatgrass is very competitive with native bunchgrasses in particular; and that introducing natives into crested wheatgrass stands may require high levels of disturbance and may be most successful in more finely-textured soils. The results of this study also suggest that management actions, both at the time of seeding and after seeding, can influence plant community characteristics. Close

• 289. [Article] Foraging ecology and reproductive energetics of the Kittlitz's murrelet (Brachyramphus brevirostris) in Southeast Alaska

  The Kittlitz's murrelet (Brachyramphus brevirostris) is a species of conservation concern over the entirety of its known range, which spans coastal Alaska and northeastern Russia. Concerns about the status ...

  Citation × Citation Citation Abstract Copy Title: Foraging ecology and reproductive energetics of the Kittlitz's murrelet (Brachyramphus brevirostris) in Southeast Alaska Author: Hatch, Nick R. The Kittlitz's murrelet (Brachyramphus brevirostris) is a species of conservation concern over the entirety of its known range, which spans coastal Alaska and northeastern Russia. Concerns about the status of the species have been raised due to evidence of population declines in key breeding areas, low reproductive output, and perceived threats to adult survival. A general lack of information related to vital rates and natural history for this species has hampered efforts to address potential threats and drivers of population decline. This thesis addresses the hypothesis that foraging conditions and nutritional stress may be related to the observed low reproductive output and apparent population declines. I used stable isotope analysis of Kittlitz's murrelet feathers and blood to assess foraging habits during four separate periods across the annual cycle. I also used stable isotope signatures (δ¹⁵N and δ¹³C) in feathers from museum specimens collected in southeastern Alaska during 1907–1984 to investigate potential long-term trends in food habits and foraging ecology. I found that δ¹⁵N progressively increased by 5‰ between the vernal pre-alternate molt and the autumnal pre-basic molt, equivalent to an increase of 1.5 trophic levels for assimilated prey, whereas seasonal patterns in δ¹³C suggest shifts in foraging habitat between breeding and non-breeding periods. These results indicate that the pre-breeding diet was comprised primarily of low trophic level prey from offshore habitats, such as macrozooplankton and/or larval fish. During the summer breeding season, Kittlitz's murrelets gradually switched to consuming higher proportions of planktivorous fish from nearshore habitats. By the post-breeding period, during the pre-basic molt, the diet was comprised almost exclusively of higher trophic level prey, presumably forage fish, from offshore habitats. Based on stable isotope signatures of murrelet feathers from museum specimens, these seasonal patterns were evident during the past century (1907-2009). δ¹³C in feathers grown during pre- and post-breeding (pre-alternate and pre-basic molts, respectively) became significantly more depleted over the last century, however, suggesting either a gradual change in diet and/or foraging habitat or a long-term shift in the isotopic composition of prey. I investigated potential energy constraints on reproduction in Kittlitz's murrelets by constructing a bioenergetics model to estimate energy budgets for breeding adult Kittlitz's murrelets under different scenarios of prey energy content and commuting distance between foraging areas and nest sites. Estimated field metabolic rate (FMR) of breeding Kittlitz's murrelets during the chick-rearing period exceeded the hypothetical maximum sustainable working capacity (MSWC; 4 times basal metabolic rate [BMR]) under empirically derived scenarios of prey energy content and commuting distance. This suggests that, under conditions of low energy content in available prey and/or long commuting distances to inland nest sites, Kittlitz's murrelets would be required to expend energy at a rate that, if maintained over an extended period, could be detrimental to subsequent adult survival and overall fitness. In addition, energy expenditure rates at the high end of the estimated range may exceed the rate at which food energy can be assimilated by adult murrelets. Metabolism of fat reserves, as indicated by mass loss during the breeding season, may be a partial, although limited, solution to periods of high energy demand for breeding adults. This thesis research is the first to indicate that Kittlitz's murrelets rely on distinctly different prey resources during different periods of the annual cycle. The previously unappreciated seasonal complexity of Kittlitz's murrelet foraging ecology offers a new perspective on potential factors limiting survival and reproduction in this species of conservation concern. In addition, my research suggests an adaptive explanation for the low breeding frequency and low reproductive output of Kittlitz's murrelets that is related to the exceptionally high energy expenditure rates required to raise young at nest sites as much as 70 km inland from the coast and up to 2,500 m above sea level. Because of their high level of reproductive effort, Kittlitz's murrelets may be more dependent on the high availability of high-lipid marine prey than other seabirds. Title: Foraging ecology and reproductive energetics of the Kittlitz's murrelet (Brachyramphus brevirostris) in Southeast Alaska Author: Hatch, Nick R. The Kittlitz's murrelet (Brachyramphus brevirostris) is a species of conservation concern over the entirety of its known range, which spans coastal Alaska and northeastern Russia. Concerns about the status of the species have been raised due to evidence of population declines in key breeding areas, low reproductive output, and perceived threats to adult survival. A general lack of information related to vital rates and natural history for this species has hampered efforts to address potential threats and drivers of population decline. This thesis addresses the hypothesis that foraging conditions and nutritional stress may be related to the observed low reproductive output and apparent population declines. I used stable isotope analysis of Kittlitz's murrelet feathers and blood to assess foraging habits during four separate periods across the annual cycle. I also used stable isotope signatures (δ¹⁵N and δ¹³C) in feathers from museum specimens collected in southeastern Alaska during 1907–1984 to investigate potential long-term trends in food habits and foraging ecology. I found that δ¹⁵N progressively increased by 5‰ between the vernal pre-alternate molt and the autumnal pre-basic molt, equivalent to an increase of 1.5 trophic levels for assimilated prey, whereas seasonal patterns in δ¹³C suggest shifts in foraging habitat between breeding and non-breeding periods. These results indicate that the pre-breeding diet was comprised primarily of low trophic level prey from offshore habitats, such as macrozooplankton and/or larval fish. During the summer breeding season, Kittlitz's murrelets gradually switched to consuming higher proportions of planktivorous fish from nearshore habitats. By the post-breeding period, during the pre-basic molt, the diet was comprised almost exclusively of higher trophic level prey, presumably forage fish, from offshore habitats. Based on stable isotope signatures of murrelet feathers from museum specimens, these seasonal patterns were evident during the past century (1907-2009). δ¹³C in feathers grown during pre- and post-breeding (pre-alternate and pre-basic molts, respectively) became significantly more depleted over the last century, however, suggesting either a gradual change in diet and/or foraging habitat or a long-term shift in the isotopic composition of prey. I investigated potential energy constraints on reproduction in Kittlitz's murrelets by constructing a bioenergetics model to estimate energy budgets for breeding adult Kittlitz's murrelets under different scenarios of prey energy content and commuting distance between foraging areas and nest sites. Estimated field metabolic rate (FMR) of breeding Kittlitz's murrelets during the chick-rearing period exceeded the hypothetical maximum sustainable working capacity (MSWC; 4 times basal metabolic rate [BMR]) under empirically derived scenarios of prey energy content and commuting distance. This suggests that, under conditions of low energy content in available prey and/or long commuting distances to inland nest sites, Kittlitz's murrelets would be required to expend energy at a rate that, if maintained over an extended period, could be detrimental to subsequent adult survival and overall fitness. In addition, energy expenditure rates at the high end of the estimated range may exceed the rate at which food energy can be assimilated by adult murrelets. Metabolism of fat reserves, as indicated by mass loss during the breeding season, may be a partial, although limited, solution to periods of high energy demand for breeding adults. This thesis research is the first to indicate that Kittlitz's murrelets rely on distinctly different prey resources during different periods of the annual cycle. The previously unappreciated seasonal complexity of Kittlitz's murrelet foraging ecology offers a new perspective on potential factors limiting survival and reproduction in this species of conservation concern. In addition, my research suggests an adaptive explanation for the low breeding frequency and low reproductive output of Kittlitz's murrelets that is related to the exceptionally high energy expenditure rates required to raise young at nest sites as much as 70 km inland from the coast and up to 2,500 m above sea level. Because of their high level of reproductive effort, Kittlitz's murrelets may be more dependent on the high availability of high-lipid marine prey than other seabirds. Close

• 290. [Article] Demographics of Piscivorous Colonial Waterbirds and Management Implications for ESA-listed Salmonids on the Columbia Plateau

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Northwest ...

  Citation × Citation Citation Abstract Copy Title: Demographics of Piscivorous Colonial Waterbirds and Management Implications for ESA-listed Salmonids on the Columbia Plateau Author: Evans, Allen F., Roby, Daniel D., Loschl, Peter J., Lyons, Donald E., Adkins, Jessica Y., Hostetter, Nathan J., Collis, Ken To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Northwest Scientific Association and can be found at: http://www.bioone.org/loi/nwsc. Title: Demographics of Piscivorous Colonial Waterbirds and Management Implications for ESA-listed Salmonids on the Columbia Plateau Author: Evans, Allen F., Roby, Daniel D., Loschl, Peter J., Lyons, Donald E., Adkins, Jessica Y., Hostetter, Nathan J., Collis, Ken To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Northwest Scientific Association and can be found at: http://www.bioone.org/loi/nwsc. Close

• 291. [Article] PrimeFish Project: Linking the Needs of the Producer, Market and Consumers

  Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, ...

  Citation × Citation Citation Abstract Copy Title: PrimeFish Project: Linking the Needs of the Producer, Market and Consumers Author: Gunnlaugsson, Valur N., Stefánsson, Guðmundur Year: 2016 Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, July 11-15, 2016. Compiled by Stefani J. Evers and Ann L. Shriver. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016. Title: PrimeFish Project: Linking the Needs of the Producer, Market and Consumers Author: Gunnlaugsson, Valur N., Stefánsson, Guðmundur Year: 2016 Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, July 11-15, 2016. Compiled by Stefani J. Evers and Ann L. Shriver. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016. Close

• 292. [Article] Short-Term Butterfly Response to Sagebrush Steppe Restoration Treatments

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the Society for Range Management and can be found at: http://www.srmjournals.or...

  Citation × Citation Citation Abstract Copy Title: Short-Term Butterfly Response to Sagebrush Steppe Restoration Treatments Author: McIver, James, Macke, Euell This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the Society for Range Management and can be found at: http://www.srmjournals.org/ Title: Short-Term Butterfly Response to Sagebrush Steppe Restoration Treatments Author: McIver, James, Macke, Euell This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the Society for Range Management and can be found at: http://www.srmjournals.org/ Close

• 293. [Article] Dynamics of leaf water relations components in co-occurring iso- and anisohydric conifer species

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by John Wiley ...

  Citation × Citation Citation Abstract Copy Title: Dynamics of leaf water relations components in co-occurring iso- and anisohydric conifer species Author: Meinzer, Frederick C., McCulloh, Katherine A., Woodruff, David R., Marias, Danielle E., Sevanto, Sanna To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by John Wiley & Sons Ltd. and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-3040. Title: Dynamics of leaf water relations components in co-occurring iso- and anisohydric conifer species Author: Meinzer, Frederick C., McCulloh, Katherine A., Woodruff, David R., Marias, Danielle E., Sevanto, Sanna To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by John Wiley & Sons Ltd. and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-3040. Close

• 294. [Article] Large wildlife removal drives immune defence increases in rodents

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the authors and the ...

  Citation × Citation Citation Abstract Copy Title: Large wildlife removal drives immune defence increases in rodents Author: Young, Hillary S., Nunn, Charles L., McCauley, Douglas J., Veblen, Kari E., Zhao, Serena, Helgen, Kristofer M., Snyder, Paul, Ezenwa, Vanessa O., Dirzo, Rodolfo To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the authors and the British Ecological Society. It is published by John Wiley & Sons, Inc. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2435/ Title: Large wildlife removal drives immune defence increases in rodents Author: Young, Hillary S., Nunn, Charles L., McCauley, Douglas J., Veblen, Kari E., Zhao, Serena, Helgen, Kristofer M., Snyder, Paul, Ezenwa, Vanessa O., Dirzo, Rodolfo To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the authors and the British Ecological Society. It is published by John Wiley & Sons, Inc. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2435/ Close

• 295. [Article] A model of Pacific Rim log and lumber markets : structure and projections

  To facilitate policy making and improve understanding of issues facing the New Zealand forest sector, a spatial equilibrium model was developed for log and lumber trade in the Pacific Rim. Regions included ...

  Citation × Citation Citation Abstract Copy Title: A model of Pacific Rim log and lumber markets : structure and projections Author: Katz, Andres To facilitate policy making and improve understanding of issues facing the New Zealand forest sector, a spatial equilibrium model was developed for log and lumber trade in the Pacific Rim. Regions included in the model were New Zealand, Chile, Australia, Japan, Eastern Canada, British Columbia: Coast and Interior, and the United States. Eight products were recognized in each market, characterized by their species group. Demand and supply relationships were econometrically estimated over the sample period 1966 to 1983; a reactive programming procedure was adopted to solve for annual market equilibrium prices and quantities. Inventory growth and drain models provided the necessary parameters to specify annual marginal cost functions for Radiata pine log supply from New Zealand and Chile. The validation procedure included simulating over a future period, from 1983 to 2010, under alternate economic and policy environments. Specifically, the model was used to investigate the impacts on Radiata pine markets of increased resource availability in New Zealand and Chile; the effects of a lower New Zealand exchange rate, and the indirect effects from a scenario of low growth in United States lumber consumption. Supply and demand for Radiata pine lumber in New Zealand were both inelastic, in contrast to Japan and Australia, reflecting lower substitution possibilities between timber species. Demand and supply behavior varied greatly between species. Baseline projections to 2010 indicated Radiata pine prices in New Zealand will decline by 23 percent, associated with a build up in inventory above the minimum harvest age. This was attributable to the high afforestation rates in New Zealand and Chile from the 1960's on. Title: A model of Pacific Rim log and lumber markets : structure and projections Author: Katz, Andres To facilitate policy making and improve understanding of issues facing the New Zealand forest sector, a spatial equilibrium model was developed for log and lumber trade in the Pacific Rim. Regions included in the model were New Zealand, Chile, Australia, Japan, Eastern Canada, British Columbia: Coast and Interior, and the United States. Eight products were recognized in each market, characterized by their species group. Demand and supply relationships were econometrically estimated over the sample period 1966 to 1983; a reactive programming procedure was adopted to solve for annual market equilibrium prices and quantities. Inventory growth and drain models provided the necessary parameters to specify annual marginal cost functions for Radiata pine log supply from New Zealand and Chile. The validation procedure included simulating over a future period, from 1983 to 2010, under alternate economic and policy environments. Specifically, the model was used to investigate the impacts on Radiata pine markets of increased resource availability in New Zealand and Chile; the effects of a lower New Zealand exchange rate, and the indirect effects from a scenario of low growth in United States lumber consumption. Supply and demand for Radiata pine lumber in New Zealand were both inelastic, in contrast to Japan and Australia, reflecting lower substitution possibilities between timber species. Demand and supply behavior varied greatly between species. Baseline projections to 2010 indicated Radiata pine prices in New Zealand will decline by 23 percent, associated with a build up in inventory above the minimum harvest age. This was attributable to the high afforestation rates in New Zealand and Chile from the 1960's on. Close

• 296. [Article] The Analysis on the Tee of China Export Aquatic Products and The Export Trend to Japan

  Japan has been the biggest export market of aquatic products of China for many years. The export of aquatic products to Japan reached more than 700,000 ton and $ 3 billion in 2007. The influence to the export ...

  Citation × Citation Citation Abstract Copy Title: The Analysis on the Tee of China Export Aquatic Products and The Export Trend to Japan Author: Che, Bin, Sun, Chen Japan has been the biggest export market of aquatic products of China for many years. The export of aquatic products to Japan reached more than 700,000 ton and $ 3 billion in 2007. The influence to the export market caused by the sweeping economic crisis will affect the benefits of the export enterprises of China. The trade complementary index shows great potential of aquatic products trade between China and Japan. However, under the circumstances of economic crisis, to set up limits of import would be the prior choice of the trade policy by Japan. The paper analyses the trade economic efficiency (TEE ) of the export aquatic products to Japan in detail. TEE is an index to reflect the export situation of one country from the economic point of view by the trend of trade price change. If TEE>1, then the trade (either export or import) of the interested country is more efficient than the average level of the world market. If TEE<1, the situation is the opposition. We choose the species which export quantity exceeds 1000 ton to analyze and find out that the TEE of only 10 species is more than 1, which refers to more efficient. The number doesn_t reach 1/3 of the sample. The TEE of some species is even not as much as 0.6. Moreover, the paper points out that the limits set up to the aquatic products of China under the economic crises by Japan will be different from those of before. According to the dual characteristics of technical trade measure, the limits set up can be based on market failure as well as on economic benefit. The purpose of former is to protect the consumers. In the latter condition, the benefit of producers is considered. The limits set up this time would be based on the economic benefits in order to protect the benefit of domestic producers. Therefore, the export of aquatic products of China may encounter dual difficulties. Not only will the TEE of export be worse, but also will the export scale be declined. Accordingly, the government should take more effective measures to improve the export environment in order to help the enterprises to get through the trouble. Title: The Analysis on the Tee of China Export Aquatic Products and The Export Trend to Japan Author: Che, Bin, Sun, Chen Japan has been the biggest export market of aquatic products of China for many years. The export of aquatic products to Japan reached more than 700,000 ton and $ 3 billion in 2007. The influence to the export market caused by the sweeping economic crisis will affect the benefits of the export enterprises of China. The trade complementary index shows great potential of aquatic products trade between China and Japan. However, under the circumstances of economic crisis, to set up limits of import would be the prior choice of the trade policy by Japan. The paper analyses the trade economic efficiency (TEE ) of the export aquatic products to Japan in detail. TEE is an index to reflect the export situation of one country from the economic point of view by the trend of trade price change. If TEE>1, then the trade (either export or import) of the interested country is more efficient than the average level of the world market. If TEE<1, the situation is the opposition. We choose the species which export quantity exceeds 1000 ton to analyze and find out that the TEE of only 10 species is more than 1, which refers to more efficient. The number doesn_t reach 1/3 of the sample. The TEE of some species is even not as much as 0.6. Moreover, the paper points out that the limits set up to the aquatic products of China under the economic crises by Japan will be different from those of before. According to the dual characteristics of technical trade measure, the limits set up can be based on market failure as well as on economic benefit. The purpose of former is to protect the consumers. In the latter condition, the benefit of producers is considered. The limits set up this time would be based on the economic benefits in order to protect the benefit of domestic producers. Therefore, the export of aquatic products of China may encounter dual difficulties. Not only will the TEE of export be worse, but also will the export scale be declined. Accordingly, the government should take more effective measures to improve the export environment in order to help the enterprises to get through the trouble. Close

• 297. [Article] The Economics of Norwegian Salmon Farming: A Review of 30 years of Production Growth

  Power Point presentation.

  Citation × Citation Citation Abstract Copy Title: The Economics of Norwegian Salmon Farming: A Review of 30 years of Production Growth Author: Rødseth, Kenneth Løvold, Guttormsen, Atle G. Power Point presentation. Title: The Economics of Norwegian Salmon Farming: A Review of 30 years of Production Growth Author: Rødseth, Kenneth Løvold, Guttormsen, Atle G. Power Point presentation. Close

• 298. [Article] Assessment of the Marine Artisanal Fisheries in Tanzania Mainland

  Presentation

  Citation × Citation Citation Abstract Copy Title: Assessment of the Marine Artisanal Fisheries in Tanzania Mainland Author: Hamidu, Upendo Presentation Title: Assessment of the Marine Artisanal Fisheries in Tanzania Mainland Author: Hamidu, Upendo Presentation Close

• 299. [Article] Reference Points for Vulnerable Fish Species Based on Bioeconomic Age-Structured Models: An Approach for Totoaba macdonaldi

  Suggested Bibliographic Reference: NAAFE Forum 2017 Proceedings, March 22-24, 2017. Compiled by Ann L. Shriver with assistance from Stefani Evers. North American Association of Fisheries Economists (NAAFE), ...

  Citation × Citation Citation Abstract Copy Title: Reference Points for Vulnerable Fish Species Based on Bioeconomic Age-Structured Models: An Approach for Totoaba macdonaldi Author: María Da-Rocha, José, Hernández-Flores, Alvaro, De Anda-Montañez, Juan Antonio, Salas-Márquez, Silvia, Rodríguez-García, Oswaldo Uriel, Valenzuela-Quiñonez, Fausto Suggested Bibliographic Reference: NAAFE Forum 2017 Proceedings, March 22-24, 2017. Compiled by Ann L. Shriver with assistance from Stefani Evers. North American Association of Fisheries Economists (NAAFE), Corvallis, 2017. Title: Reference Points for Vulnerable Fish Species Based on Bioeconomic Age-Structured Models: An Approach for Totoaba macdonaldi Author: María Da-Rocha, José, Hernández-Flores, Alvaro, De Anda-Montañez, Juan Antonio, Salas-Márquez, Silvia, Rodríguez-García, Oswaldo Uriel, Valenzuela-Quiñonez, Fausto Suggested Bibliographic Reference: NAAFE Forum 2017 Proceedings, March 22-24, 2017. Compiled by Ann L. Shriver with assistance from Stefani Evers. North American Association of Fisheries Economists (NAAFE), Corvallis, 2017. Close

• 300. [Article] Greater Sage-Grouse National Research Strategy

  The condition of the sagebrush ecosystem has been declining in the Western United States, and greater sage-grouse (Centrocercus urophasianus), a sagebrush-obligate species, has experienced concurrent decreases ...

  Citation × Citation Citation Abstract Copy Title: Greater Sage-Grouse National Research Strategy Author: Manier, Daniel J. , Hanser, Steven E. The condition of the sagebrush ecosystem has been declining in the Western United States, and greater sage-grouse (Centrocercus urophasianus), a sagebrush-obligate species, has experienced concurrent decreases in distribution and population numbers. This has prompted substantial research and management over the past two decades to improve the understanding of sage-grouse and its habitats and to address the observed decreases in distribution and population numbers. The amount of research and management has increased as the year 2015 approaches, which is when the U.S. Fish and Wildlife Service (FWS) is expected to make a final decision about whether or not to protect the species under the Endangered Species Act. In 2012, the Sage-Grouse Executive Oversight Committee (EOC) of the Western Association of Fish and Wildlife Agencies (WAFWA) requested that the U.S. Geological Survey (USGS) lead the development of a Greater Sage-Grouse National Research Strategy (hereafter Research Strategy). This request was motivated by a practical need to systematically connect existing research and conservation plans with persisting or emerging information needs. Managers and researchers also wanted to reduce redundancy and help focus limited funds on the highest priority research and management issues. The USGS undertook the development of this Research Strategy, which addresses information and science relating to the greater sage-grouse and its habitat across portions of 11Western States. This Research Strategy provides an outline of important research topics to ensure that science information gaps are identified and documented in a comprehensive manner. Further, by identifying priority topics and critical information needed for planning, research, and resource management, it provides a structure to help coordinate members of an expansive research and management community in their efforts to conduct priority research. Title: Greater Sage-Grouse National Research Strategy Author: Manier, Daniel J. , Hanser, Steven E. The condition of the sagebrush ecosystem has been declining in the Western United States, and greater sage-grouse (Centrocercus urophasianus), a sagebrush-obligate species, has experienced concurrent decreases in distribution and population numbers. This has prompted substantial research and management over the past two decades to improve the understanding of sage-grouse and its habitats and to address the observed decreases in distribution and population numbers. The amount of research and management has increased as the year 2015 approaches, which is when the U.S. Fish and Wildlife Service (FWS) is expected to make a final decision about whether or not to protect the species under the Endangered Species Act. In 2012, the Sage-Grouse Executive Oversight Committee (EOC) of the Western Association of Fish and Wildlife Agencies (WAFWA) requested that the U.S. Geological Survey (USGS) lead the development of a Greater Sage-Grouse National Research Strategy (hereafter Research Strategy). This request was motivated by a practical need to systematically connect existing research and conservation plans with persisting or emerging information needs. Managers and researchers also wanted to reduce redundancy and help focus limited funds on the highest priority research and management issues. The USGS undertook the development of this Research Strategy, which addresses information and science relating to the greater sage-grouse and its habitat across portions of 11Western States. This Research Strategy provides an outline of important research topics to ensure that science information gaps are identified and documented in a comprehensive manner. Further, by identifying priority topics and critical information needed for planning, research, and resource management, it provides a structure to help coordinate members of an expansive research and management community in their efforts to conduct priority research. Close