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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