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• 301. [Image] Research information needs on terrestrial vertebrate species of the interior Columbia River basin and northern portions of the Klamath and Great basins: research, development, and application database

  	"September 1997"; Includes bibliographical references (p. 24)
  	Citation × Citation Citation Abstract Copy Title: Research information needs on terrestrial vertebrate species of the interior Columbia River basin and northern portions of the Klamath and Great basins: research, development, and application database Author: Marcot, Bruce G. Year: 1997, 2005, 2004 "September 1997"; Includes bibliographical references (p. 24) Title: Research information needs on terrestrial vertebrate species of the interior Columbia River basin and northern portions of the Klamath and Great basins: research, development, and application database Author: Marcot, Bruce G. Year: 1997, 2005, 2004 "September 1997"; Includes bibliographical references (p. 24) Close

• 302. [Article] Vegetation and soil response to tree removal methods in invasive western juniper woodlands

  On piñon-juniper encroached sites that lack the understory fuels to carry a prescribed fire, treatment options are limited to mechanical methods. Cutting with chainsaws and leaving the trees on site has ...

  Citation × Citation Citation Abstract Copy Title: Vegetation and soil response to tree removal methods in invasive western juniper woodlands Author: O'Connor, Casey A. On piñon-juniper encroached sites that lack the understory fuels to carry a prescribed fire, treatment options are limited to mechanical methods. Cutting with chainsaws and leaving the trees on site has been the primary treatment method for such sites, however this method creates a potential fire hazard, particularly in the first 2-3 years when needles remain suspended on downed trees. Follow-up treatments to remove juniper fuels, such as broadcast burning downed trees or moving slash into piles with machinery followed by burning are becoming more common practices on private and public lands. There is limited information on the impacts of mechanical and fire treatments on herbaceous recovery and impacts to soil nutrients and characteristics. It is important to evaluate these treatments to provide resource managers with ecological information to assist in developing appropriate fuel reduction measures. This study sampled herbaceous vegetation and soil attributes of three common mechanical treatments used to treat invasive western juniper (Juniperus occidentalis var. occidentalis Vasek) woodlands: Cut & Leave, Cut & Burn, and Pile & Burn. Sampling consisted of cover and density of herbaceous species and life forms (groups of species that function similarly), as well as total ground cover, and soil attributes including: carbon (C), nitrogen (N), carbon:nitrogen ratio (C:N), phosphorus (P), potassium (K), sulfate-sulfur (SO4-), calcium(Ca), magnesium (Mg), organic matter (OM~loss on ignition), cation exchange capacity (CEC), and power of hydrogen (pH). A randomized complete block experimental design (RCBD) was used with five 1-hectare blocks and three treatment plots per block (with piling plots being ½ hectare in size, and the other two treatment plots each ¼ hectare in size). Within each treatment plot, herbaceous vegetation sampling was stratified between three microsites: the slash microsite (beneath the three slash treatments; cut trees, burned trees, and burned piles), in the litter deposition microsite (litter zone around the stump) and the interspace microsite (between trees). Soil attributes were only sampled in the slash and interspace microsites, at two depths (0-4cm and 0-25cm). Each microsite within each plot was sampled by 40, 0.2m2 herbaceous frames and three composited soil samples from each depth. Mechanical treatments were completed in the fall of 2005 and prescribed fire treatments were completed in the fall of 2006. Treatment analysis compared pre and post treatment herbaceous data from 2005 and 2007, and soil attribute data from 2006 and 2007. Bare ground increased and litter and cover and density of most herbaceous species/life form groups declined beneath Cut & Burn and Pile & Burn treatments compared to the Cut & Leave treatment. The largest declines in cover and density of herbaceous species/life forms were recorded beneath burned piles. The largest changes measured adjacent to slash treatment locations (in the litter deposition and interspace microsites) were in the Cut & Burn plots due to fire spreading out burned trees. In the litter deposition microsite of the Cut & Burn treatment in 2007 total herbaceous cover was 1/3 and 1/2 that measured in the Cut & Leave and Pile & Burn plots, respectively. Contrarily the interspace microsite of the Cut & Burn treatment in 2007 indicated a slight (although insignificant) increase in herbaceous cover, with annual forb cover twice that measured in either of the other treatments. Concentrations of C, N, OM, and CEC were largely unchanged from pre-treatment levels in the compared treatments, however SO4, Mg, Ca, K, and pH all increased in response to burning compared to the Cut & Leave treatment. Implications of this research are limited to the first year post burn-treatment. However, these findings can be used as a general guide to choosing slash treatments to meet specific objectives. Determination of which of these treatments to use is largely dependent upon management objectives and site conditions. The high degree of vegetation disturbance and nutrient release measured beneath the Pile & Burn slash treatment could pose potential problems with invasive species establishment. However, the Cut & Burn treatment had similar, although less dramatic, vegetation disturbances and nutrient releases beneath burned slash, which covered a larger proportion of area than the Pile & Burn treatment. If a similar degree of invasive species establishment occurs in both of these slash burning treatments, the Pile & Burn treatment may be a better option due to the smaller area impacted. Measurements indicated little impact to vegetation in the Cut & Leave treatment, however wildfire risk could diminish the short term benefits of this treatment. Long term monitoring of herbaceous vegetation and soil attribute response among these three slash treatments is needed to make solid inferences of the site recovery following treatments to assist in land management decisions. Title: Vegetation and soil response to tree removal methods in invasive western juniper woodlands Author: O'Connor, Casey A. On piñon-juniper encroached sites that lack the understory fuels to carry a prescribed fire, treatment options are limited to mechanical methods. Cutting with chainsaws and leaving the trees on site has been the primary treatment method for such sites, however this method creates a potential fire hazard, particularly in the first 2-3 years when needles remain suspended on downed trees. Follow-up treatments to remove juniper fuels, such as broadcast burning downed trees or moving slash into piles with machinery followed by burning are becoming more common practices on private and public lands. There is limited information on the impacts of mechanical and fire treatments on herbaceous recovery and impacts to soil nutrients and characteristics. It is important to evaluate these treatments to provide resource managers with ecological information to assist in developing appropriate fuel reduction measures. This study sampled herbaceous vegetation and soil attributes of three common mechanical treatments used to treat invasive western juniper (Juniperus occidentalis var. occidentalis Vasek) woodlands: Cut & Leave, Cut & Burn, and Pile & Burn. Sampling consisted of cover and density of herbaceous species and life forms (groups of species that function similarly), as well as total ground cover, and soil attributes including: carbon (C), nitrogen (N), carbon:nitrogen ratio (C:N), phosphorus (P), potassium (K), sulfate-sulfur (SO4-), calcium(Ca), magnesium (Mg), organic matter (OM~loss on ignition), cation exchange capacity (CEC), and power of hydrogen (pH). A randomized complete block experimental design (RCBD) was used with five 1-hectare blocks and three treatment plots per block (with piling plots being ½ hectare in size, and the other two treatment plots each ¼ hectare in size). Within each treatment plot, herbaceous vegetation sampling was stratified between three microsites: the slash microsite (beneath the three slash treatments; cut trees, burned trees, and burned piles), in the litter deposition microsite (litter zone around the stump) and the interspace microsite (between trees). Soil attributes were only sampled in the slash and interspace microsites, at two depths (0-4cm and 0-25cm). Each microsite within each plot was sampled by 40, 0.2m2 herbaceous frames and three composited soil samples from each depth. Mechanical treatments were completed in the fall of 2005 and prescribed fire treatments were completed in the fall of 2006. Treatment analysis compared pre and post treatment herbaceous data from 2005 and 2007, and soil attribute data from 2006 and 2007. Bare ground increased and litter and cover and density of most herbaceous species/life form groups declined beneath Cut & Burn and Pile & Burn treatments compared to the Cut & Leave treatment. The largest declines in cover and density of herbaceous species/life forms were recorded beneath burned piles. The largest changes measured adjacent to slash treatment locations (in the litter deposition and interspace microsites) were in the Cut & Burn plots due to fire spreading out burned trees. In the litter deposition microsite of the Cut & Burn treatment in 2007 total herbaceous cover was 1/3 and 1/2 that measured in the Cut & Leave and Pile & Burn plots, respectively. Contrarily the interspace microsite of the Cut & Burn treatment in 2007 indicated a slight (although insignificant) increase in herbaceous cover, with annual forb cover twice that measured in either of the other treatments. Concentrations of C, N, OM, and CEC were largely unchanged from pre-treatment levels in the compared treatments, however SO4, Mg, Ca, K, and pH all increased in response to burning compared to the Cut & Leave treatment. Implications of this research are limited to the first year post burn-treatment. However, these findings can be used as a general guide to choosing slash treatments to meet specific objectives. Determination of which of these treatments to use is largely dependent upon management objectives and site conditions. The high degree of vegetation disturbance and nutrient release measured beneath the Pile & Burn slash treatment could pose potential problems with invasive species establishment. However, the Cut & Burn treatment had similar, although less dramatic, vegetation disturbances and nutrient releases beneath burned slash, which covered a larger proportion of area than the Pile & Burn treatment. If a similar degree of invasive species establishment occurs in both of these slash burning treatments, the Pile & Burn treatment may be a better option due to the smaller area impacted. Measurements indicated little impact to vegetation in the Cut & Leave treatment, however wildfire risk could diminish the short term benefits of this treatment. Long term monitoring of herbaceous vegetation and soil attribute response among these three slash treatments is needed to make solid inferences of the site recovery following treatments to assist in land management decisions. Close

• 303. [Article] Breeding ecology and nest site selection of Kittlitz's murrelets on Kodiak Island, Alaska

  The Kittlitz's murrelet (Brachyramphus brevirostris) is a rare member of the seabird family Alcidae that breeds in coastal areas of Alaska and Beringian Russia. The species belongs to the genus Brachyramphus, ...

  Citation × Citation Citation Abstract Copy Title: Breeding ecology and nest site selection of Kittlitz's murrelets on Kodiak Island, Alaska Author: Lawonn, Matthew James The Kittlitz's murrelet (Brachyramphus brevirostris) is a rare member of the seabird family Alcidae that breeds in coastal areas of Alaska and Beringian Russia. The species belongs to the genus Brachyramphus, an unusual seabird taxon in which all three extant species nest non-colonially, situating their nests up to 75 km inland from coastal marine waters. This nesting strategy is different from that of most seabird species, which tend to nest colonially on remote islands or sea cliffs, where terrestrial predators are generally absent or cannot easily access nests. Within the genus Brachyramphus, Kittlitz's murrelet is notable because a majority of the global population appears to nest on the surface of the ground in rocky alpine habitat near inland or tidewater glaciers, foraging in adjacent marine waters influenced by glacial outflows. The unusual nesting habits of Kittlitz's murrelet have made the study of its nesting ecology difficult, and gaps therefore exist in our understanding of the species' breeding biology. Kittlitz's murrelet populations have declined substantially in core areas of its range, causing the U. S. Fish and Wildlife Service to designate the species as a candidate for protection under the Endangered Species Act. A better understanding of Kittlitz's murrelet nesting ecology is crucial for determining potential causes of these declines and for future management of the species. To this end, I studied Kittlitz's murrelet breeding ecology and nest site selection during 2008-2011 on Kodiak Island, Alaska, in an unglaciated area that was recently found to have large numbers of accessible nests. I and my colleagues found 53 active Kittlitz's murrelet nests in inland scree-dominated habitats and placed remote, motion-sensing cameras at 33 nests. Adults exchanged incubation duties at the nest every 24 or 48 h, almost exclusively during early morning twilight. Following hatching of eggs, parents provisioned their single nestling with an average of 3.9 to 4.8 fish per day, depending on the year. Parental visits to the nest during chick-rearing occurred primarily after sunrise in the early to mid-morning hours, and during evening twilight. Fish were delivered singly to the chick, and Pacific sand lance (Ammodytes hexapterus), a high-lipid forage fish, accounted for about 92% of all identifiable chick meal deliveries. Chick growth rates were high relative to confamilial species, consistent with the high quality of chick diets; the logistic growth rate constant (K) was 0.291, greater than that for any other semi-precocial alcid. Chicks fledged an average of 24.8 d after hatching and asymptotic chick body mass averaged about 135.5 g, approximately 58% of adult body mass. Age at fledging, asymptotic chick body mass (% adult mass), and the number of meal deliveries required to fledge a chick were all lower than or as low as any other species of semi-precocial alcid. The average estimated nest survival rate during 2008-2011 was 0.093 (95% CI = 0.01–0.30), which is extremely low compared to other species in the family Alcidae, and is almost certainly insufficient to sustain a stable population. The primary causes of nest failure were depredation (47% of total nest fates), mostly by red foxes (Vulpes vulpes), and unexplained nestling mortality on the nest (21% of nest fates). Saxitoxin and/or pathogenic endoparasite burdens were observed in five of six necropsied chick carcasses, suggesting possible causes for chick mortality not directly attributable to predation. Habitat characteristics of Kittlitz's murrelet nest sites differed significantly from unused sites at several scales. At a small scale (within 5 m of the nest), nest sites had a lower percent coverage of vegetation and higher percent coverage of intermediate-sized rocks (5–30 cm diameter), compared to randomly selected unused sites. Nest sites were also located on steeper, more north-facing slopes compared to randomly selected sites. Nest sites also had a lower percent coverage of vegetation than randomly-selected sites at larger scales (within 25 m and 50 m of the nest site). Nest sites were located significantly farther from the edge of densely-vegetated habitats than random sites. There was no evidence that nest sites were different from randomly-selected sites in terms of elevation, proximity to ridgelines, or proximity to the open ocean, although a low degree of variation within the study area for these habitat characteristics may have precluded detection of potential differences. Nest survival rates did not co-vary with slope, percent vegetation coverage, distance from vegetated edges, or percent cover of intermediate-sized rocks; however, this result may be an artifact of a limited sample size. The results of this thesis will provide managers with a better understanding of the factors that may limit Kittlitz's murrelet nesting success, such as nest predation and forage fish availability, as well as factors that may influence the quality and distribution of Kittlitz’s murrelet nesting habitat in the future, given on-going and progressive climate change. Title: Breeding ecology and nest site selection of Kittlitz's murrelets on Kodiak Island, Alaska Author: Lawonn, Matthew James The Kittlitz's murrelet (Brachyramphus brevirostris) is a rare member of the seabird family Alcidae that breeds in coastal areas of Alaska and Beringian Russia. The species belongs to the genus Brachyramphus, an unusual seabird taxon in which all three extant species nest non-colonially, situating their nests up to 75 km inland from coastal marine waters. This nesting strategy is different from that of most seabird species, which tend to nest colonially on remote islands or sea cliffs, where terrestrial predators are generally absent or cannot easily access nests. Within the genus Brachyramphus, Kittlitz's murrelet is notable because a majority of the global population appears to nest on the surface of the ground in rocky alpine habitat near inland or tidewater glaciers, foraging in adjacent marine waters influenced by glacial outflows. The unusual nesting habits of Kittlitz's murrelet have made the study of its nesting ecology difficult, and gaps therefore exist in our understanding of the species' breeding biology. Kittlitz's murrelet populations have declined substantially in core areas of its range, causing the U. S. Fish and Wildlife Service to designate the species as a candidate for protection under the Endangered Species Act. A better understanding of Kittlitz's murrelet nesting ecology is crucial for determining potential causes of these declines and for future management of the species. To this end, I studied Kittlitz's murrelet breeding ecology and nest site selection during 2008-2011 on Kodiak Island, Alaska, in an unglaciated area that was recently found to have large numbers of accessible nests. I and my colleagues found 53 active Kittlitz's murrelet nests in inland scree-dominated habitats and placed remote, motion-sensing cameras at 33 nests. Adults exchanged incubation duties at the nest every 24 or 48 h, almost exclusively during early morning twilight. Following hatching of eggs, parents provisioned their single nestling with an average of 3.9 to 4.8 fish per day, depending on the year. Parental visits to the nest during chick-rearing occurred primarily after sunrise in the early to mid-morning hours, and during evening twilight. Fish were delivered singly to the chick, and Pacific sand lance (Ammodytes hexapterus), a high-lipid forage fish, accounted for about 92% of all identifiable chick meal deliveries. Chick growth rates were high relative to confamilial species, consistent with the high quality of chick diets; the logistic growth rate constant (K) was 0.291, greater than that for any other semi-precocial alcid. Chicks fledged an average of 24.8 d after hatching and asymptotic chick body mass averaged about 135.5 g, approximately 58% of adult body mass. Age at fledging, asymptotic chick body mass (% adult mass), and the number of meal deliveries required to fledge a chick were all lower than or as low as any other species of semi-precocial alcid. The average estimated nest survival rate during 2008-2011 was 0.093 (95% CI = 0.01–0.30), which is extremely low compared to other species in the family Alcidae, and is almost certainly insufficient to sustain a stable population. The primary causes of nest failure were depredation (47% of total nest fates), mostly by red foxes (Vulpes vulpes), and unexplained nestling mortality on the nest (21% of nest fates). Saxitoxin and/or pathogenic endoparasite burdens were observed in five of six necropsied chick carcasses, suggesting possible causes for chick mortality not directly attributable to predation. Habitat characteristics of Kittlitz's murrelet nest sites differed significantly from unused sites at several scales. At a small scale (within 5 m of the nest), nest sites had a lower percent coverage of vegetation and higher percent coverage of intermediate-sized rocks (5–30 cm diameter), compared to randomly selected unused sites. Nest sites were also located on steeper, more north-facing slopes compared to randomly selected sites. Nest sites also had a lower percent coverage of vegetation than randomly-selected sites at larger scales (within 25 m and 50 m of the nest site). Nest sites were located significantly farther from the edge of densely-vegetated habitats than random sites. There was no evidence that nest sites were different from randomly-selected sites in terms of elevation, proximity to ridgelines, or proximity to the open ocean, although a low degree of variation within the study area for these habitat characteristics may have precluded detection of potential differences. Nest survival rates did not co-vary with slope, percent vegetation coverage, distance from vegetated edges, or percent cover of intermediate-sized rocks; however, this result may be an artifact of a limited sample size. The results of this thesis will provide managers with a better understanding of the factors that may limit Kittlitz's murrelet nesting success, such as nest predation and forage fish availability, as well as factors that may influence the quality and distribution of Kittlitz’s murrelet nesting habitat in the future, given on-going and progressive climate change. Close

• 304. [Article] New England Commercial Ground-fishermen: Adaptation and Transition

  Fishing years 2012 -2013 brought declines in socio-economic performance for the Northeast groundfish fishery. Severe reductions in catch limits for key species such as Atlantic cod have constrained fishing ...

  Citation × Citation Citation Abstract Copy Title: New England Commercial Ground-fishermen: Adaptation and Transition Author: Murphy, Tammy, Henry, Anna Fishing years 2012 -2013 brought declines in socio-economic performance for the Northeast groundfish fishery. Severe reductions in catch limits for key species such as Atlantic cod have constrained fishing behavior and declining groundfish revenues cannot be offset by non-groundfish revenues earned by the fleet. Little is known about the way groundfish fishermen are making decisions in response to changes in the fishery. We present results from approximately 60 ethnographic interviews with previously active groundfish fishermen who exited the fishery and current active participants who are considering transitioning out of the fishery. Interviews focused on level of participation in the groundfish fishery, changes since the implementation of catch shares and factors that have influenced decision-making around continued participation or exiting the groundfish fishery. The information collected suggests that adaptation strategies and impacts vary considerably with factors such as the fisherman’s age, initial quota allocation, level of debt, and presence of a second earner in the household. We develop a descriptive theory that characterizes actual choices being made currently by New England fishermen, with the goal of improving the ability to predict responses to future regulatory changes. Decision-making processes appear to differ from typical economic models used to analyze proposed regulatory actions. A richer understanding of these decision-making processes will lead to improved analysis of regulatory impacts. Title: New England Commercial Ground-fishermen: Adaptation and Transition Author: Murphy, Tammy, Henry, Anna Fishing years 2012 -2013 brought declines in socio-economic performance for the Northeast groundfish fishery. Severe reductions in catch limits for key species such as Atlantic cod have constrained fishing behavior and declining groundfish revenues cannot be offset by non-groundfish revenues earned by the fleet. Little is known about the way groundfish fishermen are making decisions in response to changes in the fishery. We present results from approximately 60 ethnographic interviews with previously active groundfish fishermen who exited the fishery and current active participants who are considering transitioning out of the fishery. Interviews focused on level of participation in the groundfish fishery, changes since the implementation of catch shares and factors that have influenced decision-making around continued participation or exiting the groundfish fishery. The information collected suggests that adaptation strategies and impacts vary considerably with factors such as the fisherman’s age, initial quota allocation, level of debt, and presence of a second earner in the household. We develop a descriptive theory that characterizes actual choices being made currently by New England fishermen, with the goal of improving the ability to predict responses to future regulatory changes. Decision-making processes appear to differ from typical economic models used to analyze proposed regulatory actions. A richer understanding of these decision-making processes will lead to improved analysis of regulatory impacts. Close

• 305. [Article] Using forest ecology exercises in science fairs to increase interest in forest resources education: an example from a stand development study.

  Presented at the 7th Biennial Conference on University Education in Natural Resources, March 13-15, 2008, Corvallis, Oregon

  Citation × Citation Citation Abstract Copy Title: Using forest ecology exercises in science fairs to increase interest in forest resources education: an example from a stand development study. Author: Lockhart, Brian Roy, Cronk, Buddy Presented at the 7th Biennial Conference on University Education in Natural Resources, March 13-15, 2008, Corvallis, Oregon Title: Using forest ecology exercises in science fairs to increase interest in forest resources education: an example from a stand development study. Author: Lockhart, Brian Roy, Cronk, Buddy Presented at the 7th Biennial Conference on University Education in Natural Resources, March 13-15, 2008, Corvallis, Oregon Close

• 306. [Article] Influence of precommercial thinning on understory vegetation of young-growth Sitka spruce forests in southeastern Alaska

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

  Citation × Citation Citation Abstract Copy Title: Influence of precommercial thinning on understory vegetation of young-growth Sitka spruce forests in southeastern Alaska Author: Hanley, Thomas A., Newton, Michael, Cole, Elizabeth 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 published article is copyrighted by NRC Research Press and can be found at: http://www.nrcresearchpress.com/journal/cjfr. Title: Influence of precommercial thinning on understory vegetation of young-growth Sitka spruce forests in southeastern Alaska Author: Hanley, Thomas A., Newton, Michael, Cole, Elizabeth 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 published article is copyrighted by NRC Research Press and can be found at: http://www.nrcresearchpress.com/journal/cjfr. Close

• 307. [Article] Factors influencing spawner success in a spring Chinook salmon (Oncorhynchus tshawytscha) reintroduction program

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Canadian Science Publishing, NRC Research Press and can be found at: http://www...

  Citation × Citation Citation Abstract Copy Title: Factors influencing spawner success in a spring Chinook salmon (Oncorhynchus tshawytscha) reintroduction program Author: Jacobson, Dave P., O'Malley, Kathleen G., Johnson, Marc A., Sard, Nicholas M., Hogansen, Michael J., Banks, Michael A. This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Canadian Science Publishing, NRC Research Press and can be found at: http://www.nrcresearchpress.com/doi/10.1139/cjfas-2015-0007#.VuHGB3rci0j Title: Factors influencing spawner success in a spring Chinook salmon (Oncorhynchus tshawytscha) reintroduction program Author: Jacobson, Dave P., O'Malley, Kathleen G., Johnson, Marc A., Sard, Nicholas M., Hogansen, Michael J., Banks, Michael A. This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Canadian Science Publishing, NRC Research Press and can be found at: http://www.nrcresearchpress.com/doi/10.1139/cjfas-2015-0007#.VuHGB3rci0j Close

• 308. [Article] Ecology and decline of a rare western minnow : the Oregon chub (Oregonichthys crameri)

  Once historically widespread throughout the Willamette and Umpqua River drainages, the Willamette Oregon chub is now restricted to scattered populations along 15 miles of the Middle Fork of the Willamette ...

  Citation × Citation Citation Abstract Copy Title: Ecology and decline of a rare western minnow : the Oregon chub (Oregonichthys crameri) Author: Pearsons, Todd N. Once historically widespread throughout the Willamette and Umpqua River drainages, the Willamette Oregon chub is now restricted to scattered populations along 15 miles of the Middle Fork of the Willamette River whereas the Umpqua Oregon chub is still widely distributed. The decline in the Willamette drainage was more severe because changes in the physical and biological habitat were more severe when compared to the Umpqua drainage. The Willamette Oregon chub may be more sensitive to environmental degradations than the Umpqua Oregon chub. The difference in sensitivity to degradation is a result of ecological differences between Willamette and Umpqua Oregon chub. Willamette Oregon chub inhabited areas with primarily very little if any current, fed in the water column, and spawned in aquatic vegetation. Umpqua Oregon chub inhabited areas with primarily slow water velocities, fed on benthic prey, and spawned over gravel substrate. Because Willamette Oregon chub inhabit slackwater habitats they may be more sensitive to water velocity increases and exotic species, whereas Umpqua Oregon chub have a habitat refuge in relatively faster water velocity habitats. Willamette Oregon chub larval stages are described and illustrated. The following combination of characters distinguish Willamette Oregon chub larvae from other cyprinid larvae found in the Willamette drainage: 33-37 myomeres, preanal length of 52-61%, and absence of snout pigment. Willamette Oregon chub larvae generally congregated in nearshore areas, in the upper layers of the water column, in shallow water. They fed primarily in the water column, and ate primarily rotifers and cladocerans. Title: Ecology and decline of a rare western minnow : the Oregon chub (Oregonichthys crameri) Author: Pearsons, Todd N. Once historically widespread throughout the Willamette and Umpqua River drainages, the Willamette Oregon chub is now restricted to scattered populations along 15 miles of the Middle Fork of the Willamette River whereas the Umpqua Oregon chub is still widely distributed. The decline in the Willamette drainage was more severe because changes in the physical and biological habitat were more severe when compared to the Umpqua drainage. The Willamette Oregon chub may be more sensitive to environmental degradations than the Umpqua Oregon chub. The difference in sensitivity to degradation is a result of ecological differences between Willamette and Umpqua Oregon chub. Willamette Oregon chub inhabited areas with primarily very little if any current, fed in the water column, and spawned in aquatic vegetation. Umpqua Oregon chub inhabited areas with primarily slow water velocities, fed on benthic prey, and spawned over gravel substrate. Because Willamette Oregon chub inhabit slackwater habitats they may be more sensitive to water velocity increases and exotic species, whereas Umpqua Oregon chub have a habitat refuge in relatively faster water velocity habitats. Willamette Oregon chub larval stages are described and illustrated. The following combination of characters distinguish Willamette Oregon chub larvae from other cyprinid larvae found in the Willamette drainage: 33-37 myomeres, preanal length of 52-61%, and absence of snout pigment. Willamette Oregon chub larvae generally congregated in nearshore areas, in the upper layers of the water column, in shallow water. They fed primarily in the water column, and ate primarily rotifers and cladocerans. Close

• 309. [Article] Harbor dredging and benthic infauna : a case study

  This study of the immediate, localized effects of a small dredging operation on the benthic invertebrate community in the shipping channel of Coos Bay, Oregon, was designed: 1) to measure the extent of ...

  Citation × Citation Citation Abstract Copy Title: Harbor dredging and benthic infauna : a case study Author: Parr, Robert Alexander This study of the immediate, localized effects of a small dredging operation on the benthic invertebrate community in the shipping channel of Coos Bay, Oregon, was designed: 1) to measure the extent of the physical removal of benthic macro- and meiofauna by hopper dredging; 2) to record the subsequent benthic effects of mid-channel spoiling; and 3) to monitor the rate and pattern of biological readjustment in the affected areas. Replicate Shipek grab samples before and after dredge operations were restricted spatially and temporally to delineate rapid and localized biological responses. Faunal abundance, taxa composition, species diversity and qualitative sediment characteristics were studied. Immediate declines in faunal abundance at the dredge and spoil sites were temporary and re-adjusted to pre-dredging abundance levels within 28 days. Temporary increases in diversity reflected changes in the relative abundance of taxa arising from siltation and burial of organisms. Following re-adjustment, populations increased in all areas except the dredge channel. Localized population declines are hypothesized to result from the unsuitability of newly exposed sediment for settlement of pelagic larvae. Although most taxa were adversely affected by dredging activity, Capitella ovincola was relatively unaffected and increased dramatically within the dredge channel within 18 days after dredging. Qualitative sediment characteristics were generally the same before and after dredge operations except for localized increases in wood debris at both dredge and spoil sites. The effects of dredging activity are thought to be dependent on: 1) the size and duration of the dredge operation, 2) pre-dredging history and frequency of dredging, 3) the type of benthic community, 4) depth of water and sediment type, 5) draft and size of the dredging vessel and 6) shipping and related harbor activities. The direct, benthic effects of this dredging operation were short term. The temporary nature of these changes was linked to the small scope of the dredging operation and the adaptability of the benthic community. It is hypothesized that periodic disruption of the sediment surface by small scale maintenance operations may have less effect on the benthic community than the daily presence of heavy shipping and industrial and domestic pollution. Title: Harbor dredging and benthic infauna : a case study Author: Parr, Robert Alexander This study of the immediate, localized effects of a small dredging operation on the benthic invertebrate community in the shipping channel of Coos Bay, Oregon, was designed: 1) to measure the extent of the physical removal of benthic macro- and meiofauna by hopper dredging; 2) to record the subsequent benthic effects of mid-channel spoiling; and 3) to monitor the rate and pattern of biological readjustment in the affected areas. Replicate Shipek grab samples before and after dredge operations were restricted spatially and temporally to delineate rapid and localized biological responses. Faunal abundance, taxa composition, species diversity and qualitative sediment characteristics were studied. Immediate declines in faunal abundance at the dredge and spoil sites were temporary and re-adjusted to pre-dredging abundance levels within 28 days. Temporary increases in diversity reflected changes in the relative abundance of taxa arising from siltation and burial of organisms. Following re-adjustment, populations increased in all areas except the dredge channel. Localized population declines are hypothesized to result from the unsuitability of newly exposed sediment for settlement of pelagic larvae. Although most taxa were adversely affected by dredging activity, Capitella ovincola was relatively unaffected and increased dramatically within the dredge channel within 18 days after dredging. Qualitative sediment characteristics were generally the same before and after dredge operations except for localized increases in wood debris at both dredge and spoil sites. The effects of dredging activity are thought to be dependent on: 1) the size and duration of the dredge operation, 2) pre-dredging history and frequency of dredging, 3) the type of benthic community, 4) depth of water and sediment type, 5) draft and size of the dredging vessel and 6) shipping and related harbor activities. The direct, benthic effects of this dredging operation were short term. The temporary nature of these changes was linked to the small scope of the dredging operation and the adaptability of the benthic community. It is hypothesized that periodic disruption of the sediment surface by small scale maintenance operations may have less effect on the benthic community than the daily presence of heavy shipping and industrial and domestic pollution. Close

• 310. [Article] Factors influencing spawning migration of bull trout (Salvelinus confluentus) in the North Fork Skokomish River, Olympic National Park, Washington

  Distribution and life history characteristics of lacustrine-adfluvial bull trout (Salvelinus confluentus) were described in the North Fork Skokomish River Basin (including Lake Cushman, a reservoir) from ...

  Citation × Citation Citation Abstract Copy Title: Factors influencing spawning migration of bull trout (Salvelinus confluentus) in the North Fork Skokomish River, Olympic National Park, Washington Author: Brenkman, Samuel J. Distribution and life history characteristics of lacustrine-adfluvial bull trout (Salvelinus confluentus) were described in the North Fork Skokomish River Basin (including Lake Cushman, a reservoir) from 1994 to 1996. Day snorkeling was conducted in the river to determine initiation of the bull trout spawning migration, abundance of spawners, and duration of spawning. Declining photoperiod, increased river discharge, and decreased water temperature appeared to influence timing of migration and spawning. Lacustrine-adfluvial bull trout typically entered the North Fork Skokomish River in October although some fish entered as early as May. Mean lengths of spawners consistently increased from June to December 1996, and early migrating bull trout were shorter than those fish that entered after river discharge increased in October. The presence of two phases of the spawning migration may be indicative of two populations spawning in the river. Bull trout spawned between mid-September and December in the river and tributaries after water temperatures declined. All spawning occurred at temperatures less than 7.5°C. Comparisons with studies of other lacustrine-adfiuvial bull trout populations that inhabit river and reservoir complexes suggested that bull trout exhibit specific migratory strategies related to local environmental conditions. In the North Fork Skokomish River, changes in abundance of bull trout, mountain whitefish (Prosopium wilhamsom), cutthroat trout (Oncorhynchus dark), and rainbow trout (Oncorhynchus mykiss) revealed distinct temporal segregation among these species. Olympic National Park, a designated Biosphere Reserve, contains one of the largest remaining areas of relatively pristine habitat in the range of bull trout. Knowledge of responses of bull trout to changes in river discharge and temperature from relatively undisturbed systems, such as the North Fork Skokomish River, may be useful in understanding patterns observed in degraded environments. Title: Factors influencing spawning migration of bull trout (Salvelinus confluentus) in the North Fork Skokomish River, Olympic National Park, Washington Author: Brenkman, Samuel J. Distribution and life history characteristics of lacustrine-adfluvial bull trout (Salvelinus confluentus) were described in the North Fork Skokomish River Basin (including Lake Cushman, a reservoir) from 1994 to 1996. Day snorkeling was conducted in the river to determine initiation of the bull trout spawning migration, abundance of spawners, and duration of spawning. Declining photoperiod, increased river discharge, and decreased water temperature appeared to influence timing of migration and spawning. Lacustrine-adfluvial bull trout typically entered the North Fork Skokomish River in October although some fish entered as early as May. Mean lengths of spawners consistently increased from June to December 1996, and early migrating bull trout were shorter than those fish that entered after river discharge increased in October. The presence of two phases of the spawning migration may be indicative of two populations spawning in the river. Bull trout spawned between mid-September and December in the river and tributaries after water temperatures declined. All spawning occurred at temperatures less than 7.5°C. Comparisons with studies of other lacustrine-adfiuvial bull trout populations that inhabit river and reservoir complexes suggested that bull trout exhibit specific migratory strategies related to local environmental conditions. In the North Fork Skokomish River, changes in abundance of bull trout, mountain whitefish (Prosopium wilhamsom), cutthroat trout (Oncorhynchus dark), and rainbow trout (Oncorhynchus mykiss) revealed distinct temporal segregation among these species. Olympic National Park, a designated Biosphere Reserve, contains one of the largest remaining areas of relatively pristine habitat in the range of bull trout. Knowledge of responses of bull trout to changes in river discharge and temperature from relatively undisturbed systems, such as the North Fork Skokomish River, may be useful in understanding patterns observed in degraded environments. Close

• 311. [Article] Evidence of Fishing Down Marine Food Webs in Galician (Nw Spain) Small-Scale Fisheries

  No poster available.

  Citation × Citation Citation Abstract Copy Title: Evidence of Fishing Down Marine Food Webs in Galician (Nw Spain) Small-Scale Fisheries Author: Villasante, Sebastian, Rodriguez, Gonzalo No poster available. Title: Evidence of Fishing Down Marine Food Webs in Galician (Nw Spain) Small-Scale Fisheries Author: Villasante, Sebastian, Rodriguez, Gonzalo No poster available. Close

• 312. [Article] Measuring Differential Changes in Commercial Fishing Ports: A Shift- Share Analysis of North-Central California

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Measuring Differential Changes in Commercial Fishing Ports: A Shift- Share Analysis of North-Central California Author: Sutinen, Jon, Speir, Cameron, Pomeroy, Caroline, Thomson, Cynthia Abstract only. Title: Measuring Differential Changes in Commercial Fishing Ports: A Shift- Share Analysis of North-Central California Author: Sutinen, Jon, Speir, Cameron, Pomeroy, Caroline, Thomson, Cynthia Abstract only. Close

• 313. [Article] The Collapse of the Atlanto-Scandian Herring Fishery: Effects on the Icelandic Economy

  Research Paper

  Citation × Citation Citation Abstract Copy Title: The Collapse of the Atlanto-Scandian Herring Fishery: Effects on the Icelandic Economy Author: Sigurdsson, Thorir Research Paper Title: The Collapse of the Atlanto-Scandian Herring Fishery: Effects on the Icelandic Economy Author: Sigurdsson, Thorir Research Paper Close

• 314. [Article] Recent Adjustments in Northeast US Fresh Groundfish and Scallop Processing and Marketing

  The North Atlantic U.S. groundfish and scallop processing industries are a tale of two fisheries. The groundfish processing industry has suffered a steep, almost continual decline in landings starting ...

  Citation × Citation Citation Abstract Copy Title: Recent Adjustments in Northeast US Fresh Groundfish and Scallop Processing and Marketing Author: Georgianna, Daniel, Lee, Min-Yang The North Atlantic U.S. groundfish and scallop processing industries are a tale of two fisheries. The groundfish processing industry has suffered a steep, almost continual decline in landings starting in 1984 that resulted in 2014 landings that were only 16% of 1983 landings. US scallop landings increased from 5 million mt in 1998 to 30 mill mt in 2004, remaining around that peak until 2012. Both processing industries had to adjust: groundfish processors had to find new sources of fresh groundfish and other products to fill customers’ orders and scallop processors had to find new customers to buy its surplus product. This study used interviews with processors and data on landings, imports and exports to examine the marketing strategies of these processing industries to adjust to trends in landings and to evaluate their success within the confines the US Magnuson-Stevens Act. After imported whole groundfish from Canada were eliminated as substitutes for local landings, groundfish processors increased diversification of products as substitute for fresh groundfish to fill their customers’ orders, scouring the world for products such as Pacific cod, other groundfish, and some pelagic species. They also skipped the wholesale market to sell direct to retailers and restaurants. Not all succeeded, processing plants declined by almost half since 1990. Scallop processors successfully developed new markets for scallops, through exports and IQF packing for restaurants. The doubling of ex-vessel scallop prices, adjusted for inflation, since 2000 shows their success, which also supports processors’ claims that steady increasing supply improves product sales. Title: Recent Adjustments in Northeast US Fresh Groundfish and Scallop Processing and Marketing Author: Georgianna, Daniel, Lee, Min-Yang The North Atlantic U.S. groundfish and scallop processing industries are a tale of two fisheries. The groundfish processing industry has suffered a steep, almost continual decline in landings starting in 1984 that resulted in 2014 landings that were only 16% of 1983 landings. US scallop landings increased from 5 million mt in 1998 to 30 mill mt in 2004, remaining around that peak until 2012. Both processing industries had to adjust: groundfish processors had to find new sources of fresh groundfish and other products to fill customers’ orders and scallop processors had to find new customers to buy its surplus product. This study used interviews with processors and data on landings, imports and exports to examine the marketing strategies of these processing industries to adjust to trends in landings and to evaluate their success within the confines the US Magnuson-Stevens Act. After imported whole groundfish from Canada were eliminated as substitutes for local landings, groundfish processors increased diversification of products as substitute for fresh groundfish to fill their customers’ orders, scouring the world for products such as Pacific cod, other groundfish, and some pelagic species. They also skipped the wholesale market to sell direct to retailers and restaurants. Not all succeeded, processing plants declined by almost half since 1990. Scallop processors successfully developed new markets for scallops, through exports and IQF packing for restaurants. The doubling of ex-vessel scallop prices, adjusted for inflation, since 2000 shows their success, which also supports processors’ claims that steady increasing supply improves product sales. Close

• 315. [Article] Investigating Variation in Coral Reef Morphology with Photomosaics and Analysis of Percent Cover

  42 pages

  Citation × Citation Citation Abstract Copy Title: Investigating Variation in Coral Reef Morphology with Photomosaics and Analysis of Percent Cover Author: Culman, Justin Year: 2017 42 pages Title: Investigating Variation in Coral Reef Morphology with Photomosaics and Analysis of Percent Cover Author: Culman, Justin Year: 2017 42 pages Close

• 316. [Article] Fish tales : salmon stories, 1945-1980

  Approximately $1 billion a year is spent on salmon in the Pacific Northwest. Spending has escalated, yet the number of wild runs placed under the protection of the Endangered Species Act has increased, ...

  Citation × Citation Citation Abstract Copy Title: Fish tales : salmon stories, 1945-1980 Author: Finley, Carmel Approximately $1 billion a year is spent on salmon in the Pacific Northwest. Spending has escalated, yet the number of wild runs placed under the protection of the Endangered Species Act has increased, creating social and political controversy. For more than 100 years, salmon management in the Pacific Northwest has evolved around a fundamental concept, that hatcheries could replace the numbers of salmon lost as the region underwent industrialization. Spending on hatcheries makes up approximately 40 percent of expenditures on Northwest salmon issues. Four new studies have identified hatcheries as one of the reasons for the decline of some wild salmon stocks. Yet hatcheries are also considered one of the most important tools for saving wild runs. This thesis examines some of the national and international forces that shaped the modern hatchery program in the Pacific Northwest. After World War II, scientists and policy makers worldwide were motivated by idealistic dreams of using science and technology to end world hunger. With the creation of factory processing ships, and the discovery of such strategically important minerals such as manganese, there was growing political pressure to protect national resources through the creation of 200- mile limits. As part of this worldwide interest in increasing the marine harvest, hatchery programs for salmon were expanded in Japan, the U.S.S.R., Canada and the United States. At the same time, human activities, including logging, mining, agriculture and urbanization, contributed to the decline of salmon in the Northwest. This thesis examines some of the national and international forces that contributed to the expansion of the hatchery system in the Pacific Northwest. Title: Fish tales : salmon stories, 1945-1980 Author: Finley, Carmel Approximately $1 billion a year is spent on salmon in the Pacific Northwest. Spending has escalated, yet the number of wild runs placed under the protection of the Endangered Species Act has increased, creating social and political controversy. For more than 100 years, salmon management in the Pacific Northwest has evolved around a fundamental concept, that hatcheries could replace the numbers of salmon lost as the region underwent industrialization. Spending on hatcheries makes up approximately 40 percent of expenditures on Northwest salmon issues. Four new studies have identified hatcheries as one of the reasons for the decline of some wild salmon stocks. Yet hatcheries are also considered one of the most important tools for saving wild runs. This thesis examines some of the national and international forces that shaped the modern hatchery program in the Pacific Northwest. After World War II, scientists and policy makers worldwide were motivated by idealistic dreams of using science and technology to end world hunger. With the creation of factory processing ships, and the discovery of such strategically important minerals such as manganese, there was growing political pressure to protect national resources through the creation of 200- mile limits. As part of this worldwide interest in increasing the marine harvest, hatchery programs for salmon were expanded in Japan, the U.S.S.R., Canada and the United States. At the same time, human activities, including logging, mining, agriculture and urbanization, contributed to the decline of salmon in the Northwest. This thesis examines some of the national and international forces that contributed to the expansion of the hatchery system in the Pacific Northwest. Close

• 317. [Article] Quantifying dilution and amplification in a community of hosts for tick-borne pathogens

  Data associated with this paper have been deposited in the KNB Data Repository: https://knb.ecoinformatics.org/#view/ knb.779.2

  Citation × Citation Citation Abstract Copy Title: Quantifying dilution and amplification in a community of hosts for tick-borne pathogens Author: Ostfeld, Richard S., Keesing, Felicia, Holt, Robert D., Levi, Taal, Barfield, Michael Data associated with this paper have been deposited in the KNB Data Repository: https://knb.ecoinformatics.org/#view/ knb.779.2 Title: Quantifying dilution and amplification in a community of hosts for tick-borne pathogens Author: Ostfeld, Richard S., Keesing, Felicia, Holt, Robert D., Levi, Taal, Barfield, Michael Data associated with this paper have been deposited in the KNB Data Repository: https://knb.ecoinformatics.org/#view/ knb.779.2 Close

• 318. [Article] Complex restoration challenges: Weeds, seeds, and roads in a forested Wildland Urban Interface

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

  Citation × Citation Citation Abstract Copy Title: Complex restoration challenges: Weeds, seeds, and roads in a forested Wildland Urban Interface Author: Doescher, Paul S., Snider, Gabrielle, Kerns, Becky K., Buonopane, Michelle To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Title: Complex restoration challenges: Weeds, seeds, and roads in a forested Wildland Urban Interface Author: Doescher, Paul S., Snider, Gabrielle, Kerns, Becky K., Buonopane, Michelle To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Close

• 319. [Article] Multi-scale spatial controls of understory vegetation in Douglas-fir–western hemlock forests of western Oregon, USA

  This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Ecological Society of America. The published article can be found at: http://www.esajournal...

  Citation × Citation Citation Abstract Copy Title: Multi-scale spatial controls of understory vegetation in Douglas-fir–western hemlock forests of western Oregon, USA Author: Ganio, Lisa M., Burton, Julia I., Puettmann, Klaus J. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Ecological Society of America. The published article can be found at: http://www.esajournals.org/loi/ecsp. Title: Multi-scale spatial controls of understory vegetation in Douglas-fir–western hemlock forests of western Oregon, USA Author: Ganio, Lisa M., Burton, Julia I., Puettmann, Klaus J. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Ecological Society of America. The published article can be found at: http://www.esajournals.org/loi/ecsp. Close

• 320. [Article] Experimental reintroduction of northern wormwood (Artemisia campestris var. wormskioldii), a rare species of dynamic cobble bar environments on the Columbia River

  Rare plant reintroductions that result in additional or more viable wild populations are important conservation tools for maintaining biodiverse ecosystems. Ideally, such projects are best designed as ...

  Citation × Citation Citation Abstract Copy Title: Experimental reintroduction of northern wormwood (Artemisia campestris var. wormskioldii), a rare species of dynamic cobble bar environments on the Columbia River Author: Brickner, Alexis H. Rare plant reintroductions that result in additional or more viable wild populations are important conservation tools for maintaining biodiverse ecosystems. Ideally, such projects are best designed as experiments, to improve biological and ecological knowledge of the selected species and monitoring long-term results. Northern wormwood (Artemisia campestris var. wormskioldii: Asteraceae), a nearly extinct, early seral species restricted to Columbia River riparian habitat, is only known from two native populations in Washington, set 300 river kilometers apart. Both populations are declining and show minimal recruitment. In cooperation with the U.S. Fish and Wildlife Service and Army Corps of Engineers, we set up an experimental reintroduction project with the objectives of: (1) investigating the effect of environmental factors on survival of northern wormwood, to gain a better understanding of this species' habitat requirements; and (2) creating a second viable population to further recovery objectives. To achieve these goals, we obtained seeds from multiple sources in order to increase the diversity of the founding population and determine germination rates for each source. We then planted 2,100 greenhouse-grown plants on Rufus Island, Oregon, in October, 2011. We transplanted 1,450 of these in experimental plots to examine the impacts of three environmental factors: (1) substrate type; (2) distance from the water line; and (3) presence or absence of the invasive shrub false indigo (Amorpha fruticosa). The remaining plants were placed in four surplus populations in order to increase the founding population size and create a viable population. Results showed that seeds germinated at different rates across sources and years. Success of transplants was measured by survivorship and reproductive output. Transplants were most successful when planted in sand substrate and at least nine meters from the water line. The presence of false indigo, a listed invasive species, did not have a significant effect on survival of transplants. Reproductive output showed that this population produced viable seeds and recruitment was observed by way of eleven seedlings. The results from this project present new information on northern wormwood habitat requirements, as well as provide a protocol for future recovery efforts. Title: Experimental reintroduction of northern wormwood (Artemisia campestris var. wormskioldii), a rare species of dynamic cobble bar environments on the Columbia River Author: Brickner, Alexis H. Rare plant reintroductions that result in additional or more viable wild populations are important conservation tools for maintaining biodiverse ecosystems. Ideally, such projects are best designed as experiments, to improve biological and ecological knowledge of the selected species and monitoring long-term results. Northern wormwood (Artemisia campestris var. wormskioldii: Asteraceae), a nearly extinct, early seral species restricted to Columbia River riparian habitat, is only known from two native populations in Washington, set 300 river kilometers apart. Both populations are declining and show minimal recruitment. In cooperation with the U.S. Fish and Wildlife Service and Army Corps of Engineers, we set up an experimental reintroduction project with the objectives of: (1) investigating the effect of environmental factors on survival of northern wormwood, to gain a better understanding of this species' habitat requirements; and (2) creating a second viable population to further recovery objectives. To achieve these goals, we obtained seeds from multiple sources in order to increase the diversity of the founding population and determine germination rates for each source. We then planted 2,100 greenhouse-grown plants on Rufus Island, Oregon, in October, 2011. We transplanted 1,450 of these in experimental plots to examine the impacts of three environmental factors: (1) substrate type; (2) distance from the water line; and (3) presence or absence of the invasive shrub false indigo (Amorpha fruticosa). The remaining plants were placed in four surplus populations in order to increase the founding population size and create a viable population. Results showed that seeds germinated at different rates across sources and years. Success of transplants was measured by survivorship and reproductive output. Transplants were most successful when planted in sand substrate and at least nine meters from the water line. The presence of false indigo, a listed invasive species, did not have a significant effect on survival of transplants. Reproductive output showed that this population produced viable seeds and recruitment was observed by way of eleven seedlings. The results from this project present new information on northern wormwood habitat requirements, as well as provide a protocol for future recovery efforts. Close

• 321. [Article] Resource partitioning and reproductive success of three species of hawks (Buteo spp.) in an Oregon prairie

  In a native prairie of Oregon (363 km²) red-tailed (Buteo jamaicensis), ferruginous (Buteo regalis), and Swainson's hawks (Buteo swainsoni) coexist in one of the highest nesting Buteo densities in North ...

  Citation × Citation Citation Abstract Copy Title: Resource partitioning and reproductive success of three species of hawks (Buteo spp.) in an Oregon prairie Author: Cottrell, Marcy Jean In a native prairie of Oregon (363 km²) red-tailed (Buteo jamaicensis), ferruginous (Buteo regalis), and Swainson's hawks (Buteo swainsoni) coexist in one of the highest nesting Buteo densities in North America. In 1979 and 1980, the distribution, density, and productivity of the three species was studied in relation to availability of food and nesting habitat. The degree of ecological segregation among the three species was also investigated. Red-tailed and ferruginous hawks showed considerable overlap in the timing of their nesting cycles; the Swainson's hawk nested about one month later in the spring. The major food item of all three species was the Belding ground squirrel (Spennophilus beldingi). The total dietary overlap among the three hawk species was high: in 1979 and 1980, red-tailed and ferruginous hawks overlapped 90 percent and 80 percent, red-tailed and Swainson's hawks 88 percent and 83 percent, and ferruginous and Swainson's hawks 83 percent and 95 percent. Although timing and use of food resources exhibited considerable overlap, habitat was partitioned. Nine major habitat types occurred within the study area. Red-tailed hawks had almost exclusive use of pine groves and cultivated areas with cottonwood trees. Ferruginous hawks had almost exclusive use of south exposure sites where large rocky outcrops occurred. Use of other habitat types overlapped to some degree. The total habitat overlap between the red-tailed and ferruginous hawk in 1979 and 1980 was 33 percent and 37 percent. The Swainson's hawk exhibited slightly greater overlaps in 1979 and 1980 of 54 percent and 52 percent with red-tailed hawks and 47 percent and 41 percent with ferruginous hawks. Habitat overlap of the Swainson's hawk tended to be minimized by its selection of nest trees whose configuration differed from red-tailed and ferruginous hawks. Space was also partitioned by the maintenance of intraspecific and, to a lesser degree, interspecific nesting territories. Nest success of red-tailed and ferruginous hawks significantly declined when nesting pairs were visible to one another. This suggests that competition for space was a mechanism affecting distribution, density, and nest success. Based on the findings from this study, Buteo management could involve: (1) range management for prey species, which in this case is in accord with good management for cattle, (2) range management for nesting habitat, and (3) maintenance of properly spaced nesting sites. Title: Resource partitioning and reproductive success of three species of hawks (Buteo spp.) in an Oregon prairie Author: Cottrell, Marcy Jean In a native prairie of Oregon (363 km²) red-tailed (Buteo jamaicensis), ferruginous (Buteo regalis), and Swainson's hawks (Buteo swainsoni) coexist in one of the highest nesting Buteo densities in North America. In 1979 and 1980, the distribution, density, and productivity of the three species was studied in relation to availability of food and nesting habitat. The degree of ecological segregation among the three species was also investigated. Red-tailed and ferruginous hawks showed considerable overlap in the timing of their nesting cycles; the Swainson's hawk nested about one month later in the spring. The major food item of all three species was the Belding ground squirrel (Spennophilus beldingi). The total dietary overlap among the three hawk species was high: in 1979 and 1980, red-tailed and ferruginous hawks overlapped 90 percent and 80 percent, red-tailed and Swainson's hawks 88 percent and 83 percent, and ferruginous and Swainson's hawks 83 percent and 95 percent. Although timing and use of food resources exhibited considerable overlap, habitat was partitioned. Nine major habitat types occurred within the study area. Red-tailed hawks had almost exclusive use of pine groves and cultivated areas with cottonwood trees. Ferruginous hawks had almost exclusive use of south exposure sites where large rocky outcrops occurred. Use of other habitat types overlapped to some degree. The total habitat overlap between the red-tailed and ferruginous hawk in 1979 and 1980 was 33 percent and 37 percent. The Swainson's hawk exhibited slightly greater overlaps in 1979 and 1980 of 54 percent and 52 percent with red-tailed hawks and 47 percent and 41 percent with ferruginous hawks. Habitat overlap of the Swainson's hawk tended to be minimized by its selection of nest trees whose configuration differed from red-tailed and ferruginous hawks. Space was also partitioned by the maintenance of intraspecific and, to a lesser degree, interspecific nesting territories. Nest success of red-tailed and ferruginous hawks significantly declined when nesting pairs were visible to one another. This suggests that competition for space was a mechanism affecting distribution, density, and nest success. Based on the findings from this study, Buteo management could involve: (1) range management for prey species, which in this case is in accord with good management for cattle, (2) range management for nesting habitat, and (3) maintenance of properly spaced nesting sites. Close

• 322. [Article] Population dynamics of three early seral herb species in Pacific Northwest forests

  I investigated the population dynamics of fireweed (Epilobium angustfolium), foxglove (Digitalis purpurea) , and woodland groundsel (Senecio sylvaticus) to understand their colonization, persistence, and ...

  Citation × Citation Citation Abstract Copy Title: Population dynamics of three early seral herb species in Pacific Northwest forests Author: Hanson, D. Eric I investigated the population dynamics of fireweed (Epilobium angustfolium), foxglove (Digitalis purpurea) , and woodland groundsel (Senecio sylvaticus) to understand their colonization, persistence, and extirpation in Pacific Northwest Douglas-fir forests. Factors affecting the species' frequency and abundance in forest communities were evaluated. Their population dynamics were modeled and field experiments examined nitrogen fertilization and competition effects on population parameters. Experimental variation made the population models stochastic and sequential transition matrices incorporated the effects of competition into them. Plant community ordination suggested a negative relationship between foxglove and elevation. Indicator species analysis revealed that foxglove is favored by disturbance, i.e., broadcast silvicultural treatments, and by high site productivity, while fireweed responds to low productivity and lack of disturbance. Regression analysis related the species' frequency and cover to factors such as stand age, elevation, and UTM meters east. Simulated woodland groundsel population increased most rapidly. Increased competition tended to reduce its biomass accumulation and seed production per plant but did not affect seeds produced per unit area. Competition also reduced established immature plant survival. Incorporating these factors into the population model, the rate of population growth declined. The projected foxglove population grew at a lower rate than did woodland groundsel but faster than fireweed. Foxglove was adversely affected by competition, which generally reduced its size, biomass, and seed production. Interspecific competition reduced established plant survival, rosette persistence, perenniation, and flowering. Nitrogen fertilization stimulated seed germination, rosette persistence, and flowering but decreased perenniation. Nitrogen fertilization rate did not influence population growth when modeled but application timing did. Nitrogen applied at transplanting resulted in extinction of the population. Transplanting one year after fertilization resulted in constant population growth. Fireweed, with the most complex life cycle, had the lowest population growth rate. Its persistence was entirely due to vegetative reproduction--without it the population would rapidly become extinct. Competition and fertilization had little effect on this species and population projections based on the field experiments indicated constant growth. These results suggest life history and competitive ability regulate succession of pioneer species in Douglas-fir forests and increases population persistence comes at the expense of their growth rate. Title: Population dynamics of three early seral herb species in Pacific Northwest forests Author: Hanson, D. Eric I investigated the population dynamics of fireweed (Epilobium angustfolium), foxglove (Digitalis purpurea) , and woodland groundsel (Senecio sylvaticus) to understand their colonization, persistence, and extirpation in Pacific Northwest Douglas-fir forests. Factors affecting the species' frequency and abundance in forest communities were evaluated. Their population dynamics were modeled and field experiments examined nitrogen fertilization and competition effects on population parameters. Experimental variation made the population models stochastic and sequential transition matrices incorporated the effects of competition into them. Plant community ordination suggested a negative relationship between foxglove and elevation. Indicator species analysis revealed that foxglove is favored by disturbance, i.e., broadcast silvicultural treatments, and by high site productivity, while fireweed responds to low productivity and lack of disturbance. Regression analysis related the species' frequency and cover to factors such as stand age, elevation, and UTM meters east. Simulated woodland groundsel population increased most rapidly. Increased competition tended to reduce its biomass accumulation and seed production per plant but did not affect seeds produced per unit area. Competition also reduced established immature plant survival. Incorporating these factors into the population model, the rate of population growth declined. The projected foxglove population grew at a lower rate than did woodland groundsel but faster than fireweed. Foxglove was adversely affected by competition, which generally reduced its size, biomass, and seed production. Interspecific competition reduced established plant survival, rosette persistence, perenniation, and flowering. Nitrogen fertilization stimulated seed germination, rosette persistence, and flowering but decreased perenniation. Nitrogen fertilization rate did not influence population growth when modeled but application timing did. Nitrogen applied at transplanting resulted in extinction of the population. Transplanting one year after fertilization resulted in constant population growth. Fireweed, with the most complex life cycle, had the lowest population growth rate. Its persistence was entirely due to vegetative reproduction--without it the population would rapidly become extinct. Competition and fertilization had little effect on this species and population projections based on the field experiments indicated constant growth. These results suggest life history and competitive ability regulate succession of pioneer species in Douglas-fir forests and increases population persistence comes at the expense of their growth rate. Close

• 323. [Article] The effects of supercritical CO₂ on the bending properties and treatment defects of four refractory wood species

  It is difficult to treat the heartwood of many wood species with liquid preservatives using conventional liquid processes. Supercritical fluids (SCF) used as carriers of preservatives to impregnate refractory ...

  Citation × Citation Citation Abstract Copy Title: The effects of supercritical CO₂ on the bending properties and treatment defects of four refractory wood species Author: Anderson, Matthew E. It is difficult to treat the heartwood of many wood species with liquid preservatives using conventional liquid processes. Supercritical fluids (SCF) used as carriers of preservatives to impregnate refractory wood species may be an attractive alternative to conventional liquid carriers. While SCF impregnation has many potential advantages, some wood species exposed to elevated pressures can be subjected to excessive pressure gradients during treatment. These gradients can lead to treatment defects, such as collapse and splitting, and may also result in significant losses in bending properties. This study examined the effects of three treatment parameters on the bending properties and the development of treatment defects in Douglas-fir (Pseudotsuga menziesii), yellow poplar (Liriodendron tuhpifera), western redcedar (Thuja phcata), and Engelmann spruce (Picea engelmannii). Two rates of pressurization (0.34, 3.44 MPa/min.), two treatment pressures (10.34, 20.69 MPa) and two rates of venting (0.34, 3.44 MPa/min.) were examined on small clear specimens of each species using one treatment temperature (60 °C) and one treatment time (30 min.). SCF treatment of yellow poplar produced no significant reduction in bending properties, while bending properties increased in Douglas-fir. The latter increase appears to have resulted from differences in mean specific gravities between treatments since pressurization rate, treatment pressure, or venting rate did not significantly affect bending properties. Bending properties in western redcedar and Engelmann spruce were significantly reduced when exposed to SCF treatment conditions. Comparisons between treatment and control in western redcedar specimens showed 21.7 to 23.1% reductions in MOR and 26.0 to 31.0% reductions in WML. Properties of Engelmann spruce declined 10.8 to 21.6% in MOR, 16.0 to 21.4% in MOE, and 7.2 to 29.0% in WML following SCF treatment. Rapid venting, at a rate of 3.44 MPa/min., produced the most significant reductions on bending properties for western redcedar, while Engelmann spruce was affected by both the 0.34 and 3.44 MPa/min. pressurization and venting rates. Examination of transverse sections for all species revealed that collapse can occur externally as well as internally within SCF treated samples of Douglas-fir, western redcedar and Engelmann spruce, while the anatomical characteristics of yellow poplar were observed to be unaffected by SCF treatments. The results indicate that SCF treatments, while effective for treating refractory woods, must be used with some caution to avoid inducing negative effects on wood properties. Title: The effects of supercritical CO₂ on the bending properties and treatment defects of four refractory wood species Author: Anderson, Matthew E. It is difficult to treat the heartwood of many wood species with liquid preservatives using conventional liquid processes. Supercritical fluids (SCF) used as carriers of preservatives to impregnate refractory wood species may be an attractive alternative to conventional liquid carriers. While SCF impregnation has many potential advantages, some wood species exposed to elevated pressures can be subjected to excessive pressure gradients during treatment. These gradients can lead to treatment defects, such as collapse and splitting, and may also result in significant losses in bending properties. This study examined the effects of three treatment parameters on the bending properties and the development of treatment defects in Douglas-fir (Pseudotsuga menziesii), yellow poplar (Liriodendron tuhpifera), western redcedar (Thuja phcata), and Engelmann spruce (Picea engelmannii). Two rates of pressurization (0.34, 3.44 MPa/min.), two treatment pressures (10.34, 20.69 MPa) and two rates of venting (0.34, 3.44 MPa/min.) were examined on small clear specimens of each species using one treatment temperature (60 °C) and one treatment time (30 min.). SCF treatment of yellow poplar produced no significant reduction in bending properties, while bending properties increased in Douglas-fir. The latter increase appears to have resulted from differences in mean specific gravities between treatments since pressurization rate, treatment pressure, or venting rate did not significantly affect bending properties. Bending properties in western redcedar and Engelmann spruce were significantly reduced when exposed to SCF treatment conditions. Comparisons between treatment and control in western redcedar specimens showed 21.7 to 23.1% reductions in MOR and 26.0 to 31.0% reductions in WML. Properties of Engelmann spruce declined 10.8 to 21.6% in MOR, 16.0 to 21.4% in MOE, and 7.2 to 29.0% in WML following SCF treatment. Rapid venting, at a rate of 3.44 MPa/min., produced the most significant reductions on bending properties for western redcedar, while Engelmann spruce was affected by both the 0.34 and 3.44 MPa/min. pressurization and venting rates. Examination of transverse sections for all species revealed that collapse can occur externally as well as internally within SCF treated samples of Douglas-fir, western redcedar and Engelmann spruce, while the anatomical characteristics of yellow poplar were observed to be unaffected by SCF treatments. The results indicate that SCF treatments, while effective for treating refractory woods, must be used with some caution to avoid inducing negative effects on wood properties. Close

• 324. [Article] Interactions among Invasive Pacific Red Lionfish, Fish Parasites, and Cleaning Mutualisms Native to Atlantic Coral Reefs

  What makes invasive species successful, and how do they affect native populations and communities? I addressed these key questions in the context of the invasion of Atlantic coral reefs by Pacific red ...

  Citation × Citation Citation Abstract Copy Title: Interactions among Invasive Pacific Red Lionfish, Fish Parasites, and Cleaning Mutualisms Native to Atlantic Coral Reefs Author: Tuttle, Lillian J. What makes invasive species successful, and how do they affect native populations and communities? I addressed these key questions in the context of the invasion of Atlantic coral reefs by Pacific red lionfish (Pterois volitans). To assess the role of parasites in contributing to the success of this invasion, I compared infection rates of lionfish with syntopic carnivorous fishes at multiple locations in both the invasive and native ranges of lionfish. Invasive Atlantic lionfish had extremely few parasites when compared both to native Pacific lionfish and to ecologically similar native Atlantic reef fishes. Such “enemy release” may help to explain this successful invasion if lionfish consequently allocate more energy to growth and reproduction than to costly immune defenses. With few parasites limiting them, lionfish may consume ecologically important species, including Elacatinus spp. cleaning gobies: ubiquitous, conspicuous fishes that remove ectoparasites from other reef fishes. Although juvenile lionfish ate cleaner goby (E. genie) during laboratory experiments, they quickly learned to avoid them, likely due to a previously undescribed skin toxin in these gobies. Field experiments further revealed no change in the survival and growth rates of newly recruited cohorts of the cleaner goby in the presence vs. absence of lionfish. However, lionfish caused declines in the densities of the most abundant facultative cleaner, juvenile bluehead wrasse (Thalassoma bifasciatum), and of transient fishes that are often cleaned while visiting coral patch reefs. Therefore, lionfish do not have uniformly negative effects on native species; distasteful to potential predators, the cleaner goby is among the remarkably few small fish to escape predation by lionfish. The continued presence of Elacatinus spp. cleaning gobies, the predominant cleaners on invaded reefs, should limit cascading effects of lionfish on other Atlantic coral-reef inhabitants. Nonetheless, given their broad and voracious appetites, invasive lionfish will likely continue to affect native reef communities via predation on other cleaners and ecologically important fishes. Title: Interactions among Invasive Pacific Red Lionfish, Fish Parasites, and Cleaning Mutualisms Native to Atlantic Coral Reefs Author: Tuttle, Lillian J. What makes invasive species successful, and how do they affect native populations and communities? I addressed these key questions in the context of the invasion of Atlantic coral reefs by Pacific red lionfish (Pterois volitans). To assess the role of parasites in contributing to the success of this invasion, I compared infection rates of lionfish with syntopic carnivorous fishes at multiple locations in both the invasive and native ranges of lionfish. Invasive Atlantic lionfish had extremely few parasites when compared both to native Pacific lionfish and to ecologically similar native Atlantic reef fishes. Such “enemy release” may help to explain this successful invasion if lionfish consequently allocate more energy to growth and reproduction than to costly immune defenses. With few parasites limiting them, lionfish may consume ecologically important species, including Elacatinus spp. cleaning gobies: ubiquitous, conspicuous fishes that remove ectoparasites from other reef fishes. Although juvenile lionfish ate cleaner goby (E. genie) during laboratory experiments, they quickly learned to avoid them, likely due to a previously undescribed skin toxin in these gobies. Field experiments further revealed no change in the survival and growth rates of newly recruited cohorts of the cleaner goby in the presence vs. absence of lionfish. However, lionfish caused declines in the densities of the most abundant facultative cleaner, juvenile bluehead wrasse (Thalassoma bifasciatum), and of transient fishes that are often cleaned while visiting coral patch reefs. Therefore, lionfish do not have uniformly negative effects on native species; distasteful to potential predators, the cleaner goby is among the remarkably few small fish to escape predation by lionfish. The continued presence of Elacatinus spp. cleaning gobies, the predominant cleaners on invaded reefs, should limit cascading effects of lionfish on other Atlantic coral-reef inhabitants. Nonetheless, given their broad and voracious appetites, invasive lionfish will likely continue to affect native reef communities via predation on other cleaners and ecologically important fishes. Close

• 325. [Article] Influence of ruminant digestive processes on germination of ingested seeds

  Managing cattle to disseminate seeds of desirable plants, or alternatively, to restrict weed seed contamination on rangelands is of interest to managers. Four experiments were conducted to determine effects ...

  Citation × Citation Citation Abstract Copy Title: Influence of ruminant digestive processes on germination of ingested seeds Author: Lowry, Amaya A. Managing cattle to disseminate seeds of desirable plants, or alternatively, to restrict weed seed contamination on rangelands is of interest to managers. Four experiments were conducted to determine effects of ruminant digestion on germination of ingested seeds. A number of plant species representing a variety of seed size and seed coat hardness were subjected to in vitro digestion. Experiment one was conducted to determine effect of varying lengths of digestion time on seed germination. Seed germination varied by plant species in response to length of digestion. Germination of large soft-coated seeds, such as bluebunch wheatgrass (Agropyron spicatum (Pursh) Scribn. & Smith Goldar) and basin wildrye (Elymus cinereus Scribn & Merril Magnar), was reduced to 0%. Smaller grass seeds, such as Sherman big bluegrass (Poa secunda Presl. Sherman), survived but germination declined following 24-hour, 48-hour, and 72-hour digestion. Experiment two examined effect of different stages of ruminant digestion on seed germination. The combination of Stage I (rumen-simulated digestion) and Stage II (abomasal-simulated digestion) resulted in greatest seed mortality. Two water treatments were included to evaluate the effects of high temperatures (39°C), moisture uptake, and lack of oxygen. Water + O₂ and Water + CO₂ reduced germination, however not as much as Stage I and Stage II treatments. The third experiment determined effects of diet quality on seed germination. Seeds digested in rumen fluid collected from steers fed a 72% corn concentrate diet resulted in 0% germination for all species. Grass seed germination was low for seeds digested in rumen fluid collected from steers fed a forage diet. Whitetop (Cardaria draba (L.) Hand.) germination was 24% and 28% for 35-hour and 59-hour roughage treatment, respectively, and germination was 0% for 35-hour and 59-hour concentrate treatments. Germination of water-only treatments for most species was reduced in comparison to the control treatment, but was greater than remaining treatments. Experiment four evaluated germination of seeds exposed to in situ versus in vitro digestion. In situ digestion resulted in lower seed germination than in vitro digestion for all species examined. Large, soft grass seeds may not be suitable candidates for reseeding rangelands. However, it is important for managers to recognize that cattle may distribute viable weed seeds in feces. Confining cattle or supplementing with high concentrate diets may help prevent spread of weedy species. Title: Influence of ruminant digestive processes on germination of ingested seeds Author: Lowry, Amaya A. Managing cattle to disseminate seeds of desirable plants, or alternatively, to restrict weed seed contamination on rangelands is of interest to managers. Four experiments were conducted to determine effects of ruminant digestion on germination of ingested seeds. A number of plant species representing a variety of seed size and seed coat hardness were subjected to in vitro digestion. Experiment one was conducted to determine effect of varying lengths of digestion time on seed germination. Seed germination varied by plant species in response to length of digestion. Germination of large soft-coated seeds, such as bluebunch wheatgrass (Agropyron spicatum (Pursh) Scribn. & Smith Goldar) and basin wildrye (Elymus cinereus Scribn & Merril Magnar), was reduced to 0%. Smaller grass seeds, such as Sherman big bluegrass (Poa secunda Presl. Sherman), survived but germination declined following 24-hour, 48-hour, and 72-hour digestion. Experiment two examined effect of different stages of ruminant digestion on seed germination. The combination of Stage I (rumen-simulated digestion) and Stage II (abomasal-simulated digestion) resulted in greatest seed mortality. Two water treatments were included to evaluate the effects of high temperatures (39°C), moisture uptake, and lack of oxygen. Water + O₂ and Water + CO₂ reduced germination, however not as much as Stage I and Stage II treatments. The third experiment determined effects of diet quality on seed germination. Seeds digested in rumen fluid collected from steers fed a 72% corn concentrate diet resulted in 0% germination for all species. Grass seed germination was low for seeds digested in rumen fluid collected from steers fed a forage diet. Whitetop (Cardaria draba (L.) Hand.) germination was 24% and 28% for 35-hour and 59-hour roughage treatment, respectively, and germination was 0% for 35-hour and 59-hour concentrate treatments. Germination of water-only treatments for most species was reduced in comparison to the control treatment, but was greater than remaining treatments. Experiment four evaluated germination of seeds exposed to in situ versus in vitro digestion. In situ digestion resulted in lower seed germination than in vitro digestion for all species examined. Large, soft grass seeds may not be suitable candidates for reseeding rangelands. However, it is important for managers to recognize that cattle may distribute viable weed seeds in feces. Confining cattle or supplementing with high concentrate diets may help prevent spread of weedy species. Close

• 326. [Article] Differences in Evolutionary History and Ploidy Type Shape the Interactions of Populus tremuloides Michx. with Climate

  Quaking aspen (Populus tremuloides Michx) is a species with high phenotypic plasticity and a broad distribution that, in the last decade, has experienced climate stress-induced mortality called Sudden ...

  Citation × Citation Citation Abstract Copy Title: Differences in Evolutionary History and Ploidy Type Shape the Interactions of Populus tremuloides Michx. with Climate Author: Greer, Burke Thomas Quaking aspen (Populus tremuloides Michx) is a species with high phenotypic plasticity and a broad distribution that, in the last decade, has experienced climate stress-induced mortality called Sudden Aspen Decline (SAD). In order to help mitigate the effects of SAD in the future, we need a better understanding of aspen’s climate adaptation. We also need to learn more about how aspen structure and function relate to climate. To that end, this dissertation seeks to improve our understanding of aspen biogeography by exploring multi-scale genetic-climate interactions. First, we examined aspen climate adaptation, asking if genetic relatedness corresponded to any similarities or differences in climate niche across aspen’s range. We found that two aspen sub-populations, with genetic differences, had distinctly different climate niches and we concluded that aspen species distribution models should include genetic relatedness to predict species range more accurately. We also studied how polyploidy in aspen affected the structure and function of leaves, branches, and ramets. We found that diploid and triploid aspen had differences in leaf traits that ultimately drove greater triploid maximum photosynthetic rates, stomatal conductance, and intrinsic water-use efficiency (iWUE). However, despite greater iWUE in triploids, we found that they were actually more prone to climate-induced stress because of higher stomatal conductance rates and less stomatal sensitivity and control than diploids. Finally, we measured growth and iWUE in tree rings from diploid and triploid aspen. We learned that diploid growth had statistically significant positive correlations with total precipitation and the last day with snow on the ground. We also found that triploid growth had a statistically significant positive correlation with total precipitation, and a negative correlation with vapor pressure deficit. In addition, we found that while iWUE in both diploids and triploids increased during years with less available water, iWUE was nearly 4% greater in triploid aspen in every year. To maintain this ~4% greater iWUE when there was less available water, it is likely that triploid aspen did not reduce photosynthetic rates and stomatal conductance as much as diploids. Again, this suggests that triploids may be more prone than diploids to climate-induced stress because triploids require more water than diploids when there is less water available. Overall, our findings improve our understanding of macroscale and local scale interactions between aspen and climate. Title: Differences in Evolutionary History and Ploidy Type Shape the Interactions of Populus tremuloides Michx. with Climate Author: Greer, Burke Thomas Quaking aspen (Populus tremuloides Michx) is a species with high phenotypic plasticity and a broad distribution that, in the last decade, has experienced climate stress-induced mortality called Sudden Aspen Decline (SAD). In order to help mitigate the effects of SAD in the future, we need a better understanding of aspen’s climate adaptation. We also need to learn more about how aspen structure and function relate to climate. To that end, this dissertation seeks to improve our understanding of aspen biogeography by exploring multi-scale genetic-climate interactions. First, we examined aspen climate adaptation, asking if genetic relatedness corresponded to any similarities or differences in climate niche across aspen’s range. We found that two aspen sub-populations, with genetic differences, had distinctly different climate niches and we concluded that aspen species distribution models should include genetic relatedness to predict species range more accurately. We also studied how polyploidy in aspen affected the structure and function of leaves, branches, and ramets. We found that diploid and triploid aspen had differences in leaf traits that ultimately drove greater triploid maximum photosynthetic rates, stomatal conductance, and intrinsic water-use efficiency (iWUE). However, despite greater iWUE in triploids, we found that they were actually more prone to climate-induced stress because of higher stomatal conductance rates and less stomatal sensitivity and control than diploids. Finally, we measured growth and iWUE in tree rings from diploid and triploid aspen. We learned that diploid growth had statistically significant positive correlations with total precipitation and the last day with snow on the ground. We also found that triploid growth had a statistically significant positive correlation with total precipitation, and a negative correlation with vapor pressure deficit. In addition, we found that while iWUE in both diploids and triploids increased during years with less available water, iWUE was nearly 4% greater in triploid aspen in every year. To maintain this ~4% greater iWUE when there was less available water, it is likely that triploid aspen did not reduce photosynthetic rates and stomatal conductance as much as diploids. Again, this suggests that triploids may be more prone than diploids to climate-induced stress because triploids require more water than diploids when there is less water available. Overall, our findings improve our understanding of macroscale and local scale interactions between aspen and climate. Close

• 327. [Article] Chemical analysis of three forage plants collected from pastures suspected of inciting acute bovine pulmonary emphysema

  A two-year study was made of pastures suspected of inciting acute bovine pulmonary emphysema (ABPE) in east-central Oregon. Objectives of this study were (1) to determine the vegetation composition of ...

  Citation × Citation Citation Abstract Copy Title: Chemical analysis of three forage plants collected from pastures suspected of inciting acute bovine pulmonary emphysema Author: Van Zwoll, Wayne Cornell A two-year study was made of pastures suspected of inciting acute bovine pulmonary emphysema (ABPE) in east-central Oregon. Objectives of this study were (1) to determine the vegetation composition of these pastures, (2) to determine seasonal trends of tryptophan, crude protein, and nitrogen/sulfur ratios in selected pasture plants, (3) to determine daily utilization immediately after cattle were introduced to these pastures, (4) to relate cattle foraging habits to development of symptoms of ABPE, and (5) to determine common herd characteristics and management practices on ranches frequently affected by ABPE. Frequency data collected from plant communities on inciting pastures on the Lemcke and Palmer ranches showed a large number of species on these meadows. Kentucky bluegrass, Nebraska sedge, and common rush were common to me sic portions of all pastures studied. These three species were collected over the 1973 growing season and analyzed for tryptophan, crude protein and the nitrogen/sulfur ratio. Tryptophan content decreased from May 24 to September 4, with the largest change occurring over the first half of the season. It was determined that a 1000 lb cow eating the forage with the highest tryptophan level would have to ingest 43.8 kg (dry weight) of material to assimilate an equivalent amount of a single dose of tryptophan administered in laboratory induction of ABPE. This amount of forage could only be ingested over a period of several days. Crude protein content of Nebraska sedge, common rush, and Kentucky bluegrass declined from the first sampling to the last and decreased most rapidly early in the season. Crude protein of all plants was adequate for lactating range cattle through the soft dough stages of plants sampled. Crude protein content of Kentucky bluegrass in latter stages of seed development were not adequate to maintain lactating range cows. Nitrogen/sulfur ratios of Nebraska sedge, common rush, and Kentucky bluegrass varied more than tryptophan or crude protein within sampling periods. A decrease in nitrogen/sulfur ratios was noted over the season, the most rapid decline occurring during the last part. Sulfur content of all samples was adequate to maintain lactating range cows. No conclusions were drawn concerning the involvement of the nitrogen/ sulfur ratio in ABPE. Utilization measurements taken on me sic portions of the Lemcke and Palmer pastures showed Kentucky bluegrass, common rush, and Nebraska sedge utilized on the Lemcke ranch and birdsfoot trefoil, Kentucky bluegrass, bluebunch wheatgrass, smooth brome, and Nebraska sedge selected by cattle on the Palmer ranch. Observations of grazing habits of cattle on the Lemcke and Palmer pastures in 1972 and 1973 failed to correlate grazing patterns with development of symptoms of ABPE. Questionnaires were completed for six ranch operations that had recent histories of ABPE. Factors common to all six areas were (1) occurrence of the disease between early July and mid-October, (2) appearance of symptoms after a change from relatively dry, sparse to relatively succulent, abundant forage, (3) a natural water source, (4) apparent high susceptibility of mature, lactating Herefords, (5) unpredictable morbidity, and (6) high probability of recurrence of symptoms after ABPE had been diagnosed in a herd. Determination of cattle diets on ABPE-inciting pastures and chemical analysis of additional plant species is suggested for future work. Investigation of summer forage on frequently victimized ranches and continued compilation of case history information is also needed. Title: Chemical analysis of three forage plants collected from pastures suspected of inciting acute bovine pulmonary emphysema Author: Van Zwoll, Wayne Cornell A two-year study was made of pastures suspected of inciting acute bovine pulmonary emphysema (ABPE) in east-central Oregon. Objectives of this study were (1) to determine the vegetation composition of these pastures, (2) to determine seasonal trends of tryptophan, crude protein, and nitrogen/sulfur ratios in selected pasture plants, (3) to determine daily utilization immediately after cattle were introduced to these pastures, (4) to relate cattle foraging habits to development of symptoms of ABPE, and (5) to determine common herd characteristics and management practices on ranches frequently affected by ABPE. Frequency data collected from plant communities on inciting pastures on the Lemcke and Palmer ranches showed a large number of species on these meadows. Kentucky bluegrass, Nebraska sedge, and common rush were common to me sic portions of all pastures studied. These three species were collected over the 1973 growing season and analyzed for tryptophan, crude protein and the nitrogen/sulfur ratio. Tryptophan content decreased from May 24 to September 4, with the largest change occurring over the first half of the season. It was determined that a 1000 lb cow eating the forage with the highest tryptophan level would have to ingest 43.8 kg (dry weight) of material to assimilate an equivalent amount of a single dose of tryptophan administered in laboratory induction of ABPE. This amount of forage could only be ingested over a period of several days. Crude protein content of Nebraska sedge, common rush, and Kentucky bluegrass declined from the first sampling to the last and decreased most rapidly early in the season. Crude protein of all plants was adequate for lactating range cattle through the soft dough stages of plants sampled. Crude protein content of Kentucky bluegrass in latter stages of seed development were not adequate to maintain lactating range cows. Nitrogen/sulfur ratios of Nebraska sedge, common rush, and Kentucky bluegrass varied more than tryptophan or crude protein within sampling periods. A decrease in nitrogen/sulfur ratios was noted over the season, the most rapid decline occurring during the last part. Sulfur content of all samples was adequate to maintain lactating range cows. No conclusions were drawn concerning the involvement of the nitrogen/ sulfur ratio in ABPE. Utilization measurements taken on me sic portions of the Lemcke and Palmer pastures showed Kentucky bluegrass, common rush, and Nebraska sedge utilized on the Lemcke ranch and birdsfoot trefoil, Kentucky bluegrass, bluebunch wheatgrass, smooth brome, and Nebraska sedge selected by cattle on the Palmer ranch. Observations of grazing habits of cattle on the Lemcke and Palmer pastures in 1972 and 1973 failed to correlate grazing patterns with development of symptoms of ABPE. Questionnaires were completed for six ranch operations that had recent histories of ABPE. Factors common to all six areas were (1) occurrence of the disease between early July and mid-October, (2) appearance of symptoms after a change from relatively dry, sparse to relatively succulent, abundant forage, (3) a natural water source, (4) apparent high susceptibility of mature, lactating Herefords, (5) unpredictable morbidity, and (6) high probability of recurrence of symptoms after ABPE had been diagnosed in a herd. Determination of cattle diets on ABPE-inciting pastures and chemical analysis of additional plant species is suggested for future work. Investigation of summer forage on frequently victimized ranches and continued compilation of case history information is also needed. Close

• 328. [Article] Effects of sheep grazing to control weeds in a pine plantation on weed reproductive success, trees and sheep performance

  Use of sheep to control weeds in a ryegrass-white clover pasture in which Knob Cone-Monterrey hybrid pine trees had been planted was investigated in Corvallis, Oregon during 1997-1998. Treatments consisted ...

  Citation × Citation Citation Abstract Copy Title: Effects of sheep grazing to control weeds in a pine plantation on weed reproductive success, trees and sheep performance Author: Milliman, Lisa J. Use of sheep to control weeds in a ryegrass-white clover pasture in which Knob Cone-Monterrey hybrid pine trees had been planted was investigated in Corvallis, Oregon during 1997-1998. Treatments consisted of an ungrazed control (C) and grazing applications to achieve 25 (L), 50 (M) or 75 (H) percent utilization of the understory vegetation. The treatments were applied three times between May and July of 1998 (T1, T2, and T3). Cover and phenological stage by plant group was measured after each treatment application. Two species of interest, Himalayan blackberry and bull thistle, were also studied independently of the other forbs. Their growth was measured at T1, T2, T3 and also in October of 1998 (T4). All yearling ewes were weighed at the beginning of the trial, before T1, and again after T3. Sheep used in the trial were also weighed after T2. Initially understory vegetation covered about 90% of the ground, approximately 20% of which was perennial ryegrass (RYE). Incidence of other perennial grasses (OPG) remained constant at about 20% where ungrazed but declined from 20% to 10% during the study in all grazed treatments. Annual grasses (AG) performed similarly to OPG, remaining at 25% in C throughout the trial but declining to 8% or less in all grazed treatments by T3. Forb cover was variable throughout the site, ranging from about 20 to 50% before initial grazing. Grazing at T1 reduced forb cover by 44% (L) to 80% (H) from initial levels. Forbs did not fully recover by T2 and constituted about 25% of the cover in C and L and <10% in M and H. Grazing at T2 reduced forb presence by 25% in L, with little change in M and H due to the low presence of forbs in those treatments. Late season forbs began to appear by T2 and were dominant by T3 when grazing reduced total forb cover to 15% in L and <10% in M and H. Grazing also delayed maturation of all plant groups, with some affected more than others. All grazing treatments resulted in delayed RYE maturation compared to C (p<0.01). By T3 80% of RYE plants were reproductive in C, while less than 50% were scored as reproductive in grazed areas. Almost 90% of OPG in C had set seed by T2. By comparison, in the grazed treatments an average of 53% of OPG plants had set seed prior to T2 grazing and this was reduced to 13% post-grazing (p=0.0001). The more intensive grazing treatments reduced seed set compared to L (33% vs. 3%, p=0.001) but there was no difference in seed set between M and H. By T2 all AG sampled in ungrazed, control cells and 60% of AG plants in L had set seed. In M and H most were still flowering with nearly none having yet set seed (p<0.01). By T3 there was very little AG present in any of the grazed cells. At T2 about 50% of the forbs had set seed in C while most of the remainder were still vegetative, reflecting a transition in species present from early season species to late season species. Late season forbs were actively growing at T3 and nearly all forbs in C were reproductive. In C the proportion of forbs having set seed was about 40% at T2 and T3, compared to 25% or less in any of the grazed treatments at either T2 or T3 (p<0.01). Grazing had no effect on the number of bull thistle flowers produced per plant but did reduce plant height. Thistles in C averaged 71 cm in October (T4) compared to 42 cm in L and 32 cm for M and H (p<0.01). Himalayan blackberry cane length was also affected by grazing, reaching 81 cm in length in C by T3 but was reduced to 31 cm in L, 23 cm in M and 13 cm in H (p<0.01). No increases in cane length were observed after T3 in C. However, the canes continued to grow between T3 and T4 in the grazed treatments to achieve lengths of 37 cm (L), 41 cm (M) and 27 cm (H). Intense grazing at T1 resulted in browsing of nearly all available pine branches in H compared to <30% browsed in L and M. Tree browsing in L was slightly higher at T2 than at T1 and was 25% higher in M. No additional browsing occurred at T3 in any treatment (p>0.3). Sheep performance was not affected by the grazing treatments. There were no significant differences in weight gain among the three groups of yearling ewes used in the trial. Moderate levels of sheep grazing can be an effective tool to reduce competition from many undesirable species including Himalayan blackberry. Title: Effects of sheep grazing to control weeds in a pine plantation on weed reproductive success, trees and sheep performance Author: Milliman, Lisa J. Use of sheep to control weeds in a ryegrass-white clover pasture in which Knob Cone-Monterrey hybrid pine trees had been planted was investigated in Corvallis, Oregon during 1997-1998. Treatments consisted of an ungrazed control (C) and grazing applications to achieve 25 (L), 50 (M) or 75 (H) percent utilization of the understory vegetation. The treatments were applied three times between May and July of 1998 (T1, T2, and T3). Cover and phenological stage by plant group was measured after each treatment application. Two species of interest, Himalayan blackberry and bull thistle, were also studied independently of the other forbs. Their growth was measured at T1, T2, T3 and also in October of 1998 (T4). All yearling ewes were weighed at the beginning of the trial, before T1, and again after T3. Sheep used in the trial were also weighed after T2. Initially understory vegetation covered about 90% of the ground, approximately 20% of which was perennial ryegrass (RYE). Incidence of other perennial grasses (OPG) remained constant at about 20% where ungrazed but declined from 20% to 10% during the study in all grazed treatments. Annual grasses (AG) performed similarly to OPG, remaining at 25% in C throughout the trial but declining to 8% or less in all grazed treatments by T3. Forb cover was variable throughout the site, ranging from about 20 to 50% before initial grazing. Grazing at T1 reduced forb cover by 44% (L) to 80% (H) from initial levels. Forbs did not fully recover by T2 and constituted about 25% of the cover in C and L and <10% in M and H. Grazing at T2 reduced forb presence by 25% in L, with little change in M and H due to the low presence of forbs in those treatments. Late season forbs began to appear by T2 and were dominant by T3 when grazing reduced total forb cover to 15% in L and <10% in M and H. Grazing also delayed maturation of all plant groups, with some affected more than others. All grazing treatments resulted in delayed RYE maturation compared to C (p<0.01). By T3 80% of RYE plants were reproductive in C, while less than 50% were scored as reproductive in grazed areas. Almost 90% of OPG in C had set seed by T2. By comparison, in the grazed treatments an average of 53% of OPG plants had set seed prior to T2 grazing and this was reduced to 13% post-grazing (p=0.0001). The more intensive grazing treatments reduced seed set compared to L (33% vs. 3%, p=0.001) but there was no difference in seed set between M and H. By T2 all AG sampled in ungrazed, control cells and 60% of AG plants in L had set seed. In M and H most were still flowering with nearly none having yet set seed (p<0.01). By T3 there was very little AG present in any of the grazed cells. At T2 about 50% of the forbs had set seed in C while most of the remainder were still vegetative, reflecting a transition in species present from early season species to late season species. Late season forbs were actively growing at T3 and nearly all forbs in C were reproductive. In C the proportion of forbs having set seed was about 40% at T2 and T3, compared to 25% or less in any of the grazed treatments at either T2 or T3 (p<0.01). Grazing had no effect on the number of bull thistle flowers produced per plant but did reduce plant height. Thistles in C averaged 71 cm in October (T4) compared to 42 cm in L and 32 cm for M and H (p<0.01). Himalayan blackberry cane length was also affected by grazing, reaching 81 cm in length in C by T3 but was reduced to 31 cm in L, 23 cm in M and 13 cm in H (p<0.01). No increases in cane length were observed after T3 in C. However, the canes continued to grow between T3 and T4 in the grazed treatments to achieve lengths of 37 cm (L), 41 cm (M) and 27 cm (H). Intense grazing at T1 resulted in browsing of nearly all available pine branches in H compared to <30% browsed in L and M. Tree browsing in L was slightly higher at T2 than at T1 and was 25% higher in M. No additional browsing occurred at T3 in any treatment (p>0.3). Sheep performance was not affected by the grazing treatments. There were no significant differences in weight gain among the three groups of yearling ewes used in the trial. Moderate levels of sheep grazing can be an effective tool to reduce competition from many undesirable species including Himalayan blackberry. Close

• 329. [Article] Long-term Fire Effects on Plant Succession and Exotic Weeds in Protected Area Sagebrush Steppe, John Day Fossil Beds National Monument, Oregon

  The historical function of fire in sagebrush steppe has been altered by 19th century overgrazing, active fire suppression, annual grass invasion and encroachment of woody species. The significance of ...

  Citation × Citation Citation Abstract Copy Title: Long-term Fire Effects on Plant Succession and Exotic Weeds in Protected Area Sagebrush Steppe, John Day Fossil Beds National Monument, Oregon Author: Reed-Dustin, Claire Marie The historical function of fire in sagebrush steppe has been altered by 19th century overgrazing, active fire suppression, annual grass invasion and encroachment of woody species. The significance of fire to these systems is known, but research on long-term fire effects are limited. The Sheep Rock management unit of the John Day Fossil Beds National Monument, Oregon offers an opportunity to study long-term (15 year) responses of Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) communities to fire. Using generalized linear mixed models, this study examined responses of A. tridentata ssp. wyomingensis, Bromus tectorum (cheatgrass), Gutierrezia sarothrae (broom snakeweed), Poa secunda (Sandberg bluegrass), Pseudoroegneria spicata (bluebunch wheatgrass) and Taeniatherum caput-medusae (medusahead), along gradients of community type and topography through time post-fire. Community types were differentiated between A. tridentata ssp. wyomingensis dominant plots (brush plots) and Juniperus occidentalis (western juniper) dominant plots (forest plots). Cover of B. tectorum was greatest in brush plots. Bromus tectorum cover increased dramatically 2 years post-burn. At 5 years post-burn cover of B. tectorum was 135% of pre-burn cover in brush plots and 301% of pre-burn cover in forest plots. Analysis determined abundance of T. caput-medusae was not enough pre-burn to analyze fire effects. Examination of mean T. caput-medusae cover, in plots through time, suggests it is expanding within the Sheep Rock management unit. Pseudoroegneria spicata is more abundant in forest plots than in brush plots. In forest plots, P. spicata cover decreased by 49% 1 year post-burn, but recovered by 5 years post-burn. In brush plots, cover of P. spicata declined, but not significantly through time post-fire. On northern exposures recovery of P. spicata cover occurred between 1 and 2 years post-burn, whereas on southern exposures recovery occurred between 2 and 5 years post-burn. The cover of P. secunda did not show a dramatic response to fire through time post-burn. Fire reduced A. tridentata ssp. wyomingensis cover in brush plots by 99% and 100% on northern and southern exposures, respectively. In forest plots, fire reduced A. tridentata ssp. wyomingensis cover by 86% and 47% on northern and southern exposures, respectively. Similarly, A. tridentata ssp. wyomingensis density in brush plots declined by 96% on both northern and southern exposures 1 year post-fire. In forest plots fire reduced A. tridentata ssp. wyomingensis density by 71% on northern exposures and 0% on southern exposures. The cover and density of A. tridentata ssp. wyomingensis did not change significantly through time after an initial decrease 1 year post-burn, except for density in forest plots, which didn’t show significant change through time. Artemisia tridentata is a long-lived species and therefore continuation of this study is required to gain a fuller perspective on its long term response to fire. Cover of G. sarothrae declined by 92% in brush plots and by 73% in forest plots. Gutierrezia sarothrae cover returned to pre-burn cover by 5 years post burn in brush plots, but did not recover in forest plots. Topography was not identified as a significant parameter for G. sarothrae cover in response to fire. Similarly to G. sarothrae cover, G. sarothrae density decreased 1 year post-burn and recovered by 5 years post burn in brush plots, but it did not recover in forest plots. In contrast to G. sarothrae cover, topography was identified as a significant parameter for the response of G. sarothrae density. We hypothesize south slopes favor G. sarothrae establishment, while north slopes favor increased G. sarothrae size, which explains topographic significance for density, but not for cover. Results of this study can be used by land managers to consider species specific responses to fire in both the short and long-term. This information is useful when developing plans for reintroducing fire into A. tridentata ssp. wyomingensis systems or when developing post-wildfire management strategies. Title: Long-term Fire Effects on Plant Succession and Exotic Weeds in Protected Area Sagebrush Steppe, John Day Fossil Beds National Monument, Oregon Author: Reed-Dustin, Claire Marie The historical function of fire in sagebrush steppe has been altered by 19th century overgrazing, active fire suppression, annual grass invasion and encroachment of woody species. The significance of fire to these systems is known, but research on long-term fire effects are limited. The Sheep Rock management unit of the John Day Fossil Beds National Monument, Oregon offers an opportunity to study long-term (15 year) responses of Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) communities to fire. Using generalized linear mixed models, this study examined responses of A. tridentata ssp. wyomingensis, Bromus tectorum (cheatgrass), Gutierrezia sarothrae (broom snakeweed), Poa secunda (Sandberg bluegrass), Pseudoroegneria spicata (bluebunch wheatgrass) and Taeniatherum caput-medusae (medusahead), along gradients of community type and topography through time post-fire. Community types were differentiated between A. tridentata ssp. wyomingensis dominant plots (brush plots) and Juniperus occidentalis (western juniper) dominant plots (forest plots). Cover of B. tectorum was greatest in brush plots. Bromus tectorum cover increased dramatically 2 years post-burn. At 5 years post-burn cover of B. tectorum was 135% of pre-burn cover in brush plots and 301% of pre-burn cover in forest plots. Analysis determined abundance of T. caput-medusae was not enough pre-burn to analyze fire effects. Examination of mean T. caput-medusae cover, in plots through time, suggests it is expanding within the Sheep Rock management unit. Pseudoroegneria spicata is more abundant in forest plots than in brush plots. In forest plots, P. spicata cover decreased by 49% 1 year post-burn, but recovered by 5 years post-burn. In brush plots, cover of P. spicata declined, but not significantly through time post-fire. On northern exposures recovery of P. spicata cover occurred between 1 and 2 years post-burn, whereas on southern exposures recovery occurred between 2 and 5 years post-burn. The cover of P. secunda did not show a dramatic response to fire through time post-burn. Fire reduced A. tridentata ssp. wyomingensis cover in brush plots by 99% and 100% on northern and southern exposures, respectively. In forest plots, fire reduced A. tridentata ssp. wyomingensis cover by 86% and 47% on northern and southern exposures, respectively. Similarly, A. tridentata ssp. wyomingensis density in brush plots declined by 96% on both northern and southern exposures 1 year post-fire. In forest plots fire reduced A. tridentata ssp. wyomingensis density by 71% on northern exposures and 0% on southern exposures. The cover and density of A. tridentata ssp. wyomingensis did not change significantly through time after an initial decrease 1 year post-burn, except for density in forest plots, which didn’t show significant change through time. Artemisia tridentata is a long-lived species and therefore continuation of this study is required to gain a fuller perspective on its long term response to fire. Cover of G. sarothrae declined by 92% in brush plots and by 73% in forest plots. Gutierrezia sarothrae cover returned to pre-burn cover by 5 years post burn in brush plots, but did not recover in forest plots. Topography was not identified as a significant parameter for G. sarothrae cover in response to fire. Similarly to G. sarothrae cover, G. sarothrae density decreased 1 year post-burn and recovered by 5 years post burn in brush plots, but it did not recover in forest plots. In contrast to G. sarothrae cover, topography was identified as a significant parameter for the response of G. sarothrae density. We hypothesize south slopes favor G. sarothrae establishment, while north slopes favor increased G. sarothrae size, which explains topographic significance for density, but not for cover. Results of this study can be used by land managers to consider species specific responses to fire in both the short and long-term. This information is useful when developing plans for reintroducing fire into A. tridentata ssp. wyomingensis systems or when developing post-wildfire management strategies. Close

• 330. [Article] Mitochondrial decay in the aging rat heart : changes in fatty acid-supported bioenergetics and macromolecular organization of the electron transport system

  Decline in cardiac pump function is a hallmark of aging where mitochondrial decay is an important underlying cause. Although certainly multifactorial in nature, both dysfunction of the machinery involved ...

  Citation × Citation Citation Abstract Copy Title: Mitochondrial decay in the aging rat heart : changes in fatty acid-supported bioenergetics and macromolecular organization of the electron transport system Author: Gomez Ramirez, Luis A. (Luis Alejandro) Decline in cardiac pump function is a hallmark of aging where mitochondrial decay is an important underlying cause. Although certainly multifactorial in nature, both dysfunction of the machinery involved in the chemiosmotic process of energy transduction and lower capacity to maintain fatty acid-driven respiration are identified as intrinsic factors of mitochondrial decay in the aged myocardium. Age-associated destabilization of electron transport supercomplexes as a potential factor of mitochondrial decay in the rat heart. Defective operation of the electron transport chain (ETC) constitutes a key mechanism involved in the age-associated loss of mitochondrial energy metabolism. Nevertheless, the molecular events underlying inefficient electron flux that ultimately leads to higher superoxide appearance and impaired respiration are not fully known. As recent biophysical evidence shows that the ETC may form large macromolecular assemblies (i.e. supercomplexes) that disintegrate in certain pathologies (e.g. heart failure or Barth syndrome) reminiscent of aging, we investigated the hypothesis that alterations in supercomplexes are partly responsible for the age-related loss of cardiac ETC function. In this dissertation, age-associated changes in supercomplex organization and stability were investigated in subsarcolemmal (SSM) and interfibrillary (IFM) mitochondria isolated from cardiac tissue from young (3-5 months) and old (24-28 months) male Fischer 344 rats. Blue native-PAGE (BN-PAGE) analysis of digitonin-solubilized mitochondrial membranes coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to investigate supercomplex organization. Results show that both SSM and IFM display supercomplexes comprised of various stoichiometries of complexes I, III and IV (never complex II), which typically organize as high mass (1500-2300 kDa) assemblies containing up to four copies of complex IV (i.e. I₁III₂IV[subscript N]-type supercomplexes). Interestingly, analysis of IFM proteins showed that, in general, supercomplex levels declined by up to 15 % (p < 0.05) with age; however, different degrees of supercomplex deterioration were observed, depending on the particular supercomplex investigated. Supercomplexes of the highest molecular weights (i.e. 1900-2300 kDa), which were also composed of the most complex stoichiometries (i.e. I1III2IVN, N ≥ 2), were primarily lost with age. In particular, I₁III₂IV₂, I₁III₂IV₃ and I₁III₂IV₄ supercomplexes were found to decline by 13% (p < 0.05), 30% (p < 0.05) and 45% (p < 0.05), respectively, on an age basis. Therefore, the age-associated loss of supercomplexes in IFM stems from destabilization of the assemblies that comprise several copies of complex IV, which could partially limit proper electron transfer to O₂ for its reduction, affecting mitochondrial respiratory capacity. In contrast to IFM, the aging defects of SSM supercomplexes appeared to be confined to the assembly comprised of only one copy of complex IV (I₁III₂IV₁, 1700 kDa) (37% loss; p = 0.06), while the higher molecular weight supercomplex sub-types that were most affected in IFM (i.e. I₁III₂IV[subscript N], N ≥ 2) were not significantly altered with age. Thus, the results from this dissertation indicate that mitochondria from different subcellular locations in the myocyte show different degrees of supercomplex destabilization in the aging rat heart. The more robust supercomplex deficits noted for IFM fit well with previous observations that electron transport characteristics of this subpopulation are more adversely affected with age than SSM. Although the underlying factor(s) of supercomplex deterioration are not fully known, the hypothesis that age-related alterations of certain constituents of the IMM (e.g. cardiolipin) may be important factors of supercomplex destabilization in cardiac mitochondria was investigated in this dissertation. To this end, LC-MS/MS characterization of supercomplex proteins and HPLC analysis of cardiolipin were used as approaches to elucidate potential factor(s) of supercomplex destabilization in the aging rat heart. Age-related alterations of cardiolipin levels and its acyl-chain content showed a strong parallel to the age-associated destabilization of supercomplexes. Specifically, cardiolipin levels declined by 10% (p < 0.05) in IFM, the mitochondrial subpopulation displaying the highest degree of supercomplex deterioration. In addition, the content of (18:2)₄-cardiolipin, the predominant species in the heart, was found to decline by 50% (p < 0.05) on average in both populations of cardiac mitochondria. Therefore, the data presented in this dissertation indicate that changes in cardiolipin may be at least one of the factors involved in supercomplex destabilization in the aging heart. Age-related decline in carnitine palmitoyltransferase I (CPT1) activity as a mitochondrial lesion that limits fatty acid catabolism in the rat heart. Loss of fatty acid utilization, another intrinsic factor of mitochondrial decay in the aged myocardium, has been associated with age-related alterations in the activity of carnitine palmitoyltransferase 1 (CPT1), the rate-controlling enzyme for overall fatty acid β-oxidation. Nevertheless, the exact molecular mechanism involved in the age-related loss of fatty acid-driven bioenergetics is not fully understood. In this dissertation, it was also investigated whether the aging lesion for fatty oxidation lies in a particular mitochondrial subpopulation or more generally results from cardiac decrements in L-carnitine levels. In order to clarify the role of each one of these factors, the effect of long-term dietary supplementation with the L-carnitine analogue, acetyl-L-carnitine (ALCAR), was also investigated. Results show that aging selectively decreases CPT1 activity in IFM by reducing enzyme catalytic efficiency for palmitoyl-CoA. IFM displayed a 28% (p < 0.05) loss of CPT1 activity, which correlated with a decline (41%, p < 0.05) in palmitoyl-CoA-driven state 3 respiration. Interestingly, SSM had preserved enzyme function and efficiently utilized palmitate. Analysis of IFM CPT1 kinetics showed both diminished V[subscript max] and K[subscript m] (60% and 49% respectively, p < 0.05) when palmitoyl-CoA was the substrate. However, no age-related changes in enzyme kinetics were evident with respect to L-carnitine. ALCAR supplementation restored CPT1 activity in heart IFM, but not apparently through remediation of L-carnitine levels. Rather, ALCAR influenced enzyme activity over time, potentially by modulating conditions in the aging heart that ultimately affect palmitoyl-CoA binding and CPT1 kinetics. In conclusion, this dissertation presents a characterization of age-associated alterations in the macromolecular organization of the IMM components that could partly explain the loss of mitochondrial oxidative capacity that affects the aging heart. In addition, the characterization of an age-related lesion of the controlling enzyme for β-oxidation is presented as another important factor that limits mitochondrial function and energy metabolism in cardiac mitochondria. Title: Mitochondrial decay in the aging rat heart : changes in fatty acid-supported bioenergetics and macromolecular organization of the electron transport system Author: Gomez Ramirez, Luis A. (Luis Alejandro) Decline in cardiac pump function is a hallmark of aging where mitochondrial decay is an important underlying cause. Although certainly multifactorial in nature, both dysfunction of the machinery involved in the chemiosmotic process of energy transduction and lower capacity to maintain fatty acid-driven respiration are identified as intrinsic factors of mitochondrial decay in the aged myocardium. Age-associated destabilization of electron transport supercomplexes as a potential factor of mitochondrial decay in the rat heart. Defective operation of the electron transport chain (ETC) constitutes a key mechanism involved in the age-associated loss of mitochondrial energy metabolism. Nevertheless, the molecular events underlying inefficient electron flux that ultimately leads to higher superoxide appearance and impaired respiration are not fully known. As recent biophysical evidence shows that the ETC may form large macromolecular assemblies (i.e. supercomplexes) that disintegrate in certain pathologies (e.g. heart failure or Barth syndrome) reminiscent of aging, we investigated the hypothesis that alterations in supercomplexes are partly responsible for the age-related loss of cardiac ETC function. In this dissertation, age-associated changes in supercomplex organization and stability were investigated in subsarcolemmal (SSM) and interfibrillary (IFM) mitochondria isolated from cardiac tissue from young (3-5 months) and old (24-28 months) male Fischer 344 rats. Blue native-PAGE (BN-PAGE) analysis of digitonin-solubilized mitochondrial membranes coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to investigate supercomplex organization. Results show that both SSM and IFM display supercomplexes comprised of various stoichiometries of complexes I, III and IV (never complex II), which typically organize as high mass (1500-2300 kDa) assemblies containing up to four copies of complex IV (i.e. I₁III₂IV[subscript N]-type supercomplexes). Interestingly, analysis of IFM proteins showed that, in general, supercomplex levels declined by up to 15 % (p < 0.05) with age; however, different degrees of supercomplex deterioration were observed, depending on the particular supercomplex investigated. Supercomplexes of the highest molecular weights (i.e. 1900-2300 kDa), which were also composed of the most complex stoichiometries (i.e. I1III2IVN, N ≥ 2), were primarily lost with age. In particular, I₁III₂IV₂, I₁III₂IV₃ and I₁III₂IV₄ supercomplexes were found to decline by 13% (p < 0.05), 30% (p < 0.05) and 45% (p < 0.05), respectively, on an age basis. Therefore, the age-associated loss of supercomplexes in IFM stems from destabilization of the assemblies that comprise several copies of complex IV, which could partially limit proper electron transfer to O₂ for its reduction, affecting mitochondrial respiratory capacity. In contrast to IFM, the aging defects of SSM supercomplexes appeared to be confined to the assembly comprised of only one copy of complex IV (I₁III₂IV₁, 1700 kDa) (37% loss; p = 0.06), while the higher molecular weight supercomplex sub-types that were most affected in IFM (i.e. I₁III₂IV[subscript N], N ≥ 2) were not significantly altered with age. Thus, the results from this dissertation indicate that mitochondria from different subcellular locations in the myocyte show different degrees of supercomplex destabilization in the aging rat heart. The more robust supercomplex deficits noted for IFM fit well with previous observations that electron transport characteristics of this subpopulation are more adversely affected with age than SSM. Although the underlying factor(s) of supercomplex deterioration are not fully known, the hypothesis that age-related alterations of certain constituents of the IMM (e.g. cardiolipin) may be important factors of supercomplex destabilization in cardiac mitochondria was investigated in this dissertation. To this end, LC-MS/MS characterization of supercomplex proteins and HPLC analysis of cardiolipin were used as approaches to elucidate potential factor(s) of supercomplex destabilization in the aging rat heart. Age-related alterations of cardiolipin levels and its acyl-chain content showed a strong parallel to the age-associated destabilization of supercomplexes. Specifically, cardiolipin levels declined by 10% (p < 0.05) in IFM, the mitochondrial subpopulation displaying the highest degree of supercomplex deterioration. In addition, the content of (18:2)₄-cardiolipin, the predominant species in the heart, was found to decline by 50% (p < 0.05) on average in both populations of cardiac mitochondria. Therefore, the data presented in this dissertation indicate that changes in cardiolipin may be at least one of the factors involved in supercomplex destabilization in the aging heart. Age-related decline in carnitine palmitoyltransferase I (CPT1) activity as a mitochondrial lesion that limits fatty acid catabolism in the rat heart. Loss of fatty acid utilization, another intrinsic factor of mitochondrial decay in the aged myocardium, has been associated with age-related alterations in the activity of carnitine palmitoyltransferase 1 (CPT1), the rate-controlling enzyme for overall fatty acid β-oxidation. Nevertheless, the exact molecular mechanism involved in the age-related loss of fatty acid-driven bioenergetics is not fully understood. In this dissertation, it was also investigated whether the aging lesion for fatty oxidation lies in a particular mitochondrial subpopulation or more generally results from cardiac decrements in L-carnitine levels. In order to clarify the role of each one of these factors, the effect of long-term dietary supplementation with the L-carnitine analogue, acetyl-L-carnitine (ALCAR), was also investigated. Results show that aging selectively decreases CPT1 activity in IFM by reducing enzyme catalytic efficiency for palmitoyl-CoA. IFM displayed a 28% (p < 0.05) loss of CPT1 activity, which correlated with a decline (41%, p < 0.05) in palmitoyl-CoA-driven state 3 respiration. Interestingly, SSM had preserved enzyme function and efficiently utilized palmitate. Analysis of IFM CPT1 kinetics showed both diminished V[subscript max] and K[subscript m] (60% and 49% respectively, p < 0.05) when palmitoyl-CoA was the substrate. However, no age-related changes in enzyme kinetics were evident with respect to L-carnitine. ALCAR supplementation restored CPT1 activity in heart IFM, but not apparently through remediation of L-carnitine levels. Rather, ALCAR influenced enzyme activity over time, potentially by modulating conditions in the aging heart that ultimately affect palmitoyl-CoA binding and CPT1 kinetics. In conclusion, this dissertation presents a characterization of age-associated alterations in the macromolecular organization of the IMM components that could partly explain the loss of mitochondrial oxidative capacity that affects the aging heart. In addition, the characterization of an age-related lesion of the controlling enzyme for β-oxidation is presented as another important factor that limits mitochondrial function and energy metabolism in cardiac mitochondria. Close

• 331. [Article] Scappoose Bay Watershed Assessment

  Abstract -- The Scappoose Bay Watershed Assessment focuses on habitat conditions for salmonids (salmon, steelhead and trout) in the watershed. The report follows the guidelines of the Oregon Watershed ...

  Citation × Citation Citation Abstract Copy Title: Scappoose Bay Watershed Assessment Abstract -- The Scappoose Bay Watershed Assessment focuses on habitat conditions for salmonids (salmon, steelhead and trout) in the watershed. The report follows the guidelines of the Oregon Watershed Enhancement Manual (WPN 1999). The Scappoose Bay Watershed Assessment presents the existing baseline information on watershed conditions (based on available reports and data) and oral history interviews. A Geographic Information System (GIS) was built to display, analyze and store much of the data. Habitat factors for the decline of salmonids are compared, and major protection and restoration opportunities are identified and prioritized. This Phase I assessment does not generally provide the detailed field reconnaissance and comprehensive field studies that are necessary for proceeding with specific protection and restoration projects. Rather, this assessment lays out the groundwork for a second phase of assessment that bridges the gap between identifying major areas for action and conducting specific projects. Topics included are preliminary analysis of existing data, GIS base map and baseline information, historical habitat conditions, channel habitat typing, fisheries resource and habitat assessment, channel modifications, sediment sources, riparian and wetland conditions, water quality, water use and hydrology, refugia, watershed condition, data gaps, significant legal and public issues, prioritized preservation and restoration, opportunities, and GIS metadata. Title: Scappoose Bay Watershed Assessment Abstract -- The Scappoose Bay Watershed Assessment focuses on habitat conditions for salmonids (salmon, steelhead and trout) in the watershed. The report follows the guidelines of the Oregon Watershed Enhancement Manual (WPN 1999). The Scappoose Bay Watershed Assessment presents the existing baseline information on watershed conditions (based on available reports and data) and oral history interviews. A Geographic Information System (GIS) was built to display, analyze and store much of the data. Habitat factors for the decline of salmonids are compared, and major protection and restoration opportunities are identified and prioritized. This Phase I assessment does not generally provide the detailed field reconnaissance and comprehensive field studies that are necessary for proceeding with specific protection and restoration projects. Rather, this assessment lays out the groundwork for a second phase of assessment that bridges the gap between identifying major areas for action and conducting specific projects. Topics included are preliminary analysis of existing data, GIS base map and baseline information, historical habitat conditions, channel habitat typing, fisheries resource and habitat assessment, channel modifications, sediment sources, riparian and wetland conditions, water quality, water use and hydrology, refugia, watershed condition, data gaps, significant legal and public issues, prioritized preservation and restoration, opportunities, and GIS metadata. Close

• 332. [Article] “A Caretaker Responsibility”: Revisiting Klamath and Modoc Traditions of Plant Community Management

  Conventionally, the Klamath and Modoc Indians of south-central Oregon and northeastern California are depicted as hunter-gatherers, who took no active role in the management of plant communities. In the ...

  Citation × Citation Citation Abstract Copy Title: “A Caretaker Responsibility”: Revisiting Klamath and Modoc Traditions of Plant Community Management Author: Deur, Douglas Year: 2009 Conventionally, the Klamath and Modoc Indians of south-central Oregon and northeastern California are depicted as hunter-gatherers, who took no active role in the management of plant communities. In the course of a multi-year ethnographic effort, however, tribal elders have identified a complex of interrelated plant management practices that are consistent with contemporary definitions of plant cultivation. These include the management of black huckleberry (Vaccinium membranaceum) yields in subalpine environments, the management of marsh-edge environments for yellow pond lily (Nuphar polysepalum), the tending of ‘‘epos’’ or yampah (Perideridia spp.) digging sites, and the selective harvest of tree cambium, sap, and wood – especially from pines (Pinus spp.) and junipers (Juniperus spp). Together, these accounts suggest that plant management was widespread, that it often served to geographically concentrate culturally preferred species, and that it was rooted as much in cosmological motivations as economic ones. Factors contributing to the decline of traditional management practices are also briefly addressed. Title: “A Caretaker Responsibility”: Revisiting Klamath and Modoc Traditions of Plant Community Management Author: Deur, Douglas Year: 2009 Conventionally, the Klamath and Modoc Indians of south-central Oregon and northeastern California are depicted as hunter-gatherers, who took no active role in the management of plant communities. In the course of a multi-year ethnographic effort, however, tribal elders have identified a complex of interrelated plant management practices that are consistent with contemporary definitions of plant cultivation. These include the management of black huckleberry (Vaccinium membranaceum) yields in subalpine environments, the management of marsh-edge environments for yellow pond lily (Nuphar polysepalum), the tending of ‘‘epos’’ or yampah (Perideridia spp.) digging sites, and the selective harvest of tree cambium, sap, and wood – especially from pines (Pinus spp.) and junipers (Juniperus spp). Together, these accounts suggest that plant management was widespread, that it often served to geographically concentrate culturally preferred species, and that it was rooted as much in cosmological motivations as economic ones. Factors contributing to the decline of traditional management practices are also briefly addressed. Close

• 333. [Article] Predation by zooplankton on Batrachochytrium dendrobatidis: Biological control of the deadly amphibian chytrid fungus?

  This is the authors’ post-peer review version of the final article. The final published version is copyrighted by Springer and can be found at: http://www.springer.com/life+sciences/evolutionary+%26+de...

  Citation × Citation Citation Abstract Copy Title: Predation by zooplankton on Batrachochytrium dendrobatidis: Biological control of the deadly amphibian chytrid fungus? Author: Buck, Julia C., Truong, Lisa, Blaustein, Andrew R. This is the authors’ post-peer review version of the final article. The final published version is copyrighted by Springer and can be found at: http://www.springer.com/life+sciences/evolutionary+%26+developmental+biology/journal/10531. Title: Predation by zooplankton on Batrachochytrium dendrobatidis: Biological control of the deadly amphibian chytrid fungus? Author: Buck, Julia C., Truong, Lisa, Blaustein, Andrew R. This is the authors’ post-peer review version of the final article. The final published version is copyrighted by Springer and can be found at: http://www.springer.com/life+sciences/evolutionary+%26+developmental+biology/journal/10531. Close

• 334. [Article] Distribution and abundance of marbled murrelets at sea on the Oregon coast in 1992 : final report

  "Marbled Murrelets (Brachyramphus marmoratus) are small diving seabirds who have the unique adaptation of flying inland to nest in large forest trees along the west coast of North America (see review in ...

  Citation × Citation Citation Abstract Copy Title: Distribution and abundance of marbled murrelets at sea on the Oregon coast in 1992 : final report Author: Cruz, Janice H., Gaffney, Ian, Strong, Craig S., Gilardi, John R. "Marbled Murrelets (Brachyramphus marmoratus) are small diving seabirds who have the unique adaptation of flying inland to nest in large forest trees along the west coast of North America (see review in Marshall, 1988). The dual nature of their life history, as forest bird and as seabird, presents problems to studying their biology as well as to conservation efforts. Loss of nesting forest habitat, extreme vulnerability to oil pollution (King and Sanger, 1979), and speculation that the population is in serious decline has led to their listing as a federally threatened species in October, 1992. There is currently a great need to understand more about Marbled Murrelet nesting and at-sea biology and behavior, so that appropriate conservation management plans can be developed. This report summarizes our findings from marine transect surveys of Marbled Murrelets along the open Oregon coast from June to August, 1992." (From Introduction) Title: Distribution and abundance of marbled murrelets at sea on the Oregon coast in 1992 : final report Author: Cruz, Janice H., Gaffney, Ian, Strong, Craig S., Gilardi, John R. "Marbled Murrelets (Brachyramphus marmoratus) are small diving seabirds who have the unique adaptation of flying inland to nest in large forest trees along the west coast of North America (see review in Marshall, 1988). The dual nature of their life history, as forest bird and as seabird, presents problems to studying their biology as well as to conservation efforts. Loss of nesting forest habitat, extreme vulnerability to oil pollution (King and Sanger, 1979), and speculation that the population is in serious decline has led to their listing as a federally threatened species in October, 1992. There is currently a great need to understand more about Marbled Murrelet nesting and at-sea biology and behavior, so that appropriate conservation management plans can be developed. This report summarizes our findings from marine transect surveys of Marbled Murrelets along the open Oregon coast from June to August, 1992." (From Introduction) Close

• 335. [Article] Land manager's guide to aspen management in Oregon

  Published September 2010. Reviewed November 2014. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog

  Citation × Citation Citation Abstract Copy Title: Land manager's guide to aspen management in Oregon Author: Littlefield, Betsy, Strong, Nicole, Oregon State University. Extension Service, Welch, Teresa, Stringer, Darin Published September 2010. Reviewed November 2014. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Land manager's guide to aspen management in Oregon Author: Littlefield, Betsy, Strong, Nicole, Oregon State University. Extension Service, Welch, Teresa, Stringer, Darin Published September 2010. Reviewed November 2014. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 336. [Article] The ecological and cultural importance of a species at risk of extinction, Pacific lamprey

  The cultural and ecological values of Pacific lamprey (Lampetra tridentata) have not been understood by Euro-Americans and thus their great decline has almost gone unnoticed except by Native Americans, ...

  Citation × Citation Citation Abstract Copy Title: The ecological and cultural importance of a species at risk of extinction, Pacific lamprey Author: Close, David A., Li, Hiram W., Fitzpatrick, Martin S. The cultural and ecological values of Pacific lamprey (Lampetra tridentata) have not been understood by Euro-Americans and thus their great decline has almost gone unnoticed except by Native Americans, who elevated the issue and initiated research to restore its populations, at least in the Columbia Basin. They regard Pacific lamprey as a highly valued resource and as a result ksuyas (lamprey) has become one of their cultural icons. Ksuyas are harvested to this day as a subsistence food by various tribes along the Pacific coast and are highly regarded for their cultural value. Interestingly, our review suggests that the Pacific lamprey plays an important role in the food web, may have acted as a buffer for salmon from predators, and may have been an important source of marine nutrients to oligotrophic watersheds. This is very different from the Euro- American perception that lampreys are pests. We suggest that cultural biases affected management policies. Title: The ecological and cultural importance of a species at risk of extinction, Pacific lamprey Author: Close, David A., Li, Hiram W., Fitzpatrick, Martin S. The cultural and ecological values of Pacific lamprey (Lampetra tridentata) have not been understood by Euro-Americans and thus their great decline has almost gone unnoticed except by Native Americans, who elevated the issue and initiated research to restore its populations, at least in the Columbia Basin. They regard Pacific lamprey as a highly valued resource and as a result ksuyas (lamprey) has become one of their cultural icons. Ksuyas are harvested to this day as a subsistence food by various tribes along the Pacific coast and are highly regarded for their cultural value. Interestingly, our review suggests that the Pacific lamprey plays an important role in the food web, may have acted as a buffer for salmon from predators, and may have been an important source of marine nutrients to oligotrophic watersheds. This is very different from the Euro- American perception that lampreys are pests. We suggest that cultural biases affected management policies. Close

• 337. [Article] Shifts in Microbial Communities Based Upon Transect Habitat

  Coral reef health has been in severe decline around the globe in the past several decades, in many cases due to direct human impact. Human action, such as overfishing, habitat destruction and nutrient ...

  Citation × Citation Citation Abstract Copy Title: Shifts in Microbial Communities Based Upon Transect Habitat Author: Greydanus, Logan Coral reef health has been in severe decline around the globe in the past several decades, in many cases due to direct human impact. Human action, such as overfishing, habitat destruction and nutrient loading, has caused coral coverage to drop to record lows, threatening the future of these critically important biodiversity hotspots. This study investigates the changes in microbial community along reef transects on the South Pacific island of Moorea. Samples were collected at three distinct habitats along reef transects: Fringing Reef, Back Reef, and Cresting Reef. Reef habitats were compared between three regions around the island: North, East and West. Results indicate that there is a significant difference in Bacterial and Archaeal (16S) species between the inner fringing reef habitat and the outer Cresting and Back reef habitats. This difference can consistently be seen across all regions sampled around Moorea. Comparison of the 16S communities based solely on region resulted in no significant difference, suggesting that the primary driver of microbial diversity is location on transect and not region. Based on these results, it appears the Bacterial and Archaeal communities are defined by the reef habitat they belong to and that these communities are not unique to region. Title: Shifts in Microbial Communities Based Upon Transect Habitat Author: Greydanus, Logan Coral reef health has been in severe decline around the globe in the past several decades, in many cases due to direct human impact. Human action, such as overfishing, habitat destruction and nutrient loading, has caused coral coverage to drop to record lows, threatening the future of these critically important biodiversity hotspots. This study investigates the changes in microbial community along reef transects on the South Pacific island of Moorea. Samples were collected at three distinct habitats along reef transects: Fringing Reef, Back Reef, and Cresting Reef. Reef habitats were compared between three regions around the island: North, East and West. Results indicate that there is a significant difference in Bacterial and Archaeal (16S) species between the inner fringing reef habitat and the outer Cresting and Back reef habitats. This difference can consistently be seen across all regions sampled around Moorea. Comparison of the 16S communities based solely on region resulted in no significant difference, suggesting that the primary driver of microbial diversity is location on transect and not region. Based on these results, it appears the Bacterial and Archaeal communities are defined by the reef habitat they belong to and that these communities are not unique to region. Close

• 338. [Article] Population structure and genetic variation in the Hawaiian Opakapaka (Pristipomoides filamentosus): Evidence of a genetic bottleneck in offspring of a captive broodstock

  The Hawaiian Archipelago is a biologically diverse environment with dynamic interactions between human and biological populations. Political, social, and scientific communities are placing importance on ...

  Citation × Citation Citation Abstract Copy Title: Population structure and genetic variation in the Hawaiian Opakapaka (Pristipomoides filamentosus): Evidence of a genetic bottleneck in offspring of a captive broodstock Author: Meltvedt, Ariana The Hawaiian Archipelago is a biologically diverse environment with dynamic interactions between human and biological populations. Political, social, and scientific communities are placing importance on sustainable management of fisheries resources throughout the islands. Many economically important bottomfish in Hawaii have declined in population size due to anthropogenic and environmental pressures. Efforts to develop stock enhancement programs to supplement wild populations are in development for several species, including the Hawaiian pink snapper, Opakapaka (Pristipomoides filamentosus). This study contributes knowledge of spawning behavior in a captive broodstock and genetic variation in spawned embryos on Oahu through population analyses. Spawning frequency in the broodstock appears to be synchronized with lunar cycles and is potentially affected by combinations of environmental parameters. This study documented low genetic diversity and heterozygosity in the captive stock offspring in comparison to other populations, raising questions on the potential success for stock enhancement initiatives. F-statistic analyses and other genetic tools reveal significantly differentiated population structure in the broodstock offspring from other populations, providing evidence for the presence of a genetic bottleneck in captive broodstock offspring. This study presents this knowledge with implications for future Opakapaka management and stock enhancement practices in Pacific bottomfish. Title: Population structure and genetic variation in the Hawaiian Opakapaka (Pristipomoides filamentosus): Evidence of a genetic bottleneck in offspring of a captive broodstock Author: Meltvedt, Ariana The Hawaiian Archipelago is a biologically diverse environment with dynamic interactions between human and biological populations. Political, social, and scientific communities are placing importance on sustainable management of fisheries resources throughout the islands. Many economically important bottomfish in Hawaii have declined in population size due to anthropogenic and environmental pressures. Efforts to develop stock enhancement programs to supplement wild populations are in development for several species, including the Hawaiian pink snapper, Opakapaka (Pristipomoides filamentosus). This study contributes knowledge of spawning behavior in a captive broodstock and genetic variation in spawned embryos on Oahu through population analyses. Spawning frequency in the broodstock appears to be synchronized with lunar cycles and is potentially affected by combinations of environmental parameters. This study documented low genetic diversity and heterozygosity in the captive stock offspring in comparison to other populations, raising questions on the potential success for stock enhancement initiatives. F-statistic analyses and other genetic tools reveal significantly differentiated population structure in the broodstock offspring from other populations, providing evidence for the presence of a genetic bottleneck in captive broodstock offspring. This study presents this knowledge with implications for future Opakapaka management and stock enhancement practices in Pacific bottomfish. Close

• 339. [Article] Play behavior in the golden hamster

  Intensive observations were made of play behavior in the young hamster (Mesocricetus auratus) from 14 to 54 days of age. Behavior was recorded using movie film and a multi-channel event recorder. Play ...

  Citation × Citation Citation Abstract Copy Title: Play behavior in the golden hamster Author: Kreitlow, Jean Louise Intensive observations were made of play behavior in the young hamster (Mesocricetus auratus) from 14 to 54 days of age. Behavior was recorded using movie film and a multi-channel event recorder. Play was first seen at 14 days of age. The amount of play increased rapidly thereafter, remaining relatively high until about day 40. Playing then decreased, becoming sporadic by day 54. This decline corresponded to an increase in agonistic encounters. Play bouts were generally shorter during the first days of play, and also shorter after day 40, as aggression increased. When play bout duration was plotted as a survivorship function, the result was significantly different from a straight line, indicating that the probability of a bout ending is not independent of how long it has lasted. Play bouts were relatively simple at first, becoming more complex as motor patterns were added during ontogeny. The sequence of motor patterns in playful interactions resembled the patterns later seen in agonistic encounters. The data are discussed with regard to some of the current theories of play. Play does not seem to function for exercise or the formation of positive social bonds. It is hypothesized that play in this species may be only the ontogeny of agonistic behavior. Title: Play behavior in the golden hamster Author: Kreitlow, Jean Louise Intensive observations were made of play behavior in the young hamster (Mesocricetus auratus) from 14 to 54 days of age. Behavior was recorded using movie film and a multi-channel event recorder. Play was first seen at 14 days of age. The amount of play increased rapidly thereafter, remaining relatively high until about day 40. Playing then decreased, becoming sporadic by day 54. This decline corresponded to an increase in agonistic encounters. Play bouts were generally shorter during the first days of play, and also shorter after day 40, as aggression increased. When play bout duration was plotted as a survivorship function, the result was significantly different from a straight line, indicating that the probability of a bout ending is not independent of how long it has lasted. Play bouts were relatively simple at first, becoming more complex as motor patterns were added during ontogeny. The sequence of motor patterns in playful interactions resembled the patterns later seen in agonistic encounters. The data are discussed with regard to some of the current theories of play. Play does not seem to function for exercise or the formation of positive social bonds. It is hypothesized that play in this species may be only the ontogeny of agonistic behavior. Close

• 340. [Article] Supply and Demand Analysis for Mussels in the Eu Market

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Supply and Demand Analysis for Mussels in the Eu Market Author: Nguyen, Thong Tien Abstract only. Title: Supply and Demand Analysis for Mussels in the Eu Market Author: Nguyen, Thong Tien Abstract only. Close

• 341. [Article] How Deep Is the European Union Fleet Fishing?

  No poster available.

  Citation × Citation Citation Abstract Copy Title: How Deep Is the European Union Fleet Fishing? Author: Villasante, Sebastian No poster available. Title: How Deep Is the European Union Fleet Fishing? Author: Villasante, Sebastian No poster available. Close

• 342. [Article] Is Aquaculture Production Growing in Latin America and the Caribbean?

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Is Aquaculture Production Growing in Latin America and the Caribbean? Author: Villasante, Sebastian, Rodriguez, Gonzalo Abstract only. Title: Is Aquaculture Production Growing in Latin America and the Caribbean? Author: Villasante, Sebastian, Rodriguez, Gonzalo Abstract only. Close

• 343. [Article] Sea Turtles of Bahia Magdalena, Baja California Sur, Mexico: Demand and Supply of an Endangered Species

  Sea turtles have historically been a primary resource for many of the coastal inhabitants of Bahia Magdalena, Baja California Sur, Mexico. Despite their endangered status and the implementation in 1990 ...

  Citation × Citation Citation Abstract Copy Title: Sea Turtles of Bahia Magdalena, Baja California Sur, Mexico: Demand and Supply of an Endangered Species Author: Garcia-Martinez, S., Nichols, W.J. Year: 2001 Sea turtles have historically been a primary resource for many of the coastal inhabitants of Bahia Magdalena, Baja California Sur, Mexico. Despite their endangered status and the implementation in 1990 of Mexican laws prohibiting the harvest of sea turtles, the demand for and the supply of these animals has persisted to some degree. To determine the current demand for sea turtles 122 surveys and 56 interviews were conducted (June 12th-30th, 1999) throughout the Bahia Magdalena region. Through a generalized least squares (GLS) analysis it was estimated that 35.7% of the variation in demand was explained by six independent variables. The GLS model shows that the family size, special occasions of consumption such as birthdays, and the decline in sea turtle populations positively affect the demand function. The person's occupation, monthly income, and the 1990 ban on sea turtle harvest negatively affect this demand. Ninety-four surveys and seventy interviews conducted in the region (July 24th-August 1st, 1999) were used to describe a supply function. The GLS estimation indicates that 27.8% of the variation in the supply of sea turtles in the bay is influenced by nine variables. Age, level of education, fishing practices, number of dependents, availability of sea turtles, and culture significantly affect the supply of sea turtles in the Bahia Magdalena region. Title: Sea Turtles of Bahia Magdalena, Baja California Sur, Mexico: Demand and Supply of an Endangered Species Author: Garcia-Martinez, S., Nichols, W.J. Year: 2001 Sea turtles have historically been a primary resource for many of the coastal inhabitants of Bahia Magdalena, Baja California Sur, Mexico. Despite their endangered status and the implementation in 1990 of Mexican laws prohibiting the harvest of sea turtles, the demand for and the supply of these animals has persisted to some degree. To determine the current demand for sea turtles 122 surveys and 56 interviews were conducted (June 12th-30th, 1999) throughout the Bahia Magdalena region. Through a generalized least squares (GLS) analysis it was estimated that 35.7% of the variation in demand was explained by six independent variables. The GLS model shows that the family size, special occasions of consumption such as birthdays, and the decline in sea turtle populations positively affect the demand function. The person's occupation, monthly income, and the 1990 ban on sea turtle harvest negatively affect this demand. Ninety-four surveys and seventy interviews conducted in the region (July 24th-August 1st, 1999) were used to describe a supply function. The GLS estimation indicates that 27.8% of the variation in the supply of sea turtles in the bay is influenced by nine variables. Age, level of education, fishing practices, number of dependents, availability of sea turtles, and culture significantly affect the supply of sea turtles in the Bahia Magdalena region. Close

• 344. [Article] Distribution and population estimates of marbled murrelets at sea in Oregon during the summers of 1992 and 1993 : final report

  "In the past 6 years research effort on the Marbled Murrelet (Brachyramphus marmoratus) has increased in response to an apparent dramatic decline in their numbers on the west coast south of British Columbia ...

  Citation × Citation Citation Abstract Copy Title: Distribution and population estimates of marbled murrelets at sea in Oregon during the summers of 1992 and 1993 : final report Author: Strong, Craig S., Oregon. Dept. of Fish and Wildlife "In the past 6 years research effort on the Marbled Murrelet (Brachyramphus marmoratus) has increased in response to an apparent dramatic decline in their numbers on the west coast south of British Columbia (Marshall, 1988, Carter and Erickson 1992, Nelson et al. 1992). Their recent listing as a federally threatened species (Federal Register, Oct. 1992) adds a further imperative to learn more of this birds nesting and at-sea biology, population size, and reproductive parameters so that meaningful management and recovery plans may be developed. This project was initiated to fill a gap in knowledge of abundance, distribution, and at-sea biology of Marbled Murrelets along the Oregon coast." (from the Introduction) Title: Distribution and population estimates of marbled murrelets at sea in Oregon during the summers of 1992 and 1993 : final report Author: Strong, Craig S., Oregon. Dept. of Fish and Wildlife "In the past 6 years research effort on the Marbled Murrelet (Brachyramphus marmoratus) has increased in response to an apparent dramatic decline in their numbers on the west coast south of British Columbia (Marshall, 1988, Carter and Erickson 1992, Nelson et al. 1992). Their recent listing as a federally threatened species (Federal Register, Oct. 1992) adds a further imperative to learn more of this birds nesting and at-sea biology, population size, and reproductive parameters so that meaningful management and recovery plans may be developed. This project was initiated to fill a gap in knowledge of abundance, distribution, and at-sea biology of Marbled Murrelets along the Oregon coast." (from the Introduction) Close

• 345. [Article] Building economically resilient rural communities

  Rural communities will continue to be disproportionately shocked by economic fluctuations. Market forces are likely to lead to the decline of many rural communities and they will need to be economically ...

  Citation × Citation Citation Abstract Copy Title: Building economically resilient rural communities Author: Sorte, Bruce Michael Rural communities will continue to be disproportionately shocked by economic fluctuations. Market forces are likely to lead to the decline of many rural communities and they will need to be economically resilient to survive. This thesis draws on several social sciences and the natural sciences to develop ideas that communities can use to respond effectively to economic shocks. Specifically, it uses concepts from Douglas North (institutions, organizations and entrepreneurs), A. 0. Hirschman (exit, voice and loyalty), Emery Castle (rural capital) and others to develop a definition of economic resilience and consider how organizations in rural communities may affect economic resilience. It provides an example of how input-output analysis can be used to compare the impacts of a hypothetical shock under two simulated community response scenarios. Findings of this work include: 1) Resilience and keystone species are two of many concepts developed by the natural sciences that can be adapted to the social sciences to help explain and predict the dynamics of economic change. 2) Organizations, in this simulation, significantly reinforced individual efforts to return to equilibrium after a shock. 3) Institutions, primarily informal ones, will determine the latitude that organizations have to build economic resilience in rural communities. This thesis has shown, within the context of a hypothetical shock and simulated scenarios, that effective organizations, which take responsibility for maintaining community resources and processes, can significantly improve economic resilience. Title: Building economically resilient rural communities Author: Sorte, Bruce Michael Rural communities will continue to be disproportionately shocked by economic fluctuations. Market forces are likely to lead to the decline of many rural communities and they will need to be economically resilient to survive. This thesis draws on several social sciences and the natural sciences to develop ideas that communities can use to respond effectively to economic shocks. Specifically, it uses concepts from Douglas North (institutions, organizations and entrepreneurs), A. 0. Hirschman (exit, voice and loyalty), Emery Castle (rural capital) and others to develop a definition of economic resilience and consider how organizations in rural communities may affect economic resilience. It provides an example of how input-output analysis can be used to compare the impacts of a hypothetical shock under two simulated community response scenarios. Findings of this work include: 1) Resilience and keystone species are two of many concepts developed by the natural sciences that can be adapted to the social sciences to help explain and predict the dynamics of economic change. 2) Organizations, in this simulation, significantly reinforced individual efforts to return to equilibrium after a shock. 3) Institutions, primarily informal ones, will determine the latitude that organizations have to build economic resilience in rural communities. This thesis has shown, within the context of a hypothetical shock and simulated scenarios, that effective organizations, which take responsibility for maintaining community resources and processes, can significantly improve economic resilience. Close

• 346. [Article] Leaf-feeding sawflies in wheat

  Published October 2003. Reviewed July 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog

  Citation × Citation Citation Abstract Copy Title: Leaf-feeding sawflies in wheat Author: Corp, Mary K., Fisher, Glenn C., Oregon State University. Extension Service Published October 2003. Reviewed July 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Leaf-feeding sawflies in wheat Author: Corp, Mary K., Fisher, Glenn C., Oregon State University. Extension Service Published October 2003. Reviewed July 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 347. [Article] OWEB Project Number 216-5042-12451 Phase IV - Wallowa Mountains Bull Trout Monitoring, Final Report

  Abstract -- Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. Spawning survey data is important for determining relative abundance and distribution ...

  Citation × Citation Citation Abstract Copy Title: OWEB Project Number 216-5042-12451 Phase IV - Wallowa Mountains Bull Trout Monitoring, Final Report Abstract -- Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. Spawning survey data is important for determining relative abundance and distribution trends in bull trout populations. Without adequate funding, it has been difficult to find sufficient numbers of experienced bull trout surveyors and packers for surveys in the back-country, and to obtain adequate supplies to get the work accomplished. OWEB funding supported the continued survey of bull trout spawning areas in years 2016 through 2018 in the Grande Ronde and Imnaha drainages of northeast Oregon. Surveys were conducted by fisheries consultants, the Service, Nez Perce Tribe, the Oregon Department of Fish and Wildlife, U.S. Forest Service, Freshwater Trust, Wallowa Resources, Anderson Perry, Inc., Grande Ronde Model Watershed, and volunteers. Timing of spawning, total redds, redd sizes, and redd locations are documented in the attached report. In 2016-2018, surveys were located on the Lostine and Imnaha Rivers, and Big Sheep and Bear Creeks. In addition, the Upper Minam and Wenaha were surveyed in 2018. OWEB funding helped to accomplish a total of 43.3, 41.1, and 71.7 stream miles surveyed in 2016, 2017, and 2018, respectively. Title: OWEB Project Number 216-5042-12451 Phase IV - Wallowa Mountains Bull Trout Monitoring, Final Report Abstract -- Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. Spawning survey data is important for determining relative abundance and distribution trends in bull trout populations. Without adequate funding, it has been difficult to find sufficient numbers of experienced bull trout surveyors and packers for surveys in the back-country, and to obtain adequate supplies to get the work accomplished. OWEB funding supported the continued survey of bull trout spawning areas in years 2016 through 2018 in the Grande Ronde and Imnaha drainages of northeast Oregon. Surveys were conducted by fisheries consultants, the Service, Nez Perce Tribe, the Oregon Department of Fish and Wildlife, U.S. Forest Service, Freshwater Trust, Wallowa Resources, Anderson Perry, Inc., Grande Ronde Model Watershed, and volunteers. Timing of spawning, total redds, redd sizes, and redd locations are documented in the attached report. In 2016-2018, surveys were located on the Lostine and Imnaha Rivers, and Big Sheep and Bear Creeks. In addition, the Upper Minam and Wenaha were surveyed in 2018. OWEB funding helped to accomplish a total of 43.3, 41.1, and 71.7 stream miles surveyed in 2016, 2017, and 2018, respectively. Close

• 348. [Article] Long-term Responses of Phalaris arundinacea and Columbia River Bottomland Vegetation to Managed Flooding

  I sought to determine the effect of managed flooding on Phalaris arundinacea L. and other plant species distributions in a large wetland complex, Smith and Bybee Wetlands (SBW), in northwestern Oregon. ...

  Citation × Citation Citation Abstract Copy Title: Long-term Responses of Phalaris arundinacea and Columbia River Bottomland Vegetation to Managed Flooding Author: Farrelly, Tina Schantz Year: 2012 I sought to determine the effect of managed flooding on Phalaris arundinacea L. and other plant species distributions in a large wetland complex, Smith and Bybee Wetlands (SBW), in northwestern Oregon. Altered hydrology has reduced historically high spring flow and prematurely initiated the historic summer drying period at SBW. This alteration has increased the coverage of invasive plants (e.g., P. arundinacea) causing a decrease in native plant cover and thus degrading ecological functions. SBW managers installed a water control structure (WCS) between SBW and the Columbia Slough/River system to impound winter rainfall and thus approximate the ecological benefits that natural flooding provided as well as reduce the abundance of P. arundinacea. Prior researchers conducted intensive vegetation and hydrological monitoring in 2003 (during the season immediately before WCS installation) and 2004. I conducted similar analysis in the fifth and sixth years, 2008 and 2009, following establishment of the WCS. Both study years, I determined percent cover of all vegetation on transects established in 2003. The results, including 2004, as well as 2008 and 2009 showed a reduced cover of P. arundinacea in areas experiencing at least 0.6 meters of inundation and an increased cover of native plant communities when compared to the 2003 baseline data. Native Carex aperta Boott. cover increased 7-fold from 0.3% to 2.3%; Polygonum species cover increased from 20.0% to 52.6%; and Salix lucida Muhl. ssp. lasiandra (Benth.) E. Murray cover increased from 10.9% to 15.5% cover. P. arundinacea declined by over one-third from 44.4% to 28.1% cover following water management. Since hydrology management began, the native Polygonum species community replaced P. arundinacea as the dominant species in the emergent zone. The results of this study refined the suggested depth of inundation needed to reduce P. arundinacea cover in such lake-wetland complexes as SBW from 0.85 meters (based on 2004 study results) to 0.6 meters. Shannon Diversity decreased following water management. The findings of this study demonstrated that water management can enhance native bottomland communities, especially those comprised of obligate wetland species, and reduce P. arundinacea cover in areas experiencing at least 0.6 meters of inundation. Title: Long-term Responses of Phalaris arundinacea and Columbia River Bottomland Vegetation to Managed Flooding Author: Farrelly, Tina Schantz Year: 2012 I sought to determine the effect of managed flooding on Phalaris arundinacea L. and other plant species distributions in a large wetland complex, Smith and Bybee Wetlands (SBW), in northwestern Oregon. Altered hydrology has reduced historically high spring flow and prematurely initiated the historic summer drying period at SBW. This alteration has increased the coverage of invasive plants (e.g., P. arundinacea) causing a decrease in native plant cover and thus degrading ecological functions. SBW managers installed a water control structure (WCS) between SBW and the Columbia Slough/River system to impound winter rainfall and thus approximate the ecological benefits that natural flooding provided as well as reduce the abundance of P. arundinacea. Prior researchers conducted intensive vegetation and hydrological monitoring in 2003 (during the season immediately before WCS installation) and 2004. I conducted similar analysis in the fifth and sixth years, 2008 and 2009, following establishment of the WCS. Both study years, I determined percent cover of all vegetation on transects established in 2003. The results, including 2004, as well as 2008 and 2009 showed a reduced cover of P. arundinacea in areas experiencing at least 0.6 meters of inundation and an increased cover of native plant communities when compared to the 2003 baseline data. Native Carex aperta Boott. cover increased 7-fold from 0.3% to 2.3%; Polygonum species cover increased from 20.0% to 52.6%; and Salix lucida Muhl. ssp. lasiandra (Benth.) E. Murray cover increased from 10.9% to 15.5% cover. P. arundinacea declined by over one-third from 44.4% to 28.1% cover following water management. Since hydrology management began, the native Polygonum species community replaced P. arundinacea as the dominant species in the emergent zone. The results of this study refined the suggested depth of inundation needed to reduce P. arundinacea cover in such lake-wetland complexes as SBW from 0.85 meters (based on 2004 study results) to 0.6 meters. Shannon Diversity decreased following water management. The findings of this study demonstrated that water management can enhance native bottomland communities, especially those comprised of obligate wetland species, and reduce P. arundinacea cover in areas experiencing at least 0.6 meters of inundation. Close

• 349. [Article] Of Grouse and Golden Eggs: Can Ecosystems Be Managed Within a Species-Based Regulatory Framework?

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

  Citation × Citation Citation Abstract Copy Title: Of Grouse and Golden Eggs: Can Ecosystems Be Managed Within a Species-Based Regulatory Framework? Author: Johnson, Dustin D., Boyd, Chad S., Kerby, Jay D., Svejcar, Tony J., Davies, Kirk W. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Society for Range Management and can be found at: http://www.srmjournals.org/. Title: Of Grouse and Golden Eggs: Can Ecosystems Be Managed Within a Species-Based Regulatory Framework? Author: Johnson, Dustin D., Boyd, Chad S., Kerby, Jay D., Svejcar, Tony J., Davies, Kirk W. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Society for Range Management and can be found at: http://www.srmjournals.org/. Close

• 350. [Article] Ectomycorrhizal communities of ponderosa pine and lodgepole pine in the south-central Oregon pumice zone

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

  Citation × Citation Citation Abstract Copy Title: Ectomycorrhizal communities of ponderosa pine and lodgepole pine in the south-central Oregon pumice zone Author: Luoma, Daniel L., Garcia, Maria O., Jones, Melanie D., Smith, Jane E. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/572 Title: Ectomycorrhizal communities of ponderosa pine and lodgepole pine in the south-central Oregon pumice zone Author: Luoma, Daniel L., Garcia, Maria O., Jones, Melanie D., Smith, Jane E. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/572 Close

• 351. [Article] Responses and relationships among Fusarium species, sweet corn, and western spotted cucumber beetles

  Sweet corn (Zea mays L.) yields in the Willamette Valley of Oregon have been declining since the early 1990’s. Studies were done to determine if there is a relationship between ear weight and several ...

  Citation × Citation Citation Abstract Copy Title: Responses and relationships among Fusarium species, sweet corn, and western spotted cucumber beetles Author: Miller, Nathan L. (Nathan Louis) Sweet corn (Zea mays L.) yields in the Willamette Valley of Oregon have been declining since the early 1990’s. Studies were done to determine if there is a relationship between ear weight and several disease parameters including necrotic crowns or stalk nodes, nodal root rot, radicle root rot, and sub-crown internode rot. Regression analysis indicated that plants with more necrotic crown tissues have lower ear weights and crown necrosis was the best predictor of ear weight at harvest. Fungal isolations from crown tissues indicated that presence of Fusarium oxysporum was associated with more necrotic crowns and lower ear weights. Fusarium verticillioides was also associated with darker crowns and nodes. Fluid conductance tests indicated that plants with darker stalk nodes had a reduction in fluid passage through a 30-cm stalk section. Isolates of several species of Fusarium were examined for their ability to cause crown and stalk node rot in two field and two greenhouse trials. Seed kernel inoculation with F. oxysporum and F. verticillioides resulted in plants with darker crowns and lower ear weights, although differences were not always significant. Both of these fungi were recovered from crown tissues of the majority of mature corn plants sampled in pathogenicity trials. It was also observed that seed kernel inoculation with these Fusarium species resulted in plants having greater root damage attributed to the western spotted cucumber beetle (WSCB), Diabrotica undecimpunctata undecimpunctata. Studies were conducted to determine if the beetles show feeding or oviposition preferences when sweet corn plants were grown from kernels inoculated with Fusarium species. Generally, plants grown from Fusarium-treated kernels had significantly more leaf-feeding injury of corn seedling from adult WSCB compared to the disinfested control. Plants grown from Fusarium-treated kernels were also found to have increased larval root feeding in field pathogenicity trials. It appears that sweet corn ear yield reductions in the Willamette Valley is at least partly attributed to crown and stalk node rot incited by Fusarium species, and WSCB injury could be compounded with Fusarium injury, causing further stress of diseased sweet corn plants when these beetles are present. Title: Responses and relationships among Fusarium species, sweet corn, and western spotted cucumber beetles Author: Miller, Nathan L. (Nathan Louis) Sweet corn (Zea mays L.) yields in the Willamette Valley of Oregon have been declining since the early 1990’s. Studies were done to determine if there is a relationship between ear weight and several disease parameters including necrotic crowns or stalk nodes, nodal root rot, radicle root rot, and sub-crown internode rot. Regression analysis indicated that plants with more necrotic crown tissues have lower ear weights and crown necrosis was the best predictor of ear weight at harvest. Fungal isolations from crown tissues indicated that presence of Fusarium oxysporum was associated with more necrotic crowns and lower ear weights. Fusarium verticillioides was also associated with darker crowns and nodes. Fluid conductance tests indicated that plants with darker stalk nodes had a reduction in fluid passage through a 30-cm stalk section. Isolates of several species of Fusarium were examined for their ability to cause crown and stalk node rot in two field and two greenhouse trials. Seed kernel inoculation with F. oxysporum and F. verticillioides resulted in plants with darker crowns and lower ear weights, although differences were not always significant. Both of these fungi were recovered from crown tissues of the majority of mature corn plants sampled in pathogenicity trials. It was also observed that seed kernel inoculation with these Fusarium species resulted in plants having greater root damage attributed to the western spotted cucumber beetle (WSCB), Diabrotica undecimpunctata undecimpunctata. Studies were conducted to determine if the beetles show feeding or oviposition preferences when sweet corn plants were grown from kernels inoculated with Fusarium species. Generally, plants grown from Fusarium-treated kernels had significantly more leaf-feeding injury of corn seedling from adult WSCB compared to the disinfested control. Plants grown from Fusarium-treated kernels were also found to have increased larval root feeding in field pathogenicity trials. It appears that sweet corn ear yield reductions in the Willamette Valley is at least partly attributed to crown and stalk node rot incited by Fusarium species, and WSCB injury could be compounded with Fusarium injury, causing further stress of diseased sweet corn plants when these beetles are present. Close

• 352. [Article] Impacts of post-fire salvage logging on soil chemistry, physical properties and bacterial community composition in a mixed-conifer forest in central Oregon

  Land managers, scientists, and the interested public are confronted with uncertainty about the impacts of salvage logging on soil productivity. In recent years, stand-replacing wildfires in the western ...

  Citation × Citation Citation Abstract Copy Title: Impacts of post-fire salvage logging on soil chemistry, physical properties and bacterial community composition in a mixed-conifer forest in central Oregon Author: Jennings, Tara Nicolle Land managers, scientists, and the interested public are confronted with uncertainty about the impacts of salvage logging on soil productivity. In recent years, stand-replacing wildfires in the western United States have increased in frequency, prompting the need to evaluate the effect of post-fire treatments on forest ecosystem recovery. This study examined whether compaction and subsoiling after post-fire salvage logging impacted the structure, metabolism, and function of soil bacterial communities, which were assessed using terminal restriction fragment length polymorphism (T-RFLP) and Biolog Ecoplates. Supporting data for these salvage logging effects included soil biological activities, soil chemistry, and physical soil properties in a mixed conifer forest in central Oregon. Post-fire salvage logging treatments had little effect on soil bacterial community richness, suggesting that soil bacteria in these post-fire landscapes are both tolerant of the occurrence of fires and resilient to disturbance. However, even though a statistically significant difference in bacterial species richness was not detected among treatments, a greater cumulative mean number of species was found across six sampling seasons in the compacted soil treatment compared to the fire-only and subsoiled treatments. This trend may be due to less predation on the soil bacteria by microbivores in the soil pores reduced in size by compaction. Additionally, there was a significant decline in the mean number of species after the spring 2007 sampling. A NMS ordination of the mean number of species suggested that the bacterial community composition changed after spring 2007. Furthermore, the lack of difference in mean number of species among treatments suggests that time since fire had a stronger effect on the structure of the soil bacterial community than did logging disturbance. Plant-available phosphorus and nitrogen concentrations were lower in the mechanically disturbed treatments than in the fire-only treatment. Soil respiration and soil phosphatase rates both were higher in the fire-only treatment. Mechanical disturbance may have long-lasting effects in an already nutrient limited system. No other differences among treatments for soil chemical properties were detected. Soil bulk density was lowest in the subsoiled treatment. Microbial community responses to burning and compaction caused by harvesting can be negative, neutral, or positive. While many factors, in addition to soil chemical and physical properties, affect the microbial community richness and functional diversity, our results support other recent studies showing that soil bacteria are resilient in disturbed environments. Title: Impacts of post-fire salvage logging on soil chemistry, physical properties and bacterial community composition in a mixed-conifer forest in central Oregon Author: Jennings, Tara Nicolle Land managers, scientists, and the interested public are confronted with uncertainty about the impacts of salvage logging on soil productivity. In recent years, stand-replacing wildfires in the western United States have increased in frequency, prompting the need to evaluate the effect of post-fire treatments on forest ecosystem recovery. This study examined whether compaction and subsoiling after post-fire salvage logging impacted the structure, metabolism, and function of soil bacterial communities, which were assessed using terminal restriction fragment length polymorphism (T-RFLP) and Biolog Ecoplates. Supporting data for these salvage logging effects included soil biological activities, soil chemistry, and physical soil properties in a mixed conifer forest in central Oregon. Post-fire salvage logging treatments had little effect on soil bacterial community richness, suggesting that soil bacteria in these post-fire landscapes are both tolerant of the occurrence of fires and resilient to disturbance. However, even though a statistically significant difference in bacterial species richness was not detected among treatments, a greater cumulative mean number of species was found across six sampling seasons in the compacted soil treatment compared to the fire-only and subsoiled treatments. This trend may be due to less predation on the soil bacteria by microbivores in the soil pores reduced in size by compaction. Additionally, there was a significant decline in the mean number of species after the spring 2007 sampling. A NMS ordination of the mean number of species suggested that the bacterial community composition changed after spring 2007. Furthermore, the lack of difference in mean number of species among treatments suggests that time since fire had a stronger effect on the structure of the soil bacterial community than did logging disturbance. Plant-available phosphorus and nitrogen concentrations were lower in the mechanically disturbed treatments than in the fire-only treatment. Soil respiration and soil phosphatase rates both were higher in the fire-only treatment. Mechanical disturbance may have long-lasting effects in an already nutrient limited system. No other differences among treatments for soil chemical properties were detected. Soil bulk density was lowest in the subsoiled treatment. Microbial community responses to burning and compaction caused by harvesting can be negative, neutral, or positive. While many factors, in addition to soil chemical and physical properties, affect the microbial community richness and functional diversity, our results support other recent studies showing that soil bacteria are resilient in disturbed environments. Close

• 353. [Article] Contrasting demographic history and gene flow patterns of two mangrove species on either side of the Central American Isthmus

  This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by John Wiley & Sons Ltd. The published article can be found at: http://onlinelibrary.wiley.com/jo...

  Citation × Citation Citation Abstract Copy Title: Contrasting demographic history and gene flow patterns of two mangrove species on either side of the Central American Isthmus Author: Cerón‐Souza, Ivania, Schwarzbach, Andrea E., Gonzalez, Elena G. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by John Wiley & Sons Ltd. The published article can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%292045-7758 Title: Contrasting demographic history and gene flow patterns of two mangrove species on either side of the Central American Isthmus Author: Cerón‐Souza, Ivania, Schwarzbach, Andrea E., Gonzalez, Elena G. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by John Wiley & Sons Ltd. The published article can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%292045-7758 Close

• 354. [Article] Phylogeography and population structure of least terns (Sterna antillarum)

  Historically, least terns (Sterna antillarum) were one of the most common tern species in North America. However, population declines have resulted from direct and indirect anthropogenic pressures on ...

  Citation × Citation Citation Abstract Copy Title: Phylogeography and population structure of least terns (Sterna antillarum) Author: Draheim, Hope Historically, least terns (Sterna antillarum) were one of the most common tern species in North America. However, population declines have resulted from direct and indirect anthropogenic pressures on their breeding and foraging habitat. Three subspecies of least terns have been described within the United States: California least tern (S. a. browni), Interior least tern (S. a. athalassos), and East Coast least tern (S. a. antillarum). California and Interior subspecies are listed as endangered under the U.S. Endangered Species Act. However, the taxonomic status of least terns is a highly contentious issue which has implications for setting conservation priorities at erroneous levels of taxonomic distinctness. Thus, understanding population structure and taxonomy is critical for successful conservation of least terns. To clarify the phylogeographic patterns and population structure and evaluate the traditional subspecific designations, we examined variation in two mitochondrial DNA (mtDNA) genes and 10 microsatellite loci among least terns in North America. MtDNA control region sequences and 10 polymorphic microsatellite loci were used to evaluate traditional subspecific designations and genetic structure in least terns. While highly variable, results from mtDNA control region sequences and microsatellite loci did not support the three traditional subspecies that occur in the United States. However, mtDNA pairwise θST comparisons and AMOVA analyses indicated some genetic structure between the California and the remaining Interior/East Coast breeding areas indicating restriction to female-mediated gene flow. We evaluated phylogeographic patterns and demographic history of least terns using the mtDNA NADH dehydrogenase subunit 6 (ND6) sequences. Phylogeographic analysis revealed no association with geography or traditional subspecies designations. Population genetic analysis did reveal slight genetic differentiation between the California breeding areas and all other Interior/East Coast breeding areas. ND6 data indicate least terns have undergone a recent population expansion. Temporal comparisons between four contemporary breeding areas and their historical counterparts found significant difference in nucleotide diversity and seven historical haplotypes were absent from contemporary breeding areas suggesting loss of genetic diversity. This study is the most comprehensive evaluation of the genetic status of least terns, or any tern species, to date. It points to the need for better information on breeding site fidelity and natal philopatry across the species range was well as population-specific movements throughout the annual cycle. These finding should provide a helpful perspective to those planning conservation efforts throughout the species range. Title: Phylogeography and population structure of least terns (Sterna antillarum) Author: Draheim, Hope Historically, least terns (Sterna antillarum) were one of the most common tern species in North America. However, population declines have resulted from direct and indirect anthropogenic pressures on their breeding and foraging habitat. Three subspecies of least terns have been described within the United States: California least tern (S. a. browni), Interior least tern (S. a. athalassos), and East Coast least tern (S. a. antillarum). California and Interior subspecies are listed as endangered under the U.S. Endangered Species Act. However, the taxonomic status of least terns is a highly contentious issue which has implications for setting conservation priorities at erroneous levels of taxonomic distinctness. Thus, understanding population structure and taxonomy is critical for successful conservation of least terns. To clarify the phylogeographic patterns and population structure and evaluate the traditional subspecific designations, we examined variation in two mitochondrial DNA (mtDNA) genes and 10 microsatellite loci among least terns in North America. MtDNA control region sequences and 10 polymorphic microsatellite loci were used to evaluate traditional subspecific designations and genetic structure in least terns. While highly variable, results from mtDNA control region sequences and microsatellite loci did not support the three traditional subspecies that occur in the United States. However, mtDNA pairwise θST comparisons and AMOVA analyses indicated some genetic structure between the California and the remaining Interior/East Coast breeding areas indicating restriction to female-mediated gene flow. We evaluated phylogeographic patterns and demographic history of least terns using the mtDNA NADH dehydrogenase subunit 6 (ND6) sequences. Phylogeographic analysis revealed no association with geography or traditional subspecies designations. Population genetic analysis did reveal slight genetic differentiation between the California breeding areas and all other Interior/East Coast breeding areas. ND6 data indicate least terns have undergone a recent population expansion. Temporal comparisons between four contemporary breeding areas and their historical counterparts found significant difference in nucleotide diversity and seven historical haplotypes were absent from contemporary breeding areas suggesting loss of genetic diversity. This study is the most comprehensive evaluation of the genetic status of least terns, or any tern species, to date. It points to the need for better information on breeding site fidelity and natal philopatry across the species range was well as population-specific movements throughout the annual cycle. These finding should provide a helpful perspective to those planning conservation efforts throughout the species range. Close

• 355. [Article] The differential response of Fraxinus pennsylvanica, Liquidambar styraciflua, and Acer saccharinum to picloram as measured by CO₂ absorption and evolution

  The tolerance of woody plants to picloram (4amino-3,5,6-trichloropicolinic acid) has been shown by field applications to vary from mild to extreme. A laboratory study was done to investigate the basic ...

  Citation × Citation Citation Abstract Copy Title: The differential response of Fraxinus pennsylvanica, Liquidambar styraciflua, and Acer saccharinum to picloram as measured by CO₂ absorption and evolution Author: Webb, Warren Lewis, 1935- The tolerance of woody plants to picloram (4amino-3,5,6-trichloropicolinic acid) has been shown by field applications to vary from mild to extreme. A laboratory study was done to investigate the basic causes for this range of tolerance known to exist among three woody plant species, Fraxinus pennsylvanics, March, (green ash) resistant, Liquidambar styraoiflua L., (sweet gum) intermediate, and Acer saccharinum L., (silver maple) susceptible. Seedlings of each species were grown in a nutrient solution in a controlled environment room for at least three weeks prior to treatment with picloram. Comparable response curves of all three species were determined by measuring the change in CO₂ absorption and evolution rates as a function of picloram concentration in the nutrient solution. A second experiment measured the time-dependent change in plant CO₂ absorption and evolution at 0.1 ppm picloram. Photosynthesis and respiratory rates were measured by monitoring the change in CO₂ concentration in a closed flow system with a CO₂ gas analyzer. For plants in a similar physiological state, it was postulated that picloram-induced changes in CO₂ absorption and evolution are comparable measures of special response. The results of the second experiment show a recovery in the photosynthetic rates of green ash (B) and sweet gum (I) following 6 - 12 days of steady decline. This seems to indicate a resistance mechanism resulting from a shift in the primary biochemical pathways. Such a mechanism is not evident in silver maple. The respiration rate of sweet gum is slightly stimulated by 0.1 ppm picloram while that of silver maple is depressed to 30 per cent of its original value. This is further evidence for a relative biochemical tolerance of sweet gum. Also, an experiment designed to compare leaf absorption of 10 ppm picloram between sweet gum and silver maple showed no practical difference to exist. Inspection of the concentration-response curves (CO₂ absorption) indicates silver maple to be slightly less tolerant to picloram at 0.3 and 1.0 ppm than either sweet gum or green ash. However, the characteristic "dip" in the photosynthetic rates of sweet gum and green ash, as noted in experiment two, corresponds to the period (ten days) of picloram exposure. Therefore, sweet gum and green ash are shown to be less tolerant than is actually the case. Future work utilizing this means of measuring relative plant response among species should include a determination of this higher concentrations to damp the fluctuations. The picloram uptake pattern of each species was determined by sampling the nutrient solution at times corresponding to photosynthesis and respiration measurements. (Experiment tow) The picloram concentration was determined with gas chromatography. Green ash was shwed a slow accumulation of picloram while both silver maple and sweet gum showed similar patterns of initial picloram uptake followed by a release back to the nutrient solution. The release by silver maple is thought to be due to general plant deterioration with a resulting flow along the concentration gradient. The release from sweet gum is thought to be the result of active exudation processes which may also be a resistance mechanism. Title: The differential response of Fraxinus pennsylvanica, Liquidambar styraciflua, and Acer saccharinum to picloram as measured by CO₂ absorption and evolution Author: Webb, Warren Lewis, 1935- The tolerance of woody plants to picloram (4amino-3,5,6-trichloropicolinic acid) has been shown by field applications to vary from mild to extreme. A laboratory study was done to investigate the basic causes for this range of tolerance known to exist among three woody plant species, Fraxinus pennsylvanics, March, (green ash) resistant, Liquidambar styraoiflua L., (sweet gum) intermediate, and Acer saccharinum L., (silver maple) susceptible. Seedlings of each species were grown in a nutrient solution in a controlled environment room for at least three weeks prior to treatment with picloram. Comparable response curves of all three species were determined by measuring the change in CO₂ absorption and evolution rates as a function of picloram concentration in the nutrient solution. A second experiment measured the time-dependent change in plant CO₂ absorption and evolution at 0.1 ppm picloram. Photosynthesis and respiratory rates were measured by monitoring the change in CO₂ concentration in a closed flow system with a CO₂ gas analyzer. For plants in a similar physiological state, it was postulated that picloram-induced changes in CO₂ absorption and evolution are comparable measures of special response. The results of the second experiment show a recovery in the photosynthetic rates of green ash (B) and sweet gum (I) following 6 - 12 days of steady decline. This seems to indicate a resistance mechanism resulting from a shift in the primary biochemical pathways. Such a mechanism is not evident in silver maple. The respiration rate of sweet gum is slightly stimulated by 0.1 ppm picloram while that of silver maple is depressed to 30 per cent of its original value. This is further evidence for a relative biochemical tolerance of sweet gum. Also, an experiment designed to compare leaf absorption of 10 ppm picloram between sweet gum and silver maple showed no practical difference to exist. Inspection of the concentration-response curves (CO₂ absorption) indicates silver maple to be slightly less tolerant to picloram at 0.3 and 1.0 ppm than either sweet gum or green ash. However, the characteristic "dip" in the photosynthetic rates of sweet gum and green ash, as noted in experiment two, corresponds to the period (ten days) of picloram exposure. Therefore, sweet gum and green ash are shown to be less tolerant than is actually the case. Future work utilizing this means of measuring relative plant response among species should include a determination of this higher concentrations to damp the fluctuations. The picloram uptake pattern of each species was determined by sampling the nutrient solution at times corresponding to photosynthesis and respiration measurements. (Experiment tow) The picloram concentration was determined with gas chromatography. Green ash was shwed a slow accumulation of picloram while both silver maple and sweet gum showed similar patterns of initial picloram uptake followed by a release back to the nutrient solution. The release by silver maple is thought to be due to general plant deterioration with a resulting flow along the concentration gradient. The release from sweet gum is thought to be the result of active exudation processes which may also be a resistance mechanism. Close

• 356. [Article] Foraging in disturbed areas : a study of sweat bees (Hymenoptera: Halictidae) in Oregon

  Bees provide vital ecosystem services for cropping systems as well as natural landscapes. Declines in both both native bee and managed honey bee (Apis mellifera L.) populations has brought attention to ...

  Citation × Citation Citation Abstract Copy Title: Foraging in disturbed areas : a study of sweat bees (Hymenoptera: Halictidae) in Oregon Author: Broussard, Melissa Bees provide vital ecosystem services for cropping systems as well as natural landscapes. Declines in both both native bee and managed honey bee (Apis mellifera L.) populations has brought attention to the significance of their role as pollinators in managed and native ecosystems. As a result, conservation efforts have been undertaken to preserve them. While considerable attention has been given to honey bees, relatively little is known about many native bee species. Of particular interest is the family Halictidae, which can comprise the majority of observed individuals in many habitats. These, often small, bees are difficult to identify, and, as a result, relatively little is known about their preferred floral hosts. Because bee species assemblages vary significantly from region to region, it is important to have an understanding of local populations and their floral hosts. It is also important to understand factors which affect the quantity and quality of floral resources, such as anthropogenic disturbance. The Pacific Northwest is a diverse landscape, with rich agricultural and wildland environments that require pollinators in order to continue to thrive. Two studies examine the interface between these two systems, the first explores how roadside disturbance, which is prevalent across the world, impacts native pollinators across habitat types, and the second explores the diet of common native species, and how that diet changes across habitat types. In these studies, it was found that roadside disturbance was associated with reduced native bee diversity and abundance in the seasonally wet Willamette Valley of Oregon, but not in the more xeric Central Oregon. Bee abundance was positively correlated with temperature. Bee diet was more diverse in areas of scarce floral resources. In both regions, exotic plants were important floral hosts, representing nearly half of observed floral visitations. This thesis presents results of species analysis, floral richness and density correlations, and comparisons of floral resources used by different bee species. Implications and recommendations for land management are discussed. Title: Foraging in disturbed areas : a study of sweat bees (Hymenoptera: Halictidae) in Oregon Author: Broussard, Melissa Bees provide vital ecosystem services for cropping systems as well as natural landscapes. Declines in both both native bee and managed honey bee (Apis mellifera L.) populations has brought attention to the significance of their role as pollinators in managed and native ecosystems. As a result, conservation efforts have been undertaken to preserve them. While considerable attention has been given to honey bees, relatively little is known about many native bee species. Of particular interest is the family Halictidae, which can comprise the majority of observed individuals in many habitats. These, often small, bees are difficult to identify, and, as a result, relatively little is known about their preferred floral hosts. Because bee species assemblages vary significantly from region to region, it is important to have an understanding of local populations and their floral hosts. It is also important to understand factors which affect the quantity and quality of floral resources, such as anthropogenic disturbance. The Pacific Northwest is a diverse landscape, with rich agricultural and wildland environments that require pollinators in order to continue to thrive. Two studies examine the interface between these two systems, the first explores how roadside disturbance, which is prevalent across the world, impacts native pollinators across habitat types, and the second explores the diet of common native species, and how that diet changes across habitat types. In these studies, it was found that roadside disturbance was associated with reduced native bee diversity and abundance in the seasonally wet Willamette Valley of Oregon, but not in the more xeric Central Oregon. Bee abundance was positively correlated with temperature. Bee diet was more diverse in areas of scarce floral resources. In both regions, exotic plants were important floral hosts, representing nearly half of observed floral visitations. This thesis presents results of species analysis, floral richness and density correlations, and comparisons of floral resources used by different bee species. Implications and recommendations for land management are discussed. Close

• 357. [Article] The Effects of Road Noise on Pacific Chorus Frog Communication

  Amphibians are experiencing global population declines and are one of the most threatened groups of vertebrates. This can be attributed to multiple environmental stressors such as habitat loss, disease, ...

  Citation × Citation Citation Abstract Copy Title: The Effects of Road Noise on Pacific Chorus Frog Communication Author: Nelson, Danielle V. Amphibians are experiencing global population declines and are one of the most threatened groups of vertebrates. This can be attributed to multiple environmental stressors such as habitat loss, disease, invasive species, and climate change. For vocal amphibian species, loss of acoustic habitat due to anthropogenic noise may be yet another environmental stressor. The Pacific chorus frog (Pseudacris regilla) is the most common vocal species of the Pacific Northwest. It is described as a generalist that can occupy human-dominated habitat types, including agricultural and urban wetlands. As such, this species is exposed to anthropogenic noise which can interfere with vocalizations during the breeding season. We hypothesized that Pacific chorus frogs would alter the spatial and temporal structure of their breeding vocalizations to accommodate a widespread anthropogenic stressor: road noise. We compared Pacific chorus frog call structure and ambient road noise levels at 8 sites along a gradient of noise exposures in the Willamette Valley, Oregon, USA. We used both passive acoustic monitoring and directional recordings to determine source level (i.e. amplitude or volume), dominant frequency (i.e. pitch), call duration, and call rate of individual frogs and to quantify ambient road noise levels. We found that Pacific chorus frogs significantly reduced their call rate at relatively higher levels of ambient road noise, leading to a reduction in the amount of total time spent calling. We found no other changes to call structure (e.g. frequency and duration). The absence of additional call structure changes to mediate the impact of road noise resulted in a drastic reduction in the active call space of an individual frog. Coupled with the decrease in call rate, this signifies that communication is significantly reduced both spatially and temporally. This may have implications for the reproductive success of this species, which appears to rely on specific call repertoires to portray relative fitness and attract mates. Reduction of acoustic habitat by anthropogenic noise may emerge as a compounding environmental stressor for an already sensitive taxonomic group. Title: The Effects of Road Noise on Pacific Chorus Frog Communication Author: Nelson, Danielle V. Amphibians are experiencing global population declines and are one of the most threatened groups of vertebrates. This can be attributed to multiple environmental stressors such as habitat loss, disease, invasive species, and climate change. For vocal amphibian species, loss of acoustic habitat due to anthropogenic noise may be yet another environmental stressor. The Pacific chorus frog (Pseudacris regilla) is the most common vocal species of the Pacific Northwest. It is described as a generalist that can occupy human-dominated habitat types, including agricultural and urban wetlands. As such, this species is exposed to anthropogenic noise which can interfere with vocalizations during the breeding season. We hypothesized that Pacific chorus frogs would alter the spatial and temporal structure of their breeding vocalizations to accommodate a widespread anthropogenic stressor: road noise. We compared Pacific chorus frog call structure and ambient road noise levels at 8 sites along a gradient of noise exposures in the Willamette Valley, Oregon, USA. We used both passive acoustic monitoring and directional recordings to determine source level (i.e. amplitude or volume), dominant frequency (i.e. pitch), call duration, and call rate of individual frogs and to quantify ambient road noise levels. We found that Pacific chorus frogs significantly reduced their call rate at relatively higher levels of ambient road noise, leading to a reduction in the amount of total time spent calling. We found no other changes to call structure (e.g. frequency and duration). The absence of additional call structure changes to mediate the impact of road noise resulted in a drastic reduction in the active call space of an individual frog. Coupled with the decrease in call rate, this signifies that communication is significantly reduced both spatially and temporally. This may have implications for the reproductive success of this species, which appears to rely on specific call repertoires to portray relative fitness and attract mates. Reduction of acoustic habitat by anthropogenic noise may emerge as a compounding environmental stressor for an already sensitive taxonomic group. Close

• 358. [Article] Mixed-Severity Fire Effects on Biological Legacies and Vegetation Response in Pseudotsuga Forests of Western Oregon's Central Cascades, USA

  Mixed-severity fire occurrence is increasingly recognized in Pseudotsuga forests of the Pacific Northwest, but questions remain about how tree mortality varies, and forest structure is altered, across ...

  Citation × Citation Citation Abstract Copy Title: Mixed-Severity Fire Effects on Biological Legacies and Vegetation Response in Pseudotsuga Forests of Western Oregon's Central Cascades, USA Author: Dunn, Christopher J. Mixed-severity fire occurrence is increasingly recognized in Pseudotsuga forests of the Pacific Northwest, but questions remain about how tree mortality varies, and forest structure is altered, across the disturbance gradient observed in these fires. Therefore, we sampled live and dead biological legacies at 45 one ha plots, with four 0.10 ha nested plots, stratified across an unburned, low, moderate and high-severity fire gradient. We used severity estimates based on differenced Normalized Burn Ratio (dNBR), and captured a disturbance gradient, but plots in our low-severity class underestimated fire effects because of misclassification or delayed mortality. We estimated probability of mortality for shade-intolerant (Douglas-fir, incense-cedar, sugar pine) and shade-tolerant (western hemlock, western redcedar, true fir) trees from 5,079 sampled trees and snags. The probability of mortality was higher for shade-tolerant species across all fire-severity classes, and decreased with increasing DBH except for western hemlock. Only large, shade-intolerant trees survived high-severity fire. Post-fire snag fall and fragmentation were estimated from 2,746 sampled snags and logs. The probability of snag fall decreased with increasing DBH for all species, and was positively correlated with fire severity, except for Douglas-fir that had a higher probability following low-severity fire. Snag fragmentation was positively correlated with DBH and fire severity for all species. We also estimated the coefficient of variation within- and among-plots by fire severity class, as well as across all sampled conditions. Structural attributes varied more within- than among-plots, likely a result of increasing sub-hectare patchy mortality as fire intensity increased. Although vertical and horizontal structural diversity increased at sub-hectare scales, the coefficient of variation was highest for all structural attributes when compared across all fire severity classes. Therefore, the range of fire effects observed in mixed-severity fires may be functionally important in creating structural complexity across landscapes, which is an important attribute of old-growth forests in the Pacific Northwest. Understory vegetation response to mixed-severity fires has not been characterized for these forests even though the majority of vegetation diversity is found in these vegetation layers. Therefore, we sampled forest structure (1000 m² circular plots) and understory vegetation (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. We focused on shrub species, but sampled forbs, graminoids, ferns and moss as functional groups. Offsite colonization and fire stimulated soil seedbanks increased the total species richness from 23 to 46. The life-history strategies of residual and colonizing species resulted in three dominant species response-curves to the magnitude of disturbance: 1) 'disturbance-sensitive', when relative abundance was highest in unburned plots and continued to decline with increasing fire severity, 2) 'disturbance-stimulated', when relative abundance was highest following low or moderate-severity fire and 3) 'disturbance-amplified', when relative abundance increased with increasing fire severity. Residual and colonizing species assemblages promoted five or six distinct understory communities, dominantly driven by legacy tree basal area rather than the proportion of basal area killed. Understory communities were rarely associated with one disturbance severity class as fire refugia, variation in overstory and understory fire severity, and compensatory conditions offset fire effects. Early-seral habitats were the most different from unburned forests, but were not the only post-fire conditions important across these burned landscapes. Interactions among live and dead forest structures following low or moderate-severity fire, and the vegetation response to these conditions, are also unique to the post-fire landscape and likely important for various wildlife species. Therefore, if ecological forestry paradigms focus dominantly on creating old-growth structure or early-seral habitats, they might exclude important conditions that contribute to the landscape structural complexity created by mixed-severity fires. Additionally, tree regeneration response to mixed-severity fires has not been characterized for these forests even though they offer insight into one aspect of the resilience of these ecosystems to disturbance. Therefore, we sampled forest structure (1000 m² circular plots) and regeneration dynamics (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. The largest marginal increase in tree mortality (stems ha⁻¹) occurred between unburned and low-severity fires, given preferential mortality of small trees and shade-tolerant species, but basal area mortality had the largest marginal increase moving from moderate to high-severity. Pairwise comparisons of legacy tree basal area between low and moderate-severity weren’t as significant as other comparisons, but did capture a gradient of increasing fire effects. Quadratic mean diameter and canopy base height were positively correlated with fire severity as incrementally larger trees were killed and canopy ascension followed. Regeneration density increased regardless of severity, relative to unburned forests (median density of 1,384 trees ha⁻¹), but the highest median density (16,220 trees ha⁻¹) followed low-severity fire at the Tiller Complex and moderate-severity fire (14,472 trees ha⁻¹) at Warner Fire. Plot-level average species richness was highest following these same fire severity classes, supporting the Intermediate Disturbance Hypothesis. Statistically distinct regeneration communities occurred across the fire severity gradient at both fire sites. The relative abundance of shade-tolerant tree species decreased as fire severity increased, except for a divergent response following stand-initiation at the Warner Fire. While divergent successional pathways were evident within a couple decades following stand-initiation, low or moderate-severity fires also modified successional trajectories and may be the most functionally important disturbance magnitude because it has the greatest potential to increase compositional and structural diversity. Incorporating mixed-severity fire effects into landscape management of Pseudotsuga forests could increase structural complexity at stand and landscape-scales. Title: Mixed-Severity Fire Effects on Biological Legacies and Vegetation Response in Pseudotsuga Forests of Western Oregon's Central Cascades, USA Author: Dunn, Christopher J. Mixed-severity fire occurrence is increasingly recognized in Pseudotsuga forests of the Pacific Northwest, but questions remain about how tree mortality varies, and forest structure is altered, across the disturbance gradient observed in these fires. Therefore, we sampled live and dead biological legacies at 45 one ha plots, with four 0.10 ha nested plots, stratified across an unburned, low, moderate and high-severity fire gradient. We used severity estimates based on differenced Normalized Burn Ratio (dNBR), and captured a disturbance gradient, but plots in our low-severity class underestimated fire effects because of misclassification or delayed mortality. We estimated probability of mortality for shade-intolerant (Douglas-fir, incense-cedar, sugar pine) and shade-tolerant (western hemlock, western redcedar, true fir) trees from 5,079 sampled trees and snags. The probability of mortality was higher for shade-tolerant species across all fire-severity classes, and decreased with increasing DBH except for western hemlock. Only large, shade-intolerant trees survived high-severity fire. Post-fire snag fall and fragmentation were estimated from 2,746 sampled snags and logs. The probability of snag fall decreased with increasing DBH for all species, and was positively correlated with fire severity, except for Douglas-fir that had a higher probability following low-severity fire. Snag fragmentation was positively correlated with DBH and fire severity for all species. We also estimated the coefficient of variation within- and among-plots by fire severity class, as well as across all sampled conditions. Structural attributes varied more within- than among-plots, likely a result of increasing sub-hectare patchy mortality as fire intensity increased. Although vertical and horizontal structural diversity increased at sub-hectare scales, the coefficient of variation was highest for all structural attributes when compared across all fire severity classes. Therefore, the range of fire effects observed in mixed-severity fires may be functionally important in creating structural complexity across landscapes, which is an important attribute of old-growth forests in the Pacific Northwest. Understory vegetation response to mixed-severity fires has not been characterized for these forests even though the majority of vegetation diversity is found in these vegetation layers. Therefore, we sampled forest structure (1000 m² circular plots) and understory vegetation (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. We focused on shrub species, but sampled forbs, graminoids, ferns and moss as functional groups. Offsite colonization and fire stimulated soil seedbanks increased the total species richness from 23 to 46. The life-history strategies of residual and colonizing species resulted in three dominant species response-curves to the magnitude of disturbance: 1) 'disturbance-sensitive', when relative abundance was highest in unburned plots and continued to decline with increasing fire severity, 2) 'disturbance-stimulated', when relative abundance was highest following low or moderate-severity fire and 3) 'disturbance-amplified', when relative abundance increased with increasing fire severity. Residual and colonizing species assemblages promoted five or six distinct understory communities, dominantly driven by legacy tree basal area rather than the proportion of basal area killed. Understory communities were rarely associated with one disturbance severity class as fire refugia, variation in overstory and understory fire severity, and compensatory conditions offset fire effects. Early-seral habitats were the most different from unburned forests, but were not the only post-fire conditions important across these burned landscapes. Interactions among live and dead forest structures following low or moderate-severity fire, and the vegetation response to these conditions, are also unique to the post-fire landscape and likely important for various wildlife species. Therefore, if ecological forestry paradigms focus dominantly on creating old-growth structure or early-seral habitats, they might exclude important conditions that contribute to the landscape structural complexity created by mixed-severity fires. Additionally, tree regeneration response to mixed-severity fires has not been characterized for these forests even though they offer insight into one aspect of the resilience of these ecosystems to disturbance. Therefore, we sampled forest structure (1000 m² circular plots) and regeneration dynamics (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. The largest marginal increase in tree mortality (stems ha⁻¹) occurred between unburned and low-severity fires, given preferential mortality of small trees and shade-tolerant species, but basal area mortality had the largest marginal increase moving from moderate to high-severity. Pairwise comparisons of legacy tree basal area between low and moderate-severity weren’t as significant as other comparisons, but did capture a gradient of increasing fire effects. Quadratic mean diameter and canopy base height were positively correlated with fire severity as incrementally larger trees were killed and canopy ascension followed. Regeneration density increased regardless of severity, relative to unburned forests (median density of 1,384 trees ha⁻¹), but the highest median density (16,220 trees ha⁻¹) followed low-severity fire at the Tiller Complex and moderate-severity fire (14,472 trees ha⁻¹) at Warner Fire. Plot-level average species richness was highest following these same fire severity classes, supporting the Intermediate Disturbance Hypothesis. Statistically distinct regeneration communities occurred across the fire severity gradient at both fire sites. The relative abundance of shade-tolerant tree species decreased as fire severity increased, except for a divergent response following stand-initiation at the Warner Fire. While divergent successional pathways were evident within a couple decades following stand-initiation, low or moderate-severity fires also modified successional trajectories and may be the most functionally important disturbance magnitude because it has the greatest potential to increase compositional and structural diversity. Incorporating mixed-severity fire effects into landscape management of Pseudotsuga forests could increase structural complexity at stand and landscape-scales. Close

• 359. [Image] Federal Register - Endangered and Threatened Wildlife and Plants; Notice of Revised 90-Day Petition Finding and Initiation of a 5-Year Status Review of the Lost River Sucker and Shortnose Sucker

  	We, the U.S. Fish and Wildlife Service (Service), announce a revised 90-day finding for a petition to remove the Lost River sucker [Deltistes luxatus) and shortnose sucker [Chasmistes brevirostris) throughout ...
  	Citation × Citation Citation Abstract Copy Title: Federal Register - Endangered and Threatened Wildlife and Plants; Notice of Revised 90-Day Petition Finding and Initiation of a 5-Year Status Review of the Lost River Sucker and Shortnose Sucker Author: Larsen, Ron Year: 2004, 2008, 2005 We, the U.S. Fish and Wildlife Service (Service), announce a revised 90-day finding for a petition to remove the Lost River sucker [Deltistes luxatus) and shortnose sucker [Chasmistes brevirostris) throughout their ranges from the Federal List of Threatened and Endangered Wildlife and Plants (List), pursuant to the Endangered Species Act (Act) (16 U.S.C. 1531 et seq.). We find that the petition does not present substantial scientific or commercial information indicating that delisting of the Lost River and shortnose suckers may be warranted. As a result of the 1995, 1996, and 1997 fish die-offs, the endangered suckers experienced significant losses of thousands of adult suckers and have not recovered. Although the petition and information in our files do not provide new information relevant to the status of the Lost River and shortnose suckers, we are initiating a 5-year review of these species under section 4(c)(2)(A) of the Act to consider any new information that has become available as a result of recent actions to reduce threats to the species, and to provide the States, tribes, agencies, university researchers, and the public an opportunity to provide information on the status of the species. We are requesting any new information on the Lost River and shortnose suckers since their original listing as endangered species in 1988 (53 FR 27130) Title: Federal Register - Endangered and Threatened Wildlife and Plants; Notice of Revised 90-Day Petition Finding and Initiation of a 5-Year Status Review of the Lost River Sucker and Shortnose Sucker Author: Larsen, Ron Year: 2004, 2008, 2005 We, the U.S. Fish and Wildlife Service (Service), announce a revised 90-day finding for a petition to remove the Lost River sucker [Deltistes luxatus) and shortnose sucker [Chasmistes brevirostris) throughout their ranges from the Federal List of Threatened and Endangered Wildlife and Plants (List), pursuant to the Endangered Species Act (Act) (16 U.S.C. 1531 et seq.). We find that the petition does not present substantial scientific or commercial information indicating that delisting of the Lost River and shortnose suckers may be warranted. As a result of the 1995, 1996, and 1997 fish die-offs, the endangered suckers experienced significant losses of thousands of adult suckers and have not recovered. Although the petition and information in our files do not provide new information relevant to the status of the Lost River and shortnose suckers, we are initiating a 5-year review of these species under section 4(c)(2)(A) of the Act to consider any new information that has become available as a result of recent actions to reduce threats to the species, and to provide the States, tribes, agencies, university researchers, and the public an opportunity to provide information on the status of the species. We are requesting any new information on the Lost River and shortnose suckers since their original listing as endangered species in 1988 (53 FR 27130) Close

• 360. [Article] The Impact of Weather on Kingbird Foraging Behavior

  Foraging data on Eastern Kingbirds (Tyrannus tyrannus) were collected during the early breeding season in eastern Kansas to test the hypothesis that foraging rate and other aspects of foraging behavior ...

  Citation × Citation Citation Abstract Copy Title: The Impact of Weather on Kingbird Foraging Behavior Author: Murphy, Michael T. Year: 1987 Foraging data on Eastern Kingbirds (Tyrannus tyrannus) were collected during the early breeding season in eastern Kansas to test the hypothesis that foraging rate and other aspects of foraging behavior vary with weather. Foraging characteristics of five additional kingbird species were also examined to assess Fitzpatrick's (1980) generalization that kingbirds (Tyrannus spp.) are aerial hawking specialists. In Eastern Kingbirds, total foraging rate was independent of air temperature, cloud cover, wind speed, and time of day, but the rate of aerial hawking varied directly with air temperature and inversely with cloud cover (both P < 0.05). Effects of the two variables were additive. The percentage of foraging movements that were aerial hawks also increased with temperature and declined with cloud cover, and, hover-gleaning and perch-to-ground sallying were observed mainly during cloudy weather. Sally (i.e., foraging flight) distance correlated directly with perch height and air temperature, and large insects were captured almost exclusively in long upward or horizontal flights. I interpret these data to indicate that foraging behavior and the capture of large, flying insects depends on weather because of how it affects the activity of insect prey. Foraging data on kingbirds support Fitzpatrick's generalization, but the relative use of aerial hawking varies considerably among species. Resident Tropical Kingbirds( T. melancholicus) are the most specialized foragers, whereas the migrant and widely distributed Eastern Kingbird appears to be the most generalized. Certain habitats also appear to favor the use of particular foraging methods (e.g., outward striking in grasslands and perch-to-ground sallying in drier, open habitats). Title: The Impact of Weather on Kingbird Foraging Behavior Author: Murphy, Michael T. Year: 1987 Foraging data on Eastern Kingbirds (Tyrannus tyrannus) were collected during the early breeding season in eastern Kansas to test the hypothesis that foraging rate and other aspects of foraging behavior vary with weather. Foraging characteristics of five additional kingbird species were also examined to assess Fitzpatrick's (1980) generalization that kingbirds (Tyrannus spp.) are aerial hawking specialists. In Eastern Kingbirds, total foraging rate was independent of air temperature, cloud cover, wind speed, and time of day, but the rate of aerial hawking varied directly with air temperature and inversely with cloud cover (both P < 0.05). Effects of the two variables were additive. The percentage of foraging movements that were aerial hawks also increased with temperature and declined with cloud cover, and, hover-gleaning and perch-to-ground sallying were observed mainly during cloudy weather. Sally (i.e., foraging flight) distance correlated directly with perch height and air temperature, and large insects were captured almost exclusively in long upward or horizontal flights. I interpret these data to indicate that foraging behavior and the capture of large, flying insects depends on weather because of how it affects the activity of insect prey. Foraging data on kingbirds support Fitzpatrick's generalization, but the relative use of aerial hawking varies considerably among species. Resident Tropical Kingbirds( T. melancholicus) are the most specialized foragers, whereas the migrant and widely distributed Eastern Kingbird appears to be the most generalized. Certain habitats also appear to favor the use of particular foraging methods (e.g., outward striking in grasslands and perch-to-ground sallying in drier, open habitats). Close

• 361. [Article] A Behavior-Based Framework for Assessing Barrier Effects to Wildlife from Vehicle Traffic Volume

  Roads, while central to the function of human society, create barriers to animal movement through collisions and habitat fragmentation. Barriers to animal movement affect the evolution and trajectory of ...

  Citation × Citation Citation Abstract Copy Title: A Behavior-Based Framework for Assessing Barrier Effects to Wildlife from Vehicle Traffic Volume Author: Jacobson, Sandra L., Bliss-Ketchum, Leslie L., de Rivera, Catherine E., Smith, Winston P. Year: 2016 Roads, while central to the function of human society, create barriers to animal movement through collisions and habitat fragmentation. Barriers to animal movement affect the evolution and trajectory of populations. Investigators have attempted to use traffic volume, the number of vehicles passing a point on a road segment, to predict effects to wildlife populations approximately linearly and along taxonomic lines; however, taxonomic groupings cannot provide sound predictions because closely related species often respond differently. We assess the role of wildlife behavioral responses to traffic volume as a tool to predict barrier effects from vehicle-caused mortality and avoidance, to provide an early warning system that recognizes traffic volume as a trigger for mitigation, and to better interpret roadkill data. We propose four categories of behavioral response based on the perceived danger to traffic: Nonresponders, Pausers, Speeders, and Avoiders. Nonresponders attempt to cross highways regardless of traffic volume. Pausers stop in the face of danger so have a low probability of successful crossing when traffic volume increases. Hence, highway barrier effects are primarily due to mortality for Nonresponders and Pausers at high traffic volumes. Speeders run away from danger but are unable to do so successfully as traffic volume increases. At moderate to high volume, Speeders are repelled by traffic danger. Avoiders face lower mortality than other categories because they begin to avoid traffic at relatively low traffic volumes. Hence, avoidance causes barrier effects more than mortality for Speeders and Avoiders even at relatively moderate traffic volumes. By considering a species’ risk-avoidance response to traffic, managers can make more appropriate and timely decisions to mitigate effects before populations decline or become locally extinct. Title: A Behavior-Based Framework for Assessing Barrier Effects to Wildlife from Vehicle Traffic Volume Author: Jacobson, Sandra L., Bliss-Ketchum, Leslie L., de Rivera, Catherine E., Smith, Winston P. Year: 2016 Roads, while central to the function of human society, create barriers to animal movement through collisions and habitat fragmentation. Barriers to animal movement affect the evolution and trajectory of populations. Investigators have attempted to use traffic volume, the number of vehicles passing a point on a road segment, to predict effects to wildlife populations approximately linearly and along taxonomic lines; however, taxonomic groupings cannot provide sound predictions because closely related species often respond differently. We assess the role of wildlife behavioral responses to traffic volume as a tool to predict barrier effects from vehicle-caused mortality and avoidance, to provide an early warning system that recognizes traffic volume as a trigger for mitigation, and to better interpret roadkill data. We propose four categories of behavioral response based on the perceived danger to traffic: Nonresponders, Pausers, Speeders, and Avoiders. Nonresponders attempt to cross highways regardless of traffic volume. Pausers stop in the face of danger so have a low probability of successful crossing when traffic volume increases. Hence, highway barrier effects are primarily due to mortality for Nonresponders and Pausers at high traffic volumes. Speeders run away from danger but are unable to do so successfully as traffic volume increases. At moderate to high volume, Speeders are repelled by traffic danger. Avoiders face lower mortality than other categories because they begin to avoid traffic at relatively low traffic volumes. Hence, avoidance causes barrier effects more than mortality for Speeders and Avoiders even at relatively moderate traffic volumes. By considering a species’ risk-avoidance response to traffic, managers can make more appropriate and timely decisions to mitigate effects before populations decline or become locally extinct. Close

• 362. [Article] Mangrove-Exported Nutrient Incorporation by Sessile Coral Reef Invertebrates

  Coastal mangrove forests were historically considered as a source of organic matter (OM) for adjacent marine systems due to high net primary production; yet recent research suggesting little uptake through ...

  Citation × Citation Citation Abstract Copy Title: Mangrove-Exported Nutrient Incorporation by Sessile Coral Reef Invertebrates Author: Granek, Elise F., Compton, Jana E., Phillips, Donald L. Year: 2009 Coastal mangrove forests were historically considered as a source of organic matter (OM) for adjacent marine systems due to high net primary production; yet recent research suggesting little uptake through the food web because of low nutritional quality, challenges the concept of trophic linkage between mangrove forests and coral reefs. To examine the importance of mangrove forests to coral reef nutrient availability, we examined sessile reef-forming invertebrate consumers including hard corals, sponges, a bivalve mollusc, polychaete annelid and tunicate, and potential sources of OM (decaying mangrove leaves, microalgae, macroalgae, and seagrass) in Bocas del Toro, Panama. Using stable isotope analyses of δ34S and δ13C and a concentration-dependent version of the IsoSource mixing model, we were able to discriminate among and determine the range of potential contributions of our four OM sources to consumers. Contributions of microalgae and macroalgae were often indeterminate due to high variability, yet seagrass and mangrove contributions were often substantial. Mangrove OM ranged across sites and species of filter feeders from 0 to 57%, 7 to 41%, and 18 to 52% for sponges, file clams, and feather duster worms, respectively. Mangrove contribution to corals (Acropora cervicornis, Agaricia fragilis, Agaricia tenuifolia, Montastrea annularis, Diploria sp.) ranged from 0 to 44%. To examine whether OM contribution varied with distance from mangroves, we conducted a sponge transplant experiment that demonstrated declining mangrove contribution across three sponge species with increasing distance from the shore. These results supported the hypothesis of mangrove-coral reef nutrient linkages, providing the first evidence that mangrove inputs of OM to sessile invertebrates are substantial, accounting for 0–57% of the composition. Title: Mangrove-Exported Nutrient Incorporation by Sessile Coral Reef Invertebrates Author: Granek, Elise F., Compton, Jana E., Phillips, Donald L. Year: 2009 Coastal mangrove forests were historically considered as a source of organic matter (OM) for adjacent marine systems due to high net primary production; yet recent research suggesting little uptake through the food web because of low nutritional quality, challenges the concept of trophic linkage between mangrove forests and coral reefs. To examine the importance of mangrove forests to coral reef nutrient availability, we examined sessile reef-forming invertebrate consumers including hard corals, sponges, a bivalve mollusc, polychaete annelid and tunicate, and potential sources of OM (decaying mangrove leaves, microalgae, macroalgae, and seagrass) in Bocas del Toro, Panama. Using stable isotope analyses of δ34S and δ13C and a concentration-dependent version of the IsoSource mixing model, we were able to discriminate among and determine the range of potential contributions of our four OM sources to consumers. Contributions of microalgae and macroalgae were often indeterminate due to high variability, yet seagrass and mangrove contributions were often substantial. Mangrove OM ranged across sites and species of filter feeders from 0 to 57%, 7 to 41%, and 18 to 52% for sponges, file clams, and feather duster worms, respectively. Mangrove contribution to corals (Acropora cervicornis, Agaricia fragilis, Agaricia tenuifolia, Montastrea annularis, Diploria sp.) ranged from 0 to 44%. To examine whether OM contribution varied with distance from mangroves, we conducted a sponge transplant experiment that demonstrated declining mangrove contribution across three sponge species with increasing distance from the shore. These results supported the hypothesis of mangrove-coral reef nutrient linkages, providing the first evidence that mangrove inputs of OM to sessile invertebrates are substantial, accounting for 0–57% of the composition. Close

• 363. [Article] Assessing the feasibility of policy prescriptions in the Salmon 2100 Project

  Wild salmon populations are in decline in the Pacific Northwest. In the region populations and runs of Chinook (Oncorhynchus tshawytsha), Chum (Oncorhynchus keta), Coho (Oncorhynchus kisutch), Sockey (Oncorhynchus ...

  Citation × Citation Citation Abstract Copy Title: Assessing the feasibility of policy prescriptions in the Salmon 2100 Project Author: Whitehead, Katharine S. Wild salmon populations are in decline in the Pacific Northwest. In the region populations and runs of Chinook (Oncorhynchus tshawytsha), Chum (Oncorhynchus keta), Coho (Oncorhynchus kisutch), Sockey (Oncorhynchus nerka), and Steelhead (Oncorhynchus mykiss) have been listed as threatened and/or endangered under the Endangered Species Act (ESA) in the U.S. and/or the Species at Risk Act (SARA) in Canada in the years 1991-2007. Considerable time, money and brainpower has been put into salmon recovery with mixed results. The future for wild salmon in the Pacific Northwest remains uncertain. In 2006 Salmon 2100: The Future of Wild Pacific Salmon was published. The book is made up of 23 essays by 33 authors who were challenged to each develop a comprehensive policy prescription in response to the question: “What specific policies must be implemented in order to have a high probability of sustaining significant runs of wild salmon through 2100 in California, Oregon, Washington, Idaho, and southern British Columbia?” A qualitative study was designed to assess whether any of the policy prescriptions presented in Salmon 2100: The Future of Wild Pacific Salmon are feasible or viable in the real world. A thorough document analysis was conducted of Salmon 2100: The Future of Wild Pacific Salmon. The Social Construction Framework was used to categorize the target populations, code the policy prescriptions, and identify the benefits and burdens of each policy prescription for each target population. This information was then used to assess the feasibility of each policy prescription, based on the Social Construction Framework. The findings suggest that some of the policy prescriptions are feasible and could be developed for successful implementation in the real world. There is evidence that projects similar to the Salmon 2100 project could provide useful information and potential solutions to other natural resource policy challenges. Title: Assessing the feasibility of policy prescriptions in the Salmon 2100 Project Author: Whitehead, Katharine S. Wild salmon populations are in decline in the Pacific Northwest. In the region populations and runs of Chinook (Oncorhynchus tshawytsha), Chum (Oncorhynchus keta), Coho (Oncorhynchus kisutch), Sockey (Oncorhynchus nerka), and Steelhead (Oncorhynchus mykiss) have been listed as threatened and/or endangered under the Endangered Species Act (ESA) in the U.S. and/or the Species at Risk Act (SARA) in Canada in the years 1991-2007. Considerable time, money and brainpower has been put into salmon recovery with mixed results. The future for wild salmon in the Pacific Northwest remains uncertain. In 2006 Salmon 2100: The Future of Wild Pacific Salmon was published. The book is made up of 23 essays by 33 authors who were challenged to each develop a comprehensive policy prescription in response to the question: “What specific policies must be implemented in order to have a high probability of sustaining significant runs of wild salmon through 2100 in California, Oregon, Washington, Idaho, and southern British Columbia?” A qualitative study was designed to assess whether any of the policy prescriptions presented in Salmon 2100: The Future of Wild Pacific Salmon are feasible or viable in the real world. A thorough document analysis was conducted of Salmon 2100: The Future of Wild Pacific Salmon. The Social Construction Framework was used to categorize the target populations, code the policy prescriptions, and identify the benefits and burdens of each policy prescription for each target population. This information was then used to assess the feasibility of each policy prescription, based on the Social Construction Framework. The findings suggest that some of the policy prescriptions are feasible and could be developed for successful implementation in the real world. There is evidence that projects similar to the Salmon 2100 project could provide useful information and potential solutions to other natural resource policy challenges. Close

• 364. [Article] Widespread Mesopredator Effects After Wolf Extirpation

  This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/biological-cons...

  Citation × Citation Citation Abstract Copy Title: Widespread Mesopredator Effects After Wolf Extirpation Author: Wilmers, Christopher C., Wirsing, Aaron J., Letnic, Mike, Ripple, William J. This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/biological-conservation/. Title: Widespread Mesopredator Effects After Wolf Extirpation Author: Wilmers, Christopher C., Wirsing, Aaron J., Letnic, Mike, Ripple, William J. This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/biological-conservation/. Close

• 365. [Article] Regional variation in mtDNA of the lesser prairie-chicken

  This is the publisher’s final pdf. The article is copyrighted by Cooper Ornithological Society and published by Central Ornithology Publication Office. It can be found at: http://www.aoucospubs.org/loi...

  Citation × Citation Citation Abstract Copy Title: Regional variation in mtDNA of the lesser prairie-chicken Author: Robel, Robert J., Hagen, Christian A., Applegate, Roger D., Oyler-McCance, Sara J., Pitman, James C., Wolfe, Don H., Sandercock, Brett K. This is the publisher’s final pdf. The article is copyrighted by Cooper Ornithological Society and published by Central Ornithology Publication Office. It can be found at: http://www.aoucospubs.org/loi/cond Title: Regional variation in mtDNA of the lesser prairie-chicken Author: Robel, Robert J., Hagen, Christian A., Applegate, Roger D., Oyler-McCance, Sara J., Pitman, James C., Wolfe, Don H., Sandercock, Brett K. This is the publisher’s final pdf. The article is copyrighted by Cooper Ornithological Society and published by Central Ornithology Publication Office. It can be found at: http://www.aoucospubs.org/loi/cond Close

• 366. [Article] Analysis of Landsat Satellite Data to Monitor Water Quality Parameters in Tenmile Lake, Oregon

  The health of North and South Tenmile Lakes in coastal Oregon has declined since the introduction of invasive species of fish and plant life in the 1920s. The lakes are now on the Federal Clean Water Act ...

  Citation × Citation Citation Abstract Copy Title: Analysis of Landsat Satellite Data to Monitor Water Quality Parameters in Tenmile Lake, Oregon Author: Waxter, Michael T. Year: 2014 The health of North and South Tenmile Lakes in coastal Oregon has declined since the introduction of invasive species of fish and plant life in the 1920s. The lakes are now on the Federal Clean Water Act list of impaired water bodies due, in part, to a lack of dissolved oxygen and Hazardous Algae Blooms (HAB) blooms that occur during June through September. In this report we discuss the possibility of detecting and monitoring these blooms using satellite measurements of water surface color. In-situ measurements obtained from the Tenmile Lakes Basin Partnership were used to calibrate reflectance from the Thematic Mapper on the Landsat 5 satellite. Results show a good linear correlation between turbidity and radiance, which are inversely related in algal dominated lakes. Additionally, a correlation between biovolume and reflectance was obtained. Spatial patterns of turbidity and biovolume are observed, with large concentrations observed in lake areas with large residence times. The comparatively lowest concentrations are observed along the probable pathway of cleaner water input by creeks into the lake. However, the ability to predict turbidity and biovolume from satellite reflectance data is currently complicated by the lack of coincident in-situ and satellite data, and the limited number of spectral bands available to separate turbidity from different species of bacteria and algae. Title: Analysis of Landsat Satellite Data to Monitor Water Quality Parameters in Tenmile Lake, Oregon Author: Waxter, Michael T. Year: 2014 The health of North and South Tenmile Lakes in coastal Oregon has declined since the introduction of invasive species of fish and plant life in the 1920s. The lakes are now on the Federal Clean Water Act list of impaired water bodies due, in part, to a lack of dissolved oxygen and Hazardous Algae Blooms (HAB) blooms that occur during June through September. In this report we discuss the possibility of detecting and monitoring these blooms using satellite measurements of water surface color. In-situ measurements obtained from the Tenmile Lakes Basin Partnership were used to calibrate reflectance from the Thematic Mapper on the Landsat 5 satellite. Results show a good linear correlation between turbidity and radiance, which are inversely related in algal dominated lakes. Additionally, a correlation between biovolume and reflectance was obtained. Spatial patterns of turbidity and biovolume are observed, with large concentrations observed in lake areas with large residence times. The comparatively lowest concentrations are observed along the probable pathway of cleaner water input by creeks into the lake. However, the ability to predict turbidity and biovolume from satellite reflectance data is currently complicated by the lack of coincident in-situ and satellite data, and the limited number of spectral bands available to separate turbidity from different species of bacteria and algae. Close

• 367. [Article] Diversity, productivity, and mycophagy of hypogeous mycorrhizal fungi in a variably thinned Douglas-fir forest

  Hypogeous fungi are a critical component of forest ecosystems world wide. In Pacific Northwest forests, they are the base of the food chain of the threatened Northern Spotted Owl. As part of The Forest ...

  Citation × Citation Citation Abstract Copy Title: Diversity, productivity, and mycophagy of hypogeous mycorrhizal fungi in a variably thinned Douglas-fir forest Author: Colgan, Wesley Hypogeous fungi are a critical component of forest ecosystems world wide. In Pacific Northwest forests, they are the base of the food chain of the threatened Northern Spotted Owl. As part of The Forest Ecosystem Study (a interdisciplinary study designed to increase development of suitable spotted owl habitat), diversity and productivity of truffles were studied from March 1993 through December 1996 at approximately six week intervals at the Fort Lewis Military Reservation near Olympia, Washington. Half of the stands served as controls, half were assigned a variable density thinning (VDT) treatment. A VDT stand was comprised of a mosaic of 0.16 ha- patches thinned to different densities of standing live trees. To further examine effect of thinning on sporocarp productivity and diversity, this mosaic was stratified into 2 sub-treatments, lightly thinned and heavily thinned areas. Total standing crop biomass over all seasons was significantly reduced in VDT stands compared to the control stands. However. VDT stands had greater truffle standing crop during two of the three winters sampled. This suggests that, in the short term, thinning could reduce production overall but enhance production of truffles in winter. Species richness and evenness were highest in the lightly thinned areas within the VDT stands and declined sharply in the heavily thinned areas, compared to the control stands. Two novel truffle taxa collected during this study were described. A reliable method to assess dietaries of northern flying squirrels (Glaucomys sabrinus) and Townsend's chipmunk (Tamias townsendii) was developed, and subsequently used to analyze fecal pellets collected from live trapped individuals. Collections from spring 1991 through December 1996 were analyzed to estimate dietary composition. Hypogeous basidiomycetes and ascomycetes dominated chipmunk and flying squirrel dietaries. Plant material was also a dominant component of chipmunk dietaries (both spring and fall) and fall flying squirrel dietaries. Both mammal species consistently found more fungal taxa than mycologists did during the concurrent mycological survey. Thinning did not significantly change the rank order of fungal components in the dietaries of these small mammals. Title: Diversity, productivity, and mycophagy of hypogeous mycorrhizal fungi in a variably thinned Douglas-fir forest Author: Colgan, Wesley Hypogeous fungi are a critical component of forest ecosystems world wide. In Pacific Northwest forests, they are the base of the food chain of the threatened Northern Spotted Owl. As part of The Forest Ecosystem Study (a interdisciplinary study designed to increase development of suitable spotted owl habitat), diversity and productivity of truffles were studied from March 1993 through December 1996 at approximately six week intervals at the Fort Lewis Military Reservation near Olympia, Washington. Half of the stands served as controls, half were assigned a variable density thinning (VDT) treatment. A VDT stand was comprised of a mosaic of 0.16 ha- patches thinned to different densities of standing live trees. To further examine effect of thinning on sporocarp productivity and diversity, this mosaic was stratified into 2 sub-treatments, lightly thinned and heavily thinned areas. Total standing crop biomass over all seasons was significantly reduced in VDT stands compared to the control stands. However. VDT stands had greater truffle standing crop during two of the three winters sampled. This suggests that, in the short term, thinning could reduce production overall but enhance production of truffles in winter. Species richness and evenness were highest in the lightly thinned areas within the VDT stands and declined sharply in the heavily thinned areas, compared to the control stands. Two novel truffle taxa collected during this study were described. A reliable method to assess dietaries of northern flying squirrels (Glaucomys sabrinus) and Townsend's chipmunk (Tamias townsendii) was developed, and subsequently used to analyze fecal pellets collected from live trapped individuals. Collections from spring 1991 through December 1996 were analyzed to estimate dietary composition. Hypogeous basidiomycetes and ascomycetes dominated chipmunk and flying squirrel dietaries. Plant material was also a dominant component of chipmunk dietaries (both spring and fall) and fall flying squirrel dietaries. Both mammal species consistently found more fungal taxa than mycologists did during the concurrent mycological survey. Thinning did not significantly change the rank order of fungal components in the dietaries of these small mammals. Close

• 368. [Article] An Analysis of the Economic Value of the Endangered Species Ayumodoki - A Case Study of Kameoka City, Kyoto Prefecture in Japan

  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: An Analysis of the Economic Value of the Endangered Species Ayumodoki - A Case Study of Kameoka City, Kyoto Prefecture in Japan Author: Naito, Toyokazu, Uwasu, Michinori 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 Ann L. Shriver and Stefani J. Evers. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016. Title: An Analysis of the Economic Value of the Endangered Species Ayumodoki - A Case Study of Kameoka City, Kyoto Prefecture in Japan Author: Naito, Toyokazu, Uwasu, Michinori 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 Ann L. Shriver and Stefani J. Evers. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016. Close

• 369. [Article] Cost-Benefit Analysis of DGN Swordfish Time-Area Closure

  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: Cost-Benefit Analysis of DGN Swordfish Time-Area Closure Author: Helvey, Mark, Stohs, Stephen, Squires, Dale, Chan, Valerie, Segerson, Kathleen, Herrick, Samuel Jr., Sun, Chin-Haw, Hilger, James 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: Cost-Benefit Analysis of DGN Swordfish Time-Area Closure Author: Helvey, Mark, Stohs, Stephen, Squires, Dale, Chan, Valerie, Segerson, Kathleen, Herrick, Samuel Jr., Sun, Chin-Haw, Hilger, James 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

• 370. [Article] Trends in wilderness use and their social and ecological implications

  Three studies were performed in Oregon wildernesses. The first used wilderness permit and trailhead registration data to evaluate trends in use of Three Sisters, Mt. Jefferson, and Eagle Cap Wildernesses ...

  Citation × Citation Citation Abstract Copy Title: Trends in wilderness use and their social and ecological implications Author: Hall, Troy E. Three studies were performed in Oregon wildernesses. The first used wilderness permit and trailhead registration data to evaluate trends in use of Three Sisters, Mt. Jefferson, and Eagle Cap Wildernesses from 1976 to 1994. Recreational visitor days were found to have declined, but the number of visits increased dramatically, because of large increases in the number of day users. These findings are counter to conclusions drawn in earlier research on national use trends and highlight the importance of the unit of measure to interpretation of trends. Trends implied by permit data differed from trends estimated by Forest Service personnel, and implications for Forest Service reporting are discussed. The second study compared day and overnight visitors to three high-use destinations in terms of their perception of social and ecological impacts of wilderness recreation, evaluation of impacts, and support for management actions. Overnight users were more likely to notice impacts, but predicted differences in reaction to impacts and support for management actions were not found. The only exception was that overnight users were more likely to object to management actions that would target overnight users. Results showed significant differences among study sites. The third study tested four methods of revegetating impacted campsites: scarification, importing organic material, transplanting, and transplanting with watering. These commonly used methods have not been systematically investigated previously. Six campsites in Three Sisters Wilderness were treated in 1991 and reevaluated in 1994. Importing organic material and scarification were found to improve vegetation recovery and species richness very little compared to controls, but both transplanting techniques had significant effects, often because of the presence of other species or propagules in the transplanted plugs. Watering was found to have no effect on the survival of transplanted mountain hemlock seedlings. Vegetative recovery was very slow with even the most effective treatments, which reinforces recommendations that managers adopt strategies of concentrating use. Title: Trends in wilderness use and their social and ecological implications Author: Hall, Troy E. Three studies were performed in Oregon wildernesses. The first used wilderness permit and trailhead registration data to evaluate trends in use of Three Sisters, Mt. Jefferson, and Eagle Cap Wildernesses from 1976 to 1994. Recreational visitor days were found to have declined, but the number of visits increased dramatically, because of large increases in the number of day users. These findings are counter to conclusions drawn in earlier research on national use trends and highlight the importance of the unit of measure to interpretation of trends. Trends implied by permit data differed from trends estimated by Forest Service personnel, and implications for Forest Service reporting are discussed. The second study compared day and overnight visitors to three high-use destinations in terms of their perception of social and ecological impacts of wilderness recreation, evaluation of impacts, and support for management actions. Overnight users were more likely to notice impacts, but predicted differences in reaction to impacts and support for management actions were not found. The only exception was that overnight users were more likely to object to management actions that would target overnight users. Results showed significant differences among study sites. The third study tested four methods of revegetating impacted campsites: scarification, importing organic material, transplanting, and transplanting with watering. These commonly used methods have not been systematically investigated previously. Six campsites in Three Sisters Wilderness were treated in 1991 and reevaluated in 1994. Importing organic material and scarification were found to improve vegetation recovery and species richness very little compared to controls, but both transplanting techniques had significant effects, often because of the presence of other species or propagules in the transplanted plugs. Watering was found to have no effect on the survival of transplanted mountain hemlock seedlings. Vegetative recovery was very slow with even the most effective treatments, which reinforces recommendations that managers adopt strategies of concentrating use. Close

• 371. [Article] Cavity resources in Oregon white oak and Douglas-fir stands in the mid-Willamette Valley, Oregon

  Previous studies of bird communities in the mid-Willamette Valley, Oregon, indicated that Oregon white oak (Ouercus garryana) stands supported more cavity-using bird species than sympatric stands of Douglas-fir ...

  Citation × Citation Citation Abstract Copy Title: Cavity resources in Oregon white oak and Douglas-fir stands in the mid-Willamette Valley, Oregon Author: Gumtow-Farrior, Daniel L. Previous studies of bird communities in the mid-Willamette Valley, Oregon, indicated that Oregon white oak (Ouercus garryana) stands supported more cavity-using bird species than sympatric stands of Douglas-fir (Pseudotsuga menziesii). Mature Oregon oak stands are being harvested and few are regenerating. I compared cavity availability for hole-using fauna among 10 types of stands in the mid-Willamette Valley and adjacent Coast Range foothills (6 Oregon white oak, 3 Douglas-fir and 1 mixed Oregon oak/Douglas-fir). Thirty stands (3/type of stand) were classified by their predominant tree species, average diameter class (20.0-to-34.9 cm, 35.0-to-49.9 cm, and 50.0+ cm at breast height) and area (groves <4 ha, stands >4 ha). Origin, location and estimated size were recorded for 735 cavities found in 3300 trees. Sixty-three percent of the trees examined were Oregon oak, but 93.7% of the cavities were in Oregon oak. Most cavities (70%) were products of decay following infection. Two-thirds of the cavities had entrance hole diameters between 2.5-to-5.0 cm. Groves of medium- and large- diameter oaks and stands of large-diameter oaks had the most cavities, Cavity availability was higher in the oak stands than in the Douglas-fir and mixed stands. Declines in densities of cavities through a progressive replacement of larger Oregon white oak by smaller, managed Douglas-fir will unquestionably reduce the abundance of cavities in the mid-Willamette Valley. Maintenance of existing oak stands and regeneration of Oregon oak in the mid-Willamette Valley may be desirable to maintain habitat for indigenous cavity-using fauna. Title: Cavity resources in Oregon white oak and Douglas-fir stands in the mid-Willamette Valley, Oregon Author: Gumtow-Farrior, Daniel L. Previous studies of bird communities in the mid-Willamette Valley, Oregon, indicated that Oregon white oak (Ouercus garryana) stands supported more cavity-using bird species than sympatric stands of Douglas-fir (Pseudotsuga menziesii). Mature Oregon oak stands are being harvested and few are regenerating. I compared cavity availability for hole-using fauna among 10 types of stands in the mid-Willamette Valley and adjacent Coast Range foothills (6 Oregon white oak, 3 Douglas-fir and 1 mixed Oregon oak/Douglas-fir). Thirty stands (3/type of stand) were classified by their predominant tree species, average diameter class (20.0-to-34.9 cm, 35.0-to-49.9 cm, and 50.0+ cm at breast height) and area (groves <4 ha, stands >4 ha). Origin, location and estimated size were recorded for 735 cavities found in 3300 trees. Sixty-three percent of the trees examined were Oregon oak, but 93.7% of the cavities were in Oregon oak. Most cavities (70%) were products of decay following infection. Two-thirds of the cavities had entrance hole diameters between 2.5-to-5.0 cm. Groves of medium- and large- diameter oaks and stands of large-diameter oaks had the most cavities, Cavity availability was higher in the oak stands than in the Douglas-fir and mixed stands. Declines in densities of cavities through a progressive replacement of larger Oregon white oak by smaller, managed Douglas-fir will unquestionably reduce the abundance of cavities in the mid-Willamette Valley. Maintenance of existing oak stands and regeneration of Oregon oak in the mid-Willamette Valley may be desirable to maintain habitat for indigenous cavity-using fauna. Close

• 372. [Article] The water economy of the Sage Sparrow, Amphispiza belli nevadensis (Ridgway)

  This study investigated several physiological aspects of the water economy of the Sage Sparrow, Amphispiza belli nevadensis,as they relate to the ability of this species to inhabit xeric desert environments. When ...

  Citation × Citation Citation Abstract Copy Title: The water economy of the Sage Sparrow, Amphispiza belli nevadensis (Ridgway) Author: Moldenhauer, Ralph Roy This study investigated several physiological aspects of the water economy of the Sage Sparrow, Amphispiza belli nevadensis,as they relate to the ability of this species to inhabit xeric desert environments. When maintained in captivity on a dry diet without drinking water, Sage Sparrows gradually lost weight and died. During the period of water deprivation, motor activity increased and gross energy intake declined. However, Sage Sparrows were able to maintain their body weight when provided with only succulent foods as a source of water. When birds were transferred from ad libitum drinking water to a restricted water intake of either tap water (ca 2.0 ml /day) or Tenebrio larvae (ca 2.5 ml H₂O/day), excretory water losses were diminished by about 65 percent through a reduction in both the moisture content of droppings and excrement dry weight. At the same time, there was an increase in the percentage of assimilated energy, as indicated by the utilization coefficient. The renal capacity of the Sage Sparrow for concentrating electrolytes was not exceptional, with a mean maximum urine-plasma ratio of 2.4 for chloride. Individuals lost weight on NaCl drinking solutions of 0.25 M and above. The thermoneutral zone of the Sage Sparrow ranged from 28 to 37°C with a standard metabolic rate of 7.24 kcal/day (mean body wt = 18.8 g; temperature = 35°C). The temperature coefficient was 5.6 percent. From 10 to 35°C the passive rate of evaporative water loss was relatively, constant at ca 6.5 mg/g/hr. Above 35°C, evaporative cooling was initiated, and at high ambient temperatures and low humidities, Sage Sparrows were able to dissipate all their metabolic heat production by, evaporative cooling. There was indirect evidence for a reduction in evaporative water loss with water deprivation. The physiological adaptations of Sage Sparrows to water and heat stress were not unusual for small passerine birds, and were intermediate in relation to various species of desert and non-desert birds already investigated. The successful existence of Sage Sparrows in desert environments is probably dependent upon the utilization of succulent foods to satisfy their demands for water and on temperature-dependent behavioral responses which may reduce heat stress, thereby minimizing the need for evaporative cooling. Title: The water economy of the Sage Sparrow, Amphispiza belli nevadensis (Ridgway) Author: Moldenhauer, Ralph Roy This study investigated several physiological aspects of the water economy of the Sage Sparrow, Amphispiza belli nevadensis,as they relate to the ability of this species to inhabit xeric desert environments. When maintained in captivity on a dry diet without drinking water, Sage Sparrows gradually lost weight and died. During the period of water deprivation, motor activity increased and gross energy intake declined. However, Sage Sparrows were able to maintain their body weight when provided with only succulent foods as a source of water. When birds were transferred from ad libitum drinking water to a restricted water intake of either tap water (ca 2.0 ml /day) or Tenebrio larvae (ca 2.5 ml H₂O/day), excretory water losses were diminished by about 65 percent through a reduction in both the moisture content of droppings and excrement dry weight. At the same time, there was an increase in the percentage of assimilated energy, as indicated by the utilization coefficient. The renal capacity of the Sage Sparrow for concentrating electrolytes was not exceptional, with a mean maximum urine-plasma ratio of 2.4 for chloride. Individuals lost weight on NaCl drinking solutions of 0.25 M and above. The thermoneutral zone of the Sage Sparrow ranged from 28 to 37°C with a standard metabolic rate of 7.24 kcal/day (mean body wt = 18.8 g; temperature = 35°C). The temperature coefficient was 5.6 percent. From 10 to 35°C the passive rate of evaporative water loss was relatively, constant at ca 6.5 mg/g/hr. Above 35°C, evaporative cooling was initiated, and at high ambient temperatures and low humidities, Sage Sparrows were able to dissipate all their metabolic heat production by, evaporative cooling. There was indirect evidence for a reduction in evaporative water loss with water deprivation. The physiological adaptations of Sage Sparrows to water and heat stress were not unusual for small passerine birds, and were intermediate in relation to various species of desert and non-desert birds already investigated. The successful existence of Sage Sparrows in desert environments is probably dependent upon the utilization of succulent foods to satisfy their demands for water and on temperature-dependent behavioral responses which may reduce heat stress, thereby minimizing the need for evaporative cooling. Close

• 373. [Article] Spatiotemporal Patterns and Risk Factors for Lead Exposure in Endangered California Condors during 15 Years of Reintroduction

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

  Citation × Citation Citation Abstract Copy Title: Spatiotemporal Patterns and Risk Factors for Lead Exposure in Endangered California Condors during 15 Years of Reintroduction Author: George, Daniel, Kelly, Terra R., Rivers, James W., et al., Grantham, Jesse To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Society for Conservation Biology and published by John Wiley & Sons Ltd. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291523-1739. Title: Spatiotemporal Patterns and Risk Factors for Lead Exposure in Endangered California Condors during 15 Years of Reintroduction Author: George, Daniel, Kelly, Terra R., Rivers, James W., et al., Grantham, Jesse To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the Society for Conservation Biology and published by John Wiley & Sons Ltd. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291523-1739. Close

• 374. [Article] Characterizing coal and mineral mines as a regional source of stress to stream fish assemblages

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

  Citation × Citation Citation Abstract Copy Title: Characterizing coal and mineral mines as a regional source of stress to stream fish assemblages Author: Daniel, Wesley M., Hughes, Robert M., et al., Infante, Dana M. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.sciencedirect.com/science/journal/1470160X. Title: Characterizing coal and mineral mines as a regional source of stress to stream fish assemblages Author: Daniel, Wesley M., Hughes, Robert M., et al., Infante, Dana M. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.sciencedirect.com/science/journal/1470160X. Close

• 375. [Article] Selecting locations for marine harvest refugia : a GIS study using logbook data from the Oregon trawl fishery

  This study examined the logbook record of the Oregon trawl fishery using a geographic information system (GIS) to determine the spatial and temporal distribution of English sole, Pleuronectes vetulus. ...

  Citation × Citation Citation Abstract Copy Title: Selecting locations for marine harvest refugia : a GIS study using logbook data from the Oregon trawl fishery Author: Macomber, Marcia Fraser This study examined the logbook record of the Oregon trawl fishery using a geographic information system (GIS) to determine the spatial and temporal distribution of English sole, Pleuronectes vetulus. The original logbook data for the years 1981,1982,1994,1995,1996 were filtered twice to provide both a general description of trends in the distribution of tows and catch parameters, and a more explicit ecological description of English sole catch dynamics. Tow distribution maps were used as a basis to evaluate the utility of the logbook data as a means to identify potential locations for harvest refugia. The spatial pattern of the trawl fishery changed dramatically between 1981-82 and 1994-96, although fishing activity was concentrated near ports of origin in all years. The fleet moved offshore and northward and the species composition of tows shifted from shallow water species toward deeper water fisheries. The English sole fishery remained distinct from the trawl fishery, although English sole tows and yields declined. High densities of English sole tows and the largest percentage annual English sole catch-per-unit-effort (CPUE) occurred in waters offshore Astoria, within 46 - 47°, in all years. Eight geographical regions were ranked according to their value to the production of English sole and their importance to the fishery. Sites of potential harvest refugia were selected based on their ability to contribute to the goal of long-term sustainability of the English sole fishery, by providing a buffer against errors in fishery management. Four sites were identified as potential locations, three sites in the offshore waters of the ports of Astoria, Newport and Brookings, and a fourth site in the nearshore zone along the Oregon coast, within the 50-fathom contour. The study concluded that logbook data will be useful to future planning of marine harvest refugia along the Pacific coast, because the data provide insights into fishing behavior and the relative amounts of fishing intensity that occur in different geographic regions. In addition, use of logbook data provide an opportunity for involvement of the fishing industry in the marine harvest refugia planning. Title: Selecting locations for marine harvest refugia : a GIS study using logbook data from the Oregon trawl fishery Author: Macomber, Marcia Fraser This study examined the logbook record of the Oregon trawl fishery using a geographic information system (GIS) to determine the spatial and temporal distribution of English sole, Pleuronectes vetulus. The original logbook data for the years 1981,1982,1994,1995,1996 were filtered twice to provide both a general description of trends in the distribution of tows and catch parameters, and a more explicit ecological description of English sole catch dynamics. Tow distribution maps were used as a basis to evaluate the utility of the logbook data as a means to identify potential locations for harvest refugia. The spatial pattern of the trawl fishery changed dramatically between 1981-82 and 1994-96, although fishing activity was concentrated near ports of origin in all years. The fleet moved offshore and northward and the species composition of tows shifted from shallow water species toward deeper water fisheries. The English sole fishery remained distinct from the trawl fishery, although English sole tows and yields declined. High densities of English sole tows and the largest percentage annual English sole catch-per-unit-effort (CPUE) occurred in waters offshore Astoria, within 46 - 47°, in all years. Eight geographical regions were ranked according to their value to the production of English sole and their importance to the fishery. Sites of potential harvest refugia were selected based on their ability to contribute to the goal of long-term sustainability of the English sole fishery, by providing a buffer against errors in fishery management. Four sites were identified as potential locations, three sites in the offshore waters of the ports of Astoria, Newport and Brookings, and a fourth site in the nearshore zone along the Oregon coast, within the 50-fathom contour. The study concluded that logbook data will be useful to future planning of marine harvest refugia along the Pacific coast, because the data provide insights into fishing behavior and the relative amounts of fishing intensity that occur in different geographic regions. In addition, use of logbook data provide an opportunity for involvement of the fishing industry in the marine harvest refugia planning. Close

• 376. [Article] Tucannon ecosystem analysis

  264 pp. Tables, figures, references, maps, appendices, illus. "The Tucannon River subbasin covers about 322,000 acres of Garfield and Columbia counties. Two major streams drain this subbasin, the Tucannon ...

  Citation × Citation Citation Abstract Copy Title: Tucannon ecosystem analysis Author: Pomeroy Ranger District (Or. and Wash.) Year: 2008, 2002 264 pp. Tables, figures, references, maps, appendices, illus. "The Tucannon River subbasin covers about 322,000 acres of Garfield and Columbia counties. Two major streams drain this subbasin, the Tucannon River, which flows into the Snake River, and Pataha Creek, which is the largest tributary to the Tucannon River. Other tributaries to the Tucannon River include Willow Creek, Kellogg Creek, Cummings Creek, Little Tucannon River, Panjab Creek, Sheep Creek, and Bear Creek. The upper portion of the Tucannon subbasin, which is the focus of this report, is contained within the Umatilla National Forest." Date of map appendix is August 2002. Captured June 18, 2008. Title: Tucannon ecosystem analysis Author: Pomeroy Ranger District (Or. and Wash.) Year: 2008, 2002 264 pp. Tables, figures, references, maps, appendices, illus. "The Tucannon River subbasin covers about 322,000 acres of Garfield and Columbia counties. Two major streams drain this subbasin, the Tucannon River, which flows into the Snake River, and Pataha Creek, which is the largest tributary to the Tucannon River. Other tributaries to the Tucannon River include Willow Creek, Kellogg Creek, Cummings Creek, Little Tucannon River, Panjab Creek, Sheep Creek, and Bear Creek. The upper portion of the Tucannon subbasin, which is the focus of this report, is contained within the Umatilla National Forest." Date of map appendix is August 2002. Captured June 18, 2008. Close

• 377. [Article] Population growth across heterogeneous environments: effects of harvesting and age structure

  This is the publisher’s final pdf. The published article is copyrighted by Inter-Research and can be found at: http://www.int-res.com/home/.

  Citation × Citation Citation Abstract Copy Title: Population growth across heterogeneous environments: effects of harvesting and age structure Author: Rouyer, Tristan, Yaragina, Natalia, Eikeset, Anne Maria, Hjermann, Dag O., Hidalgo, Manuel, Durant, Joel M., Stenseth, N. C., Ciannelli, Lorenzo This is the publisher’s final pdf. The published article is copyrighted by Inter-Research and can be found at: http://www.int-res.com/home/. Title: Population growth across heterogeneous environments: effects of harvesting and age structure Author: Rouyer, Tristan, Yaragina, Natalia, Eikeset, Anne Maria, Hjermann, Dag O., Hidalgo, Manuel, Durant, Joel M., Stenseth, N. C., Ciannelli, Lorenzo This is the publisher’s final pdf. The published article is copyrighted by Inter-Research and can be found at: http://www.int-res.com/home/. Close

• 378. [Article] Is the Fisheries Production Function Institution-dependent? Implications for Targeting Ability in Multispecies Fisheries

  Abstract Only

  Citation × Citation Citation Abstract Copy Title: Is the Fisheries Production Function Institution-dependent? Implications for Targeting Ability in Multispecies Fisheries Author: Abbott, Joshua, Haynie, Alan, Wilen, James, Reimer, Matthew Abstract Only Title: Is the Fisheries Production Function Institution-dependent? Implications for Targeting Ability in Multispecies Fisheries Author: Abbott, Joshua, Haynie, Alan, Wilen, James, Reimer, Matthew Abstract Only Close

• 379. [Article] Status of Nile perch Lates niloticus fishery in Lake Victoria

  Abstract Only

  Citation × Citation Citation Abstract Copy Title: Status of Nile perch Lates niloticus fishery in Lake Victoria Author: Owili, Monica, Nyamweya, Chrispine Abstract Only Title: Status of Nile perch Lates niloticus fishery in Lake Victoria Author: Owili, Monica, Nyamweya, Chrispine Abstract Only Close

• 380. [Article] Report on wintering western snowy plovers at Coos Bay north spit and impacts to plovers from the North Jetty repair project, winter 2009

  coast of the Pacific Ocean in California, Oregon, and Washington and at alkaline lakes in the interior of the western United States (Page et al. 1991). Loss of habitat, predation pressures, and disturbance ...

  Citation × Citation Citation Abstract Copy Title: Report on wintering western snowy plovers at Coos Bay north spit and impacts to plovers from the North Jetty repair project, winter 2009 Author: Institute for Natural Resources, Castelein, Kathleen A., Gaines, Eleanor P., Lauten, David J., Oregon Natural Heritage Information Center coast of the Pacific Ocean in California, Oregon, and Washington and at alkaline lakes in the interior of the western United States (Page et al. 1991). Loss of habitat, predation pressures, and disturbance have caused the decline of the coastal population of Snowy Plovers and led to the listing of the Pacific Coast Population of Western Snowy Plovers as Threatened on March 5, 1993 (U.S. Fish and Wildlife Service 1993). Oregon Western Snowy Plovers are known to winter along the coast of Oregon as well as migrate to other wintering locations, mainly in California (Lauten et al. 2001, ORNHIC unpublished data). Previous winter surveys along the Oregon coast (Oregon Department of Fish and Wildlife, unpublished data, ORNHIC unpublished data) have documented the locations of wintering Snowy Plovers. Coos Bay North Spit (CBNS) is one location where plovers are known to winter. During the winter of 2008-2009, Army Corp of Engineers (ACOE) contracted Kerr Contractors, Inc. to complete repairs on the North Jetty of the Coos River. ACOE consulted with U.S. Fish and Wildlife Service (USFWS) regarding impacts to sensitive species including Western Snowy Plover. ACOE contracted Oregon Natural Heritage Information Center (ORNHIC) to complete two Snowy Plover surveys prior to jetty repair work, two plover surveys per week during repair work, and two plover surveys post repair work to document any potential impacts to wintering plovers. Title: Report on wintering western snowy plovers at Coos Bay north spit and impacts to plovers from the North Jetty repair project, winter 2009 Author: Institute for Natural Resources, Castelein, Kathleen A., Gaines, Eleanor P., Lauten, David J., Oregon Natural Heritage Information Center coast of the Pacific Ocean in California, Oregon, and Washington and at alkaline lakes in the interior of the western United States (Page et al. 1991). Loss of habitat, predation pressures, and disturbance have caused the decline of the coastal population of Snowy Plovers and led to the listing of the Pacific Coast Population of Western Snowy Plovers as Threatened on March 5, 1993 (U.S. Fish and Wildlife Service 1993). Oregon Western Snowy Plovers are known to winter along the coast of Oregon as well as migrate to other wintering locations, mainly in California (Lauten et al. 2001, ORNHIC unpublished data). Previous winter surveys along the Oregon coast (Oregon Department of Fish and Wildlife, unpublished data, ORNHIC unpublished data) have documented the locations of wintering Snowy Plovers. Coos Bay North Spit (CBNS) is one location where plovers are known to winter. During the winter of 2008-2009, Army Corp of Engineers (ACOE) contracted Kerr Contractors, Inc. to complete repairs on the North Jetty of the Coos River. ACOE consulted with U.S. Fish and Wildlife Service (USFWS) regarding impacts to sensitive species including Western Snowy Plover. ACOE contracted Oregon Natural Heritage Information Center (ORNHIC) to complete two Snowy Plover surveys prior to jetty repair work, two plover surveys per week during repair work, and two plover surveys post repair work to document any potential impacts to wintering plovers. Close

• 381. [Article] Arboreal arthropod predation on early instar Douglas-fir tussock moth

  Loss of early instar Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) (DFTM) has been found to constitute 66-92% of intra-generation mortality and to be a key factor in inter-generation population ...

  Citation × Citation Citation Abstract Copy Title: Arboreal arthropod predation on early instar Douglas-fir tussock moth Author: Fichter, Becky L. Loss of early instar Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) (DFTM) has been found to constitute 66-92% of intra-generation mortality and to be a key factor in inter-generation population change. This death has been attributed to dispersal and to arthropod predation, two factors previously judged more important to an endemic than an outbreak population. Polyphagous arthropod predators are abundant in the forest canopy but their predaceous habits are difficult to document or quantify. The purpose of the study was to develop and test a serological assay, ELISA or enzyme-linked immunosorbent assay, for use as an indirect test of predation. Development of this assay involved production of an antiserum reactive with DFTM but not reactive with material from any coexisting lepidopteran larvae. Two-dimensional immunoelectrophoresis was used to select a minimally cross-reactive fraction of DFTM hemolymph as the antigen source so that a positive response from a field-collected predator would correlate unambiguously with predation on DFTM. Feeding trials using Podisus maculiventris Say (Hemiptera, Pentatomidae) and representative arboreal spiders established the rate of degredation of DFTM antigens ingested by these predators. An arbitrary threshold for deciding which specimens would be considered positive was established as the 95% confidence interval above the mean of controls. Half of the Podisus retained 0 reactivity for 3 days at a constant 24°C. Eighty percent of trial-fed spiders were positive in ELISA on the day on which they were fed; 80% were positive 12 days later when the test was concluded. Feeding on alternate prey decreased reactivity slightly. Fifty percent of the spiders initially fed a single first instar DFTM and subsequently fed 3 non-DFTM larvae tested positive after 0 being held 12 days at a constant 24°C. Field trials of this assay were conducted in 1979, 1980 and 1981 with arthropods collected in association with a native population of DFTM. Samples were taken at budburst from white fir from El Dorado National Forest, California. No cross-reactions with alternate prey were found in 1979 or 1980; phytophagous mirids did show false positive reactions in 1981. Cross-absorption of the conjugate prior to ELISA eliminated these heterologous reactions. All but rare species of arboreal arthropod predators were confirmed as having consumed first or second instar DFTM. A fortuitous 800-fold decline in the DFTM population occurred over these 3 study years. The proportion of predators of all guilds declined non-linearly with this decline in DFTM density. Spiders in each guild (diurnal active hunters, nocturnal active hunters, ambush hunters, larger web-spinners and minute web-spinners) consumed DFTM in linear proportion to the relative abundance of DFTM as one potential prey, i.e. were non-selective predators. Predaceous hemipterans, principally mirids, showed a strongly logarithmic response in the same analysis. Title: Arboreal arthropod predation on early instar Douglas-fir tussock moth Author: Fichter, Becky L. Loss of early instar Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) (DFTM) has been found to constitute 66-92% of intra-generation mortality and to be a key factor in inter-generation population change. This death has been attributed to dispersal and to arthropod predation, two factors previously judged more important to an endemic than an outbreak population. Polyphagous arthropod predators are abundant in the forest canopy but their predaceous habits are difficult to document or quantify. The purpose of the study was to develop and test a serological assay, ELISA or enzyme-linked immunosorbent assay, for use as an indirect test of predation. Development of this assay involved production of an antiserum reactive with DFTM but not reactive with material from any coexisting lepidopteran larvae. Two-dimensional immunoelectrophoresis was used to select a minimally cross-reactive fraction of DFTM hemolymph as the antigen source so that a positive response from a field-collected predator would correlate unambiguously with predation on DFTM. Feeding trials using Podisus maculiventris Say (Hemiptera, Pentatomidae) and representative arboreal spiders established the rate of degredation of DFTM antigens ingested by these predators. An arbitrary threshold for deciding which specimens would be considered positive was established as the 95% confidence interval above the mean of controls. Half of the Podisus retained 0 reactivity for 3 days at a constant 24°C. Eighty percent of trial-fed spiders were positive in ELISA on the day on which they were fed; 80% were positive 12 days later when the test was concluded. Feeding on alternate prey decreased reactivity slightly. Fifty percent of the spiders initially fed a single first instar DFTM and subsequently fed 3 non-DFTM larvae tested positive after 0 being held 12 days at a constant 24°C. Field trials of this assay were conducted in 1979, 1980 and 1981 with arthropods collected in association with a native population of DFTM. Samples were taken at budburst from white fir from El Dorado National Forest, California. No cross-reactions with alternate prey were found in 1979 or 1980; phytophagous mirids did show false positive reactions in 1981. Cross-absorption of the conjugate prior to ELISA eliminated these heterologous reactions. All but rare species of arboreal arthropod predators were confirmed as having consumed first or second instar DFTM. A fortuitous 800-fold decline in the DFTM population occurred over these 3 study years. The proportion of predators of all guilds declined non-linearly with this decline in DFTM density. Spiders in each guild (diurnal active hunters, nocturnal active hunters, ambush hunters, larger web-spinners and minute web-spinners) consumed DFTM in linear proportion to the relative abundance of DFTM as one potential prey, i.e. were non-selective predators. Predaceous hemipterans, principally mirids, showed a strongly logarithmic response in the same analysis. Close

• 382. [Article] Natural enemies of native bumble bees (Hymenoptera: Apidae) in western Oregon

  Bumble bees (Hymenoptera: Apidae) are important native pollinators in wild and agricultural systems, and are one of the few groups of native bees commercially bred for use in the pollination of a range ...

  Citation × Citation Citation Abstract Copy Title: Natural enemies of native bumble bees (Hymenoptera: Apidae) in western Oregon Author: Maxfield-Taylor, Sarah A. Bumble bees (Hymenoptera: Apidae) are important native pollinators in wild and agricultural systems, and are one of the few groups of native bees commercially bred for use in the pollination of a range of crops. In recent years, declines in bumble bees have been reported globally. One factor implicated in these declines, believed to affect bumble bee colonies in the wild and during rearing, is natural enemies. A diversity of fungi, protozoa, nematodes, and parasitoids has been reported to affect bumble bees, to varying extents, in different parts of the world. In contrast to reports of decline elsewhere, bumble bees have been thriving in Oregon on the West Coast of the U.S.A.. In particular, the agriculturally rich Willamette Valley in the western part of the state appears to be fostering several species. Little is known, however, about the natural enemies of bumble bees in this region. The objectives of this thesis were to: (1) identify pathogens and parasites in (a) bumble bees from the wild, and (b) bumble bees reared in captivity and (2) examine the effects of disease on bee hosts. Bumble bee queens and workers were collected from diverse locations in the Willamette Valley, in spring and summer. Bombus mixtus, Bombus nevadensis, and Bombus vosnesenskii collected from the wild were dissected and examined for pathogens and parasites, and these organisms were identified using morphological and molecular characteristics. Queens of Bombus griseocollis, Bombus nevadensis, and Bombus vosnesenskii were reared in captivity, and those that died or did not initiate nests were also examined for pathogens and parasites. In addition, the immune responses of healthy and infected bees were compared, to examine the effects of a common bumble bee gut pathogen Crithidia bombi (Kinetoplastida: Trypanosomatidae) on its host. This thesis reports that wild bumble bees in western Oregon are infected with the protozoa Apicystis bombi (Neogregarinida: Ophrocystidae) and Crithidia bombi, the fungus/microsporidian Nosema bombi (Microsporidia: Nosematidae), the nematode Sphaerularia bombi (Nematoda: Tylenchida), and two dipteran parasitoids, one unknown and one belonging to the family Conopidae (Diptera: Conopidae). In addition, this research presents the first ever report of infection by the larval pathogen Ascosphaera apis (Ascomycota: Ascosphaerales), in reared bumble bee adults. New host and distribution records are also presented for C. bombi, N. bombi, and S. bombi. The study found that bumble bees infected with C. bombi had lower activated levels of immune responses than healthy bees. The thesis discusses the long-term implications of study findings, and addresses the threat that bumble bee diseases pose to bee pollinators through shared environments Title: Natural enemies of native bumble bees (Hymenoptera: Apidae) in western Oregon Author: Maxfield-Taylor, Sarah A. Bumble bees (Hymenoptera: Apidae) are important native pollinators in wild and agricultural systems, and are one of the few groups of native bees commercially bred for use in the pollination of a range of crops. In recent years, declines in bumble bees have been reported globally. One factor implicated in these declines, believed to affect bumble bee colonies in the wild and during rearing, is natural enemies. A diversity of fungi, protozoa, nematodes, and parasitoids has been reported to affect bumble bees, to varying extents, in different parts of the world. In contrast to reports of decline elsewhere, bumble bees have been thriving in Oregon on the West Coast of the U.S.A.. In particular, the agriculturally rich Willamette Valley in the western part of the state appears to be fostering several species. Little is known, however, about the natural enemies of bumble bees in this region. The objectives of this thesis were to: (1) identify pathogens and parasites in (a) bumble bees from the wild, and (b) bumble bees reared in captivity and (2) examine the effects of disease on bee hosts. Bumble bee queens and workers were collected from diverse locations in the Willamette Valley, in spring and summer. Bombus mixtus, Bombus nevadensis, and Bombus vosnesenskii collected from the wild were dissected and examined for pathogens and parasites, and these organisms were identified using morphological and molecular characteristics. Queens of Bombus griseocollis, Bombus nevadensis, and Bombus vosnesenskii were reared in captivity, and those that died or did not initiate nests were also examined for pathogens and parasites. In addition, the immune responses of healthy and infected bees were compared, to examine the effects of a common bumble bee gut pathogen Crithidia bombi (Kinetoplastida: Trypanosomatidae) on its host. This thesis reports that wild bumble bees in western Oregon are infected with the protozoa Apicystis bombi (Neogregarinida: Ophrocystidae) and Crithidia bombi, the fungus/microsporidian Nosema bombi (Microsporidia: Nosematidae), the nematode Sphaerularia bombi (Nematoda: Tylenchida), and two dipteran parasitoids, one unknown and one belonging to the family Conopidae (Diptera: Conopidae). In addition, this research presents the first ever report of infection by the larval pathogen Ascosphaera apis (Ascomycota: Ascosphaerales), in reared bumble bee adults. New host and distribution records are also presented for C. bombi, N. bombi, and S. bombi. The study found that bumble bees infected with C. bombi had lower activated levels of immune responses than healthy bees. The thesis discusses the long-term implications of study findings, and addresses the threat that bumble bee diseases pose to bee pollinators through shared environments Close

• 383. [Image] The Water Report - Critical habitat, bull trout and politics

  	Only portions of issues of The Water Report are available in the Klamath Waters Digital Library. Includes bibliographical references. See the full report at http://www.thewaterreport.com/
  	Citation × Citation Citation Abstract Copy Title: The Water Report - Critical habitat, bull trout and politics Author: Envirotech Publications Year: 2005, 2008, 2006 Only portions of issues of The Water Report are available in the Klamath Waters Digital Library. Includes bibliographical references. See the full report at http://www.thewaterreport.com/ Title: The Water Report - Critical habitat, bull trout and politics Author: Envirotech Publications Year: 2005, 2008, 2006 Only portions of issues of The Water Report are available in the Klamath Waters Digital Library. Includes bibliographical references. See the full report at http://www.thewaterreport.com/ Close

• 384. [Image] Federal Register - Endangered and Threatened Wildlife and Plants; Notice of 90-Day Finding on a Petition to Delist the Lost River Sucker and Shortnose Sucker

  	Only portions of issues of the Federal Register are available in the Klamath Waters Digital Library. Includes bibliographical reference; 50 CFR Part 17; Action: Notice of 90-day petition finding; “FR Doc. ...
  	Citation × Citation Citation Abstract Copy Title: Federal Register - Endangered and Threatened Wildlife and Plants; Notice of 90-Day Finding on a Petition to Delist the Lost River Sucker and Shortnose Sucker Year: 2002, 2008, 2005 Only portions of issues of the Federal Register are available in the Klamath Waters Digital Library. Includes bibliographical reference; 50 CFR Part 17; Action: Notice of 90-day petition finding; “FR Doc. 02-12123 Filed 5-13-02: 8:45 a.m.;” See the Federal Register at http://www.gpoaccess.gov/fr/advanced.html Title: Federal Register - Endangered and Threatened Wildlife and Plants; Notice of 90-Day Finding on a Petition to Delist the Lost River Sucker and Shortnose Sucker Year: 2002, 2008, 2005 Only portions of issues of the Federal Register are available in the Klamath Waters Digital Library. Includes bibliographical reference; 50 CFR Part 17; Action: Notice of 90-day petition finding; “FR Doc. 02-12123 Filed 5-13-02: 8:45 a.m.;” See the Federal Register at http://www.gpoaccess.gov/fr/advanced.html Close

• 385. [Article] Greater Sage-grouse conservation assessment and strategy for Oregon: A plan to maintain and enhance populations and habitat

  Greater sage-grouse (Centrocercus urophasianus) were once found in most grassland and sagebrush (Artemisia spp.) habitats east of the Cascades in Oregon. European settlement and conversion of sagebrush ...

  Citation × Citation Citation Abstract Copy Title: Greater Sage-grouse conservation assessment and strategy for Oregon: A plan to maintain and enhance populations and habitat Author: Hagen, Christian Greater sage-grouse (Centrocercus urophasianus) were once found in most grassland and sagebrush (Artemisia spp.) habitats east of the Cascades in Oregon. European settlement and conversion of sagebrush steppe into agricultural production led to extirpation of the species in the Columbia Basin by the early part of the 1900s, but sagebrush rangelands have persisted, particularly in southeast Oregon. Populations have fluctuated markedly since the mid 1900s with notable declines in populations from the 1950s to early 1970s. These patterns in populations and habitat loss are similar to those observed for greater sage-grouse throughout its range. Population declines during the latter part of the 1900s lead to considerable concern for the species and subsequent conservation planning in all western states where it occurs. This management strategy is a result of this larger conservation effort by the Western Association of Fish and Wildlife Agencies. This updated and revised Plan describes Oregon Department of Fish and Wildlife’s management of greater sage-grouse and provides guidance to public land management agencies and land managers for sage-grouse conservation. Conservation actions should be encouraged on private lands as these contain some of the more productive sites, but conservation on private land is voluntary. Highlights of updates. Population goals have been revised based on statistically more robust methods for estimating population sizes. Accomplishments in conservation, research, and monitoring that have occurred since 2005 are discussed. The Core Area approach to strategically identifying important landscapes for sage-grouse is explained in detail from model development to implementation. Finally, there have been numerous publications on sage-grouse since 2005 and that literature has been updated to the document where appropriate. This management strategy and the supporting background information is intended to promote the conservation of greater sage-grouse and intact functioning sagebrush communities in Oregon. The strategy is tied to the life history of greater sage-grouse and uses the best science available. Although this strategy focuses on conservation of greater sage-grouse, the intent is to benefit conservation needs of other sagebrush-steppe species. Oregon greater sage-grouse are important to the North American population and management actions in the state will have implications on a much larger scale. This Plan recognizes that livestock ranching operations which manage for ecologically sustainable native rangelands is compatible with sage-grouse conservation, and necessary management activities to maintain a sustainable ranching operation are not considered “development actions” under the application of the Mitigation Policy to sage-grouse habitat. This Plan provides biological recommendations for long-term conservation of sage-grouse in Oregon based on the best available science. However, ODFW recognizes that land use planners and managers may need to consider these recommendations within the context of socialeconomic issues and decisions that are the responsibility of the respective governmental bodies. Thus, the intent of this plan is to inform decision-makers regarding the biological consequences of various actions on sage-grouse, but not to dictate land management decision. This document is divided into 6 sections. Section I explains the background and philosophy of conservation approaches in this strategy. Section II provides an overview of sage-grouse biology and ecology throughout the species range. Sections III and IV provide an assessment of populations and habitat, respectively, upon which management objectives are developed and their underlying assumptions and rationale are stated. In Section V, conservation guidelines are outlined, that describe actions needed and methods for achieving habitat objectives. Section VI outlines components for Plan implementation, includes a description of the structure and role of local implementation groups, and implications for public (state and federal) land management agencies. There are 6 appendices that provide supporting information, including a new appendix about socio-economics provided by the Association of Oregon Counties. Sections III to VI of the plan were expanded, because these sections are linked to the objectives and implementation of this Plan. Populations and habitat were assessed by BLM district boundaries because; the availability of habitat measures by district, each district approximates an eco-region, and BLM is the primary land manager within most of the district boundaries. The 23 years 1980-2003 are the relevant time period to establish a benchmark for sage-grouse populations and their habitats, because the factors of predator control methods (and take levels), grazing schedules, survey protocols, habitat treatments and harvest levels of sage-grouse were similar through this period. Title: Greater Sage-grouse conservation assessment and strategy for Oregon: A plan to maintain and enhance populations and habitat Author: Hagen, Christian Greater sage-grouse (Centrocercus urophasianus) were once found in most grassland and sagebrush (Artemisia spp.) habitats east of the Cascades in Oregon. European settlement and conversion of sagebrush steppe into agricultural production led to extirpation of the species in the Columbia Basin by the early part of the 1900s, but sagebrush rangelands have persisted, particularly in southeast Oregon. Populations have fluctuated markedly since the mid 1900s with notable declines in populations from the 1950s to early 1970s. These patterns in populations and habitat loss are similar to those observed for greater sage-grouse throughout its range. Population declines during the latter part of the 1900s lead to considerable concern for the species and subsequent conservation planning in all western states where it occurs. This management strategy is a result of this larger conservation effort by the Western Association of Fish and Wildlife Agencies. This updated and revised Plan describes Oregon Department of Fish and Wildlife’s management of greater sage-grouse and provides guidance to public land management agencies and land managers for sage-grouse conservation. Conservation actions should be encouraged on private lands as these contain some of the more productive sites, but conservation on private land is voluntary. Highlights of updates. Population goals have been revised based on statistically more robust methods for estimating population sizes. Accomplishments in conservation, research, and monitoring that have occurred since 2005 are discussed. The Core Area approach to strategically identifying important landscapes for sage-grouse is explained in detail from model development to implementation. Finally, there have been numerous publications on sage-grouse since 2005 and that literature has been updated to the document where appropriate. This management strategy and the supporting background information is intended to promote the conservation of greater sage-grouse and intact functioning sagebrush communities in Oregon. The strategy is tied to the life history of greater sage-grouse and uses the best science available. Although this strategy focuses on conservation of greater sage-grouse, the intent is to benefit conservation needs of other sagebrush-steppe species. Oregon greater sage-grouse are important to the North American population and management actions in the state will have implications on a much larger scale. This Plan recognizes that livestock ranching operations which manage for ecologically sustainable native rangelands is compatible with sage-grouse conservation, and necessary management activities to maintain a sustainable ranching operation are not considered “development actions” under the application of the Mitigation Policy to sage-grouse habitat. This Plan provides biological recommendations for long-term conservation of sage-grouse in Oregon based on the best available science. However, ODFW recognizes that land use planners and managers may need to consider these recommendations within the context of socialeconomic issues and decisions that are the responsibility of the respective governmental bodies. Thus, the intent of this plan is to inform decision-makers regarding the biological consequences of various actions on sage-grouse, but not to dictate land management decision. This document is divided into 6 sections. Section I explains the background and philosophy of conservation approaches in this strategy. Section II provides an overview of sage-grouse biology and ecology throughout the species range. Sections III and IV provide an assessment of populations and habitat, respectively, upon which management objectives are developed and their underlying assumptions and rationale are stated. In Section V, conservation guidelines are outlined, that describe actions needed and methods for achieving habitat objectives. Section VI outlines components for Plan implementation, includes a description of the structure and role of local implementation groups, and implications for public (state and federal) land management agencies. There are 6 appendices that provide supporting information, including a new appendix about socio-economics provided by the Association of Oregon Counties. Sections III to VI of the plan were expanded, because these sections are linked to the objectives and implementation of this Plan. Populations and habitat were assessed by BLM district boundaries because; the availability of habitat measures by district, each district approximates an eco-region, and BLM is the primary land manager within most of the district boundaries. The 23 years 1980-2003 are the relevant time period to establish a benchmark for sage-grouse populations and their habitats, because the factors of predator control methods (and take levels), grazing schedules, survey protocols, habitat treatments and harvest levels of sage-grouse were similar through this period. Close

• 386. [Article] Population genetics of ranid frogs : investigating effective population size and gene flow

  This dissertation focuses on the evolutionary forces of genetic drift and gene flow in frog populations. The balance of these two forces and the force of mutation largely determine the amount of neutral ...

  Citation × Citation Citation Abstract Copy Title: Population genetics of ranid frogs : investigating effective population size and gene flow Author: Phillipsen, Ivan Clayton This dissertation focuses on the evolutionary forces of genetic drift and gene flow in frog populations. The balance of these two forces and the force of mutation largely determine the amount of neutral genetic variation within populations as well as the degree of genetic similarity among populations. The stochastic evolutionary change caused by genetic drift can be quantified through the use of the effective population size (N[subscript e]) parameter. The effective size of a population is the number of breeding individuals in a conceptual, ideal population that would evolve by genetic drift at the same rate as the real population being studied. How a population responds to mutation, selection, and gene flow depends on N[subscript e], rather than the actual census population size (N). In most natural populations, N[subscript e] is considerably smaller than N. For these reasons, N[subscript e] is a fundamental parameter in basic population genetics theory as well as in applied conservation genetics. The degree of neutral genetic similarity between populations is highly dependent upon gene flow. When gene flow between a pair of populations is low, the populations are likely to become genetically differentiated. Conversely, when gene flow between populations is high, the populations will tend to be more genetically similar. Amphibians are good model organisms for studying genetic drift and gene flow because they tend to exhibit strong population structure at small spatial scales. This is a consequence of their generally small population sizes, natal philopatry, limited dispersal capabilities, and restricted habitat requirements. They are expected to have easily-detectable signatures of spatial genetic structure and genetic drift. Amphibians can be used as models to further our understanding of evolutionary processes and that understanding can be applied to the conservation of amphibians. Equipped with knowledge of what naturally influences genetic drift and gene flow in amphibians, we can apply the principles of population genetics to mitigate the genetic consequences of amphibian declines. In Chapters 2 and 3, I used molecular genetic data from frog populations to investigate N[subscript e] and the related parameter N[subscript b] (the effective number of breeders). Chapter 2 is a study of a single population of the Oregon spotted frog (Rana pretiosa). My aim was to determine where in the life cycle of this species the greatest reduction in N[subscript b] occurs. I used genetic data from microsatellites to estimate N[subscript b] at two different life stages, eggs and metamorphs, and found that estimates of N[subscript b] were similar at both stages. This result suggests that inflated variance in family size due to egg mass mortality is not a primary cause of N[subscript e] reductions relative to N in this species. Chapter 3 is a comparison of N[subscript e] estimates within and among four species of frogs in the family Ranidae: R. pretiosa, R. luteiventris, R. cascadae, and Lithobates pipiens. I obtained N[subscript e] estimates for 90 populations across the four species, using microsatellite data and several different estimators. The first three species and the western populations of L. pipiens have very small effective sizes (< 50). Eastern populations of L. pipiens are much larger, with N[subscript e] estimates in the hundreds and thousands. I also found significant correlations between N[subscript e] estimates and latitude, longitude, or altitude in R. luteiventris and L. pipiens. Chapter 4 is a study of gene flow among populations of the Cascades frog (Rana cascadae) in the Olympic Mountains of Washington. I quantified genetic differentiation among 22 R. cascadae populations with data from microsatellite markers and used a landscape genetics approach to identify environmental features that have strong influences on gene flow in this species. I used a Random Forests statistical procedure to assess which of several structural connectivity models and 15 landscape variables explained the most variation in genetic distances among populations. I found that the best-fitting Random Forests models were based on different structural connectivity models for two datasets: 'within' and 'between' genetic clusters of populations. The landscape variables identified as the most important also differed across the two datasets, suggesting that landscape influences vary across spatial scales. The results presented in this dissertation led to an increased understanding of effective population size in ranid frogs and of the environmental factors that influence population structure in R. cascadae. These studies provide a foundation for further research on the specific factors that influence genetic drift and gene flow in these species. Title: Population genetics of ranid frogs : investigating effective population size and gene flow Author: Phillipsen, Ivan Clayton This dissertation focuses on the evolutionary forces of genetic drift and gene flow in frog populations. The balance of these two forces and the force of mutation largely determine the amount of neutral genetic variation within populations as well as the degree of genetic similarity among populations. The stochastic evolutionary change caused by genetic drift can be quantified through the use of the effective population size (N[subscript e]) parameter. The effective size of a population is the number of breeding individuals in a conceptual, ideal population that would evolve by genetic drift at the same rate as the real population being studied. How a population responds to mutation, selection, and gene flow depends on N[subscript e], rather than the actual census population size (N). In most natural populations, N[subscript e] is considerably smaller than N. For these reasons, N[subscript e] is a fundamental parameter in basic population genetics theory as well as in applied conservation genetics. The degree of neutral genetic similarity between populations is highly dependent upon gene flow. When gene flow between a pair of populations is low, the populations are likely to become genetically differentiated. Conversely, when gene flow between populations is high, the populations will tend to be more genetically similar. Amphibians are good model organisms for studying genetic drift and gene flow because they tend to exhibit strong population structure at small spatial scales. This is a consequence of their generally small population sizes, natal philopatry, limited dispersal capabilities, and restricted habitat requirements. They are expected to have easily-detectable signatures of spatial genetic structure and genetic drift. Amphibians can be used as models to further our understanding of evolutionary processes and that understanding can be applied to the conservation of amphibians. Equipped with knowledge of what naturally influences genetic drift and gene flow in amphibians, we can apply the principles of population genetics to mitigate the genetic consequences of amphibian declines. In Chapters 2 and 3, I used molecular genetic data from frog populations to investigate N[subscript e] and the related parameter N[subscript b] (the effective number of breeders). Chapter 2 is a study of a single population of the Oregon spotted frog (Rana pretiosa). My aim was to determine where in the life cycle of this species the greatest reduction in N[subscript b] occurs. I used genetic data from microsatellites to estimate N[subscript b] at two different life stages, eggs and metamorphs, and found that estimates of N[subscript b] were similar at both stages. This result suggests that inflated variance in family size due to egg mass mortality is not a primary cause of N[subscript e] reductions relative to N in this species. Chapter 3 is a comparison of N[subscript e] estimates within and among four species of frogs in the family Ranidae: R. pretiosa, R. luteiventris, R. cascadae, and Lithobates pipiens. I obtained N[subscript e] estimates for 90 populations across the four species, using microsatellite data and several different estimators. The first three species and the western populations of L. pipiens have very small effective sizes (< 50). Eastern populations of L. pipiens are much larger, with N[subscript e] estimates in the hundreds and thousands. I also found significant correlations between N[subscript e] estimates and latitude, longitude, or altitude in R. luteiventris and L. pipiens. Chapter 4 is a study of gene flow among populations of the Cascades frog (Rana cascadae) in the Olympic Mountains of Washington. I quantified genetic differentiation among 22 R. cascadae populations with data from microsatellite markers and used a landscape genetics approach to identify environmental features that have strong influences on gene flow in this species. I used a Random Forests statistical procedure to assess which of several structural connectivity models and 15 landscape variables explained the most variation in genetic distances among populations. I found that the best-fitting Random Forests models were based on different structural connectivity models for two datasets: 'within' and 'between' genetic clusters of populations. The landscape variables identified as the most important also differed across the two datasets, suggesting that landscape influences vary across spatial scales. The results presented in this dissertation led to an increased understanding of effective population size in ranid frogs and of the environmental factors that influence population structure in R. cascadae. These studies provide a foundation for further research on the specific factors that influence genetic drift and gene flow in these species. Close

• 387. [Article] All in a DNA's work : conservation genetics and monitoring of the New Zealand endemic Maui's and Hector's dolphins

  The critically endangered Maui's dolphin (Cephalorhynchus hectori maui) and the endangered Hector's dolphin (C. h. hectori) are endemic to the coastal waters of New Zealand, where their primary threat ...

  Citation × Citation Citation Abstract Copy Title: All in a DNA's work : conservation genetics and monitoring of the New Zealand endemic Maui's and Hector's dolphins Author: Hamner, Rebecca Marie The critically endangered Maui's dolphin (Cephalorhynchus hectori maui) and the endangered Hector's dolphin (C. h. hectori) are endemic to the coastal waters of New Zealand, where their primary threat is fisheries-related mortality. The Maui's dolphin is among the most critically endangered cetaceans in the world, with its remnant population primarily concentrated in approximately 140 km along the central west coast of New Zealand's North Island. Its closely related sister subspecies, the Hector's dolphin, is more abundant and offers a useful comparison for studying the Maui's dolphin. My work used genetic tools to examine demographic and genetic parameters relevant for conservation considerations regarding Maui's and Hector's dolphins, as well as to build upon past genetic baselines for the purpose of long-term genetic monitoring of these subspecies. Three genetic datasets formed the basis for most analyses: (1) Maui's 01-07, including 54 Maui's dolphin individuals sampled between 2001 and 2007 (n = 70 biopsies, 12 beachcast); (2) Maui's 10-11, including 40 Maui's dolphin individuals sampled in 2010 and 2011 (n = 69 biopsies, 1 beachcast); and (3) Hector's CB11-12, including 148 Hector's dolphin individuals sampled in Cloudy Bay in 2011 and 2012 (n = 263 biopsies). Microsatellite genotypes were used to identify individuals for a genotype recapture abundance estimate of individuals age 1⁺ (N₁₊) and for the estimation of effective population size (N[subscript e]). Both populations exhibited a high N[subscript e] relative to N₁₊, consistent with expectations given their life history characteristics and the limited data available for other dolphin species. The abundance of Maui's dolphins was confirmed to be very low, Maui's 10-11 N₁₊ = 55 (95% CL = 48 - 69), and as expected, it had much lower linkage disequilibrium N[subscript e] (61, 95% CL = 29 - 338) than Hector's CB11-12 (N[subscript e] = 207, 95% CL = 127 - 447; N₁₊ = 272, 95% CL = 236 - 323). The slightly higher Ne/N₁₊ ratio of the Maui's dolphin compared to the Hector's dolphin is consistent with a recent decline in the Maui's dolphin. Although the point estimates of both N[subscript e] and N₁₊ decreased between the two Maui's dolphin datasets (Maui's 01-07: N[subscript e] = 74, 95% CL = 37 - 318; N₁₊ = 69, 95% CL = 38 - 125), the confidence intervals widely overlapped. Maui's 10-11 had significantly fewer alleles (average 4 alleles/locus) and lower heterozygosity (H₀ = 0.316, H[subscript e] = 0.319) than Hector's CB11-12 (average 7 alleles/locus, H₀ = 0.500, H[subscript e] = 0.495; all P <0.001). Interestingly, one microsatellite locus (PPHO104) had anomalously high diversity (31 to 63 alleles) in both Hector's and Maui's dolphins and appears to be influenced by diversifying selection. The observed and expected heterozygosity, internal relatedness, and F[subscript IS] of Maui's dolphins all showed patterns consistent with a decline of the subspecies, although none differed significantly over the short time interval between the two datasets collected in 2001-07 and 2010-11. The lack of significant decline in any of the parameters analyzed for Maui's dolphins is not surprising given the low power to detect a low to moderate decline over the short interval (<1 generation) between the two sampling periods. Compared to minimum viable effective population sizes proposed to guide management decisions, the Maui's dolphin has declined below the recommended threshold of N[subscript e] = 50, recently increased to N[subscript e] ≥100, thought to be necessary to avoid inbreeding depression in the short term (5 generations, ~65.2 years for Maui's and Hector's dolphins). Additionally, both the Maui's dolphin and Cloudy Bay Hector's dolphin populations are below the recommended threshold of N[subscript e] = 500, recently increased to N[subscript e] ≥1000, thought to be necessary to preserve long-term evolutionary potential. This is less of a concern for the Cloudy Bay Hector's population, which is thought to maintain gene flow with neighboring populations. However, for the small, isolated Maui's dolphin population, inbreeding depression is likely to be an increasing concern. Furthermore, each Maui's dolphin individual holds a disproportionate amount of the total genetic variation of the subspecies and would represent a disproportionately large demographic and genetic loss if it died before realizing its reproductive potential in the population. There is, however, potential for genetic restoration by interbreeding with Hector's dolphins, as genetic monitoring of Maui's dolphins revealed the first contemporary dispersal of four (two living females, one dead female, one dead male) Hector's dolphins into the Maui's dolphin distribution. Two Hector's dolphins (one dead female neonate, one living male) were also sampled along the North Island's southwest coast, outside the presumed range of either subspecies. Together, these records provide evidence of long-distance dispersal by Hector's dolphins (≥400 km) and the possibility of an unsampled Hector's dolphin population along the southwest coast of the North Island or northern South Island. These results highlight the value of genetic monitoring for subspecies lacking distinctive physical appearances, as such discoveries are not detected by other means but have important conservation implications. Although the Maui's dolphin is critically endangered, it is not necessarily doomed to extinction. The subspecies appears to be maintaining an equal sex ratio and connectivity within its remnant range, and the highly diverse locus PPHO104 could potentially offer clues to an inbreeding avoidance mechanism. If Maui's dolphins interbreed with the recently identified Hector's dolphin immigrants, it could provide genetic restoration, enhancing chances of long-term survival of the Maui's dolphin. Continued genetic monitoring and examination of recovered carcasses for phenotypic signs of inbreeding are important for gauging genetic threats to the survival of Maui's dolphins, as well as determining if any Hector's dolphin populations appear to be declining toward the critically endangered state of the Maui's dolphin. The results of this work contributed to the decision by the New Zealand Department of Conservation and Ministry for Primary Industries to conduct an updated risk assessment for Maui's dolphins and accelerate the review of the Maui's Dolphin Threat Management Plan. Consequently, commercial and recreational set net restrictions were extended slightly to reduce entanglement risk to Maui's dolphins utilizing the southern part of their distribution, as well as any Hector's dolphins that disperse north into that area. The results related to the population of Hector's dolphins in Cloudy Bay provide information that will contribute to the upcoming review of the Hector's dolphin component of the Threat Management Plan. Title: All in a DNA's work : conservation genetics and monitoring of the New Zealand endemic Maui's and Hector's dolphins Author: Hamner, Rebecca Marie The critically endangered Maui's dolphin (Cephalorhynchus hectori maui) and the endangered Hector's dolphin (C. h. hectori) are endemic to the coastal waters of New Zealand, where their primary threat is fisheries-related mortality. The Maui's dolphin is among the most critically endangered cetaceans in the world, with its remnant population primarily concentrated in approximately 140 km along the central west coast of New Zealand's North Island. Its closely related sister subspecies, the Hector's dolphin, is more abundant and offers a useful comparison for studying the Maui's dolphin. My work used genetic tools to examine demographic and genetic parameters relevant for conservation considerations regarding Maui's and Hector's dolphins, as well as to build upon past genetic baselines for the purpose of long-term genetic monitoring of these subspecies. Three genetic datasets formed the basis for most analyses: (1) Maui's 01-07, including 54 Maui's dolphin individuals sampled between 2001 and 2007 (n = 70 biopsies, 12 beachcast); (2) Maui's 10-11, including 40 Maui's dolphin individuals sampled in 2010 and 2011 (n = 69 biopsies, 1 beachcast); and (3) Hector's CB11-12, including 148 Hector's dolphin individuals sampled in Cloudy Bay in 2011 and 2012 (n = 263 biopsies). Microsatellite genotypes were used to identify individuals for a genotype recapture abundance estimate of individuals age 1⁺ (N₁₊) and for the estimation of effective population size (N[subscript e]). Both populations exhibited a high N[subscript e] relative to N₁₊, consistent with expectations given their life history characteristics and the limited data available for other dolphin species. The abundance of Maui's dolphins was confirmed to be very low, Maui's 10-11 N₁₊ = 55 (95% CL = 48 - 69), and as expected, it had much lower linkage disequilibrium N[subscript e] (61, 95% CL = 29 - 338) than Hector's CB11-12 (N[subscript e] = 207, 95% CL = 127 - 447; N₁₊ = 272, 95% CL = 236 - 323). The slightly higher Ne/N₁₊ ratio of the Maui's dolphin compared to the Hector's dolphin is consistent with a recent decline in the Maui's dolphin. Although the point estimates of both N[subscript e] and N₁₊ decreased between the two Maui's dolphin datasets (Maui's 01-07: N[subscript e] = 74, 95% CL = 37 - 318; N₁₊ = 69, 95% CL = 38 - 125), the confidence intervals widely overlapped. Maui's 10-11 had significantly fewer alleles (average 4 alleles/locus) and lower heterozygosity (H₀ = 0.316, H[subscript e] = 0.319) than Hector's CB11-12 (average 7 alleles/locus, H₀ = 0.500, H[subscript e] = 0.495; all P <0.001). Interestingly, one microsatellite locus (PPHO104) had anomalously high diversity (31 to 63 alleles) in both Hector's and Maui's dolphins and appears to be influenced by diversifying selection. The observed and expected heterozygosity, internal relatedness, and F[subscript IS] of Maui's dolphins all showed patterns consistent with a decline of the subspecies, although none differed significantly over the short time interval between the two datasets collected in 2001-07 and 2010-11. The lack of significant decline in any of the parameters analyzed for Maui's dolphins is not surprising given the low power to detect a low to moderate decline over the short interval (<1 generation) between the two sampling periods. Compared to minimum viable effective population sizes proposed to guide management decisions, the Maui's dolphin has declined below the recommended threshold of N[subscript e] = 50, recently increased to N[subscript e] ≥100, thought to be necessary to avoid inbreeding depression in the short term (5 generations, ~65.2 years for Maui's and Hector's dolphins). Additionally, both the Maui's dolphin and Cloudy Bay Hector's dolphin populations are below the recommended threshold of N[subscript e] = 500, recently increased to N[subscript e] ≥1000, thought to be necessary to preserve long-term evolutionary potential. This is less of a concern for the Cloudy Bay Hector's population, which is thought to maintain gene flow with neighboring populations. However, for the small, isolated Maui's dolphin population, inbreeding depression is likely to be an increasing concern. Furthermore, each Maui's dolphin individual holds a disproportionate amount of the total genetic variation of the subspecies and would represent a disproportionately large demographic and genetic loss if it died before realizing its reproductive potential in the population. There is, however, potential for genetic restoration by interbreeding with Hector's dolphins, as genetic monitoring of Maui's dolphins revealed the first contemporary dispersal of four (two living females, one dead female, one dead male) Hector's dolphins into the Maui's dolphin distribution. Two Hector's dolphins (one dead female neonate, one living male) were also sampled along the North Island's southwest coast, outside the presumed range of either subspecies. Together, these records provide evidence of long-distance dispersal by Hector's dolphins (≥400 km) and the possibility of an unsampled Hector's dolphin population along the southwest coast of the North Island or northern South Island. These results highlight the value of genetic monitoring for subspecies lacking distinctive physical appearances, as such discoveries are not detected by other means but have important conservation implications. Although the Maui's dolphin is critically endangered, it is not necessarily doomed to extinction. The subspecies appears to be maintaining an equal sex ratio and connectivity within its remnant range, and the highly diverse locus PPHO104 could potentially offer clues to an inbreeding avoidance mechanism. If Maui's dolphins interbreed with the recently identified Hector's dolphin immigrants, it could provide genetic restoration, enhancing chances of long-term survival of the Maui's dolphin. Continued genetic monitoring and examination of recovered carcasses for phenotypic signs of inbreeding are important for gauging genetic threats to the survival of Maui's dolphins, as well as determining if any Hector's dolphin populations appear to be declining toward the critically endangered state of the Maui's dolphin. The results of this work contributed to the decision by the New Zealand Department of Conservation and Ministry for Primary Industries to conduct an updated risk assessment for Maui's dolphins and accelerate the review of the Maui's Dolphin Threat Management Plan. Consequently, commercial and recreational set net restrictions were extended slightly to reduce entanglement risk to Maui's dolphins utilizing the southern part of their distribution, as well as any Hector's dolphins that disperse north into that area. The results related to the population of Hector's dolphins in Cloudy Bay provide information that will contribute to the upcoming review of the Hector's dolphin component of the Threat Management Plan. Close

• 388. [Article] Studies of ecological factors that affect the population and distribution of the western gray squirrel in northcentral Oregon

  The western gray squirrel (Sciurus griseus griseus Ord) occur only in the Pacific states and in a small corner of extreme western Nevada. Field studies of aspects of the ecology of the most widely distributed ...

  Citation × Citation Citation Abstract Copy Title: Studies of ecological factors that affect the population and distribution of the western gray squirrel in northcentral Oregon Author: Foster, Susan Ann Year: 1992 The western gray squirrel (Sciurus griseus griseus Ord) occur only in the Pacific states and in a small corner of extreme western Nevada. Field studies of aspects of the ecology of the most widely distributed subspecies of western gray squirrel (S. griseus) were conducted at three sites in the ponderosa pine-Oregon white oak zone on the eastern slopes of Mt. Hood, Wasco County, Oregon, between 1981 and 1989. From 1981 through 1987, a Hunter Cooperation Program provided remains of squirrels shot during the annual late summer-early autumn hunting season. Other data were gathered through capture and release studies, radiotelemetry, and habitat analysis. The age structure of these populations, as revealed by examination of squirrels killed by hunters, is predominantly mature animals. Also, the population as estimated by hunter success during the Hunter Cooperation Program and by field observations appears to be declining. In the sites studied, western gray squirrels have two seasons of reproductive activity annually. Some individuals mate from January through March; their young emerge from the nest in May and June. Other individuals mate during May and June; their young emerge in August and September. The latter matings are usually the most productive. Analysis of nest trees and their surroundings revealed that nests are most likely to be located in mature trees that have well-developed crowns and occur in stands with a high degree of canopy closure. Nest trees were usually located within approximately 180 meters of permanent water and on sites with a south-southeasterly exposure. Home ranges of squirrels examined in this study were usually large compared to home ranges reported for this species elsewhere in its range. Given the cost of having large home ranges, it seems possible that the squirrels at these study sites exist in less than optimal ecological circumstances. Human factors that may have contributed to the decline of the populations in this study may include the nature of logging activities and the timing of the annual hunting season. Limiting factors other than human activities may include competition with other mast-consuming animals (mule deer, elk, wild turkeys, and three other species of squirrels) for limited and variable mast crops. Title: Studies of ecological factors that affect the population and distribution of the western gray squirrel in northcentral Oregon Author: Foster, Susan Ann Year: 1992 The western gray squirrel (Sciurus griseus griseus Ord) occur only in the Pacific states and in a small corner of extreme western Nevada. Field studies of aspects of the ecology of the most widely distributed subspecies of western gray squirrel (S. griseus) were conducted at three sites in the ponderosa pine-Oregon white oak zone on the eastern slopes of Mt. Hood, Wasco County, Oregon, between 1981 and 1989. From 1981 through 1987, a Hunter Cooperation Program provided remains of squirrels shot during the annual late summer-early autumn hunting season. Other data were gathered through capture and release studies, radiotelemetry, and habitat analysis. The age structure of these populations, as revealed by examination of squirrels killed by hunters, is predominantly mature animals. Also, the population as estimated by hunter success during the Hunter Cooperation Program and by field observations appears to be declining. In the sites studied, western gray squirrels have two seasons of reproductive activity annually. Some individuals mate from January through March; their young emerge from the nest in May and June. Other individuals mate during May and June; their young emerge in August and September. The latter matings are usually the most productive. Analysis of nest trees and their surroundings revealed that nests are most likely to be located in mature trees that have well-developed crowns and occur in stands with a high degree of canopy closure. Nest trees were usually located within approximately 180 meters of permanent water and on sites with a south-southeasterly exposure. Home ranges of squirrels examined in this study were usually large compared to home ranges reported for this species elsewhere in its range. Given the cost of having large home ranges, it seems possible that the squirrels at these study sites exist in less than optimal ecological circumstances. Human factors that may have contributed to the decline of the populations in this study may include the nature of logging activities and the timing of the annual hunting season. Limiting factors other than human activities may include competition with other mast-consuming animals (mule deer, elk, wild turkeys, and three other species of squirrels) for limited and variable mast crops. Close

• 389. [Article] Potential Effects of Management on Caspian Tern Hydroprogne caspia Predation on Juvenile Salmonids at a Colony in San Francisco Bay, California

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

  Citation × Citation Citation Abstract Copy Title: Potential Effects of Management on Caspian Tern Hydroprogne caspia Predation on Juvenile Salmonids at a Colony in San Francisco Bay, California Author: Evans, Allen F., Adrean, Lindsay J., Roby, Daniel D., Lyons, Donald E., Collis, Ken To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is published by Taylor & Francis and can be found at: http://www.taylorandfrancis.com. Copyrighted by American Fisheries Society (http://afsjournals.org/). Title: Potential Effects of Management on Caspian Tern Hydroprogne caspia Predation on Juvenile Salmonids at a Colony in San Francisco Bay, California Author: Evans, Allen F., Adrean, Lindsay J., Roby, Daniel D., Lyons, Donald E., Collis, Ken To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is published by Taylor & Francis and can be found at: http://www.taylorandfrancis.com. Copyrighted by American Fisheries Society (http://afsjournals.org/). Close

• 390. [Article] Quantifying Resilience of Multiple Ecosystem Services and Biodiversity in a Temperate Forest Landscape

  Resilience is increasingly being considered as a new paradigm of forest management among scientists, practitioners, and policymakers. However, metrics of resilience to environmental change are lacking. ...

  Citation × Citation Citation Abstract Copy Title: Quantifying Resilience of Multiple Ecosystem Services and Biodiversity in a Temperate Forest Landscape Author: Cantarello, Elena, Newton, Adrian C., Martin, Phillip A., Evans, Paul M., Gosal, Arjan, Lucash, Melissa S. Year: 2017 Resilience is increasingly being considered as a new paradigm of forest management among scientists, practitioners, and policymakers. However, metrics of resilience to environmental change are lacking. Faced with novel disturbances, forests may be able to sustain existing ecosystem services and biodiversity by exhibiting resilience, or alternatively these attributes may undergo either a linear or nonlinear decline. Here we provide a novel quantitative approach for assessing forest resilience that focuses on three components of resilience, namely resistance, recovery, and net change, using a spatially explicit model of forest dynamics. Under the pulse set scenarios, we explored the resilience of nine ecosystem services and four biodiversity measures following a one-off disturbance applied to an increasing percentage of forest area. Under the pulse + press set scenarios, the six disturbance intensities explored during the pulse set were followed by a continuous disturbance. We detected thresholds in net change under pulse + press scenarios for the majority of the ecosystem services and biodiversity measures, which started to decline sharply when disturbance affected >40% of the landscape. Thresholds in net change were not observed under the pulse scenarios, with the exception of timber volume and ground flora species richness. Thresholds were most pronounced for aboveground biomass, timber volume with respect to the ecosystem services, and ectomycorrhizal fungi and ground flora species richness with respect to the biodiversity measures. Synthesis and applications. The approach presented here illustrates how the multidimensionality of stability research in ecology can be addressed and how forest resilience can be estimated in practice. Managers should adopt specific management actions to support each of the three components of resilience separately, as these may respond differently to disturbance. In addition, management interventions aiming to deliver resilience should incorporate an assessment of both pulse and press disturbances to ensure detection of threshold responses to disturbance, so that appropriate management interventions can be identified. Title: Quantifying Resilience of Multiple Ecosystem Services and Biodiversity in a Temperate Forest Landscape Author: Cantarello, Elena, Newton, Adrian C., Martin, Phillip A., Evans, Paul M., Gosal, Arjan, Lucash, Melissa S. Year: 2017 Resilience is increasingly being considered as a new paradigm of forest management among scientists, practitioners, and policymakers. However, metrics of resilience to environmental change are lacking. Faced with novel disturbances, forests may be able to sustain existing ecosystem services and biodiversity by exhibiting resilience, or alternatively these attributes may undergo either a linear or nonlinear decline. Here we provide a novel quantitative approach for assessing forest resilience that focuses on three components of resilience, namely resistance, recovery, and net change, using a spatially explicit model of forest dynamics. Under the pulse set scenarios, we explored the resilience of nine ecosystem services and four biodiversity measures following a one-off disturbance applied to an increasing percentage of forest area. Under the pulse + press set scenarios, the six disturbance intensities explored during the pulse set were followed by a continuous disturbance. We detected thresholds in net change under pulse + press scenarios for the majority of the ecosystem services and biodiversity measures, which started to decline sharply when disturbance affected >40% of the landscape. Thresholds in net change were not observed under the pulse scenarios, with the exception of timber volume and ground flora species richness. Thresholds were most pronounced for aboveground biomass, timber volume with respect to the ecosystem services, and ectomycorrhizal fungi and ground flora species richness with respect to the biodiversity measures. Synthesis and applications. The approach presented here illustrates how the multidimensionality of stability research in ecology can be addressed and how forest resilience can be estimated in practice. Managers should adopt specific management actions to support each of the three components of resilience separately, as these may respond differently to disturbance. In addition, management interventions aiming to deliver resilience should incorporate an assessment of both pulse and press disturbances to ensure detection of threshold responses to disturbance, so that appropriate management interventions can be identified. Close

• 391. [Article] Rate of tree carbon accumulation increases continuously with tree size

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

  Citation × Citation Citation Abstract Copy Title: Rate of tree carbon accumulation increases continuously with tree size Author: Pabst, R. J., Malizia, L. R., Bunyavejchewin, S., Lines, E. R., Tan, S., Coomes, D. A., Grau, H. R., Chuyong, G., Hao, Z., Kenfack, D., Álvarez, E., Russo, S. E., Duque, Á., Blundo, C., Su, S.-H., Sun, I-F., Morris, W. K., Zavala, M. A., Hubbell, S. P., Malizia, A., Baker, P. J., van Mantgem, P. J., Stephenson, N. L., Wiser, S. K., Davies, S. J., Beckman, N. G., Lin, Y., Wang, X., Condit, R., Ewango, C. N., Makana, J.-R., Rueger, N., Flores, O., Das, A. J., Thomas, D., Pongpattananurak, N., Harmon, M. E., Franklin, J. F. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Macmillan Publishers Limited and can be found at: http://www.nature.com/nature/index.html. Title: Rate of tree carbon accumulation increases continuously with tree size Author: Pabst, R. J., Malizia, L. R., Bunyavejchewin, S., Lines, E. R., Tan, S., Coomes, D. A., Grau, H. R., Chuyong, G., Hao, Z., Kenfack, D., Álvarez, E., Russo, S. E., Duque, Á., Blundo, C., Su, S.-H., Sun, I-F., Morris, W. K., Zavala, M. A., Hubbell, S. P., Malizia, A., Baker, P. J., van Mantgem, P. J., Stephenson, N. L., Wiser, S. K., Davies, S. J., Beckman, N. G., Lin, Y., Wang, X., Condit, R., Ewango, C. N., Makana, J.-R., Rueger, N., Flores, O., Das, A. J., Thomas, D., Pongpattananurak, N., Harmon, M. E., Franklin, J. F. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Macmillan Publishers Limited and can be found at: http://www.nature.com/nature/index.html. Close

• 392. [Article] Response of Conifer-Encroached Shrublands in the Great Basin to Prescribed Fire and Mechanical Treatments

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

  Citation × Citation Citation Abstract Copy Title: Response of Conifer-Encroached Shrublands in the Great Basin to Prescribed Fire and Mechanical Treatments Author: Miller, Richard F., Ratchford, Jaime, Hulet, April, Chambers, Jeanne, Roundy, Bruce A., Tausch, Robin J. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Society for Range Management and can be found at: http://www.bioone.org/loi/rama. Title: Response of Conifer-Encroached Shrublands in the Great Basin to Prescribed Fire and Mechanical Treatments Author: Miller, Richard F., Ratchford, Jaime, Hulet, April, Chambers, Jeanne, Roundy, Bruce A., Tausch, Robin J. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Society for Range Management and can be found at: http://www.bioone.org/loi/rama. Close

• 393. [Article] Reproduction, demography, and habitat characterization of Astragalus peckii (Fabaceae), a rare central Oregon endemic

  With little previous research on Astragalus peckii (Fabaceae), a state-listed Threatened species in Oregon, I investigated three facets of its biology which are integral to the conservation and management ...

  Citation × Citation Citation Abstract Copy Title: Reproduction, demography, and habitat characterization of Astragalus peckii (Fabaceae), a rare central Oregon endemic Author: Martin, Elizabeth F. With little previous research on Astragalus peckii (Fabaceae), a state-listed Threatened species in Oregon, I investigated three facets of its biology which are integral to the conservation and management of the species. First, a four-year demographic study of two large populations revealed increasing population growth at one site (Chiloquin) and stable to declining population growth at another (Bull Flat). Both sites had varying levels of herbivory from a microlepidopteran larva, Sparganothis tunicana. Herbivore damage, regardless of when it occurred during the plant growing season, was correlated with increased plant mortality at Bull Flat but not Chiloquin. At Chiloquin, greater moth damage was correlated with decreased reproduction, particularly when the moth was active earlier in the growing season. These reductions in plant vital rates did not appear to contribute to negative population growth at either site. Rather, below-average precipitation levels during the growing season could be correlated with periods of population decline. From a series of experiments on the reproductive biology of A. peckii, fruit and seed set were generally not limited by the quantity of pollen delivered by pollinators. Instead, high levels of seed abortion prevented most ovules from fully developing to seed. Quality of pollen (self- versus cross-pollen) also did not limit reproduction under natural pollination levels, but self-pollen reduced seed set, and to a lesser degree fruit set, during one of two years of hand-pollination experiments. Possible explanations for the treatment effect, including procedural causes, are discussed. Significant inbreeding depression was evident in the growth of greenhouse-grown seedlings but no statistical differences were found for seed germination or seedling survival. In order to minimize inbreeding depression in the field, adequate sizes of plant and pollinator populations need to be maintained. Finally, using vegetation, habitat, climate, and soil data in a habitat model, greater A. peckii abundance was correlated with patches of low litter and soil crust cover within sites. Supporting these model results, greenhouse-grown seedlings with 1 cm of juniper litter on the soil surface had lower survival than those grown with less or no litter. There were no strong vegetation associations for A. peckii, though, indicating that within its restricted geographical range, A. peckii can be found in a diversity of plant habitats that have low litter cover. Title: Reproduction, demography, and habitat characterization of Astragalus peckii (Fabaceae), a rare central Oregon endemic Author: Martin, Elizabeth F. With little previous research on Astragalus peckii (Fabaceae), a state-listed Threatened species in Oregon, I investigated three facets of its biology which are integral to the conservation and management of the species. First, a four-year demographic study of two large populations revealed increasing population growth at one site (Chiloquin) and stable to declining population growth at another (Bull Flat). Both sites had varying levels of herbivory from a microlepidopteran larva, Sparganothis tunicana. Herbivore damage, regardless of when it occurred during the plant growing season, was correlated with increased plant mortality at Bull Flat but not Chiloquin. At Chiloquin, greater moth damage was correlated with decreased reproduction, particularly when the moth was active earlier in the growing season. These reductions in plant vital rates did not appear to contribute to negative population growth at either site. Rather, below-average precipitation levels during the growing season could be correlated with periods of population decline. From a series of experiments on the reproductive biology of A. peckii, fruit and seed set were generally not limited by the quantity of pollen delivered by pollinators. Instead, high levels of seed abortion prevented most ovules from fully developing to seed. Quality of pollen (self- versus cross-pollen) also did not limit reproduction under natural pollination levels, but self-pollen reduced seed set, and to a lesser degree fruit set, during one of two years of hand-pollination experiments. Possible explanations for the treatment effect, including procedural causes, are discussed. Significant inbreeding depression was evident in the growth of greenhouse-grown seedlings but no statistical differences were found for seed germination or seedling survival. In order to minimize inbreeding depression in the field, adequate sizes of plant and pollinator populations need to be maintained. Finally, using vegetation, habitat, climate, and soil data in a habitat model, greater A. peckii abundance was correlated with patches of low litter and soil crust cover within sites. Supporting these model results, greenhouse-grown seedlings with 1 cm of juniper litter on the soil surface had lower survival than those grown with less or no litter. There were no strong vegetation associations for A. peckii, though, indicating that within its restricted geographical range, A. peckii can be found in a diversity of plant habitats that have low litter cover. Close

• 394. [Article] A study of relationships of four insects to heating in stored grain

  This study was conducted to determine the effects of insect infestation on areas of heating in stored grain, and to demonstrate the ability of four species of insects to initiate or promote the spread ...

  Citation × Citation Citation Abstract Copy Title: A study of relationships of four insects to heating in stored grain Author: Eighme, Lloyd Elwyn This study was conducted to determine the effects of insect infestation on areas of heating in stored grain, and to demonstrate the ability of four species of insects to initiate or promote the spread of these heating areas. The four insects used were the granary weevil Sitophilus granarius (L.), the lesser grain borer Rhizopertha dominica (F.), the saw-toothed grain beetle Oryzaephilus surinamensis (L.), and the red flour beetle Tribolium castaneum (Hbst.). All four of these insects are common pests of stored grain. Heating was initiated by adding moisture to a small portion of a confined mass of wheat. The term hot spot was used in reference to areas of the grain mass that showed a rise in temperature above that of the surrounding grain. Hot spots due to the growth of fungi on the moistened grain were referred to as fungus hot spots. A device was designed and constructed in which a small hot spot could be started and observed visually and electronically. It consisted of a wooden box of about one cubic foot capacity with two glass sides and an internal system of thermocouples and humidity indicators. Ten of these boxes were in operation during a period of two years in 18 laboratory experiments. A larger system of thermocouples and humidity indicators was installed in a Butler bin at the Oregon State University Entomology Farm in which 600 bushels of wheat were utilized in four different experiments. Hard white wheat was used in all experiments, and test insects were obtained from laboratory cultures. It was observed that fungus hot spots reached a peak of heating at room temperature about two weeks after moisture was added. Heating was confined to the small mass of grain that was moistened by the addition of water when no insects were present, and did not spread to the surrounding grain mass. The temperature declined rapidly unless additional moisture was forced into adjacent areas of the grain mass to start a second area of heating. Effects of insects on fungus hot spots varied according to the species of insect present. The granary weevil demonstrated the greatest ability, of the four insects tested, to promote the spread of a fungus hot spot. Hot spots involving the granary weevil, either by itself or in combination with other insects, expanded until most of the wheat in the laboratory boxes was involved. The lesser grain borer demonstrated an ability to promote the spread of a fungus hot spot almost equal to that of the granary weevil, but required a longer period of time. The red flour beetle and the saw-toothed grain beetle failed to promote the spread of a fungus hot spot, and heating declined as rapidly in their presence as without them. Field experiments on a larger scale likewise showed the granary weevil to be superior to the saw-toothed grain beetle in promoting the spread of fungus hot spots. Higher temperatures were recorded in the field experiments than in the laboratory experiments but heating was confined to the small mass of moistened grain when granary weevils were not present. Title: A study of relationships of four insects to heating in stored grain Author: Eighme, Lloyd Elwyn This study was conducted to determine the effects of insect infestation on areas of heating in stored grain, and to demonstrate the ability of four species of insects to initiate or promote the spread of these heating areas. The four insects used were the granary weevil Sitophilus granarius (L.), the lesser grain borer Rhizopertha dominica (F.), the saw-toothed grain beetle Oryzaephilus surinamensis (L.), and the red flour beetle Tribolium castaneum (Hbst.). All four of these insects are common pests of stored grain. Heating was initiated by adding moisture to a small portion of a confined mass of wheat. The term hot spot was used in reference to areas of the grain mass that showed a rise in temperature above that of the surrounding grain. Hot spots due to the growth of fungi on the moistened grain were referred to as fungus hot spots. A device was designed and constructed in which a small hot spot could be started and observed visually and electronically. It consisted of a wooden box of about one cubic foot capacity with two glass sides and an internal system of thermocouples and humidity indicators. Ten of these boxes were in operation during a period of two years in 18 laboratory experiments. A larger system of thermocouples and humidity indicators was installed in a Butler bin at the Oregon State University Entomology Farm in which 600 bushels of wheat were utilized in four different experiments. Hard white wheat was used in all experiments, and test insects were obtained from laboratory cultures. It was observed that fungus hot spots reached a peak of heating at room temperature about two weeks after moisture was added. Heating was confined to the small mass of grain that was moistened by the addition of water when no insects were present, and did not spread to the surrounding grain mass. The temperature declined rapidly unless additional moisture was forced into adjacent areas of the grain mass to start a second area of heating. Effects of insects on fungus hot spots varied according to the species of insect present. The granary weevil demonstrated the greatest ability, of the four insects tested, to promote the spread of a fungus hot spot. Hot spots involving the granary weevil, either by itself or in combination with other insects, expanded until most of the wheat in the laboratory boxes was involved. The lesser grain borer demonstrated an ability to promote the spread of a fungus hot spot almost equal to that of the granary weevil, but required a longer period of time. The red flour beetle and the saw-toothed grain beetle failed to promote the spread of a fungus hot spot, and heating declined as rapidly in their presence as without them. Field experiments on a larger scale likewise showed the granary weevil to be superior to the saw-toothed grain beetle in promoting the spread of fungus hot spots. Higher temperatures were recorded in the field experiments than in the laboratory experiments but heating was confined to the small mass of moistened grain when granary weevils were not present. Close

• 395. [Article] Quaking aspen persistence in three Oregon landscapes

  Quaking aspen (Populus tremuloides) is an important tree species in the western United States and there has been much concern about its persistence. In this thesis, I report on aspen in a portion of its ...

  Citation × Citation Citation Abstract Copy Title: Quaking aspen persistence in three Oregon landscapes Author: Seager, S. Trent Quaking aspen (Populus tremuloides) is an important tree species in the western United States and there has been much concern about its persistence. In this thesis, I report on aspen in a portion of its range that has not been previously evaluated: the eastern and western slopes of the Central Oregon Cascades and the Willamette Valley. My primary research objectives for each of the three landscapes were to: (1) assess aspen overstory recruitment across time; (2) assess the condition of aspen sprouts; (3) identify environmental and biological stressors to the aspen overstory and understory; and (4) test the aspen overstory, recent recruitment, and sprouts for correlations to ungulate herbivory and conifer encroachment. In addition, on the eastern slope of the Cascades, I tested the efficacy of piles of coarse woody debris (CWD) or jackstraw as an herbivore deterrent. On the east side of the Cascade Mountains, aspen stands were small (≤ 0.6 ha) and found in a dense conifer matrix. Small stands are expected to recruit overstory across time and expand with disturbance events. Aspen stands on the east side showed a steady decline in overstory recruitment that coincided with increase in conifer encroachment and ungulate herbivory. Aspen stands with conifer mortality attributable to mountain pine beetle (Dendroctonus ponderosae), and subsequent release of overstory competition and formation of jackstraw, recruited overstory trees at expected levels. More than 75% of all recently recruited trees (< 20 years) were behind jackstraw. Diseased sprouts protected from herbivores recruited into the overstory. My results suggest that aspen sprouts increase in height when released from herbivory and increase in density when released from conifer shading and competition. Accordingly, I suggest that the mountain pine beetle has a powerful ecological effect that can help aspen recruit at the stand level and persist at the landscape level via: (1) removal of conifer shading and resource competition; (2) creation of snags, and subsequent increase in jackstraw; and (3) the ensuing increase in sprout density and heights, which leads to overstory recruitment. Results in the two western Oregon landscapes show aspen stands are small (< 0.1 ha), rare, and in decline. Stand origins are unknown and could be genetically linked to stands on the east Cascades or to the north. While most aspen stems dated back to the early to mid 1900s, one stem originated in the mid 1800s. I classified 16 aspen stands from these two landscapes into 6 stand types: Snowfield, Upland Aspen/Conifer, Meadow Fringe, Lithic/Boulder, Pasture Valley, and Riparian Valley. One stand type was found increasing, 3 types were decreasing, and 2 types were at risk of loss. I found aspen sprouts were suppressed by herbivory, disease, and conifer encroachment. Some stand types showed aspen overstory at risk from conifer encroachment. Aspen is on the fringe of its range on the east and west slopes of the Oregon Cascades and in the Willamette Valley. A scientific understanding of aspen in these three landscapes may help the persistence of this species in the face of climate change. Title: Quaking aspen persistence in three Oregon landscapes Author: Seager, S. Trent Quaking aspen (Populus tremuloides) is an important tree species in the western United States and there has been much concern about its persistence. In this thesis, I report on aspen in a portion of its range that has not been previously evaluated: the eastern and western slopes of the Central Oregon Cascades and the Willamette Valley. My primary research objectives for each of the three landscapes were to: (1) assess aspen overstory recruitment across time; (2) assess the condition of aspen sprouts; (3) identify environmental and biological stressors to the aspen overstory and understory; and (4) test the aspen overstory, recent recruitment, and sprouts for correlations to ungulate herbivory and conifer encroachment. In addition, on the eastern slope of the Cascades, I tested the efficacy of piles of coarse woody debris (CWD) or jackstraw as an herbivore deterrent. On the east side of the Cascade Mountains, aspen stands were small (≤ 0.6 ha) and found in a dense conifer matrix. Small stands are expected to recruit overstory across time and expand with disturbance events. Aspen stands on the east side showed a steady decline in overstory recruitment that coincided with increase in conifer encroachment and ungulate herbivory. Aspen stands with conifer mortality attributable to mountain pine beetle (Dendroctonus ponderosae), and subsequent release of overstory competition and formation of jackstraw, recruited overstory trees at expected levels. More than 75% of all recently recruited trees (< 20 years) were behind jackstraw. Diseased sprouts protected from herbivores recruited into the overstory. My results suggest that aspen sprouts increase in height when released from herbivory and increase in density when released from conifer shading and competition. Accordingly, I suggest that the mountain pine beetle has a powerful ecological effect that can help aspen recruit at the stand level and persist at the landscape level via: (1) removal of conifer shading and resource competition; (2) creation of snags, and subsequent increase in jackstraw; and (3) the ensuing increase in sprout density and heights, which leads to overstory recruitment. Results in the two western Oregon landscapes show aspen stands are small (< 0.1 ha), rare, and in decline. Stand origins are unknown and could be genetically linked to stands on the east Cascades or to the north. While most aspen stems dated back to the early to mid 1900s, one stem originated in the mid 1800s. I classified 16 aspen stands from these two landscapes into 6 stand types: Snowfield, Upland Aspen/Conifer, Meadow Fringe, Lithic/Boulder, Pasture Valley, and Riparian Valley. One stand type was found increasing, 3 types were decreasing, and 2 types were at risk of loss. I found aspen sprouts were suppressed by herbivory, disease, and conifer encroachment. Some stand types showed aspen overstory at risk from conifer encroachment. Aspen is on the fringe of its range on the east and west slopes of the Oregon Cascades and in the Willamette Valley. A scientific understanding of aspen in these three landscapes may help the persistence of this species in the face of climate change. Close

• 396. [Article] Green-tree retention and ectomycorrhiza legacies : the spatial influences of retention trees on mycorrhiza community structure and diversity

  These studies are part of the Demonstration of Ecosystem Management Options (DEMO) study, a program researching the effects of different levels and patterns of green-tree retention on ecological, economic, ...

  Citation × Citation Citation Abstract Copy Title: Green-tree retention and ectomycorrhiza legacies : the spatial influences of retention trees on mycorrhiza community structure and diversity Author: Stockdale, Christopher A. These studies are part of the Demonstration of Ecosystem Management Options (DEMO) study, a program researching the effects of different levels and patterns of green-tree retention on ecological, economic, and social phenomena. We restricted our studies to the 15% basal area, evenly dispersed retention treatment. Our objectives were, first, to quantify the change in ectomycorrhiza (EM) type richness after treatment. Second, to determine if changes in EM type richness depended on proximity to retention trees by quantifying EM type richness and root density at four distance classes from retention trees. Third, to determine the relationship between photosynthetic potential of retention trees (measured by cross-sectional sapwood area), root density, and EM type richness. Finally, to determine the effects of retention-tree productivity, root density, and distance from host tree on EM community structure. Three sites (blocks) of the DEMO study were used: Hamilton Buttes, Dog Prairie, and Watson Falls. Pretreatment samples were taken between one and three years before thinning. Post-treatment samples were collected within two years of the thinning. Ectomycorrhizae were sampled using 5.5 cm diameter by 15 cm deep soil cores and identified by morphotyping techniques. We found a significant reduction in EM type richness as a result of the thinning treatment. Within the dripline of retention trees, however, there was no significant decline in the number of EM types. In areas removed from trees, there was up to a 50% decline in the mean number of EM types per soil core. Samples within the dripline and at the edge of the dripline (host-tree samples) had no significant differences in EM type richness or community structure when compared to each other. When host-tree samples were compared to soil cores taken just outside the dripline and in open areas, significantly lower EM type richness was detected, as was a shift in overall community structure. Ectomycorrhiza type richness was found to be significantly and positively correlated with fine-root tip density. Sapwood area of retention trees had no significant correlations with root density, EM type richness, or community structure. The community structure of EM, in terms of relative abundance, most closely followed the log-normal distribution. In the outside dripline soil cores, there were very few rare types observed, suggesting that the probability of an EM type being lost was linked with its pre-disturbance abundance and the loss of the host tree. Cenococcum geophilum was the most abundant EM type, accounting for 18.7% of EM tips, and occurring in nearly all samples. Retention trees serve as important refugia for EM. This biological legacy from the pre-disturbance stand may be important for recolonization of EM onto new seedlings. For those EM that are lost from these treatment units, early recolonization may occur from the spore bank or wind dispersal. Over time, hypogeous fruiting species and those adapted to conditions in a mature forest may re-colonize from neighboring forest stands, provided the distance to the edge of reserve areas is not too great for effective spore dispersal. Title: Green-tree retention and ectomycorrhiza legacies : the spatial influences of retention trees on mycorrhiza community structure and diversity Author: Stockdale, Christopher A. These studies are part of the Demonstration of Ecosystem Management Options (DEMO) study, a program researching the effects of different levels and patterns of green-tree retention on ecological, economic, and social phenomena. We restricted our studies to the 15% basal area, evenly dispersed retention treatment. Our objectives were, first, to quantify the change in ectomycorrhiza (EM) type richness after treatment. Second, to determine if changes in EM type richness depended on proximity to retention trees by quantifying EM type richness and root density at four distance classes from retention trees. Third, to determine the relationship between photosynthetic potential of retention trees (measured by cross-sectional sapwood area), root density, and EM type richness. Finally, to determine the effects of retention-tree productivity, root density, and distance from host tree on EM community structure. Three sites (blocks) of the DEMO study were used: Hamilton Buttes, Dog Prairie, and Watson Falls. Pretreatment samples were taken between one and three years before thinning. Post-treatment samples were collected within two years of the thinning. Ectomycorrhizae were sampled using 5.5 cm diameter by 15 cm deep soil cores and identified by morphotyping techniques. We found a significant reduction in EM type richness as a result of the thinning treatment. Within the dripline of retention trees, however, there was no significant decline in the number of EM types. In areas removed from trees, there was up to a 50% decline in the mean number of EM types per soil core. Samples within the dripline and at the edge of the dripline (host-tree samples) had no significant differences in EM type richness or community structure when compared to each other. When host-tree samples were compared to soil cores taken just outside the dripline and in open areas, significantly lower EM type richness was detected, as was a shift in overall community structure. Ectomycorrhiza type richness was found to be significantly and positively correlated with fine-root tip density. Sapwood area of retention trees had no significant correlations with root density, EM type richness, or community structure. The community structure of EM, in terms of relative abundance, most closely followed the log-normal distribution. In the outside dripline soil cores, there were very few rare types observed, suggesting that the probability of an EM type being lost was linked with its pre-disturbance abundance and the loss of the host tree. Cenococcum geophilum was the most abundant EM type, accounting for 18.7% of EM tips, and occurring in nearly all samples. Retention trees serve as important refugia for EM. This biological legacy from the pre-disturbance stand may be important for recolonization of EM onto new seedlings. For those EM that are lost from these treatment units, early recolonization may occur from the spore bank or wind dispersal. Over time, hypogeous fruiting species and those adapted to conditions in a mature forest may re-colonize from neighboring forest stands, provided the distance to the edge of reserve areas is not too great for effective spore dispersal. Close

• 397. [Article] Effect of livestock grazing on native bees in a Pacific Northwest bunchgrass prairie

  Native bees play an important role as pollinators of natural vegetation and agricultural crops. Yet many pollinators, including some native bees, are declining in numbers. Some of the potential causes ...

  Citation × Citation Citation Abstract Copy Title: Effect of livestock grazing on native bees in a Pacific Northwest bunchgrass prairie Author: Kimoto, Chiho Native bees play an important role as pollinators of natural vegetation and agricultural crops. Yet many pollinators, including some native bees, are declining in numbers. Some of the potential causes of these declines are habitat destruction and degradation by various human land uses, including urban development and sprawl, construction of roadways, and habitat conversion to agriculture such as crop production and livestock grazing. Livestock grazing is one of the most common land uses in western North America and it can impact floral and nesting resources that are important to native bees. These effects are likely manifested through grazing's effect on vegetation and soil characteristics. However, few studies have investigated how livestock grazing impacts native bees in North America. As a result, the overall goal of this research was to determine how a gradient of livestock grazing intensities impacts native bee communities in a threatened and poorly studied grassland of western North America, the Pacific Northwest Bunchgrass Prairie. Because no studies have examined the bee fauna of this grassland habitat, our study had two objectives: 1) describe the native bee community in the Zumwalt Prairie in northeastern Oregon, which is one of the largest remaining remnants of this unique grassland type, and how it changes through time, and 2) investigate how livestock grazing affects that native bee fauna. To address these objectives, we sampled pollinators during the summer of 2007 and 2008 in 16 40-ha pastures on a plateau in the Zumwalt Prairie using blue vane traps. Each pasture was assigned one of four cattle stocking rates (high, medium low, and no cattle), and grazing intensity was quantified by measuring utilization. Grazing treatments were applied in the early summer for two years. We measured soil and vegetation characteristics that related to floral and nesting resources of bees as well as several metrics of the bee community, including diversity, richness, abundance, and community composition. We found 92 species and 119 morphospecies of native bees in 27 genera. This diverse community of native bees showed strong interseasonal and interannual variation that appears to be related to weather and plant phenology. We also found that even after exposure to just two years of grazing, some effects on vegetation and soils were evident. For example, increased grazing intensity significantly reduced vegetation structure, the abundance of certain blooming plants, surface soil stability, and the amount of soil surface covered by herbaceous litter. In addition, increased grazing intensity significantly increased soil compaction and the amount of bare ground. Native bee communities responded grazing intensity through changes in abundance, richness, diversity and community composition. Different bee taxa responded to grazing intensity differently and this response varied temporally. For example, bumble bees were sensitive to grazing intensity early in the season, showing reduced abundance, diversity, and/or richness with increased grazing intensity. In contrast, halictid bees did not respond to grazing intensity in any season. However, even within a genus or family, different species responded to grazing intensity in different manners, potentially because of variation in life histories. This research suggests that maintaining land with a mixture of livestock grazing intensities may be the best way to conserve this important and diverse pollinator group in the Pacific Northwest Bunchgrass Prairie. Title: Effect of livestock grazing on native bees in a Pacific Northwest bunchgrass prairie Author: Kimoto, Chiho Native bees play an important role as pollinators of natural vegetation and agricultural crops. Yet many pollinators, including some native bees, are declining in numbers. Some of the potential causes of these declines are habitat destruction and degradation by various human land uses, including urban development and sprawl, construction of roadways, and habitat conversion to agriculture such as crop production and livestock grazing. Livestock grazing is one of the most common land uses in western North America and it can impact floral and nesting resources that are important to native bees. These effects are likely manifested through grazing's effect on vegetation and soil characteristics. However, few studies have investigated how livestock grazing impacts native bees in North America. As a result, the overall goal of this research was to determine how a gradient of livestock grazing intensities impacts native bee communities in a threatened and poorly studied grassland of western North America, the Pacific Northwest Bunchgrass Prairie. Because no studies have examined the bee fauna of this grassland habitat, our study had two objectives: 1) describe the native bee community in the Zumwalt Prairie in northeastern Oregon, which is one of the largest remaining remnants of this unique grassland type, and how it changes through time, and 2) investigate how livestock grazing affects that native bee fauna. To address these objectives, we sampled pollinators during the summer of 2007 and 2008 in 16 40-ha pastures on a plateau in the Zumwalt Prairie using blue vane traps. Each pasture was assigned one of four cattle stocking rates (high, medium low, and no cattle), and grazing intensity was quantified by measuring utilization. Grazing treatments were applied in the early summer for two years. We measured soil and vegetation characteristics that related to floral and nesting resources of bees as well as several metrics of the bee community, including diversity, richness, abundance, and community composition. We found 92 species and 119 morphospecies of native bees in 27 genera. This diverse community of native bees showed strong interseasonal and interannual variation that appears to be related to weather and plant phenology. We also found that even after exposure to just two years of grazing, some effects on vegetation and soils were evident. For example, increased grazing intensity significantly reduced vegetation structure, the abundance of certain blooming plants, surface soil stability, and the amount of soil surface covered by herbaceous litter. In addition, increased grazing intensity significantly increased soil compaction and the amount of bare ground. Native bee communities responded grazing intensity through changes in abundance, richness, diversity and community composition. Different bee taxa responded to grazing intensity differently and this response varied temporally. For example, bumble bees were sensitive to grazing intensity early in the season, showing reduced abundance, diversity, and/or richness with increased grazing intensity. In contrast, halictid bees did not respond to grazing intensity in any season. However, even within a genus or family, different species responded to grazing intensity in different manners, potentially because of variation in life histories. This research suggests that maintaining land with a mixture of livestock grazing intensities may be the best way to conserve this important and diverse pollinator group in the Pacific Northwest Bunchgrass Prairie. Close

• 398. [Article] A role for ceramide accumulation in age-related cardiac mitochondrial dysfunction

  Ceramides are a group of lipids in the sphingolipid family that are potent cell signaling molecules. Elevations in ceramide levels above the norm generally lead to apoptosis. Evidence from in vitro studies ...

  Citation × Citation Citation Abstract Copy Title: A role for ceramide accumulation in age-related cardiac mitochondrial dysfunction Author: Monette, Jeffrey S. Ceramides are a group of lipids in the sphingolipid family that are potent cell signaling molecules. Elevations in ceramide levels above the norm generally lead to apoptosis. Evidence from in vitro studies suggests that accumulation of ceramides within mitochondria leads to dysfunction of the mitochondria. This includes inhibition of the electron transport chain and release of reactive oxygen species (ROS). Large elevations of mitochondrial ceramide may also lead to death of the cell as they promote membrane permeability transition, which allows the release of cytochrome c and other apoptogenic factors. With age, cardiac mitochondria show a similar dysfunctional phenotype to that found in conditions of acute ceramide elevation. We therefore hypothesize that ceramides may be accumulating in cardiac mitochondria from aged animals. To elucidate the characteristics of the sphingolipidome, we developed both mitochondrial isolation techniques and tandem mass spectrometry assays to specifically and sensitively monitor mitochondrial sphingolipids. Using these techniques, it was found that mitochondria contain six distinct ceramide species with highly saturated lipid moieties. Using young (3-6 months old; which corresponds to a post-adolescent human) and old (24 to 28 months old; which corresponds to an elderly human) Fischer 344 rat hearts, we found that aging leads to a significant increase in total mitochondrial ceramides (32%, p < 0.03), with C₁₆-, C₁₈-, and C₂₄:₁-ceramides showing the largest percent increases (72.3%, 73.4%, and 77.7%, respectively, p < 0.05). Furthermore, the age-associated elevation in ceramide levels correlated to a 28% decrease in the activity of complex IV of the electron transport chain (p < 0.05), which could be replicated in vitro by inducing a ceramide accumulation in mitochondria isolated from young animals. Mitochondria do not contain enzymes for de novo ceramide biosynthesis, rather, these organelles have sphingomyelinases, a family of enzymes that cleave the phosphorylcholine headgroup from nascent pools of sphingomyelin. Specifically, mitochondria contain the magnesium-requiring isoform of sphingomyelinase with a neutral pH optima (nSMase). Recent work has shown that nSMase activity is inversely regulated by glutathione status. Because cardiac mitochondrial glutathione (mGSH) declines by up to 60% with age, we hypothesized that the loss in mGSH leads to an increase in ceramides through the upregulation of nSMase. To determine whether loss of mGSH plays a role in the regulation of mitochondrial nSMase activity, mGSH levels were depleted by treating freshly isolated hepatocytes with 3-hydroxy-4-pentenoate (3HP). It was found that 3HP rapidly depleted mGSH in a concentration-dependent manner (EC₅₀ = 232 μM, p < 0.05). Moreover, this depletion led to an increase in nSMase activity (24 ± 3% at 250 μM 3HP, p < 0.05), and an increase in total ceramide levels (27%, p < 0.05). These findings suggest that mGSH status plays a critical role in the maintenance of ceramide levels within mitochondria. Furthermore, because nSMase activity is regulated by mGSH levels, we hypothesized that any agent promoting an increase in mGSH would reverse the ceramide accumulation seen in cardiac mitochondria from aged animals. Lipoic acid (LA) is a naturally occurring dithiol compound used for many years as an anti-inflammatory agent. LA-supplementation has been shown to increase cellular and mGSH by increasing cellular cysteine levels in the aging heart. In order to determine whether LA reverses the age-associated ceramidosis in cardiac mitochondria, young and old F344 rats were pair-fed LA [0.2% (w/w) in the diet] against controls for two weeks and cardiac mitochondria were subsequently isolated and analyzed. It was found that LA-treatment reversed the age-associated decline in mGSH levels [decreased 43% with age (p < 0.05)], and reduced nSMase activity [increased 103% with age (p < 0.05)]. Ceramide levels were reduced [elevated 32% with age (p < 0.03)] so that they were no longer different from young controls and complex IV activity restored t youthful levels [declined 28% with age (p < 0.05)]. In conclusion, this dissertation provides evidence to support a new mechanism that explains, at least in part, the progression of mitochondrial dysfunction in the aging heart, and may also contribute to understanding the age-related loss of cardiomyocytes. It also provides mechanistic insights into the overall health benefits of LA supplementation and supports its use as a safe, natural, and "age-essential" micronutrient. Title: A role for ceramide accumulation in age-related cardiac mitochondrial dysfunction Author: Monette, Jeffrey S. Ceramides are a group of lipids in the sphingolipid family that are potent cell signaling molecules. Elevations in ceramide levels above the norm generally lead to apoptosis. Evidence from in vitro studies suggests that accumulation of ceramides within mitochondria leads to dysfunction of the mitochondria. This includes inhibition of the electron transport chain and release of reactive oxygen species (ROS). Large elevations of mitochondrial ceramide may also lead to death of the cell as they promote membrane permeability transition, which allows the release of cytochrome c and other apoptogenic factors. With age, cardiac mitochondria show a similar dysfunctional phenotype to that found in conditions of acute ceramide elevation. We therefore hypothesize that ceramides may be accumulating in cardiac mitochondria from aged animals. To elucidate the characteristics of the sphingolipidome, we developed both mitochondrial isolation techniques and tandem mass spectrometry assays to specifically and sensitively monitor mitochondrial sphingolipids. Using these techniques, it was found that mitochondria contain six distinct ceramide species with highly saturated lipid moieties. Using young (3-6 months old; which corresponds to a post-adolescent human) and old (24 to 28 months old; which corresponds to an elderly human) Fischer 344 rat hearts, we found that aging leads to a significant increase in total mitochondrial ceramides (32%, p < 0.03), with C₁₆-, C₁₈-, and C₂₄:₁-ceramides showing the largest percent increases (72.3%, 73.4%, and 77.7%, respectively, p < 0.05). Furthermore, the age-associated elevation in ceramide levels correlated to a 28% decrease in the activity of complex IV of the electron transport chain (p < 0.05), which could be replicated in vitro by inducing a ceramide accumulation in mitochondria isolated from young animals. Mitochondria do not contain enzymes for de novo ceramide biosynthesis, rather, these organelles have sphingomyelinases, a family of enzymes that cleave the phosphorylcholine headgroup from nascent pools of sphingomyelin. Specifically, mitochondria contain the magnesium-requiring isoform of sphingomyelinase with a neutral pH optima (nSMase). Recent work has shown that nSMase activity is inversely regulated by glutathione status. Because cardiac mitochondrial glutathione (mGSH) declines by up to 60% with age, we hypothesized that the loss in mGSH leads to an increase in ceramides through the upregulation of nSMase. To determine whether loss of mGSH plays a role in the regulation of mitochondrial nSMase activity, mGSH levels were depleted by treating freshly isolated hepatocytes with 3-hydroxy-4-pentenoate (3HP). It was found that 3HP rapidly depleted mGSH in a concentration-dependent manner (EC₅₀ = 232 μM, p < 0.05). Moreover, this depletion led to an increase in nSMase activity (24 ± 3% at 250 μM 3HP, p < 0.05), and an increase in total ceramide levels (27%, p < 0.05). These findings suggest that mGSH status plays a critical role in the maintenance of ceramide levels within mitochondria. Furthermore, because nSMase activity is regulated by mGSH levels, we hypothesized that any agent promoting an increase in mGSH would reverse the ceramide accumulation seen in cardiac mitochondria from aged animals. Lipoic acid (LA) is a naturally occurring dithiol compound used for many years as an anti-inflammatory agent. LA-supplementation has been shown to increase cellular and mGSH by increasing cellular cysteine levels in the aging heart. In order to determine whether LA reverses the age-associated ceramidosis in cardiac mitochondria, young and old F344 rats were pair-fed LA [0.2% (w/w) in the diet] against controls for two weeks and cardiac mitochondria were subsequently isolated and analyzed. It was found that LA-treatment reversed the age-associated decline in mGSH levels [decreased 43% with age (p < 0.05)], and reduced nSMase activity [increased 103% with age (p < 0.05)]. Ceramide levels were reduced [elevated 32% with age (p < 0.03)] so that they were no longer different from young controls and complex IV activity restored t youthful levels [declined 28% with age (p < 0.05)]. In conclusion, this dissertation provides evidence to support a new mechanism that explains, at least in part, the progression of mitochondrial dysfunction in the aging heart, and may also contribute to understanding the age-related loss of cardiomyocytes. It also provides mechanistic insights into the overall health benefits of LA supplementation and supports its use as a safe, natural, and "age-essential" micronutrient. Close

• 399. [Article] Tree seedling establishment on heterogenous microsites in Douglas-fir forest canopy gaps

  Tree seedling establishment and growth were studied in experimental canopy gaps to determine the effect of structural and environmental heterogeneity on species dynamics within mature and old-growth Douglas-fir ...

  Citation × Citation Citation Abstract Copy Title: Tree seedling establishment on heterogenous microsites in Douglas-fir forest canopy gaps Author: Gray, Andrew N. Tree seedling establishment and growth were studied in experimental canopy gaps to determine the effect of structural and environmental heterogeneity on species dynamics within mature and old-growth Douglas-fir forests in the Cascades of central Oregon and southern Washington. Factors examined included forest age, gap size, within-gap position. substrate, year of germination, density of understory vegetation, shading by woody debris, light, moisture, and surface temperature. Four gap sizes, with gap diameter to tree height ratios ranging from 0.2 to 1.0, were created in the fall of 1990. Seeds of Abies amabilis, Pseudotsuga menziesii, and Tsuga heterophylla were sown in controlled microsites and germination, survival, and growth were monitored for two growing seasons. Seedlings established from natural seed rain were also monitored in natural microsites. Seedling establishment was greater in gaps than in closed-canopy areas. but was relatively low in portions of large gaps exposed to direct solar radiation, particularly for Tsuga. Shade from woody debris facilitated establishment in exposed areas, while shade from understory vegetation aided establishment of Pseudotsuga but not of Tsuga. Establishment in shaded portions of gaps declined with vegetation cover, with a greater effect from herbs than from shrubs. Seedling establishment was greatest on decayed wood in closed-canopy areas and small gaps, was similar on mineral soil, litter, and wood in shaded portions of largest gaps, and was lowest on litter in exposed portions of large gaps. Species establishment patterns differed between years, apparently due to differences in weather. Seedling growth increased with gap size, and was greatest in gap centers. The growth response to increasing light was greatest for Tsuga. Some evidence for gap partitioning by seedlings was found, although all species were most abundant in similarly shaded portions of gaps. Establishment and growth of the different species was related to seed size and interacting gradients of above- and below-ground resource levels. Heterogeneity at the seedling scale often over-rode environmental gradients associated with gap size and within-gap position. While gaps may accelerate development of old-growth characteristics in these forests, establishment of Tsuga heterophylla is particularly sensitive to microsite quality. Title: Tree seedling establishment on heterogenous microsites in Douglas-fir forest canopy gaps Author: Gray, Andrew N. Tree seedling establishment and growth were studied in experimental canopy gaps to determine the effect of structural and environmental heterogeneity on species dynamics within mature and old-growth Douglas-fir forests in the Cascades of central Oregon and southern Washington. Factors examined included forest age, gap size, within-gap position. substrate, year of germination, density of understory vegetation, shading by woody debris, light, moisture, and surface temperature. Four gap sizes, with gap diameter to tree height ratios ranging from 0.2 to 1.0, were created in the fall of 1990. Seeds of Abies amabilis, Pseudotsuga menziesii, and Tsuga heterophylla were sown in controlled microsites and germination, survival, and growth were monitored for two growing seasons. Seedlings established from natural seed rain were also monitored in natural microsites. Seedling establishment was greater in gaps than in closed-canopy areas. but was relatively low in portions of large gaps exposed to direct solar radiation, particularly for Tsuga. Shade from woody debris facilitated establishment in exposed areas, while shade from understory vegetation aided establishment of Pseudotsuga but not of Tsuga. Establishment in shaded portions of gaps declined with vegetation cover, with a greater effect from herbs than from shrubs. Seedling establishment was greatest on decayed wood in closed-canopy areas and small gaps, was similar on mineral soil, litter, and wood in shaded portions of largest gaps, and was lowest on litter in exposed portions of large gaps. Species establishment patterns differed between years, apparently due to differences in weather. Seedling growth increased with gap size, and was greatest in gap centers. The growth response to increasing light was greatest for Tsuga. Some evidence for gap partitioning by seedlings was found, although all species were most abundant in similarly shaded portions of gaps. Establishment and growth of the different species was related to seed size and interacting gradients of above- and below-ground resource levels. Heterogeneity at the seedling scale often over-rode environmental gradients associated with gap size and within-gap position. While gaps may accelerate development of old-growth characteristics in these forests, establishment of Tsuga heterophylla is particularly sensitive to microsite quality. Close

• 400. [Article] The expression of functional traits during seedling establishment in two populations of Pinus ponderosa from contrasting climates

  Vegetation patterns and species distributions are strongly linked to soil moisture regimes, and populations within a species from contrasting climatic regimes could exhibit differences in the degree to ...

  Citation × Citation Citation Abstract Copy Title: The expression of functional traits during seedling establishment in two populations of Pinus ponderosa from contrasting climates Author: Kerr, Kelly L. Vegetation patterns and species distributions are strongly linked to soil moisture regimes, and populations within a species from contrasting climatic regimes could exhibit differences in the degree to which certain functional traits related to establishment are expressed. Tree seedling survival is crucial for forest regeneration, and thus may be a more important factor in determining species distributions than performance of adult trees. This study investigated the extent to which species populations from different climate zones exhibit differential expression of functional traits that facilitate their establishment. Seeds from two populations of ponderosa pine (Pinus ponderosa) from sites with contrasting climate regimes east (PIPO[subscript EAST]) and west (PIPO[subscript WEST]) of the Oregon Cascade Mountains were sown in raised soil beds in a common garden and grown under two water availability treatments (control and drought). Aboveground biomass accumulation, bud phenology, xylem anatomy, hydraulic architecture, foliar stable carbon isotope ratios (δ¹³C), gas exchange and water relations characteristics were measured in both populations and treatments. At the end of the first growing season, PIPO[subscript WEST] seedlings had grown more than PIPO[subscript EAST] seedlings in both the control (p<0.001) and drought (p=0.042) treatments, while PIPO[subscript EAST] seedlings formed dormant buds and ceased growing much earlier in the fall than PIPO[subscript WEST] seedlings, suggesting that phenological differences between the two populations could partly explain differences in their performance. Vapor pressure deficit (VPD) and low water availability likely resulted in reduced seedling water potential, turgor and rates of expansion of developing tracheids in both populations, resulting in smaller tracheid diameters at maturity, which potentially affected maximum hydraulic conductivity. Xylem-area specific hydraulic conductivity was higher in PIPO[subscript WEST] seedlings compared to PIPO[subscript EAST] seedlings in both the control (p=0.028) and drought (p=0.031) treatments. Intrinsic WUE based on δ¹³C values was higher in PIPO[subscript EAST] seedlings for both control and drought treatments (p<0.001 to p=0.027) across all sampling dates. There was a negative relationship (r²=0.95) between values of δ¹³C and leaf-specific hydraulic conductivity across populations and treatments, consistent with greater stomatal constraints on gas exchange with declining seedling hydraulic capacity. Integrated growing season assimilation and stomatal conductance estimated from foliar δ¹³C values and photosynthetic CO₂ response curves were 7% and 38% greater in PIPO[subscript WEST] seedlings. There were no significant differences found in predawn or midday water potentials between the two populations. PIPO[subscript EAST] seedlings had significantly more negative osmotic potential at full turgor and water potential at the turgor loss point compared to PIPO[subscript WEST] seedlings, suggesting that osmotic adjustment occurs in this population. Overall, PIPO[subscript EAST] seedlings exhibited more conservative behavior, suggesting that a reduction in growth is traded off for an increased resistance to drought. Results from this investigation will advance our understanding of the mechanisms involved in seedling establishment. Title: The expression of functional traits during seedling establishment in two populations of Pinus ponderosa from contrasting climates Author: Kerr, Kelly L. Vegetation patterns and species distributions are strongly linked to soil moisture regimes, and populations within a species from contrasting climatic regimes could exhibit differences in the degree to which certain functional traits related to establishment are expressed. Tree seedling survival is crucial for forest regeneration, and thus may be a more important factor in determining species distributions than performance of adult trees. This study investigated the extent to which species populations from different climate zones exhibit differential expression of functional traits that facilitate their establishment. Seeds from two populations of ponderosa pine (Pinus ponderosa) from sites with contrasting climate regimes east (PIPO[subscript EAST]) and west (PIPO[subscript WEST]) of the Oregon Cascade Mountains were sown in raised soil beds in a common garden and grown under two water availability treatments (control and drought). Aboveground biomass accumulation, bud phenology, xylem anatomy, hydraulic architecture, foliar stable carbon isotope ratios (δ¹³C), gas exchange and water relations characteristics were measured in both populations and treatments. At the end of the first growing season, PIPO[subscript WEST] seedlings had grown more than PIPO[subscript EAST] seedlings in both the control (p<0.001) and drought (p=0.042) treatments, while PIPO[subscript EAST] seedlings formed dormant buds and ceased growing much earlier in the fall than PIPO[subscript WEST] seedlings, suggesting that phenological differences between the two populations could partly explain differences in their performance. Vapor pressure deficit (VPD) and low water availability likely resulted in reduced seedling water potential, turgor and rates of expansion of developing tracheids in both populations, resulting in smaller tracheid diameters at maturity, which potentially affected maximum hydraulic conductivity. Xylem-area specific hydraulic conductivity was higher in PIPO[subscript WEST] seedlings compared to PIPO[subscript EAST] seedlings in both the control (p=0.028) and drought (p=0.031) treatments. Intrinsic WUE based on δ¹³C values was higher in PIPO[subscript EAST] seedlings for both control and drought treatments (p<0.001 to p=0.027) across all sampling dates. There was a negative relationship (r²=0.95) between values of δ¹³C and leaf-specific hydraulic conductivity across populations and treatments, consistent with greater stomatal constraints on gas exchange with declining seedling hydraulic capacity. Integrated growing season assimilation and stomatal conductance estimated from foliar δ¹³C values and photosynthetic CO₂ response curves were 7% and 38% greater in PIPO[subscript WEST] seedlings. There were no significant differences found in predawn or midday water potentials between the two populations. PIPO[subscript EAST] seedlings had significantly more negative osmotic potential at full turgor and water potential at the turgor loss point compared to PIPO[subscript WEST] seedlings, suggesting that osmotic adjustment occurs in this population. Overall, PIPO[subscript EAST] seedlings exhibited more conservative behavior, suggesting that a reduction in growth is traded off for an increased resistance to drought. Results from this investigation will advance our understanding of the mechanisms involved in seedling establishment. Close