Search

Search Results

• 1. [Article] The conservation genetics juggling act: integrating genetics and ecology, science and policy

  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 author(s) ...

  Citation × Citation Citation Abstract Copy Title: The conservation genetics juggling act: integrating genetics and ecology, science and policy Author: Mullins, Thomas D., Draheim, Hope M., Bellinger, Renee, Haig, Susan M., Mercer, Dacey M., Miller, Mark. P. 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 author(s) and published by John Wiley & Sons, Ltd. The published article can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291752-4571/ Title: The conservation genetics juggling act: integrating genetics and ecology, science and policy Author: Mullins, Thomas D., Draheim, Hope M., Bellinger, Renee, Haig, Susan M., Mercer, Dacey M., Miller, Mark. P. 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 author(s) and published by John Wiley & Sons, Ltd. The published article can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291752-4571/ Close

• 2. [Article] The More Things Change...: Oysters, Public Policy, and Species Decline in the Pamlico Sound, 1880-1900

  This paper is a case study of the interrelationship between public policy and species decline in the oyster industry of Pamlico Sound, North Carolina, in the late 19th century, with some attention paid ...

  Citation × Citation Citation Abstract Copy Title: The More Things Change...: Oysters, Public Policy, and Species Decline in the Pamlico Sound, 1880-1900 Author: Carter, Kathleen S. Year: 2001 This paper is a case study of the interrelationship between public policy and species decline in the oyster industry of Pamlico Sound, North Carolina, in the late 19th century, with some attention paid to the first decade of the 20th century. It examines the nature of the many regulatory shifts that occurred at the hands of the state legislature in the period, and it offers explanation for why these policies were ultimately less than successful at protecting and expanding the commercial viability of oystering. Tensions between smaller, local oystermen and outsiders from the Chesapeake Bay played a role, as did the influence of civic leadership in coastal communities hoping to ride the crest of economic development they hoped oysters would bring to the region. The oystermen themselves, in addition, were invited into the regulatory process rather late in the period and therefore were not inclined to work as partners with the state in efforts to preserve and restore oyster numbers. In large measure, however, the state of North Carolina sealed the fate of the oyster by responding with short-term view in its many regulatory revisions, rather than adopting a long-range mentality that might have resulted in greater stability of the species and of the coastal economy. Title: The More Things Change...: Oysters, Public Policy, and Species Decline in the Pamlico Sound, 1880-1900 Author: Carter, Kathleen S. Year: 2001 This paper is a case study of the interrelationship between public policy and species decline in the oyster industry of Pamlico Sound, North Carolina, in the late 19th century, with some attention paid to the first decade of the 20th century. It examines the nature of the many regulatory shifts that occurred at the hands of the state legislature in the period, and it offers explanation for why these policies were ultimately less than successful at protecting and expanding the commercial viability of oystering. Tensions between smaller, local oystermen and outsiders from the Chesapeake Bay played a role, as did the influence of civic leadership in coastal communities hoping to ride the crest of economic development they hoped oysters would bring to the region. The oystermen themselves, in addition, were invited into the regulatory process rather late in the period and therefore were not inclined to work as partners with the state in efforts to preserve and restore oyster numbers. In large measure, however, the state of North Carolina sealed the fate of the oyster by responding with short-term view in its many regulatory revisions, rather than adopting a long-range mentality that might have resulted in greater stability of the species and of the coastal economy. Close

• 3. [Article] Intraperitoneal implantation of life-long telemetry transmitters in otariids

  This is the publisher’s final pdf. The published article is copyrighted by BioMed Central Ltd. and can be found at: http://www.biomedcentral.com/bmcvetres/.

  Citation × Citation Citation Abstract Copy Title: Intraperitoneal implantation of life-long telemetry transmitters in otariids Author: Haulena, Martin, Mellish, Jo-Ann E., Tuomi, Pamela A, Horning, Markus This is the publisher’s final pdf. The published article is copyrighted by BioMed Central Ltd. and can be found at: http://www.biomedcentral.com/bmcvetres/. Title: Intraperitoneal implantation of life-long telemetry transmitters in otariids Author: Haulena, Martin, Mellish, Jo-Ann E., Tuomi, Pamela A, Horning, Markus This is the publisher’s final pdf. The published article is copyrighted by BioMed Central Ltd. and can be found at: http://www.biomedcentral.com/bmcvetres/. Close

• 4. [Article] Ten Principles for Managing Fisheries to Facilitate Adaptation to Uncertain Effects of Climate Change

  Climate change may cause significant changes in the distribution, abundance, and species mix of commercial fishery resources. In any given area stocks of some species may decline; stocks of other species ...

  Citation × Citation Citation Abstract Copy Title: Ten Principles for Managing Fisheries to Facilitate Adaptation to Uncertain Effects of Climate Change Author: Knapp, Gunnar Climate change may cause significant changes in the distribution, abundance, and species mix of commercial fishery resources. In any given area stocks of some species may decline; stocks of other species may increase; and new species may appear in commercially significant volumes. However, it is difficult to predict what specific changes may occur or when they will occur. This paper suggests ten principles for managing fisheries in ways that facilitate adaptation to uncertain future effects of climate change. These are (1) Expect change; (2) Conduct research; (3) Disseminate research results; (4) Give managers flexibility; (5) Allow for change in allocation agreements; (6) Reconsider restrictions on mobility of fishermen and processors; (7) Consider defining long-term access privileges more broadly; (8) Consider alternative rights-based systems which may facilitate adjustment to change; (9) Create mechanisms for managing new fisheries; and (10) Plan responses to resource decline. Title: Ten Principles for Managing Fisheries to Facilitate Adaptation to Uncertain Effects of Climate Change Author: Knapp, Gunnar Climate change may cause significant changes in the distribution, abundance, and species mix of commercial fishery resources. In any given area stocks of some species may decline; stocks of other species may increase; and new species may appear in commercially significant volumes. However, it is difficult to predict what specific changes may occur or when they will occur. This paper suggests ten principles for managing fisheries in ways that facilitate adaptation to uncertain future effects of climate change. These are (1) Expect change; (2) Conduct research; (3) Disseminate research results; (4) Give managers flexibility; (5) Allow for change in allocation agreements; (6) Reconsider restrictions on mobility of fishermen and processors; (7) Consider defining long-term access privileges more broadly; (8) Consider alternative rights-based systems which may facilitate adjustment to change; (9) Create mechanisms for managing new fisheries; and (10) Plan responses to resource decline. Close

• 5. [Article] Marbled murrelet monitoring research, 1997 : studies on distribution and productivity of marbled murrelets at sea in Oregon : final report to the Oregon Department of Fish and Wildlife

  "The value of marine surveys in obtaining critical information on the biology of the Marbled Murrelet has recently been appreciated, largely due to the decline of the species and the need to develop recovery ...

  Citation × Citation Citation Abstract Copy Title: Marbled murrelet monitoring research, 1997 : studies on distribution and productivity of marbled murrelets at sea in Oregon : final report to the Oregon Department of Fish and Wildlife Author: Fisher, Mark R., Strong, Craig S., Oregon. Dept. of Fish and Wildlife "The value of marine surveys in obtaining critical information on the biology of the Marbled Murrelet has recently been appreciated, largely due to the decline of the species and the need to develop recovery and management plans (Ralph et al. 1995, USFWS 1997). This report summarizes the results of 1997 research on at sea abundance, distribution, and productivity of Marbled Murrelets in relation to prior years, and examines population trends in central Oregon over the 6 year period. Included for comparison with Marbled Murrelets are productivity indices of Common Murres, Pigeon Guillemots, and Rhinoceros Auklets." (From Introduction) Title: Marbled murrelet monitoring research, 1997 : studies on distribution and productivity of marbled murrelets at sea in Oregon : final report to the Oregon Department of Fish and Wildlife Author: Fisher, Mark R., Strong, Craig S., Oregon. Dept. of Fish and Wildlife "The value of marine surveys in obtaining critical information on the biology of the Marbled Murrelet has recently been appreciated, largely due to the decline of the species and the need to develop recovery and management plans (Ralph et al. 1995, USFWS 1997). This report summarizes the results of 1997 research on at sea abundance, distribution, and productivity of Marbled Murrelets in relation to prior years, and examines population trends in central Oregon over the 6 year period. Included for comparison with Marbled Murrelets are productivity indices of Common Murres, Pigeon Guillemots, and Rhinoceros Auklets." (From Introduction) Close

• 6. [Article] The Role of Intraspecific Functional Trait Variation in the Differential Decline of Meadow Species Following Conifer Encroachment

  In the Oregon Cascade Range, conifer encroachment has reduced the extent of mountain meadows by as much as 50% since the mid-1940s. Although encroachment results in a general decline of meadow species ...

  Citation × Citation Citation Abstract Copy Title: The Role of Intraspecific Functional Trait Variation in the Differential Decline of Meadow Species Following Conifer Encroachment Author: Celis, Jessica In the Oregon Cascade Range, conifer encroachment has reduced the extent of mountain meadows by as much as 50% since the mid-1940s. Although encroachment results in a general decline of meadow species abundance and diversity, species differ in their sensitivities to encroachment: some show rapid declines whereas others persist in the understory for many decades. Here, we explore whether this variability can be explained by intraspecific variation in morphological traits associated with the capture of light, the resource assumed to be most limiting in the understory. These include specific leaf area (SLA; ratio of leaf area to mass), allocation of biomass to above- vs. below-ground structures, maximum shoot height, and clonality. We hypothesized that sensitivity to encroachment is greater in non-clonal species and in those that show less variation in trait expression across the light gradient. From a larger set of meadow species at Bunchgrass Ridge, Oregon, we chose 13 (10 forbs and three grasses) that varied in their rates of decline across a chronosequence of encroachment states. For each species we estimated cover and light availability at multiple locations representing the encroachment gradient (open meadow to >100-year-old forest). We modeled the relationship between cover and light and computed an index of sensitivity to encroachment, SEI, as the coefficient of variation (CV) of predicted cover across the range of light values. We then measured the morphological traits of 15-17 mature individuals of each species in locations representing the range of light environments. For each species, variation in a trait (trait variability) was expressed by the linear slope of the relationship with light. Clonality was treated as an ordinal variable with one of three value, 0 (non-clonal), 0.5 (limited clonality), or 1 (strongly clonal). To test the hypothesized relationship between sensitivity to encroachment and trait variability, we computed for each trait, the correlation between SEI and trait variability (n = 13). Clonality and intraspecific trait variability explained little variation in SEI. Although SLA increased in the shade for all meadow species (an adaptive response to shade) the magnitude of response (slope of SLA-light relationship) did not correlate with sensitivity to encroachment (r = 0.24, p = 0.46). Analyses of the components of SLA revealed a significant correlation with SEI for leaf area, but not leaf mass. Leaf area increased in the shade for less sensitive species, but declined in the shade for more sensitive species. The adaptive significance of this pattern is not clear given that leaf area and plant cover (upon which SEI is based) likely co-vary. Sensitivity to conifer encroachment may relate more to variation in the physiological traits of species (e.g., adjustment of photosynthetic systems) or in the ability of species to respond to changes in resources or limiting factors other than light. Title: The Role of Intraspecific Functional Trait Variation in the Differential Decline of Meadow Species Following Conifer Encroachment Author: Celis, Jessica In the Oregon Cascade Range, conifer encroachment has reduced the extent of mountain meadows by as much as 50% since the mid-1940s. Although encroachment results in a general decline of meadow species abundance and diversity, species differ in their sensitivities to encroachment: some show rapid declines whereas others persist in the understory for many decades. Here, we explore whether this variability can be explained by intraspecific variation in morphological traits associated with the capture of light, the resource assumed to be most limiting in the understory. These include specific leaf area (SLA; ratio of leaf area to mass), allocation of biomass to above- vs. below-ground structures, maximum shoot height, and clonality. We hypothesized that sensitivity to encroachment is greater in non-clonal species and in those that show less variation in trait expression across the light gradient. From a larger set of meadow species at Bunchgrass Ridge, Oregon, we chose 13 (10 forbs and three grasses) that varied in their rates of decline across a chronosequence of encroachment states. For each species we estimated cover and light availability at multiple locations representing the encroachment gradient (open meadow to >100-year-old forest). We modeled the relationship between cover and light and computed an index of sensitivity to encroachment, SEI, as the coefficient of variation (CV) of predicted cover across the range of light values. We then measured the morphological traits of 15-17 mature individuals of each species in locations representing the range of light environments. For each species, variation in a trait (trait variability) was expressed by the linear slope of the relationship with light. Clonality was treated as an ordinal variable with one of three value, 0 (non-clonal), 0.5 (limited clonality), or 1 (strongly clonal). To test the hypothesized relationship between sensitivity to encroachment and trait variability, we computed for each trait, the correlation between SEI and trait variability (n = 13). Clonality and intraspecific trait variability explained little variation in SEI. Although SLA increased in the shade for all meadow species (an adaptive response to shade) the magnitude of response (slope of SLA-light relationship) did not correlate with sensitivity to encroachment (r = 0.24, p = 0.46). Analyses of the components of SLA revealed a significant correlation with SEI for leaf area, but not leaf mass. Leaf area increased in the shade for less sensitive species, but declined in the shade for more sensitive species. The adaptive significance of this pattern is not clear given that leaf area and plant cover (upon which SEI is based) likely co-vary. Sensitivity to conifer encroachment may relate more to variation in the physiological traits of species (e.g., adjustment of photosynthetic systems) or in the ability of species to respond to changes in resources or limiting factors other than light. Close

• 7. [Article] The Challenges and Opportunities of a Proactive Endangered Species Act : A Case Study of the Greater Sage Grouse

  The Endangered Species Act of 1973 (ESA) is considered by many to be among the most powerful and most contentious environmental laws in the United States. Persistent challenges to the Act’s implementation ...

  Citation × Citation Citation Abstract Copy Title: The Challenges and Opportunities of a Proactive Endangered Species Act : A Case Study of the Greater Sage Grouse Author: Taylor, Casey Lynn The Endangered Species Act of 1973 (ESA) is considered by many to be among the most powerful and most contentious environmental laws in the United States. Persistent challenges to the Act’s implementation make reaching conservation goals problematic. Most notably, the very nature of the law—providing protections for species already at risk of extinction—means its protections are offered only when the situation is already dire, when conservation efforts will be the most difficult, costly, and controversial. Impacted industries and rural communities have frequently chafed under the regulations imposed by the Act, while environmentalists have seen the ESA as a reliable tool for slowing or stopping unwanted development. The U.S. Fish and Wildlife Service (FWS) has begun altering its approach to species conservation by pursuing a series of more proactive tools within the ESA in an effort to address declining species before emergency action under the Act is required. These efforts, including working collaboratively with state governments, federal management agencies, and private landowners, were highly visible in the case of the Greater Sage Grouse, a recent candidate for ESA protection in the western United States. Using the sage grouse as a focal case study, this dissertation evaluates some of the challenges and opportunities involved in these proactive, collaborative conservation efforts. In particular, analysis focuses on one of the key components of the ESA process—the selection, interpretation, and application of scientific evidence. Interviews with stakeholders across three sage grouse states—Idaho, Oregon, and Wyoming—as well as planning documents, government reports, and media accounts in these states were collected in order to understand the relationship between collaboration and the use of science in proactive conservation efforts for the sage grouse. Evidence from the three studies in this dissertation suggests that in such efforts, discussion and negotiation surrounding the nature of species threats and possible conservation actions can be hampered by the lack of trust between stakeholders and administrative agencies. The first study (Chapter 2) examines three different conservation efforts in Oregon, and finds that organizational goals, history, and scale of operations influence the degree of collaboration within a particular effort, when then influences the manner in which science is utilized in the process. The second study (Chapter 3) compares the development of voluntary conservation agreements between private landowners and FWS across three states and finds that positive working relationships and trust are critical in effectively negotiating species threats, conservation actions, and monitoring protocols. That being said, when relationships and trust are still being developed, as they often are for the FWS with regard to the ESA, these can be supplemented by partnering with other agencies and organizations with better relationships with communities on the ground, such as the NRCS. The third study (Chapter 4) asks participants from the two earlier portions of the dissertation to define the term ‘best available science,’ an ambiguous concept which is often used as a metric for decision-making in environmental law. Analysis of these responses finds substantial common ground regarding how ‘best available science’ should be defined and identified, but also points to areas of concern with the practice of science-based decision-making. Title: The Challenges and Opportunities of a Proactive Endangered Species Act : A Case Study of the Greater Sage Grouse Author: Taylor, Casey Lynn The Endangered Species Act of 1973 (ESA) is considered by many to be among the most powerful and most contentious environmental laws in the United States. Persistent challenges to the Act’s implementation make reaching conservation goals problematic. Most notably, the very nature of the law—providing protections for species already at risk of extinction—means its protections are offered only when the situation is already dire, when conservation efforts will be the most difficult, costly, and controversial. Impacted industries and rural communities have frequently chafed under the regulations imposed by the Act, while environmentalists have seen the ESA as a reliable tool for slowing or stopping unwanted development. The U.S. Fish and Wildlife Service (FWS) has begun altering its approach to species conservation by pursuing a series of more proactive tools within the ESA in an effort to address declining species before emergency action under the Act is required. These efforts, including working collaboratively with state governments, federal management agencies, and private landowners, were highly visible in the case of the Greater Sage Grouse, a recent candidate for ESA protection in the western United States. Using the sage grouse as a focal case study, this dissertation evaluates some of the challenges and opportunities involved in these proactive, collaborative conservation efforts. In particular, analysis focuses on one of the key components of the ESA process—the selection, interpretation, and application of scientific evidence. Interviews with stakeholders across three sage grouse states—Idaho, Oregon, and Wyoming—as well as planning documents, government reports, and media accounts in these states were collected in order to understand the relationship between collaboration and the use of science in proactive conservation efforts for the sage grouse. Evidence from the three studies in this dissertation suggests that in such efforts, discussion and negotiation surrounding the nature of species threats and possible conservation actions can be hampered by the lack of trust between stakeholders and administrative agencies. The first study (Chapter 2) examines three different conservation efforts in Oregon, and finds that organizational goals, history, and scale of operations influence the degree of collaboration within a particular effort, when then influences the manner in which science is utilized in the process. The second study (Chapter 3) compares the development of voluntary conservation agreements between private landowners and FWS across three states and finds that positive working relationships and trust are critical in effectively negotiating species threats, conservation actions, and monitoring protocols. That being said, when relationships and trust are still being developed, as they often are for the FWS with regard to the ESA, these can be supplemented by partnering with other agencies and organizations with better relationships with communities on the ground, such as the NRCS. The third study (Chapter 4) asks participants from the two earlier portions of the dissertation to define the term ‘best available science,’ an ambiguous concept which is often used as a metric for decision-making in environmental law. Analysis of these responses finds substantial common ground regarding how ‘best available science’ should be defined and identified, but also points to areas of concern with the practice of science-based decision-making. Close

• 8. [Article] Nesting season ecology of marbled murrelets at a remote mainland fjord in southeast Alaska

  This thesis focuses on the nesting ecology and marine space use of Marbled Murrelets (Brachyramphus marmoratus) during the 2007 and 2008 nesting seasons in and around Port Snettisham, a remote mainland ...

  Citation × Citation Citation Abstract Copy Title: Nesting season ecology of marbled murrelets at a remote mainland fjord in southeast Alaska Author: Barbaree, Blake A. This thesis focuses on the nesting ecology and marine space use of Marbled Murrelets (Brachyramphus marmoratus) during the 2007 and 2008 nesting seasons in and around Port Snettisham, a remote mainland fjord in Southeast Alaska. Marbled Murrelets (murrelets) are a declining species throughout most of their range, and their conservation is a challenging endeavor because they rely on relatively large expanses of terrestrial habitat for nesting and marine habitat for food. Murrelets are especially difficult to study because they place their nests at variable and often considerable distance from the sea in largely inaccessible locations; consequently, we know relatively little about their breeding ecology and overall life history compared to other seabirds. I used radio-telemetry to gather data on reproduction, behavior, and at-sea locations of murrelets. Herein, I describe individual and population-level marine space use, identify nesting habitat, estimate reproductive success, and characterize patterns of nest visits. Mean marine home range size for adult murrelets was significantly larger in 2008 (158.6 ± 103.7 km²) than 2007 (97.8 ± 59.4 km²), suggesting that foraging conditions were relatively poor in 2008. Similarly, mean commuting distance from at-sea location to nest sites was significantly longer in 2008 (20.0 ± 2.0 km) than 2007 (12.0 ± 0.9 km), and murrelets nesting further from the coast likely reduced their foraging ranges in 2008. Central foraging hot spots were identified throughout Port Snettisham and near Holkham Bay and Tracy Arm to the south. Boundaries of these hot spots can be used to guide management of commercial fishing and tourism, and designation of marine protected areas. I located 33 active nests in mostly inaccessible sites within forest and non-forest habitat, including visually confirmed nest sites on the branches of large conifer trees and on ledges of steep cliffs near water (e.g., waterfall, lake, river, or glacier). Widespread use of rock cliff and subalpine nesting habitats (≥ 48.5% of located nests) indicated that nesting habitat models in Southeast Alaska should include these types of habitats. Nests were located further inland (range 1.0 - 52.0 km) and at higher elevations (range 42 - 1100 m) than previously documented in Alaska, including two nest sites > 15 km east of the USA/Canada border in British Columbia, Canada. The nesting season was ca. 113 days long (25 May - 16 September), and four late-season re-nesting attempts were documented. Apparent fledge success, derived by inference from behavior of radio-tagged adults, was 17.6% (n = 6 of 34). The low reproductive success at Port Snettisham was similar to estimates from south of Alaska, and unexpected because the area has relatively high densities of murrelets and seemingly ideal conditions for nesting. This information is noteworthy to future conservation planning because it provides evidence that murrelet reproduction may be low even when conditions for nesting are relatively good. Despite an adaptation to high adult survival, murrelet populations cannot sustain themselves with similarly low levels of reproduction. Based on my results future research should focus on monitoring regional population trends, identifying causes of nest failure, estimating adult survival rates, and identifying sources of adult mortality. Title: Nesting season ecology of marbled murrelets at a remote mainland fjord in southeast Alaska Author: Barbaree, Blake A. This thesis focuses on the nesting ecology and marine space use of Marbled Murrelets (Brachyramphus marmoratus) during the 2007 and 2008 nesting seasons in and around Port Snettisham, a remote mainland fjord in Southeast Alaska. Marbled Murrelets (murrelets) are a declining species throughout most of their range, and their conservation is a challenging endeavor because they rely on relatively large expanses of terrestrial habitat for nesting and marine habitat for food. Murrelets are especially difficult to study because they place their nests at variable and often considerable distance from the sea in largely inaccessible locations; consequently, we know relatively little about their breeding ecology and overall life history compared to other seabirds. I used radio-telemetry to gather data on reproduction, behavior, and at-sea locations of murrelets. Herein, I describe individual and population-level marine space use, identify nesting habitat, estimate reproductive success, and characterize patterns of nest visits. Mean marine home range size for adult murrelets was significantly larger in 2008 (158.6 ± 103.7 km²) than 2007 (97.8 ± 59.4 km²), suggesting that foraging conditions were relatively poor in 2008. Similarly, mean commuting distance from at-sea location to nest sites was significantly longer in 2008 (20.0 ± 2.0 km) than 2007 (12.0 ± 0.9 km), and murrelets nesting further from the coast likely reduced their foraging ranges in 2008. Central foraging hot spots were identified throughout Port Snettisham and near Holkham Bay and Tracy Arm to the south. Boundaries of these hot spots can be used to guide management of commercial fishing and tourism, and designation of marine protected areas. I located 33 active nests in mostly inaccessible sites within forest and non-forest habitat, including visually confirmed nest sites on the branches of large conifer trees and on ledges of steep cliffs near water (e.g., waterfall, lake, river, or glacier). Widespread use of rock cliff and subalpine nesting habitats (≥ 48.5% of located nests) indicated that nesting habitat models in Southeast Alaska should include these types of habitats. Nests were located further inland (range 1.0 - 52.0 km) and at higher elevations (range 42 - 1100 m) than previously documented in Alaska, including two nest sites > 15 km east of the USA/Canada border in British Columbia, Canada. The nesting season was ca. 113 days long (25 May - 16 September), and four late-season re-nesting attempts were documented. Apparent fledge success, derived by inference from behavior of radio-tagged adults, was 17.6% (n = 6 of 34). The low reproductive success at Port Snettisham was similar to estimates from south of Alaska, and unexpected because the area has relatively high densities of murrelets and seemingly ideal conditions for nesting. This information is noteworthy to future conservation planning because it provides evidence that murrelet reproduction may be low even when conditions for nesting are relatively good. Despite an adaptation to high adult survival, murrelet populations cannot sustain themselves with similarly low levels of reproduction. Based on my results future research should focus on monitoring regional population trends, identifying causes of nest failure, estimating adult survival rates, and identifying sources of adult mortality. Close

• 9. [Article] Rethinking Fisheries Management: Why Fisheries Management Fails

  Fisheries management as we know it today is in a perpetual state of crisis because it is fatally flawed. Fisheries management will increasingly fail to prevent species decline, and even exacerbate those ...

  Citation × Citation Citation Abstract Copy Title: Rethinking Fisheries Management: Why Fisheries Management Fails Author: Spain, Glen Year: 2001 Fisheries management as we know it today is in a perpetual state of crisis because it is fatally flawed. Fisheries management will increasingly fail to prevent species decline, and even exacerbate those declines, unless it adopts new institutional priorities and methodologies based not on the prevalent “Industrial Model,” which is driven primarily by economic utility, but instead based on the “Biological Model,” which is primarily driven by the whole range of species’ biological needs, including limits placed by interactions with other species and by the ecosystem’s carrying capacity at each stage of a species’s lifecycle. In other words, fisheries managers – including fisheries economists – must stop just managing fishermen and learn to manage fish ecosystems by thinking more like biologists than economists. To do this, concepts such as “efficient use” and “optimization” of the resource must now be legally redefined primarily in biological and ecosystem conservation terms, and fisheries management agencies must adopt the tools of conservation biology, including investing far more heavily in the basic biological monitoring that makes such management possible. Failure to make these changes will simply lead to more stock crashes, unnecessary and probably fatal stresses on fishing-dependent communities, and ultimately extinction of whole species. Title: Rethinking Fisheries Management: Why Fisheries Management Fails Author: Spain, Glen Year: 2001 Fisheries management as we know it today is in a perpetual state of crisis because it is fatally flawed. Fisheries management will increasingly fail to prevent species decline, and even exacerbate those declines, unless it adopts new institutional priorities and methodologies based not on the prevalent “Industrial Model,” which is driven primarily by economic utility, but instead based on the “Biological Model,” which is primarily driven by the whole range of species’ biological needs, including limits placed by interactions with other species and by the ecosystem’s carrying capacity at each stage of a species’s lifecycle. In other words, fisheries managers – including fisheries economists – must stop just managing fishermen and learn to manage fish ecosystems by thinking more like biologists than economists. To do this, concepts such as “efficient use” and “optimization” of the resource must now be legally redefined primarily in biological and ecosystem conservation terms, and fisheries management agencies must adopt the tools of conservation biology, including investing far more heavily in the basic biological monitoring that makes such management possible. Failure to make these changes will simply lead to more stock crashes, unnecessary and probably fatal stresses on fishing-dependent communities, and ultimately extinction of whole species. Close

• 10. [Article] An exploratory study of the social factors of small dam removal : Chiloquin Dam at Sprague River Mile 0.87, Oregon

  Several reports related to dams and dam removal have been released this decade by non-governmental organizations including Dam Removal: Science and Decision Making by The Heinz Center which focused on ...

  Citation × Citation Citation Abstract Copy Title: An exploratory study of the social factors of small dam removal : Chiloquin Dam at Sprague River Mile 0.87, Oregon Author: Hatch, Jason M. Several reports related to dams and dam removal have been released this decade by non-governmental organizations including Dam Removal: Science and Decision Making by The Heinz Center which focused on small dams, since most of the dams removed to date as well as those likely to be removed in the near future fall into this category. The report found that there is a need for case study social research on small dam removal. Accordingly, this thesis seeks to identify the social and policy factors that influenced the decision to remove Chiloquin Dam on the Sprague River, Oregon. This irrigation diversion dam was constructed from 1914-1918 for the Klamath Tribes under the federal Indian Irrigation Service program and subsequently transferred to the Modoc Point Irrigation District in 1973, after termination of the Tribes by the federal Government. Chiloquin Dam was identified in a 1988 Endangered Species Act listing as a primary factor in Lost River and shortnose sucker species decline, a species of cultural significance for the Klamath Tribes. Although early reports, including those by Klamath Project irrigators, called for improved fish passage at Chiloquin Dam, it was not until jeopardy biological opinions triggered a shut off of water to the federal irrigation project in 2001, that Chiloquin Dam became a priority. Directed by legislation, the United States Bureau of Reclamation convened stakeholders in the Chiloquin Dam Fish Passage Study for nine months in 2002-2003 to determine a preferred alternative for fish passage, of which dam removal was recommended. To identify the social and policy factors that influenced the Chiloquin Dam removal decision, 21 informants were interviewed including participants in the Fish Passage Study as well as those involved in the 1988 Endangered Species Act (ESA) listing. Among the findings, respondents perceived that the ESA was the driving policy force, along with tribal restoration (the tribal trust responsibility) in the dam removal decision. Modoc Point Irrigation District members (Off-project) and tribal respondents believe that the dam removal was motivated by political support for Klamath Project irrigators. Despite these beliefs and divergent expectations for Chiloquin Dam fish passage, with the political imperative and resources, an agreement was reached in which each party had their needs addressed. An analysis using the social construction model found that the events of 2001 threatened to push irrigation interests from a powerful advantaged political position. The Fish Passage Study presented capacity and inducement instruments that responded to irrigation and tribal concerns and may also serve to restore the irrigation position as an advantaged social construction. Overall, uncertain science, differing beliefs of what dam removal would mean, and a lack of political priority served to delay action on fish passage at Chiloquin Dam from the ESA listing in 1988. Title: An exploratory study of the social factors of small dam removal : Chiloquin Dam at Sprague River Mile 0.87, Oregon Author: Hatch, Jason M. Several reports related to dams and dam removal have been released this decade by non-governmental organizations including Dam Removal: Science and Decision Making by The Heinz Center which focused on small dams, since most of the dams removed to date as well as those likely to be removed in the near future fall into this category. The report found that there is a need for case study social research on small dam removal. Accordingly, this thesis seeks to identify the social and policy factors that influenced the decision to remove Chiloquin Dam on the Sprague River, Oregon. This irrigation diversion dam was constructed from 1914-1918 for the Klamath Tribes under the federal Indian Irrigation Service program and subsequently transferred to the Modoc Point Irrigation District in 1973, after termination of the Tribes by the federal Government. Chiloquin Dam was identified in a 1988 Endangered Species Act listing as a primary factor in Lost River and shortnose sucker species decline, a species of cultural significance for the Klamath Tribes. Although early reports, including those by Klamath Project irrigators, called for improved fish passage at Chiloquin Dam, it was not until jeopardy biological opinions triggered a shut off of water to the federal irrigation project in 2001, that Chiloquin Dam became a priority. Directed by legislation, the United States Bureau of Reclamation convened stakeholders in the Chiloquin Dam Fish Passage Study for nine months in 2002-2003 to determine a preferred alternative for fish passage, of which dam removal was recommended. To identify the social and policy factors that influenced the Chiloquin Dam removal decision, 21 informants were interviewed including participants in the Fish Passage Study as well as those involved in the 1988 Endangered Species Act (ESA) listing. Among the findings, respondents perceived that the ESA was the driving policy force, along with tribal restoration (the tribal trust responsibility) in the dam removal decision. Modoc Point Irrigation District members (Off-project) and tribal respondents believe that the dam removal was motivated by political support for Klamath Project irrigators. Despite these beliefs and divergent expectations for Chiloquin Dam fish passage, with the political imperative and resources, an agreement was reached in which each party had their needs addressed. An analysis using the social construction model found that the events of 2001 threatened to push irrigation interests from a powerful advantaged political position. The Fish Passage Study presented capacity and inducement instruments that responded to irrigation and tribal concerns and may also serve to restore the irrigation position as an advantaged social construction. Overall, uncertain science, differing beliefs of what dam removal would mean, and a lack of political priority served to delay action on fish passage at Chiloquin Dam from the ESA listing in 1988. Close

• 11. [Article] Age-Structure Metrics for Precautionary Management- Can we save fish, time, and money?

  Abstract Only

  Citation × Citation Citation Abstract Copy Title: Age-Structure Metrics for Precautionary Management- Can we save fish, time, and money? Author: Cusack, Christopher Abstract Only Title: Age-Structure Metrics for Precautionary Management- Can we save fish, time, and money? Author: Cusack, Christopher Abstract Only Close

• 12. [Article] Wildland fire in ecosystems : effects of fire on fauna

  Fires affect animals mainly through effects on their habitat. Fires often cause short-term increases in wildlife foods that contribute to increases in populations of some animals. These increases are moderated ...

  Citation × Citation Citation Abstract Copy Title: Wildland fire in ecosystems : effects of fire on fauna Author: Schreiner, David Scott, Smith, Jane Kapler, Telfer, Edmund S., Huff, Mark H., Lyon, L. Jack, Hooper, Robert G. Fires affect animals mainly through effects on their habitat. Fires often cause short-term increases in wildlife foods that contribute to increases in populations of some animals. These increases are moderated by the animals’ ability to thrive in the altered, often simplified, structure of the postfire environment. The extent of fire effects on animal communities generally depends on the extent of change in habitat structure and species composition caused by fire. Stand-replacement fires usually cause greater changes in the faunal communities of forests than in those of grasslands. Within forests, standreplacement fires usually alter the animal community more dramatically than understory fires. Animal species are adapted to survive the pattern of fire frequency, season, size, severity, and uniformity that characterized their habitat in presettlement times. When fire frequency increases or decreases substantially or fire severity changes from presettlement patterns, habitat for many animal species declines. Title: Wildland fire in ecosystems : effects of fire on fauna Author: Schreiner, David Scott, Smith, Jane Kapler, Telfer, Edmund S., Huff, Mark H., Lyon, L. Jack, Hooper, Robert G. Fires affect animals mainly through effects on their habitat. Fires often cause short-term increases in wildlife foods that contribute to increases in populations of some animals. These increases are moderated by the animals’ ability to thrive in the altered, often simplified, structure of the postfire environment. The extent of fire effects on animal communities generally depends on the extent of change in habitat structure and species composition caused by fire. Stand-replacement fires usually cause greater changes in the faunal communities of forests than in those of grasslands. Within forests, standreplacement fires usually alter the animal community more dramatically than understory fires. Animal species are adapted to survive the pattern of fire frequency, season, size, severity, and uniformity that characterized their habitat in presettlement times. When fire frequency increases or decreases substantially or fire severity changes from presettlement patterns, habitat for many animal species declines. Close

• 13. [Article] Diversity and abundance of birds across a hardwood gradient in early seral Douglas-fir plantations

  Recent evidence suggests that population declines of some avian species may be driven primarily by reduced quantity and diversity of early-successional habitat on the breeding grounds. Increasing intensity ...

  Citation × Citation Citation Abstract Copy Title: Diversity and abundance of birds across a hardwood gradient in early seral Douglas-fir plantations Author: Ellis, Tana M. Recent evidence suggests that population declines of some avian species may be driven primarily by reduced quantity and diversity of early-successional habitat on the breeding grounds. Increasing intensity of forest management on private lands and decreased harvest rates on federal lands has resulted in a loss of the diverse early-successional stage of forest succession, typically called early seral forest. Previous studies suggest that the amount of early seral broadleaf cover within conifer forests is important to foliage-gleaning bird communities. However, information regarding bird abundance, diversity, productivity and juvenile post-breeding habitat use in highly modified plantation habitat is scant. I investigated the association between broadleaved hardwood cover and avian abundance and diversity in intensively managed early seral Douglas-fir (Pseudotsuga menziesii) stands of the Pacific Northwest. I examined this relationship at the community-level, within the insectivorous foliage-gleaning guild, and for five leaf gleaning Neotropical migrant species: orange-crowned warbler (Oreothlypis celata), Wilson's warbler (Wilsonia pusilla), MacGillivray's warbler (Oporornis tolmiei), Swainson's thrush (Catharus ustulatus), and black-headed grosbeak (Pheucticus melanocephalus). Bird species richness decreased across an elevational gradient, but did not appear to vary as a function of either local vegetation composition or structure. In contrast, bird abundance was strongly associated with hardwood cover at local and landscape scales, especially for foliage-gleaning species. We found strong support for the existence of a threshold in relative bird abundance as a function of hardwood at the stand scale; abundance doubled with an increase from 1% to ~6% hardwood and then reached a plateau. Though abundance of leaf gleaners increased even more strongly across a gradient in hardwood, evidence for a distinct threshold was less clear. Though in some cases unexplained variation was quite large, all species except MacGillivray's warbler were strongly positively associated with early seral hardwood cover as fledglings, breeding adults, or both. Management practices aimed at retaining increased amounts of early seral hardwood cover at the stand level is thus likely to accommodate a greater number of breeding pairs and young. If adopted at landscape and regional scales, such practices may positively influence population trends of many declining bird species. We conclude that when early seral hardwood forest is scarce, even small increases in hardwood may provide substantial conservation benefits. However, for some species (i.e., foliage gleaners), there may be more direct trade-offs in abundance and juvenile recruitment with management intensity. Title: Diversity and abundance of birds across a hardwood gradient in early seral Douglas-fir plantations Author: Ellis, Tana M. Recent evidence suggests that population declines of some avian species may be driven primarily by reduced quantity and diversity of early-successional habitat on the breeding grounds. Increasing intensity of forest management on private lands and decreased harvest rates on federal lands has resulted in a loss of the diverse early-successional stage of forest succession, typically called early seral forest. Previous studies suggest that the amount of early seral broadleaf cover within conifer forests is important to foliage-gleaning bird communities. However, information regarding bird abundance, diversity, productivity and juvenile post-breeding habitat use in highly modified plantation habitat is scant. I investigated the association between broadleaved hardwood cover and avian abundance and diversity in intensively managed early seral Douglas-fir (Pseudotsuga menziesii) stands of the Pacific Northwest. I examined this relationship at the community-level, within the insectivorous foliage-gleaning guild, and for five leaf gleaning Neotropical migrant species: orange-crowned warbler (Oreothlypis celata), Wilson's warbler (Wilsonia pusilla), MacGillivray's warbler (Oporornis tolmiei), Swainson's thrush (Catharus ustulatus), and black-headed grosbeak (Pheucticus melanocephalus). Bird species richness decreased across an elevational gradient, but did not appear to vary as a function of either local vegetation composition or structure. In contrast, bird abundance was strongly associated with hardwood cover at local and landscape scales, especially for foliage-gleaning species. We found strong support for the existence of a threshold in relative bird abundance as a function of hardwood at the stand scale; abundance doubled with an increase from 1% to ~6% hardwood and then reached a plateau. Though abundance of leaf gleaners increased even more strongly across a gradient in hardwood, evidence for a distinct threshold was less clear. Though in some cases unexplained variation was quite large, all species except MacGillivray's warbler were strongly positively associated with early seral hardwood cover as fledglings, breeding adults, or both. Management practices aimed at retaining increased amounts of early seral hardwood cover at the stand level is thus likely to accommodate a greater number of breeding pairs and young. If adopted at landscape and regional scales, such practices may positively influence population trends of many declining bird species. We conclude that when early seral hardwood forest is scarce, even small increases in hardwood may provide substantial conservation benefits. However, for some species (i.e., foliage gleaners), there may be more direct trade-offs in abundance and juvenile recruitment with management intensity. Close

• 14. [Article] Information-Mediated Allee Effects in Breeding Habitat Selection

  This is the publisher’s final pdf. The published article is copyrighted by University of Chicago Press and can be found at: http://www.journals.uchicago.edu/doi/10.1086/683659

  Citation × Citation Citation Abstract Copy Title: Information-Mediated Allee Effects in Breeding Habitat Selection Author: Johansson, Jacob, Schmidt, Kenneth A., Betts, Matthew G. This is the publisher’s final pdf. The published article is copyrighted by University of Chicago Press and can be found at: http://www.journals.uchicago.edu/doi/10.1086/683659 Title: Information-Mediated Allee Effects in Breeding Habitat Selection Author: Johansson, Jacob, Schmidt, Kenneth A., Betts, Matthew G. This is the publisher’s final pdf. The published article is copyrighted by University of Chicago Press and can be found at: http://www.journals.uchicago.edu/doi/10.1086/683659 Close

• 15. [Article] Evolving Bycatch Risk in the Pacific Groundfish Trawl IFQ

  Catches of several potential choke species in the Pacific groundfish IFQ are highly uncertain and tend to be concentrated while quota is broadly distributed. An analysis prior to implementation of the ...

  Citation × Citation Citation Abstract Copy Title: Evolving Bycatch Risk in the Pacific Groundfish Trawl IFQ Author: Holland, Dan Catches of several potential choke species in the Pacific groundfish IFQ are highly uncertain and tend to be concentrated while quota is broadly distributed. An analysis prior to implementation of the IFQ suggested substantial risk of individual vessels accidentally exceeding quota allocations for several rockfish species and Pacific halibut. Many fishermen lacked confidence that they would be able to acquire quota on the market to cover incidental catch and consequently joined risk pools to mitigate this risk. I update the analysis of bycatch risk using tow level catch data since implementation of the IFQ. The analysis indicates that expected catch rates of most choke species have declined suggesting more effective bycatch avoidance behavior. However, there remains a significant risk that vessels’ catch of some choke species can be several times median quota allocations, in part because many vessels have increased catch and effort by leasing quota pounds, but quota share ownership has remained distributed. The results underscore the importance of an efficient quota market to redistribute quota to match realized catches, but a recent analysis suggests that the quota market is not distributing quota effectively and is subject to high transactions costs.  This provides and explanation for the persistence of risk pools despite the fact that aggregate catches of overfished rockfish species and Pacific halibut have remained well below total quotas.   Title: Evolving Bycatch Risk in the Pacific Groundfish Trawl IFQ Author: Holland, Dan Catches of several potential choke species in the Pacific groundfish IFQ are highly uncertain and tend to be concentrated while quota is broadly distributed. An analysis prior to implementation of the IFQ suggested substantial risk of individual vessels accidentally exceeding quota allocations for several rockfish species and Pacific halibut. Many fishermen lacked confidence that they would be able to acquire quota on the market to cover incidental catch and consequently joined risk pools to mitigate this risk. I update the analysis of bycatch risk using tow level catch data since implementation of the IFQ. The analysis indicates that expected catch rates of most choke species have declined suggesting more effective bycatch avoidance behavior. However, there remains a significant risk that vessels’ catch of some choke species can be several times median quota allocations, in part because many vessels have increased catch and effort by leasing quota pounds, but quota share ownership has remained distributed. The results underscore the importance of an efficient quota market to redistribute quota to match realized catches, but a recent analysis suggests that the quota market is not distributing quota effectively and is subject to high transactions costs.  This provides and explanation for the persistence of risk pools despite the fact that aggregate catches of overfished rockfish species and Pacific halibut have remained well below total quotas.   Close

• 16. [Article] The potential of dynamic segmentation for aquatic ecosystem management : Pacific lamprey decline in the native lands of the Confederated Tribes of Siletz Indians (Oregon, USA)

  The Lamprey Eel Decline project conducted by the Confederated Tribes of Siletz Indians (CTSI) combined traditional ecological knowledge, scientific research and geographic information science. CTSI wanted ...

  Citation × Citation Citation Abstract Copy Title: The potential of dynamic segmentation for aquatic ecosystem management : Pacific lamprey decline in the native lands of the Confederated Tribes of Siletz Indians (Oregon, USA) Author: Palacios, Kelly C. The Lamprey Eel Decline project conducted by the Confederated Tribes of Siletz Indians (CTSI) combined traditional ecological knowledge, scientific research and geographic information science. CTSI wanted to learn why the Pacific lamprey (Lampetra tridentata), a culturally and ecologically important species, was declining in the streams within their native land area. The project included interviewing native elders, characterizing stream habitat, monitoring water quality, creating a geographic information system (GIS) and educating tribal members on the cultural and ecological importance of the Pacific lamprey. Dynamic segmentation, a GIS data structure, was used to link standard stream survey data on the river unit scale to a base stream coverage (1:24,000). Dynamic segmentation efficiently associates georeferenced data to a linear feature, thus allowing the data to be readily assessable on desktop computer systems. To be more useful to the tribal and local resource managers, it is recommended that these GIS coverages of aquatic habitat should be used in conjunction with additional data coverages and basic regional models for watershed analysis and better management of aquatic ecosystems. Title: The potential of dynamic segmentation for aquatic ecosystem management : Pacific lamprey decline in the native lands of the Confederated Tribes of Siletz Indians (Oregon, USA) Author: Palacios, Kelly C. The Lamprey Eel Decline project conducted by the Confederated Tribes of Siletz Indians (CTSI) combined traditional ecological knowledge, scientific research and geographic information science. CTSI wanted to learn why the Pacific lamprey (Lampetra tridentata), a culturally and ecologically important species, was declining in the streams within their native land area. The project included interviewing native elders, characterizing stream habitat, monitoring water quality, creating a geographic information system (GIS) and educating tribal members on the cultural and ecological importance of the Pacific lamprey. Dynamic segmentation, a GIS data structure, was used to link standard stream survey data on the river unit scale to a base stream coverage (1:24,000). Dynamic segmentation efficiently associates georeferenced data to a linear feature, thus allowing the data to be readily assessable on desktop computer systems. To be more useful to the tribal and local resource managers, it is recommended that these GIS coverages of aquatic habitat should be used in conjunction with additional data coverages and basic regional models for watershed analysis and better management of aquatic ecosystems. Close

• 17. [Article] The Potential of dynamic segmentation for aquatic ecosystem management : Pacific Lamprey decline in the native lands of the Confederated Tribes of Siletz Indians

  The Lamprey Eel Decline project conducted by the Confederated Tribes of Siletz Indians (CTSI) combined traditional ecological knowledge, scientific research and geographic information science. CTSI wanted ...

  Citation × Citation Citation Abstract Copy Title: The Potential of dynamic segmentation for aquatic ecosystem management : Pacific Lamprey decline in the native lands of the Confederated Tribes of Siletz Indians Author: Palacios, Kelly C. The Lamprey Eel Decline project conducted by the Confederated Tribes of Siletz Indians (CTSI) combined traditional ecological knowledge, scientific research and geographic information science. CTSI wanted to learn why the Pacific lamprey (Lampetra tridentata), a culturally and ecologically important species, was declining in the streams within their native land area. The project included interviewing native elders, characterizing stream habitat, monitoring water quality, creating a geographic information system (GIS) and educating tribal members on the cultural and ecological importance of the Pacific lamprey. Dynamic segmentation, a GIS data structure, was used to link standard stream survey data on the river unit scale to a base stream coverage (1:24,000). Dynamic segmentation efficiently associates georeferenced data to a linear feature, thus allowing the data to be readily assessable on desktop computer systems. To be more useful to the tribal and local resource managers, it is recommended that these GIS coverages of aquatic habitat should be used in conjunction with additional data coverages and basic regional models for watershed analysis and better management of aquatic ecosystems. Title: The Potential of dynamic segmentation for aquatic ecosystem management : Pacific Lamprey decline in the native lands of the Confederated Tribes of Siletz Indians Author: Palacios, Kelly C. The Lamprey Eel Decline project conducted by the Confederated Tribes of Siletz Indians (CTSI) combined traditional ecological knowledge, scientific research and geographic information science. CTSI wanted to learn why the Pacific lamprey (Lampetra tridentata), a culturally and ecologically important species, was declining in the streams within their native land area. The project included interviewing native elders, characterizing stream habitat, monitoring water quality, creating a geographic information system (GIS) and educating tribal members on the cultural and ecological importance of the Pacific lamprey. Dynamic segmentation, a GIS data structure, was used to link standard stream survey data on the river unit scale to a base stream coverage (1:24,000). Dynamic segmentation efficiently associates georeferenced data to a linear feature, thus allowing the data to be readily assessable on desktop computer systems. To be more useful to the tribal and local resource managers, it is recommended that these GIS coverages of aquatic habitat should be used in conjunction with additional data coverages and basic regional models for watershed analysis and better management of aquatic ecosystems. Close

• 18. [Article] Evidence of population bottleneck in Astragalus michauxii (Fabaceae), a narrow endemic of the southeastern United States

  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: Evidence of population bottleneck in Astragalus michauxii (Fabaceae), a narrow endemic of the southeastern United States Author: Xiang, Qiu-Yun Jenny, Knaus, Brian K., Gray, Janet B., Hohmann, Matthew G., Hoffmann, William A., Wall, Wade A., Douglas, Norman A., Wentworth, Thomas R. 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/10592. Title: Evidence of population bottleneck in Astragalus michauxii (Fabaceae), a narrow endemic of the southeastern United States Author: Xiang, Qiu-Yun Jenny, Knaus, Brian K., Gray, Janet B., Hohmann, Matthew G., Hoffmann, William A., Wall, Wade A., Douglas, Norman A., Wentworth, Thomas R. 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/10592. Close

• 19. [Article] Competitive interactions between Douglas-fir and red alder seedlings : growth analysis, resource use, and physiology

  Competitive interactions between Douglas-fir seedlings (Pseudotsuga menziesii), and seedlings of a nitrogen-fixing hardwood associate, red alder (Alnus rubra), were investigated in an addition series experiment. ...

  Citation × Citation Citation Abstract Copy Title: Competitive interactions between Douglas-fir and red alder seedlings : growth analysis, resource use, and physiology Author: Shainsky, Lauri J. Competitive interactions between Douglas-fir seedlings (Pseudotsuga menziesii), and seedlings of a nitrogen-fixing hardwood associate, red alder (Alnus rubra), were investigated in an addition series experiment. The primary objective of the research was to identify and quantify key processes underlying intra- and interspecific competitive interactions of Douglas-fir and red alder seedlings. Seedlings of both species were planted into five monoculture densities of 1, 2, 4, 8, and 16 trees m⁻², and into mixtures of all possible pairwise combinations of these densities. Stem diameter and height were measured monthly, and were used to calculate relative growth rates. Soil moisture depletion was monitored using the neutron scattering method. An index of light availability was measured through fisheye photography and computer digitization. Leaf water potential served as a physiological indicator of water stress physiology. Predictive equations were developed for estimating the affect of species densities on tree yield and growth as they changed with time. Patterns in resource use and physiology were also modeled as functions of competitive regime. Yield, absolute growth, and relative growth rates based on an index of stem volume of both species declined quantitatively in response to intra- and interspecific competition. The competitive effects of red alder intensified with time, as the dominant overstory species grew taller and shaded the understory Douglas-fir. Resource availability and physiological performance were reduced quantitatively in response to the density of each species. Manipulation of both species densities influenced productivity through the modification of canopy structure, light pentration, and soil moisture availability. This study demonstrated that species density, resources, and physiology interact in a complex fashion to produce patterns of yield in stands of competing trees. Title: Competitive interactions between Douglas-fir and red alder seedlings : growth analysis, resource use, and physiology Author: Shainsky, Lauri J. Competitive interactions between Douglas-fir seedlings (Pseudotsuga menziesii), and seedlings of a nitrogen-fixing hardwood associate, red alder (Alnus rubra), were investigated in an addition series experiment. The primary objective of the research was to identify and quantify key processes underlying intra- and interspecific competitive interactions of Douglas-fir and red alder seedlings. Seedlings of both species were planted into five monoculture densities of 1, 2, 4, 8, and 16 trees m⁻², and into mixtures of all possible pairwise combinations of these densities. Stem diameter and height were measured monthly, and were used to calculate relative growth rates. Soil moisture depletion was monitored using the neutron scattering method. An index of light availability was measured through fisheye photography and computer digitization. Leaf water potential served as a physiological indicator of water stress physiology. Predictive equations were developed for estimating the affect of species densities on tree yield and growth as they changed with time. Patterns in resource use and physiology were also modeled as functions of competitive regime. Yield, absolute growth, and relative growth rates based on an index of stem volume of both species declined quantitatively in response to intra- and interspecific competition. The competitive effects of red alder intensified with time, as the dominant overstory species grew taller and shaded the understory Douglas-fir. Resource availability and physiological performance were reduced quantitatively in response to the density of each species. Manipulation of both species densities influenced productivity through the modification of canopy structure, light pentration, and soil moisture availability. This study demonstrated that species density, resources, and physiology interact in a complex fashion to produce patterns of yield in stands of competing trees. Close

• 20. [Article] Thirty-five years of forest succession in southwest Oregon : vegetation response to three distinct logging treatments

  This study examined patterns and controls on 35-years of forest succession following logging in the 236 ha South Umpqua Experimental Forest within the Umpqua National Forest in southwestern Oregon. Prior ...

  Citation × Citation Citation Abstract Copy Title: Thirty-five years of forest succession in southwest Oregon : vegetation response to three distinct logging treatments Author: Arthur, Aaron Stone This study examined patterns and controls on 35-years of forest succession following logging in the 236 ha South Umpqua Experimental Forest within the Umpqua National Forest in southwestern Oregon. Prior to logging, the overstory in all three watersheds (~50% cover) was composed of Douglas-fir (30-40% cover), grand fir (2 to 10% cover), incense cedar (2-4% cover), western hemlock (1-2 % cover), sugar pine (1-2% cover), ponderosa pine (0-1% cover), and madrone (0-1% cover). The sapling cover in all three watersheds (30-35% cover) was dominated by grand fir (15-20%), western hemlock (6-8% cover) incense cedar (3-5% cover), and Douglas-fir (3-5% cover), with <1% cover by the other tree species. In 1971, the overstory of the four watersheds received: WS-1 (69.2 ha) a 50% basal area removal (shelterwood); WS-2 (68.4 ha) 30% in 20 small clearcuts; WS-3 (49.8 ha) 100% clearcut; WS-4 (48.6 ha) uncut control. Prior to treatment, tree, shrub, and herb cover in WS 1-3 (n = 50 plots) was visually estimated using the reconnaissance survey method, but only WS 2-3 annually through 1981 (n = 39 plots). In 2006, plots were relocated and new plots added, and resurveyed (n = 77 plots). Plots were classified by environmental (aspect, slope, soil series, vegetation community) and disturbance factors (treatment, logging method, in-watershed location, and soil disturbance). Vegetation was classed into three groups: (1) vegetation structures; (2) overstory species; and (3) residual and invader understory species. Total vegetation cover decreased slightly over the 35-year period, with a slight decrease in shrubs, saplings, and herbs, and an increase in overstory tree cover in 2006 compared to 1971. Few statistically significant differences were observed in vegetation cover change according to environmental variables. However heavily disturbed sites were characterized by low shrub cover and high overstory cover, compared to lightly disturbed sites. These differences were still apparent 35 years after logging. Between 1971 and 2006 in WS-2 and WS-3, Douglas fir, incense cedar and ponderosa pine cover significantly increased, while other overstory species declined. In contrast, over the same period in WS-1, there was a significant change in grand fir and western hemlock cover. Sapling cover of all species stayed constant or declined in all watersheds, except Douglas-fir and western hemlock, which increased in WS-1 only. In the post-logging period, cover of ponderosa pine and Douglas fir cover was significantly higher on moderately and heavily disturbed plots compared to lightly disturbed plots. Before logging, residual species cover was significantly higher than invader species cover. Disturbance appeared to have the greatest effect upon the residual-invader species relationship. Residual species maintained higher cover on lightly disturbed plots, compared to invader species cover, which was highest on moderately and heavily disturbed plots. All species declined in WS-2 and WS-3 following stem exclusion. Overall patterns of tree, shrub, and herb cover succession over the 35-year post-logging period were consistent with the expected effects of clearcutting versus thinning on light levels and their interactions with known shade tolerances of tree species. Additionally, results were consistent with previously documented site disturbance effects on regeneration of residual and invader species, and shrub-tree competition and regeneration. These results permit prediction of the likely consequences for these 35-yr-old forest stands, and the thinned mature forest, of future, planned thinning treatments. Title: Thirty-five years of forest succession in southwest Oregon : vegetation response to three distinct logging treatments Author: Arthur, Aaron Stone This study examined patterns and controls on 35-years of forest succession following logging in the 236 ha South Umpqua Experimental Forest within the Umpqua National Forest in southwestern Oregon. Prior to logging, the overstory in all three watersheds (~50% cover) was composed of Douglas-fir (30-40% cover), grand fir (2 to 10% cover), incense cedar (2-4% cover), western hemlock (1-2 % cover), sugar pine (1-2% cover), ponderosa pine (0-1% cover), and madrone (0-1% cover). The sapling cover in all three watersheds (30-35% cover) was dominated by grand fir (15-20%), western hemlock (6-8% cover) incense cedar (3-5% cover), and Douglas-fir (3-5% cover), with <1% cover by the other tree species. In 1971, the overstory of the four watersheds received: WS-1 (69.2 ha) a 50% basal area removal (shelterwood); WS-2 (68.4 ha) 30% in 20 small clearcuts; WS-3 (49.8 ha) 100% clearcut; WS-4 (48.6 ha) uncut control. Prior to treatment, tree, shrub, and herb cover in WS 1-3 (n = 50 plots) was visually estimated using the reconnaissance survey method, but only WS 2-3 annually through 1981 (n = 39 plots). In 2006, plots were relocated and new plots added, and resurveyed (n = 77 plots). Plots were classified by environmental (aspect, slope, soil series, vegetation community) and disturbance factors (treatment, logging method, in-watershed location, and soil disturbance). Vegetation was classed into three groups: (1) vegetation structures; (2) overstory species; and (3) residual and invader understory species. Total vegetation cover decreased slightly over the 35-year period, with a slight decrease in shrubs, saplings, and herbs, and an increase in overstory tree cover in 2006 compared to 1971. Few statistically significant differences were observed in vegetation cover change according to environmental variables. However heavily disturbed sites were characterized by low shrub cover and high overstory cover, compared to lightly disturbed sites. These differences were still apparent 35 years after logging. Between 1971 and 2006 in WS-2 and WS-3, Douglas fir, incense cedar and ponderosa pine cover significantly increased, while other overstory species declined. In contrast, over the same period in WS-1, there was a significant change in grand fir and western hemlock cover. Sapling cover of all species stayed constant or declined in all watersheds, except Douglas-fir and western hemlock, which increased in WS-1 only. In the post-logging period, cover of ponderosa pine and Douglas fir cover was significantly higher on moderately and heavily disturbed plots compared to lightly disturbed plots. Before logging, residual species cover was significantly higher than invader species cover. Disturbance appeared to have the greatest effect upon the residual-invader species relationship. Residual species maintained higher cover on lightly disturbed plots, compared to invader species cover, which was highest on moderately and heavily disturbed plots. All species declined in WS-2 and WS-3 following stem exclusion. Overall patterns of tree, shrub, and herb cover succession over the 35-year post-logging period were consistent with the expected effects of clearcutting versus thinning on light levels and their interactions with known shade tolerances of tree species. Additionally, results were consistent with previously documented site disturbance effects on regeneration of residual and invader species, and shrub-tree competition and regeneration. These results permit prediction of the likely consequences for these 35-yr-old forest stands, and the thinned mature forest, of future, planned thinning treatments. Close

• 21. [Article] Mapping the Global Emergence of Batrachochytrium dendrobatidis, the Amphibian Chytrid Fungus

  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 Public ...

  Citation × Citation Citation Abstract Copy Title: Mapping the Global Emergence of Batrachochytrium dendrobatidis, the Amphibian Chytrid Fungus Author: Fisher, Matthew C., Garner, Trenton W. J., Walker, Susan F., Powell, Christopher I., Weaver, George, Olson, Deanna H., Aanensen, David M., Ronnenberg, Kathryn L., Bielby, Jon, The Bd Mapping Group 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 Public Library of Science and can be found at: http://www.plos.org/. Title: Mapping the Global Emergence of Batrachochytrium dendrobatidis, the Amphibian Chytrid Fungus Author: Fisher, Matthew C., Garner, Trenton W. J., Walker, Susan F., Powell, Christopher I., Weaver, George, Olson, Deanna H., Aanensen, David M., Ronnenberg, Kathryn L., Bielby, Jon, The Bd Mapping Group 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 Public Library of Science and can be found at: http://www.plos.org/. Close

• 22. [Article] Environmental influences on host-pathogen dynamics of the amphibian chytrid fungus

  The causes of the global biodiversity crisis are varied and complex. Anthropogenic threats may act in isolation, or interact additively or synergistically with each other or with natural stressors to affect ...

  Citation × Citation Citation Abstract Copy Title: Environmental influences on host-pathogen dynamics of the amphibian chytrid fungus Author: Buck, Julia C. The causes of the global biodiversity crisis are varied and complex. Anthropogenic threats may act in isolation, or interact additively or synergistically with each other or with natural stressors to affect sensitive taxa. The recent emergence of many infectious diseases in wildlife has brought attention to the role of disease in population declines and species extinctions. Both abiotic and biotic components of the environment may mitigate or exacerbate effects of pathogens on their hosts through direct or indirect mechanisms. The effects of the environment on host-pathogen dynamics are complex, context-dependent, and in need of further examination. One particularly sensitive group, amphibians, is at the leading edge of the sixth mass extinction. The emerging infectious disease (EID) chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatis (Bd), is implicated in population declines and extinctions of amphibians globally. My disseration addresses questions pertaining to environmental influences on disease dynamics of Bd. As described in chapter 1, various abiotic and biotic components of the environment may affect host-pathogen dynamics of Bd, resulting in changes to the dynamics of Bd transmission and spread. Chapter 2 examines the influence of an abiotic factor, the insecticide (carbaryl) and three different assemblages of larval Pacific treefrogs (Pseudacris regilla) and Cascades frogs (Rana cascadae) on host-pathogen dynamics of Bd within a community context. I found separate effects of each treatment on amphibian growth and development, but no interactive effects among the treatments. However, Bd appeared to reduce phytoplankton abundance and increase periphyton biomass, an unexpected result that merited further investigation. One possible explanation for the results described in chapter 2 is that zooplankton might consume Bd zoospores, the infective stage of the pathogen, a hypothesis that I examine in chapter 3. I conducted laboratory experiments and confirmed the presence of Bd zoospores in the gut of Daphnia sp. through quantitative PCR and visual inspection. I discuss conservation implications of this finding. To determine whether predation on Bd zoospores by zooplankton could reduce infection in amphibians, I conducted a mesocosm experiment, which is described in chapter 4. I found complex effects on species interactions: competition between larval Cascades frogs and zooplankton for phytoplankton resources reduced phytoplankton concentration, zooplankton abundance, and survival of amphibians. These effects were diminished in the presence of Bd, suggesting that zooplankton may have at least partially substituted Bd zoospores for phytoplankton in their diet, thus stimulating competitive release. However, competitive effects between zooplankton and larval amphibians overshadowed indirect positive benefits of zooplankton predation on Bd zoospores. In chapter 4, competitive effects between zooplankton and larval amphibians for phytoplankton suggested that host-pathogen dynamics might be affected by the host’s supply of resources. Chapter 5 describes a mesocosm experiment that examined how eutrophication might affect Bd-infected Pacific treefrogs and other members of the aquatic community. Nutrient additions caused increased algal growth, which benefitted herbivorous larval amphibians. Larvae exposed to Bd altered their growth, development, and diet, and allocated resources differently than unexposed individuals. However, nutrient supplementation did not alter the response of larval amphibians to Bd. As described in chapter 6, consideration of hosts and pathogens as functional members of the ecological communities in which they exist can lead to important insights in host-pathogen dynamics. My PhD research may contribute to control measures for the emerging infectious disease chytridiomycosis. Title: Environmental influences on host-pathogen dynamics of the amphibian chytrid fungus Author: Buck, Julia C. The causes of the global biodiversity crisis are varied and complex. Anthropogenic threats may act in isolation, or interact additively or synergistically with each other or with natural stressors to affect sensitive taxa. The recent emergence of many infectious diseases in wildlife has brought attention to the role of disease in population declines and species extinctions. Both abiotic and biotic components of the environment may mitigate or exacerbate effects of pathogens on their hosts through direct or indirect mechanisms. The effects of the environment on host-pathogen dynamics are complex, context-dependent, and in need of further examination. One particularly sensitive group, amphibians, is at the leading edge of the sixth mass extinction. The emerging infectious disease (EID) chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatis (Bd), is implicated in population declines and extinctions of amphibians globally. My disseration addresses questions pertaining to environmental influences on disease dynamics of Bd. As described in chapter 1, various abiotic and biotic components of the environment may affect host-pathogen dynamics of Bd, resulting in changes to the dynamics of Bd transmission and spread. Chapter 2 examines the influence of an abiotic factor, the insecticide (carbaryl) and three different assemblages of larval Pacific treefrogs (Pseudacris regilla) and Cascades frogs (Rana cascadae) on host-pathogen dynamics of Bd within a community context. I found separate effects of each treatment on amphibian growth and development, but no interactive effects among the treatments. However, Bd appeared to reduce phytoplankton abundance and increase periphyton biomass, an unexpected result that merited further investigation. One possible explanation for the results described in chapter 2 is that zooplankton might consume Bd zoospores, the infective stage of the pathogen, a hypothesis that I examine in chapter 3. I conducted laboratory experiments and confirmed the presence of Bd zoospores in the gut of Daphnia sp. through quantitative PCR and visual inspection. I discuss conservation implications of this finding. To determine whether predation on Bd zoospores by zooplankton could reduce infection in amphibians, I conducted a mesocosm experiment, which is described in chapter 4. I found complex effects on species interactions: competition between larval Cascades frogs and zooplankton for phytoplankton resources reduced phytoplankton concentration, zooplankton abundance, and survival of amphibians. These effects were diminished in the presence of Bd, suggesting that zooplankton may have at least partially substituted Bd zoospores for phytoplankton in their diet, thus stimulating competitive release. However, competitive effects between zooplankton and larval amphibians overshadowed indirect positive benefits of zooplankton predation on Bd zoospores. In chapter 4, competitive effects between zooplankton and larval amphibians for phytoplankton suggested that host-pathogen dynamics might be affected by the host’s supply of resources. Chapter 5 describes a mesocosm experiment that examined how eutrophication might affect Bd-infected Pacific treefrogs and other members of the aquatic community. Nutrient additions caused increased algal growth, which benefitted herbivorous larval amphibians. Larvae exposed to Bd altered their growth, development, and diet, and allocated resources differently than unexposed individuals. However, nutrient supplementation did not alter the response of larval amphibians to Bd. As described in chapter 6, consideration of hosts and pathogens as functional members of the ecological communities in which they exist can lead to important insights in host-pathogen dynamics. My PhD research may contribute to control measures for the emerging infectious disease chytridiomycosis. Close

• 23. [Article] Consumer acceptability of Mukene (Rastrineobola argentea) value-added products in Uganda

  Abstract Only

  Citation × Citation Citation Abstract Copy Title: Consumer acceptability of Mukene (Rastrineobola argentea) value-added products in Uganda Author: Masette, Magaret, Khakasa, Elizabeth Abstract Only Title: Consumer acceptability of Mukene (Rastrineobola argentea) value-added products in Uganda Author: Masette, Magaret, Khakasa, Elizabeth Abstract Only Close

• 24. [Article] Systematic Temporal Patterns in the Relationship Between Housing Development and Forest Bird Biodiversity

  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: Systematic Temporal Patterns in the Relationship Between Housing Development and Forest Bird Biodiversity Author: Keuler, Nicholas S., Lepczyk, Christopher A., Hammer, Roger B., Pidgeon, Anna M., Radeloff, Volker C., Wood, Eric M., Flather, Curtis H., Stewart, Susan I. 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: Systematic Temporal Patterns in the Relationship Between Housing Development and Forest Bird Biodiversity Author: Keuler, Nicholas S., Lepczyk, Christopher A., Hammer, Roger B., Pidgeon, Anna M., Radeloff, Volker C., Wood, Eric M., Flather, Curtis H., Stewart, Susan I. 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

• 25. [Article] Long-term decline of a winter-resident bird community in Puerto Rico

  This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10531. To the best of our knowledge, one or more authors of this ...

  Citation × Citation Citation Abstract Copy Title: Long-term decline of a winter-resident bird community in Puerto Rico Author: Faaborg, John, Arendt, Wayne J., Toms, Judith D., Dugger, Katie M., Mora, Miguel Canals, Cox, W. Andrew This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10531. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Title: Long-term decline of a winter-resident bird community in Puerto Rico Author: Faaborg, John, Arendt, Wayne J., Toms, Judith D., Dugger, Katie M., Mora, Miguel Canals, Cox, W. Andrew This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10531. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Close

• 26. [Article] Effects of spatial scale and heterogeneity on avian occupancy dynamics and population trends in forested mountain landscapes

  Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that ...

  Citation × Citation Citation Abstract Copy Title: Effects of spatial scale and heterogeneity on avian occupancy dynamics and population trends in forested mountain landscapes Author: Frey, Sarah Jean Kiuama Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that models of both distribution dynamics and population trends accurately reflect reality. However, identification of the appropriate temporal and spatial scales of animal response, and then obtaining data at these scales present two major challenges to developing predictive models. In heterogeneous forested mountain landscapes I examined: A) the relative drivers of climatic variability at fine spatial scales under the forest canopy ('microclimate'), B) the influence of microclimate on local-scale occupancy dynamics of bird communities, and C) the effects of spatial scale and imperfect bird detection on long-term avian population trends. Climate change has been predicted to cause widespread biodiversity declines. However, the capacity of climate envelope models for predicting the future of biodiversity has been questioned due to the mismatch between the scale of available data (i.e., global climate models) and the scales at which organisms experience their environment. Local-scale variation in microclimate is hypothesized to provide potential ‘microrefugia’ for biodiversity, but the relative role of elevation, microtopography, and vegetation structure in driving microclimate is not well known. If the microrefugia hypothesis is true, I expected to see areas on the landscape that remained relatively cooler (i.e., buffered sites). To test this, I collected temperature data at 183 sites across elevation and forest structure gradients in complex terrain of the H. J. Andrews Experimental Forest in the Cascade Mountains of Oregon, USA (Chapter 2). I used boosted regression trees, a novel machine learning approach, to determine the relative influence of vegetation structure, microtopography, and elevation as drivers of microclimate and mapped fine-scale distributions of temperature across the landscape. Models performed extremely well on independent data - cross-validation correlations between testing and training data were 0.69 - 0.98 for ten selected climate variables. Elevation was the dominant driver in fine-scale microclimate patterns, although vegetation and microtopography also showed substantial relative influences. For instance, during the spring-summer transition, maximum monthly temperatures observed in old-growth sites were 2.6°C (95% CI: 1.8 - 3.3°C) cooler than plantation sites and minimum temperatures during winter months were 0.6°C (95% CI: 0.4 - 0.8°C) warmer. This suggests that older forest stands mediate changes in temperature by buffering against warming during summer months and moderating cold temperatures during the winter. Climate is generally considered most influential on species distributions at large spatial scales; however much microclimate variability exists within regional patterns. I tested whether this high degree of microclimate variability has relevance for predicting species distributions and occupancy dynamics of the Andrews Forest bird community. I collected bird occurrence data in 2012 and 2013 at all 183 sites with fine-scale temperature measurements. I used dynamic occupancy models to test the effects of temperature on occupancy and apparent within-season bird movement while statistically accounting for vegetation effects and imperfect bird detection (Chapter 3). Most species (87%) exhibited within-season shifts in response to local-scale temperature metrics. Effects of temperature on within-season occupancy dynamics were as large or larger (1 to 1.7 times) than vegetation. However, individual species were almost as likely to shift toward warmer sites as toward cooler sites, suggesting that microclimate preferences are species-specific. My results emphasize that high-resolution temperature data provide valuable insight into avian distribution dynamics in montane forest environments and that microclimate is an important variable in breeding season habitat selection by forest birds. I hypothesize that microclimate-associated distribution shifts may reflect species' potential for behavioral buffering from climate change in complex terrain. Factors influencing population trends often differ depending on the spatial scale under consideration. Further, accurate estimation of trends requires accounting for biases caused by imperfect detection. To test the degree to which population trends are consistent across scales, I estimated landscape-scale bird population trends from 1999-2012 for 38 species at the Hubbard Brook Experimental Forest (HBEF) in the White Mountains of New Hampshire, USA and compared them to regional and local trends (Chapter 4). I used a new method - open-population binomial mixture models - to test the hypothesis that imperfect detection in bird sampling has the potential to bias trend estimates. I also tested for generalities in species responses by predicting population trends as a function of life history and ecological traits. Landscape-scale trends were correlated with regional and local trends, but generally these correlations were weak (r = 0.12 - 0.4). Further, more species were declining at the regional scale compared to within the relatively undisturbed HBEF. Life history and ecological traits did not explain any of the variability in the HBEF trends. However, at the regional scale, species that occurred at higher elevations were more likely to be declining and species associated with older forests have increased. I hypothesize that these differences could be attributed to both elevated rates of land-use change in the broader region and the fact that the structure of regional data did not permit modeling of imperfect detection. Indeed, accounting for imperfect detection resulted in more accurate population trend estimates at the landscape scale; without accounting for detection we would have both missed trends and falsely identified trends where none existed. These results highlight two important cautions for trend analysis: 1) population trends estimated at fine spatial scales may not be extrapolated to broader scales and 2) accurate trends require accounting for imperfect detection. Title: Effects of spatial scale and heterogeneity on avian occupancy dynamics and population trends in forested mountain landscapes Author: Frey, Sarah Jean Kiuama Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that models of both distribution dynamics and population trends accurately reflect reality. However, identification of the appropriate temporal and spatial scales of animal response, and then obtaining data at these scales present two major challenges to developing predictive models. In heterogeneous forested mountain landscapes I examined: A) the relative drivers of climatic variability at fine spatial scales under the forest canopy ('microclimate'), B) the influence of microclimate on local-scale occupancy dynamics of bird communities, and C) the effects of spatial scale and imperfect bird detection on long-term avian population trends. Climate change has been predicted to cause widespread biodiversity declines. However, the capacity of climate envelope models for predicting the future of biodiversity has been questioned due to the mismatch between the scale of available data (i.e., global climate models) and the scales at which organisms experience their environment. Local-scale variation in microclimate is hypothesized to provide potential ‘microrefugia’ for biodiversity, but the relative role of elevation, microtopography, and vegetation structure in driving microclimate is not well known. If the microrefugia hypothesis is true, I expected to see areas on the landscape that remained relatively cooler (i.e., buffered sites). To test this, I collected temperature data at 183 sites across elevation and forest structure gradients in complex terrain of the H. J. Andrews Experimental Forest in the Cascade Mountains of Oregon, USA (Chapter 2). I used boosted regression trees, a novel machine learning approach, to determine the relative influence of vegetation structure, microtopography, and elevation as drivers of microclimate and mapped fine-scale distributions of temperature across the landscape. Models performed extremely well on independent data - cross-validation correlations between testing and training data were 0.69 - 0.98 for ten selected climate variables. Elevation was the dominant driver in fine-scale microclimate patterns, although vegetation and microtopography also showed substantial relative influences. For instance, during the spring-summer transition, maximum monthly temperatures observed in old-growth sites were 2.6°C (95% CI: 1.8 - 3.3°C) cooler than plantation sites and minimum temperatures during winter months were 0.6°C (95% CI: 0.4 - 0.8°C) warmer. This suggests that older forest stands mediate changes in temperature by buffering against warming during summer months and moderating cold temperatures during the winter. Climate is generally considered most influential on species distributions at large spatial scales; however much microclimate variability exists within regional patterns. I tested whether this high degree of microclimate variability has relevance for predicting species distributions and occupancy dynamics of the Andrews Forest bird community. I collected bird occurrence data in 2012 and 2013 at all 183 sites with fine-scale temperature measurements. I used dynamic occupancy models to test the effects of temperature on occupancy and apparent within-season bird movement while statistically accounting for vegetation effects and imperfect bird detection (Chapter 3). Most species (87%) exhibited within-season shifts in response to local-scale temperature metrics. Effects of temperature on within-season occupancy dynamics were as large or larger (1 to 1.7 times) than vegetation. However, individual species were almost as likely to shift toward warmer sites as toward cooler sites, suggesting that microclimate preferences are species-specific. My results emphasize that high-resolution temperature data provide valuable insight into avian distribution dynamics in montane forest environments and that microclimate is an important variable in breeding season habitat selection by forest birds. I hypothesize that microclimate-associated distribution shifts may reflect species' potential for behavioral buffering from climate change in complex terrain. Factors influencing population trends often differ depending on the spatial scale under consideration. Further, accurate estimation of trends requires accounting for biases caused by imperfect detection. To test the degree to which population trends are consistent across scales, I estimated landscape-scale bird population trends from 1999-2012 for 38 species at the Hubbard Brook Experimental Forest (HBEF) in the White Mountains of New Hampshire, USA and compared them to regional and local trends (Chapter 4). I used a new method - open-population binomial mixture models - to test the hypothesis that imperfect detection in bird sampling has the potential to bias trend estimates. I also tested for generalities in species responses by predicting population trends as a function of life history and ecological traits. Landscape-scale trends were correlated with regional and local trends, but generally these correlations were weak (r = 0.12 - 0.4). Further, more species were declining at the regional scale compared to within the relatively undisturbed HBEF. Life history and ecological traits did not explain any of the variability in the HBEF trends. However, at the regional scale, species that occurred at higher elevations were more likely to be declining and species associated with older forests have increased. I hypothesize that these differences could be attributed to both elevated rates of land-use change in the broader region and the fact that the structure of regional data did not permit modeling of imperfect detection. Indeed, accounting for imperfect detection resulted in more accurate population trend estimates at the landscape scale; without accounting for detection we would have both missed trends and falsely identified trends where none existed. These results highlight two important cautions for trend analysis: 1) population trends estimated at fine spatial scales may not be extrapolated to broader scales and 2) accurate trends require accounting for imperfect detection. Close

• 27. [Article] Characterizing early-seral competitive mechanisms influencing Douglas-fir seedling growth, vegetation community development, and physiology of selected weedy plant species

  Three studies were conducted to characterize and present early-seral competition between Douglas-fir seedlings and the surrounding vegetation communities during Pacific Northwest forest establishment. ...

  Citation × Citation Citation Abstract Copy Title: Characterizing early-seral competitive mechanisms influencing Douglas-fir seedling growth, vegetation community development, and physiology of selected weedy plant species Author: Dinger, Eric J. Three studies were conducted to characterize and present early-seral competition between Douglas-fir seedlings and the surrounding vegetation communities during Pacific Northwest forest establishment. The first experiment served as the foundation for this dissertation and was designed to quantify tradeoffs associated with delaying forest establishment activities by introducing a fallow year in order to provide longer-term management of competing vegetation. A range of six operationally relevant treatments were applied over two growing seasons that included in the first (1) a no-action control, (2) a spring release only, (3) a fall site preparation without sulfometuron methyl followed by a spring release, as well as (4) a fall site preparation with sulfometuron methyl and a spring release. In the second year, there was (5) a fall site preparation without sulfometuron methyl followed by a spring release and also in the second year (6) a fall site preparation with sulfometuron methyl and a spring release. Treatments 5 and 6 were left fallow without planting during the first year. These treatments were applied in two replicated experiments within the Oregon Coast Range. After adjusting for initial seedling size, year-3 results indicated that plantation establishment and competition control immediately after harvest (i.e. no fallow period) enabled seedlings to be physically larger than those planted after a one year delay. At the Boot study site, limiting vegetation below 20% for the first growing season improved year-3 Douglas-fir seedling stem volume over 273 cm³. Delaying establishment activities one year and reducing competing vegetation below 11% enabled seedling volume after two years to be statistically the same as three year old seedlings in the no-action control, a volume range of between 148 to 166 cm³. Delaying forest establishment at Jackson Mast improved seedling survivorship over 88% when a spring heat event reduced survivorship of trees planted a year earlier to less than 69%. The combined effect of applying a fall site preparation and spring release was necessary to reduce competitive cover below 10% in the year following treatment and provided longer-lasting control of woody/semi-woody plants. Less intense control measures (i.e. no-action control and treatment 2) were not able to restrain woody/semi-woody plant cover which grew to nearly 40% at Boot and over 24% at Jackson Mast in three years. No treatment regime provided multi-year control of herbaceous species. Including sulfometuron methyl in the fall site preparation tank-mix did not have a negative effect on seedling growth or provide significant reductions in plant community abundance in the year following application when compared to similar regimes that did not include the chemical. Delaying establishment lengthened the amount of time associated with forest regeneration except on a site that accentuated a spring heat event. In the second study, horizontal distance and azimuth readings provided by a ground-based laser were used to stem map seedling locations and experimental unit features at Boot. These data were used to create a relative Cartesian coordinate system that defined spatially explicit polygons enabling, for the first time, the ability to collect positional data on competing forest vegetation within an entire experimental unit. Deemed "vixels" or vegetation pixels, these polygons were assessed for measures of total cover and cover of the top three most abundance species during the initial three years of establishment. An alternate validity check of research protocols was provided when total cover resulting from this vixel technique was compared to a more traditional survey of four randomly located subplots. The resulting linear regression equation had an adjusted R² of 0.90 between these two techniques of assessing total cover. When compared within a treatment and year, total cover differed by less than 12 percentage points between the two techniques. Analysis of year-3 woody/semi-woody plant cover produced by the techniques led to identical treatment differences. Two treatments resulted in woody/semi-woody cover of approximately 1500 ft² by the vixel method and nearly 40% cover by the subplot method while the remaining four treatments were grouped below 600 ft² or 20% cover, respectively. With continued refinement, these techniques could visually present forest development through all phases and provide long-term information used to bolster growth and yield models, measures of site productivity, as well as community ecology research. The third study evaluated the season-long gas exchange and biomass partitioning of four weedy plant species capable of rapidly colonizing Pacific Northwest regenerating forests. Cirsium arvense, Cirsium vulgare, Rubus ursinus and Senecio sylvaticus were studied at two sites. A greenhouse was used to introduce two levels of irrigation (well-watered and droughty). These species were also studied while growing among a larger vegetation community at a field site. Irrigation treatments had little impact on gas exchange rates. Species achieved maximum photosynthetic rates of 30, 20, 15 and 25 μmol CO₂ m⁻² s⁻¹ (respectively) prior to mid-July coinciding with an active phase of vegetative growth. As the season progressed, photosynthetic rates declined in spite of well-watered conditions while transpiration rates remained relatively consistent even when soil water decreased below 0.25 m³ H₂O/m³ soil. Water use efficiency was high until late-July for all study species, after which time it decreased below 5 μmol CO₂ · mmol H₂O⁻¹. Multi-leaf gas exchange measurements as well as biomass data provided a holistic view of plantlevel mechanisms used to shunt activity toward developing tissues. Herbaceous species had assimilation rates that differed vertically (within each species) by as much as 10 to 20 μmol CO₂ m⁻² s⁻¹ from July to September as lower leaves senesced in favor of those higher on study plants. Specific leaf area was greatest in June for all species then declined indicating species placed little effort into sacrificial early season leaves when compared to those higher on the plant that could continue to support flowering or vegetative growth. The study of seasonal gas exchange in the presence of declining water availability has helped to describe competitive mechanisms at work during forest regeneration as well as provide physiologic support for the application of vegetation management regimes. Title: Characterizing early-seral competitive mechanisms influencing Douglas-fir seedling growth, vegetation community development, and physiology of selected weedy plant species Author: Dinger, Eric J. Three studies were conducted to characterize and present early-seral competition between Douglas-fir seedlings and the surrounding vegetation communities during Pacific Northwest forest establishment. The first experiment served as the foundation for this dissertation and was designed to quantify tradeoffs associated with delaying forest establishment activities by introducing a fallow year in order to provide longer-term management of competing vegetation. A range of six operationally relevant treatments were applied over two growing seasons that included in the first (1) a no-action control, (2) a spring release only, (3) a fall site preparation without sulfometuron methyl followed by a spring release, as well as (4) a fall site preparation with sulfometuron methyl and a spring release. In the second year, there was (5) a fall site preparation without sulfometuron methyl followed by a spring release and also in the second year (6) a fall site preparation with sulfometuron methyl and a spring release. Treatments 5 and 6 were left fallow without planting during the first year. These treatments were applied in two replicated experiments within the Oregon Coast Range. After adjusting for initial seedling size, year-3 results indicated that plantation establishment and competition control immediately after harvest (i.e. no fallow period) enabled seedlings to be physically larger than those planted after a one year delay. At the Boot study site, limiting vegetation below 20% for the first growing season improved year-3 Douglas-fir seedling stem volume over 273 cm³. Delaying establishment activities one year and reducing competing vegetation below 11% enabled seedling volume after two years to be statistically the same as three year old seedlings in the no-action control, a volume range of between 148 to 166 cm³. Delaying forest establishment at Jackson Mast improved seedling survivorship over 88% when a spring heat event reduced survivorship of trees planted a year earlier to less than 69%. The combined effect of applying a fall site preparation and spring release was necessary to reduce competitive cover below 10% in the year following treatment and provided longer-lasting control of woody/semi-woody plants. Less intense control measures (i.e. no-action control and treatment 2) were not able to restrain woody/semi-woody plant cover which grew to nearly 40% at Boot and over 24% at Jackson Mast in three years. No treatment regime provided multi-year control of herbaceous species. Including sulfometuron methyl in the fall site preparation tank-mix did not have a negative effect on seedling growth or provide significant reductions in plant community abundance in the year following application when compared to similar regimes that did not include the chemical. Delaying establishment lengthened the amount of time associated with forest regeneration except on a site that accentuated a spring heat event. In the second study, horizontal distance and azimuth readings provided by a ground-based laser were used to stem map seedling locations and experimental unit features at Boot. These data were used to create a relative Cartesian coordinate system that defined spatially explicit polygons enabling, for the first time, the ability to collect positional data on competing forest vegetation within an entire experimental unit. Deemed "vixels" or vegetation pixels, these polygons were assessed for measures of total cover and cover of the top three most abundance species during the initial three years of establishment. An alternate validity check of research protocols was provided when total cover resulting from this vixel technique was compared to a more traditional survey of four randomly located subplots. The resulting linear regression equation had an adjusted R² of 0.90 between these two techniques of assessing total cover. When compared within a treatment and year, total cover differed by less than 12 percentage points between the two techniques. Analysis of year-3 woody/semi-woody plant cover produced by the techniques led to identical treatment differences. Two treatments resulted in woody/semi-woody cover of approximately 1500 ft² by the vixel method and nearly 40% cover by the subplot method while the remaining four treatments were grouped below 600 ft² or 20% cover, respectively. With continued refinement, these techniques could visually present forest development through all phases and provide long-term information used to bolster growth and yield models, measures of site productivity, as well as community ecology research. The third study evaluated the season-long gas exchange and biomass partitioning of four weedy plant species capable of rapidly colonizing Pacific Northwest regenerating forests. Cirsium arvense, Cirsium vulgare, Rubus ursinus and Senecio sylvaticus were studied at two sites. A greenhouse was used to introduce two levels of irrigation (well-watered and droughty). These species were also studied while growing among a larger vegetation community at a field site. Irrigation treatments had little impact on gas exchange rates. Species achieved maximum photosynthetic rates of 30, 20, 15 and 25 μmol CO₂ m⁻² s⁻¹ (respectively) prior to mid-July coinciding with an active phase of vegetative growth. As the season progressed, photosynthetic rates declined in spite of well-watered conditions while transpiration rates remained relatively consistent even when soil water decreased below 0.25 m³ H₂O/m³ soil. Water use efficiency was high until late-July for all study species, after which time it decreased below 5 μmol CO₂ · mmol H₂O⁻¹. Multi-leaf gas exchange measurements as well as biomass data provided a holistic view of plantlevel mechanisms used to shunt activity toward developing tissues. Herbaceous species had assimilation rates that differed vertically (within each species) by as much as 10 to 20 μmol CO₂ m⁻² s⁻¹ from July to September as lower leaves senesced in favor of those higher on study plants. Specific leaf area was greatest in June for all species then declined indicating species placed little effort into sacrificial early season leaves when compared to those higher on the plant that could continue to support flowering or vegetative growth. The study of seasonal gas exchange in the presence of declining water availability has helped to describe competitive mechanisms at work during forest regeneration as well as provide physiologic support for the application of vegetation management regimes. Close

• 28. [Article] Human influences on historical and current wildlife distributions from Lewis & Clark to today

  Although it is well known that humans are strong modifiers of their environment, there is a need for greater understanding of human-wildlife interactions, both historically as well as currently. Historical ...

  Citation × Citation Citation Abstract Copy Title: Human influences on historical and current wildlife distributions from Lewis & Clark to today Author: Laliberte, Andrea S. Although it is well known that humans are strong modifiers of their environment, there is a need for greater understanding of human-wildlife interactions, both historically as well as currently. Historical journals can help shed light on early human-wildlife interactions, and the Lewis & Clark journals contain some of the earliest and detailed written descriptions of a large part of the United States before Euro-American settlement. I used the journal entries to assess the influence of humans on wildlife distribution and abundance. Areas with denser human population, the Columbia Basin and the Pacific Coast, had lower species diversity and abundance of large mammals. The opposite was observed on the Plains. Overhunting before Euro- American contact accentuated by the introduction of the horse may have been major contributors responsible for the historic absence of some species that are present in the archaeological record. The information gained from the Lewis & Clark journals shows the considerable human influence on wildlife under relatively low human population densities. This has major implications for conservation biology and ecological restoration, since human influence is often underestimated when considering the pre-settlement condition. Species ranges are dynamic and change greatly over time. In order to identify large-scale patterns in range contractions and/or expansions, I compared historic and current geographical ranges of 43 North American carnivores and ungulates. Seventeen of the species had undergone range contractions over >20% of their historic range. In areas of higher human influence, species were more likely to contract and less likely to persist. Species richness declined considerably since historic times, and the temperate grasslands and temperate broadleaf/mixed forest biomes lost the highest average number of species, while the boreal forest and tundra showed fewer numbers of species lost. The study of species range changes contributed new quantitative information about human influences on range contractions in North America. The results can be used to improve our knowledge of historical reference conditions, for the creation of wildlife reserves, and for wildlife re-introductions. Title: Human influences on historical and current wildlife distributions from Lewis & Clark to today Author: Laliberte, Andrea S. Although it is well known that humans are strong modifiers of their environment, there is a need for greater understanding of human-wildlife interactions, both historically as well as currently. Historical journals can help shed light on early human-wildlife interactions, and the Lewis & Clark journals contain some of the earliest and detailed written descriptions of a large part of the United States before Euro-American settlement. I used the journal entries to assess the influence of humans on wildlife distribution and abundance. Areas with denser human population, the Columbia Basin and the Pacific Coast, had lower species diversity and abundance of large mammals. The opposite was observed on the Plains. Overhunting before Euro- American contact accentuated by the introduction of the horse may have been major contributors responsible for the historic absence of some species that are present in the archaeological record. The information gained from the Lewis & Clark journals shows the considerable human influence on wildlife under relatively low human population densities. This has major implications for conservation biology and ecological restoration, since human influence is often underestimated when considering the pre-settlement condition. Species ranges are dynamic and change greatly over time. In order to identify large-scale patterns in range contractions and/or expansions, I compared historic and current geographical ranges of 43 North American carnivores and ungulates. Seventeen of the species had undergone range contractions over >20% of their historic range. In areas of higher human influence, species were more likely to contract and less likely to persist. Species richness declined considerably since historic times, and the temperate grasslands and temperate broadleaf/mixed forest biomes lost the highest average number of species, while the boreal forest and tundra showed fewer numbers of species lost. The study of species range changes contributed new quantitative information about human influences on range contractions in North America. The results can be used to improve our knowledge of historical reference conditions, for the creation of wildlife reserves, and for wildlife re-introductions. Close

• 29. [Article] Native bees, honeybees and pollination in Oregon cranberries (BioResource Research)

  Farmers rely almost exclusively on the imported European honeybee (Apis mellifera L.) for fruit and vegetable crop pollination services. The recent decline in honeybee health has underscored the danger ...

  Citation × Citation Citation Abstract Copy Title: Native bees, honeybees and pollination in Oregon cranberries (BioResource Research) Author: McKenney, Melissa A. Farmers rely almost exclusively on the imported European honeybee (Apis mellifera L.) for fruit and vegetable crop pollination services. The recent decline in honeybee health has underscored the danger of relying on a single species to provide vital services. Increasing pollinator biodiversity with native bees may provide biological insurance against the decline of any particular species. By examining cropping systems, it is possible to determine which native bees are providing pollination services and then augment habitat to increase their numbers or attempt domestication. In this study, we examined the native bee populations in the cranberry growing area of southern coastal Oregon in order to determine if native bees play a significant role in cranberry pollination. This two-year study surveyed four farms across a 22 km north-south gradient. At least 27 bee species were observed during cranberry bloom (mid-May to late June), of which five were observed foraging on the cranberry flowers. The imported European honeybee and bumble bees (Bombus spp.) comprised 99.7% of foragers. While honeybees and bumble bees foraged at comparable wind speeds, Bombus spp. foraged at significantly lower average temperatures (P<0.0001). Both honeybees and bumble bees collected cranberry pollen while foraging, but 37.2% of honeybees were observed nectar-robbing (collecting nectar but no pollen) versus only 11.3% of bumble bees. Bumble bees in general, and the western yellow-faced bumble bee (Bombus vosnesenskii Radoszkowski) in particular, are abundant native pollinators of cranberry, and may provide adequate pollination for small Oregon cranberry farms. Conservation of bumble bee habitat and development of managed colonies will help maintain pollination services. Title: Native bees, honeybees and pollination in Oregon cranberries (BioResource Research) Author: McKenney, Melissa A. Farmers rely almost exclusively on the imported European honeybee (Apis mellifera L.) for fruit and vegetable crop pollination services. The recent decline in honeybee health has underscored the danger of relying on a single species to provide vital services. Increasing pollinator biodiversity with native bees may provide biological insurance against the decline of any particular species. By examining cropping systems, it is possible to determine which native bees are providing pollination services and then augment habitat to increase their numbers or attempt domestication. In this study, we examined the native bee populations in the cranberry growing area of southern coastal Oregon in order to determine if native bees play a significant role in cranberry pollination. This two-year study surveyed four farms across a 22 km north-south gradient. At least 27 bee species were observed during cranberry bloom (mid-May to late June), of which five were observed foraging on the cranberry flowers. The imported European honeybee and bumble bees (Bombus spp.) comprised 99.7% of foragers. While honeybees and bumble bees foraged at comparable wind speeds, Bombus spp. foraged at significantly lower average temperatures (P<0.0001). Both honeybees and bumble bees collected cranberry pollen while foraging, but 37.2% of honeybees were observed nectar-robbing (collecting nectar but no pollen) versus only 11.3% of bumble bees. Bumble bees in general, and the western yellow-faced bumble bee (Bombus vosnesenskii Radoszkowski) in particular, are abundant native pollinators of cranberry, and may provide adequate pollination for small Oregon cranberry farms. Conservation of bumble bee habitat and development of managed colonies will help maintain pollination services. Close

• 30. [Article] Native bees, honeybees and pollination in Oregon cranberries (Library Undergraduate Honors Award Paper)

  Farmers rely almost exclusively on the imported European honeybee (Apis mellifera L.) for fruit and vegetable crop pollination services. The recent decline in honeybee health has underscored he danger ...

  Citation × Citation Citation Abstract Copy Title: Native bees, honeybees and pollination in Oregon cranberries (Library Undergraduate Honors Award Paper) Author: McKenney, Melissa A. Farmers rely almost exclusively on the imported European honeybee (Apis mellifera L.) for fruit and vegetable crop pollination services. The recent decline in honeybee health has underscored he danger of relying on a single species to provide vital services. Increasing pollinator biodiversity with native bees may provide biological insurance against the decline of any particular species. By examining cropping systems, it is possible to determine which native bees are providing pollination services and then augment habitat to increase their numbers or attempt domestication. In this study, we examined the native bee populations in the cranberry growing area of southern coastal Oregon in order to determine if native bees play a significant role in cranberry pollination. This two-year study surveyed four farms across a 22 km north-south gradient. At least 27 bee species were observed during cranberry bloom (mid-May to late June), of which five were observed foraging on the cranberry flowers. The imported European honeybees and bumble bees foraged at comparable wind speeds, Bombus spp. Foraged at significantly lower average temperatures (P<0.0001). Both honeybees and bumble bees collected cranberry pollen while foraging, but 37.2% of honeybees were observed nectar-robbing (collecting nectar but no pollen) versus only 11.3% of bumble bees. Bumble bees in general , and the western yellow-faced bumble bee (Bombus vosnesenskii Randoszkowski) in particular, are abundant native pollinators of cranberry, and may provide adequate pollination for small Oregon cranberry farms. Conservation of bumble bee habitat and development of managed colonies will help maintain pollination services. Title: Native bees, honeybees and pollination in Oregon cranberries (Library Undergraduate Honors Award Paper) Author: McKenney, Melissa A. Farmers rely almost exclusively on the imported European honeybee (Apis mellifera L.) for fruit and vegetable crop pollination services. The recent decline in honeybee health has underscored he danger of relying on a single species to provide vital services. Increasing pollinator biodiversity with native bees may provide biological insurance against the decline of any particular species. By examining cropping systems, it is possible to determine which native bees are providing pollination services and then augment habitat to increase their numbers or attempt domestication. In this study, we examined the native bee populations in the cranberry growing area of southern coastal Oregon in order to determine if native bees play a significant role in cranberry pollination. This two-year study surveyed four farms across a 22 km north-south gradient. At least 27 bee species were observed during cranberry bloom (mid-May to late June), of which five were observed foraging on the cranberry flowers. The imported European honeybees and bumble bees foraged at comparable wind speeds, Bombus spp. Foraged at significantly lower average temperatures (P<0.0001). Both honeybees and bumble bees collected cranberry pollen while foraging, but 37.2% of honeybees were observed nectar-robbing (collecting nectar but no pollen) versus only 11.3% of bumble bees. Bumble bees in general , and the western yellow-faced bumble bee (Bombus vosnesenskii Randoszkowski) in particular, are abundant native pollinators of cranberry, and may provide adequate pollination for small Oregon cranberry farms. Conservation of bumble bee habitat and development of managed colonies will help maintain pollination services. Close

• 31. [Article] Bridging environmental physiology and community ecology : temperature effects at the community level

  Most climate change predictions focus on the response of individual species to changing local conditions and ignore species interactions, largely due to the lack of a sound theoretical foundation for how ...

  Citation × Citation Citation Abstract Copy Title: Bridging environmental physiology and community ecology : temperature effects at the community level Author: Iles, Alison C. Most climate change predictions focus on the response of individual species to changing local conditions and ignore species interactions, largely due to the lack of a sound theoretical foundation for how interactions are expected to change with climate and how to incorporate them into climate change models. Much of the variability in species interaction strengths may be governed by fundamental constraints on physiological rates, possibly providing a framework for including species interactions into climate change models. Metabolic rates, ingestion rates and many other physiological rates are relatively predictable from body size and body temperature due to constraints imposed by the physical and chemical laws that govern fluid dynamics and the kinetics of biochemical reaction times. My dissertation assesses the usefulness of this framework by exploring the community-level consequences of physiological constraints. In Chapter 2, I incorporated temperature and body size scaling into the biological rate parameters of a series of realistically structured trophic network models. The relative magnitude of the temperature scaling parameters affecting consumer energetic costs (metabolic rates) and energetic gains (ingestion rates) determined how consumer energetic efficiency changed with temperature. I systematically changed consumer energetic efficiency and examined the sensitivity of network stability and species persistence to various temperatures. I found that a species' probability of extinction depended primarily on the effects of organismal physiology (body size and energetic efficiency with respect to temperature) and secondarily on the effects of local food web structure (trophic level and consumer generality). This suggests that physiology is highly influential on the structure and dynamics of ecological communities. If consumer energetic efficiency declined as temperature increased, that is, species did best at lower temperatures, then the simulated networks had greater stability at lower temperatures. The opposite scenario resulted in greater stability at higher temperatures. Thus, much of the community-level response depends on what species energetic efficiencies at the organismal-level really are, which formed the research question for Chapter 3: How does consumer energetic efficiency change with temperature? Existing evidence is scarce but suggestive of decreasing consumer energetic efficiency with increasing temperature. I tested this hypothesis on seven rocky intertidal invertebrate species by measuring the relative temperature scaling of their metabolic and ingestion rates as well as consumer interaction strength under lab conditions. Energetic efficiencies of these rocky intertidal invertebrates declined and species interaction strengths tended to increase with temperature. Thus, in the rocky intertidal, the mechanistic effect of temperature would be to lower community stability at higher temperatures. Chapter 4 tests if the mechanistic effects of temperature on ingestion rates and species interaction strengths seen in the lab are apparent under field conditions. Bruce Menge and I related bio-mimetic estimates of body temperatures to estimates of per capita mussel ingestion rates and species interaction strengths by the ochre sea star Pisaster ochraceus, a keystone predator of the rocky intertidal. We found a strong, positive effect of body temperature on both per capita ingestion rates and interaction strengths. However, the effects of season and the unique way in which P. ochraceus regulates body temperatures were also apparent, leaving room for adaptation and acclimation to partially compensate for the mechanistic constraint of body temperature. Community structure of the rocky intertidal is associated with environmental forcing due to upwelling, which delivers cold, nutrient rich water to the nearshore environment. As upwelling is driven by large-scale atmospheric pressure gradients, climate change has the potential to affect a wide range of significant ecological processes through changes in water temperature. In Chapter 5, my coauthors and I identified long-term trends in the phenology of upwelling events that are consistent with climate change predictions: upwelling events are becoming stronger and longer. As expected, longer upwelling events were related to lower average water temperatures in the rocky intertidal. Furthermore, recruitment rates of barnacles and mussels were associated with the phenology of upwelling events. Thus climate change is altering the mode and the tempo of environmental forcing in nearshore ecosystems, with ramifications for community structure and function. Ongoing, long-term changes in environmental forcing in rocky intertidal ecosystems provide an opportunity to understand how temperature shapes community structure and the ramifications of climate change. My dissertation research demonstrates that the effect of temperature on organismal performance is an important force structuring ecological communities and has potential as a tractable framework for predicting the community level effects of climate change. Title: Bridging environmental physiology and community ecology : temperature effects at the community level Author: Iles, Alison C. Most climate change predictions focus on the response of individual species to changing local conditions and ignore species interactions, largely due to the lack of a sound theoretical foundation for how interactions are expected to change with climate and how to incorporate them into climate change models. Much of the variability in species interaction strengths may be governed by fundamental constraints on physiological rates, possibly providing a framework for including species interactions into climate change models. Metabolic rates, ingestion rates and many other physiological rates are relatively predictable from body size and body temperature due to constraints imposed by the physical and chemical laws that govern fluid dynamics and the kinetics of biochemical reaction times. My dissertation assesses the usefulness of this framework by exploring the community-level consequences of physiological constraints. In Chapter 2, I incorporated temperature and body size scaling into the biological rate parameters of a series of realistically structured trophic network models. The relative magnitude of the temperature scaling parameters affecting consumer energetic costs (metabolic rates) and energetic gains (ingestion rates) determined how consumer energetic efficiency changed with temperature. I systematically changed consumer energetic efficiency and examined the sensitivity of network stability and species persistence to various temperatures. I found that a species' probability of extinction depended primarily on the effects of organismal physiology (body size and energetic efficiency with respect to temperature) and secondarily on the effects of local food web structure (trophic level and consumer generality). This suggests that physiology is highly influential on the structure and dynamics of ecological communities. If consumer energetic efficiency declined as temperature increased, that is, species did best at lower temperatures, then the simulated networks had greater stability at lower temperatures. The opposite scenario resulted in greater stability at higher temperatures. Thus, much of the community-level response depends on what species energetic efficiencies at the organismal-level really are, which formed the research question for Chapter 3: How does consumer energetic efficiency change with temperature? Existing evidence is scarce but suggestive of decreasing consumer energetic efficiency with increasing temperature. I tested this hypothesis on seven rocky intertidal invertebrate species by measuring the relative temperature scaling of their metabolic and ingestion rates as well as consumer interaction strength under lab conditions. Energetic efficiencies of these rocky intertidal invertebrates declined and species interaction strengths tended to increase with temperature. Thus, in the rocky intertidal, the mechanistic effect of temperature would be to lower community stability at higher temperatures. Chapter 4 tests if the mechanistic effects of temperature on ingestion rates and species interaction strengths seen in the lab are apparent under field conditions. Bruce Menge and I related bio-mimetic estimates of body temperatures to estimates of per capita mussel ingestion rates and species interaction strengths by the ochre sea star Pisaster ochraceus, a keystone predator of the rocky intertidal. We found a strong, positive effect of body temperature on both per capita ingestion rates and interaction strengths. However, the effects of season and the unique way in which P. ochraceus regulates body temperatures were also apparent, leaving room for adaptation and acclimation to partially compensate for the mechanistic constraint of body temperature. Community structure of the rocky intertidal is associated with environmental forcing due to upwelling, which delivers cold, nutrient rich water to the nearshore environment. As upwelling is driven by large-scale atmospheric pressure gradients, climate change has the potential to affect a wide range of significant ecological processes through changes in water temperature. In Chapter 5, my coauthors and I identified long-term trends in the phenology of upwelling events that are consistent with climate change predictions: upwelling events are becoming stronger and longer. As expected, longer upwelling events were related to lower average water temperatures in the rocky intertidal. Furthermore, recruitment rates of barnacles and mussels were associated with the phenology of upwelling events. Thus climate change is altering the mode and the tempo of environmental forcing in nearshore ecosystems, with ramifications for community structure and function. Ongoing, long-term changes in environmental forcing in rocky intertidal ecosystems provide an opportunity to understand how temperature shapes community structure and the ramifications of climate change. My dissertation research demonstrates that the effect of temperature on organismal performance is an important force structuring ecological communities and has potential as a tractable framework for predicting the community level effects of climate change. Close

• 32. [Article] Cone and seed insects and their impact on whitebark pine

  Whitebark pine, Pinus albicaulis Engelm. is an important but declining high-elevation tree species in western forests. Regeneration of this species has been difficult and the impact of cone and seed insects ...

  Citation × Citation Citation Abstract Copy Title: Cone and seed insects and their impact on whitebark pine Author: United States. Forest Service. Northern Region, Kegley, Sandy, United States. Forest Health Protection Whitebark pine, Pinus albicaulis Engelm. is an important but declining high-elevation tree species in western forests. Regeneration of this species has been difficult and the impact of cone and seed insects unknown. Seven sites selected from the geographical range of whitebark pine in Idaho, Montana, Washington, Oregon, and California were examined for cone and seed insects and their impact. Ten different insect species were found affecting various reproductive structures of whitebark pine. Insects having the greatest impact across most sites were fir coneworm (Dioryctria abietivorella (Grote)) and western conifer seed bug (Leptoglossus occidentalis Heidemann). Coneworms infested up to 68% of cones collected, destroying up to 13% of the seed extracted. Seed bugs damaged up to 27% of the seeds. Pheromone traps for the ponderosa pine cone beetle (Conophthorus ponderosae Hopkins) and coneworms were tested. Ponderosa pine cone beetles were trapped at three of seven sites. Coneworms were trapped at two sites where pheromone traps were deployed. Further studies incorporating different cone crop levels of whitebark pine and other associated tree species are needed to fully determine the effect of cone and seed insects on whitebark pine seed and reproduction. Title: Cone and seed insects and their impact on whitebark pine Author: United States. Forest Service. Northern Region, Kegley, Sandy, United States. Forest Health Protection Whitebark pine, Pinus albicaulis Engelm. is an important but declining high-elevation tree species in western forests. Regeneration of this species has been difficult and the impact of cone and seed insects unknown. Seven sites selected from the geographical range of whitebark pine in Idaho, Montana, Washington, Oregon, and California were examined for cone and seed insects and their impact. Ten different insect species were found affecting various reproductive structures of whitebark pine. Insects having the greatest impact across most sites were fir coneworm (Dioryctria abietivorella (Grote)) and western conifer seed bug (Leptoglossus occidentalis Heidemann). Coneworms infested up to 68% of cones collected, destroying up to 13% of the seed extracted. Seed bugs damaged up to 27% of the seeds. Pheromone traps for the ponderosa pine cone beetle (Conophthorus ponderosae Hopkins) and coneworms were tested. Ponderosa pine cone beetles were trapped at three of seven sites. Coneworms were trapped at two sites where pheromone traps were deployed. Further studies incorporating different cone crop levels of whitebark pine and other associated tree species are needed to fully determine the effect of cone and seed insects on whitebark pine seed and reproduction. Close

• 33. [Article] Twenty-year changes in riparian bird communities of east-central Oregon

  Over the last 50 years, riparian zones in the semi-arid West have gained recognition as disproportionately important habitats for both breeding bird communities and agricultural operations. Despite growing ...

  Citation × Citation Citation Abstract Copy Title: Twenty-year changes in riparian bird communities of east-central Oregon Author: Ellis, Michael S. Over the last 50 years, riparian zones in the semi-arid West have gained recognition as disproportionately important habitats for both breeding bird communities and agricultural operations. Despite growing interest in exploring avian-habitat relationships in these systems to better inform land management, few studies have attempted to describe temporal changes in the region's riparian bird communities. To provide a frame of reference for these changes, we compared indices of avian abundance and diversity from three streamside vegetation associations in east-central Oregon during the 2014 breeding season with baseline data collected by TA Sanders and WD Edge in 1993 and 1994 (Sanders and Edge 1998). Our objectives were to identify patterns of change in the avian community with a focus on riparian shrub-dependent species, to re-examine previously reported relationships between avian abundance and vegetation volume, and to identify possible causes of declines in abundance and diversity with the goal of providing land managers in the semi-arid region information to be used in the guidance and adaptation of management practices. We combined field protocols used by Sanders and Edge to survey birds along point count transects and to measure riparian vegetation with modern analytical techniques. We found few major differences in overall diversity between study periods, but documented precipitous declines in detections for two of three riparian shrub-dependent focal species - Yellow Warbler (Setophaga petechia) and Willow Flycatcher (Empidonax trailii). Song Sparrow (Melospiza melodia) detections declined by a smaller margin. Changes in number of detections for these species did not reflect trends in mesic shrub volume, which had been identified as a likely driver of obligate species abundance by Sanders and Edge but remained relatively unchanged between study periods. Declines of all three focal species reflected regional Breeding Bird Survey trends, corroborating our finding that their declines may not be a result of changes in local site conditions. Compositional similarity between avian communities was significantly higher in 2014 than in 1993-1994, exhibiting a shift toward greater homogenization between structurally distinct riparian habitats. Our results suggest managing working lands for riparian shrub cover or volume, an important metric of grazing intensity and riparian system health, may not be enough to conserve diversity and abundance of riparian-shrub dependent birds, and more work should be done to identify and alleviate factors contributing to these species' declines. Title: Twenty-year changes in riparian bird communities of east-central Oregon Author: Ellis, Michael S. Over the last 50 years, riparian zones in the semi-arid West have gained recognition as disproportionately important habitats for both breeding bird communities and agricultural operations. Despite growing interest in exploring avian-habitat relationships in these systems to better inform land management, few studies have attempted to describe temporal changes in the region's riparian bird communities. To provide a frame of reference for these changes, we compared indices of avian abundance and diversity from three streamside vegetation associations in east-central Oregon during the 2014 breeding season with baseline data collected by TA Sanders and WD Edge in 1993 and 1994 (Sanders and Edge 1998). Our objectives were to identify patterns of change in the avian community with a focus on riparian shrub-dependent species, to re-examine previously reported relationships between avian abundance and vegetation volume, and to identify possible causes of declines in abundance and diversity with the goal of providing land managers in the semi-arid region information to be used in the guidance and adaptation of management practices. We combined field protocols used by Sanders and Edge to survey birds along point count transects and to measure riparian vegetation with modern analytical techniques. We found few major differences in overall diversity between study periods, but documented precipitous declines in detections for two of three riparian shrub-dependent focal species - Yellow Warbler (Setophaga petechia) and Willow Flycatcher (Empidonax trailii). Song Sparrow (Melospiza melodia) detections declined by a smaller margin. Changes in number of detections for these species did not reflect trends in mesic shrub volume, which had been identified as a likely driver of obligate species abundance by Sanders and Edge but remained relatively unchanged between study periods. Declines of all three focal species reflected regional Breeding Bird Survey trends, corroborating our finding that their declines may not be a result of changes in local site conditions. Compositional similarity between avian communities was significantly higher in 2014 than in 1993-1994, exhibiting a shift toward greater homogenization between structurally distinct riparian habitats. Our results suggest managing working lands for riparian shrub cover or volume, an important metric of grazing intensity and riparian system health, may not be enough to conserve diversity and abundance of riparian-shrub dependent birds, and more work should be done to identify and alleviate factors contributing to these species' declines. Close

• 34. [Article] Seed and establishment limitation contribute to long-term native forb declines in California grasslands

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

  Citation × Citation Citation Abstract Copy Title: Seed and establishment limitation contribute to long-term native forb declines in California grasslands Author: Brandt, Angela J., Seabloom, Eric W. This is the publisher’s final pdf. The published article is copyrighted by Ecological Society of America and can be found at: http://www.esa.org/. Title: Seed and establishment limitation contribute to long-term native forb declines in California grasslands Author: Brandt, Angela J., Seabloom, Eric W. This is the publisher’s final pdf. The published article is copyrighted by Ecological Society of America and can be found at: http://www.esa.org/. Close

• 35. [Article] Agricultural impacts on amphibian survival, growth, and distributions

  The potential impact of chemical contaminants and conservation practices on amphibians in agricultural landscapes is a key research topic globally. Amphibians represent a common group in many freshwater ...

  Citation × Citation Citation Abstract Copy Title: Agricultural impacts on amphibian survival, growth, and distributions Author: Baker, Nick J. The potential impact of chemical contaminants and conservation practices on amphibians in agricultural landscapes is a key research topic globally. Amphibians represent a common group in many freshwater systems and are currently experiencing worldwide population declines. Global amphibian declines may be attributed to a number of causes, including habitat loss, introduced species, global climate change, disease, and chemical contaminants; most species declines are not a function of only one factor, but a result of interacting factors and synergistic impacts. I analyzed the impact of field conservation efforts employed in the Calapooia watershed, located in the central Willamette Valley in Oregon, on amphibian species diversity using Simpson's Diversity Index. In the Calapooia watershed the value of this index increased when conservation efforts, such as retaining crop residue and riparian buffers, were present. This suggests that species diversity increased with increased conservation effort at the field level. In addition, I found species-specific habitat associations in the Calapooia watershed. Long-toed salamanders (Ambystoma macrodactylum) were associated with stream channel cover. Rough-skinned newts (Taricha granulosa) and Red-legged frogs (Rana aurora) showed similar relationships to pH, bank width, depth, and riparian habitat where as Pacific treefrogs (Pseudacris regilla) showed strong relationships to increased structural heterogeneity, increased distance to nearest agricultural field, and increased human disturbance. These results indicate that conservation efforts can impact amphibian biodiversity, and that there are species-specific habitat associations in the Calapooia watershed. My third chapter looked at pesticides and fertilizers, which have been shown to negatively affect many species of amphibians. I used meta-analytic techniques to quantify the lethal and sub-lethal effects of pesticides and fertilizers on amphibians in an effort to review the published work to date. I found that, in general, pesticides and fertilizers negatively affect amphibians by reducing both survival and growth. Pesticide and fertilizer chemical classes showed differences in their impacts on amphibians: inorganic fertilizers, organophosphates, phosphonoglycines, and triazines negatively affected amphibian survival, while, organophosphates and triazines negatively affected amphibian growth. Title: Agricultural impacts on amphibian survival, growth, and distributions Author: Baker, Nick J. The potential impact of chemical contaminants and conservation practices on amphibians in agricultural landscapes is a key research topic globally. Amphibians represent a common group in many freshwater systems and are currently experiencing worldwide population declines. Global amphibian declines may be attributed to a number of causes, including habitat loss, introduced species, global climate change, disease, and chemical contaminants; most species declines are not a function of only one factor, but a result of interacting factors and synergistic impacts. I analyzed the impact of field conservation efforts employed in the Calapooia watershed, located in the central Willamette Valley in Oregon, on amphibian species diversity using Simpson's Diversity Index. In the Calapooia watershed the value of this index increased when conservation efforts, such as retaining crop residue and riparian buffers, were present. This suggests that species diversity increased with increased conservation effort at the field level. In addition, I found species-specific habitat associations in the Calapooia watershed. Long-toed salamanders (Ambystoma macrodactylum) were associated with stream channel cover. Rough-skinned newts (Taricha granulosa) and Red-legged frogs (Rana aurora) showed similar relationships to pH, bank width, depth, and riparian habitat where as Pacific treefrogs (Pseudacris regilla) showed strong relationships to increased structural heterogeneity, increased distance to nearest agricultural field, and increased human disturbance. These results indicate that conservation efforts can impact amphibian biodiversity, and that there are species-specific habitat associations in the Calapooia watershed. My third chapter looked at pesticides and fertilizers, which have been shown to negatively affect many species of amphibians. I used meta-analytic techniques to quantify the lethal and sub-lethal effects of pesticides and fertilizers on amphibians in an effort to review the published work to date. I found that, in general, pesticides and fertilizers negatively affect amphibians by reducing both survival and growth. Pesticide and fertilizer chemical classes showed differences in their impacts on amphibians: inorganic fertilizers, organophosphates, phosphonoglycines, and triazines negatively affected amphibian survival, while, organophosphates and triazines negatively affected amphibian growth. Close

• 36. [Article] Island survivors: population genetic structure and demography of the critically endangered giant lizard of La Gomera, Gallotia bravoana

  This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by BioMed Central Ltd. The published article can be found at: http://www.biomedcentral.com/bmcgene...

  Citation × Citation Citation Abstract Copy Title: Island survivors: population genetic structure and demography of the critically endangered giant lizard of La Gomera, Gallotia bravoana Author: Cerón-Souza, Ivania, Mateo, José A., Zardoya, Rafael, Gonzalez, Elena G. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by BioMed Central Ltd. The published article can be found at: http://www.biomedcentral.com/bmcgenet/. Title: Island survivors: population genetic structure and demography of the critically endangered giant lizard of La Gomera, Gallotia bravoana Author: Cerón-Souza, Ivania, Mateo, José A., Zardoya, Rafael, Gonzalez, Elena G. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by BioMed Central Ltd. The published article can be found at: http://www.biomedcentral.com/bmcgenet/. Close

• 37. [Article] Heart rate, survivorship, oxygen consumption, and metabolic end product accumulations in the intertidal limpets Collisella pelta and Collisella digitalis in relation to desiccation and hypoxia

  The heart rate, oxygen consumption, survivorship, and 1-lactate accumulation were determined in the intertidal limpets Collisella pelta and Collisella digitalis in relation to laboratory desiccation at ...

  Citation × Citation Citation Abstract Copy Title: Heart rate, survivorship, oxygen consumption, and metabolic end product accumulations in the intertidal limpets Collisella pelta and Collisella digitalis in relation to desiccation and hypoxia Author: Boese, Bruce Leon The heart rate, oxygen consumption, survivorship, and 1-lactate accumulation were determined in the intertidal limpets Collisella pelta and Collisella digitalis in relation to laboratory desiccation at 15°C or 30°C. Water loss was computed as a percentage of total initial body water (wet weight - dry weight). Although water was lost faster in C. digitalis than in C. pelta, C. digitalis tolerated more water loss and survived longer than C. pelta at both experimental temperatures. During the first few hours of desiccation at 15°C the heart rate of C. digitalis was constant while in C. pelta the heart rate declined rapidly. During desiccation at 30°C the heart rates of both species declined rapidly. No change was noted in control heart rates, determined under moist aerial conditions, in either species during a 40 hour exposure period. Oxygen consumption of C. digitalis declined gradually during desiccation at 15°C to about 60% of the undesiccated aerial control rate after 46 hours of exposure. During desiccation at 30°C the decline in oxygen consumption was much more pronounced. In C. pelta during desiccation at 15°C oxygen consumption progressively declined with increasing length of exposure to approximately 50% of control rates for the first 16 hours of exposure at which time rates became constant. At 30°C a more pronounced reduction in oxygen consumption occurred. Whole-body lactate accumulated in both species during desiccation at 15°C and 30°C in comparison with controls. At 15°C accumulation in C. pelta began after 15 hours of desiccation while at 30°C accumulations were evident after 4 hours. In contrast, C. digitalis gradually accumulated lactate during the entire length of exposure to desiccation conditions at 15°C. Upon exposure to moist nitrogen atmosphere both species exhibited a rapid bradycardia. Heart rates recovered rapidly after exposure and overshot pre-exposure rates indicating oxygen debt repayment. Of the three anaerobic end products examined (alanine, succinate and lactate) only lactate accumulated to any degree in either species during anoxia. During anoxia C. digitalis accumulated more lactate than C. pelta. C. pelta reached a maximum accumulation after 4 hours of anoxia while C. digitalis continued to accumulate lactate over the entire length of exposure to moist nitrogen. The results suggest differences between C. digitalis and C. pelta in metabolic adaptations which may be related to intertidal zonational differences. Title: Heart rate, survivorship, oxygen consumption, and metabolic end product accumulations in the intertidal limpets Collisella pelta and Collisella digitalis in relation to desiccation and hypoxia Author: Boese, Bruce Leon The heart rate, oxygen consumption, survivorship, and 1-lactate accumulation were determined in the intertidal limpets Collisella pelta and Collisella digitalis in relation to laboratory desiccation at 15°C or 30°C. Water loss was computed as a percentage of total initial body water (wet weight - dry weight). Although water was lost faster in C. digitalis than in C. pelta, C. digitalis tolerated more water loss and survived longer than C. pelta at both experimental temperatures. During the first few hours of desiccation at 15°C the heart rate of C. digitalis was constant while in C. pelta the heart rate declined rapidly. During desiccation at 30°C the heart rates of both species declined rapidly. No change was noted in control heart rates, determined under moist aerial conditions, in either species during a 40 hour exposure period. Oxygen consumption of C. digitalis declined gradually during desiccation at 15°C to about 60% of the undesiccated aerial control rate after 46 hours of exposure. During desiccation at 30°C the decline in oxygen consumption was much more pronounced. In C. pelta during desiccation at 15°C oxygen consumption progressively declined with increasing length of exposure to approximately 50% of control rates for the first 16 hours of exposure at which time rates became constant. At 30°C a more pronounced reduction in oxygen consumption occurred. Whole-body lactate accumulated in both species during desiccation at 15°C and 30°C in comparison with controls. At 15°C accumulation in C. pelta began after 15 hours of desiccation while at 30°C accumulations were evident after 4 hours. In contrast, C. digitalis gradually accumulated lactate during the entire length of exposure to desiccation conditions at 15°C. Upon exposure to moist nitrogen atmosphere both species exhibited a rapid bradycardia. Heart rates recovered rapidly after exposure and overshot pre-exposure rates indicating oxygen debt repayment. Of the three anaerobic end products examined (alanine, succinate and lactate) only lactate accumulated to any degree in either species during anoxia. During anoxia C. digitalis accumulated more lactate than C. pelta. C. pelta reached a maximum accumulation after 4 hours of anoxia while C. digitalis continued to accumulate lactate over the entire length of exposure to moist nitrogen. The results suggest differences between C. digitalis and C. pelta in metabolic adaptations which may be related to intertidal zonational differences. Close

• 38. [Article] An analysis of the population dynamics of selected avian species

  The impact that pesticides may have had on the mortality rates and productivity rates of non-game birds during the last 25 years was evaluated by studying the population dynamics of 16 species. A mathematical ...

  Citation × Citation Citation Abstract Copy Title: An analysis of the population dynamics of selected avian species Author: Henny, Charles J. The impact that pesticides may have had on the mortality rates and productivity rates of non-game birds during the last 25 years was evaluated by studying the population dynamics of 16 species. A mathematical model showing the relationships between population parameters that yielded stable populations was developed. The information needed for the model included: (1) mortality rate schedule (obtained from recoveries of banded birds), (2) productivity rates, and (3) the age of sexual maturity. Production requirements for a stable population and annual rate of change (increase or decrease) in population levels were estimated. Population parameters were compared to determine if changes had occurred between time periods (i.e, 1925-1945 vs. 1946-1965). The great horned owl, red-shouldered hawk, sparrow hawk, osprey, barn owl, Cooper's hawk, red-tailed hawk, great blue heron, black-crowned night heron, brown pelican, barn owl, chimney swift, blue jay, black-capped chickadee, cardinal, and robin were subjected to this analysis. No increase in post-fledging mortality rates in any of the species has occurred since 1945. Therefore, accelerated decline in the species studied must have resulted from lowered reproductive rates. Mortality rates have decreased in the Cooper's hawk, sparrow hawk, great blue heron, and brown pelican. A decrease in shooting pressure was associated with decreased mortality rates. Evidence of declining reproductive rates were found in the brown pelican, osprey, Cooper's hawk, red-shouldered hawk, and sparrow hawk. No changes in reproductive rates were noted in the red-tailed hawk, great horned owl, or barn owl. Information on productivity rates was not available for comparison with the other species although rates of productivity essential for a stable population were estimated. This work will provide the basis for making comparisons in future studies. No change in reproductive rates was apparent among species feeding primarily on mammals. Species exhibiting a lowered reproductive success since 1945 were those whose major food items consisted of fish, reptiles, amphibians, or birds. Lowered reproductive success was accompanied by a decrease in eggshell thickness. Other investigators have reported that sparrow hawks and mallard ducks fed a diet of DDE and dieldrin have produced thin eggshells under laboratory conditions, and exhibited a lower reproductive success. Many bird species which consume food in which chlorinated hydrocarbon pesticides have been concentrated through a series of transfers along food chains have declined. The chlorinated hydrocarbon pesticides are believed responsible. Title: An analysis of the population dynamics of selected avian species Author: Henny, Charles J. The impact that pesticides may have had on the mortality rates and productivity rates of non-game birds during the last 25 years was evaluated by studying the population dynamics of 16 species. A mathematical model showing the relationships between population parameters that yielded stable populations was developed. The information needed for the model included: (1) mortality rate schedule (obtained from recoveries of banded birds), (2) productivity rates, and (3) the age of sexual maturity. Production requirements for a stable population and annual rate of change (increase or decrease) in population levels were estimated. Population parameters were compared to determine if changes had occurred between time periods (i.e, 1925-1945 vs. 1946-1965). The great horned owl, red-shouldered hawk, sparrow hawk, osprey, barn owl, Cooper's hawk, red-tailed hawk, great blue heron, black-crowned night heron, brown pelican, barn owl, chimney swift, blue jay, black-capped chickadee, cardinal, and robin were subjected to this analysis. No increase in post-fledging mortality rates in any of the species has occurred since 1945. Therefore, accelerated decline in the species studied must have resulted from lowered reproductive rates. Mortality rates have decreased in the Cooper's hawk, sparrow hawk, great blue heron, and brown pelican. A decrease in shooting pressure was associated with decreased mortality rates. Evidence of declining reproductive rates were found in the brown pelican, osprey, Cooper's hawk, red-shouldered hawk, and sparrow hawk. No changes in reproductive rates were noted in the red-tailed hawk, great horned owl, or barn owl. Information on productivity rates was not available for comparison with the other species although rates of productivity essential for a stable population were estimated. This work will provide the basis for making comparisons in future studies. No change in reproductive rates was apparent among species feeding primarily on mammals. Species exhibiting a lowered reproductive success since 1945 were those whose major food items consisted of fish, reptiles, amphibians, or birds. Lowered reproductive success was accompanied by a decrease in eggshell thickness. Other investigators have reported that sparrow hawks and mallard ducks fed a diet of DDE and dieldrin have produced thin eggshells under laboratory conditions, and exhibited a lower reproductive success. Many bird species which consume food in which chlorinated hydrocarbon pesticides have been concentrated through a series of transfers along food chains have declined. The chlorinated hydrocarbon pesticides are believed responsible. Close

• 39. [Article] Riparian bird communities in Portland, Oregon : habitat, urbanization, and spatial scale patterns

  Urban ecosystems are characterized by human disturbance and changes in the amount, types, and spatial arrangement of wildlife habitat. The relative importance of habitat and human associated variables ...

  Citation × Citation Citation Abstract Copy Title: Riparian bird communities in Portland, Oregon : habitat, urbanization, and spatial scale patterns Author: Hennings, Lori A. Urban ecosystems are characterized by human disturbance and changes in the amount, types, and spatial arrangement of wildlife habitat. The relative importance of habitat and human associated variables to urban birds is unknown. In 1999, I surveyed spring bird and plant communities along 54 perennial streams in the Portland, Oregon metropolitan region. My objectives were to determine (1) what habitat and human-associated variables were related to avian community measures, (2) how far from riparian areas did relationships between avifauna and canopy cover and development extend, and (3) habitat characteristics associated with individual bird species. I used Principal Components Analysis to cluster and reduce the number of explanatory variables, and regressed bird community variables against the resulting principal components. Total and nonnative bird abundance were negatively related to the first principal component, PC 1 (high-scoring PC 1 sites had wide, structurally complex native forests) (r2 = 0.38, P < 0.0001 and r2 = 0.63, P < 0.0001, respectively). Several weak (r2 = 0.17-0.31, P < 0.003) curvilinear relationships emerged between overall and native species richness and diversity versus PC 1. Neotropical migratory bird (NMB) species richness and diversity were negatively related to human development variables, and positively related to native shrubs (adjusted r2 = 0.21 and 0.18, respectively; P < 0.003). I regressed bird community variables against canopy cover and street density for each of ten 50-m buffers around sites, then plotted the model fit (r) against buffer width. Native and nonnative abundance measures were negatively related to canopy cover. Total abundance was best predicted by canopy cover 300-350 m from the stream whereas normative abundance was predicted nearly equally by canopy cover in each buffer. The relationships between total species richness, native species richness, total diversity and native diversity were curvilinearly related to canopy cover, with canopy in the first 50 m appearing most important. Neotropical migratory bird species richness, diversity and abundance were negatively related to street density within 150 m of the stream. Brown-headed Cowbird (Molothrus ater) abundance was increasingly, negatively related to canopy cover as spatial scale increased. I used logistic regression to identify habitat and/or human-associated variables that predicted the occurrence of 32 species. The occurrence of four species (American Crow [Corvus brachyrhynchos], House Finch [Carpodacus mexicanus], Red-breasted Nuthatch [Sitta canadensis], and Vaux's Swift [Chaetura vauxi]) was positively, and five species (Black-headed Grosbeak [Pheucticus melanocephalus], Common Yellowthroat [Geothlypis trichas], Rufous Hummingbird [Selasphorus rufus], Steller's Jay [Cyanocitta setlleri], and Swainson's Thrush [Catharus ustulatus]) negatively related to human-associated variables. My results suggest that increasing urban canopy cover is the most valuable land management action for many breeding bird species. Preserving large undeveloped habitats and controlling urban sprawl may help prevent regional declines of NMB species. Title: Riparian bird communities in Portland, Oregon : habitat, urbanization, and spatial scale patterns Author: Hennings, Lori A. Urban ecosystems are characterized by human disturbance and changes in the amount, types, and spatial arrangement of wildlife habitat. The relative importance of habitat and human associated variables to urban birds is unknown. In 1999, I surveyed spring bird and plant communities along 54 perennial streams in the Portland, Oregon metropolitan region. My objectives were to determine (1) what habitat and human-associated variables were related to avian community measures, (2) how far from riparian areas did relationships between avifauna and canopy cover and development extend, and (3) habitat characteristics associated with individual bird species. I used Principal Components Analysis to cluster and reduce the number of explanatory variables, and regressed bird community variables against the resulting principal components. Total and nonnative bird abundance were negatively related to the first principal component, PC 1 (high-scoring PC 1 sites had wide, structurally complex native forests) (r2 = 0.38, P < 0.0001 and r2 = 0.63, P < 0.0001, respectively). Several weak (r2 = 0.17-0.31, P < 0.003) curvilinear relationships emerged between overall and native species richness and diversity versus PC 1. Neotropical migratory bird (NMB) species richness and diversity were negatively related to human development variables, and positively related to native shrubs (adjusted r2 = 0.21 and 0.18, respectively; P < 0.003). I regressed bird community variables against canopy cover and street density for each of ten 50-m buffers around sites, then plotted the model fit (r) against buffer width. Native and nonnative abundance measures were negatively related to canopy cover. Total abundance was best predicted by canopy cover 300-350 m from the stream whereas normative abundance was predicted nearly equally by canopy cover in each buffer. The relationships between total species richness, native species richness, total diversity and native diversity were curvilinearly related to canopy cover, with canopy in the first 50 m appearing most important. Neotropical migratory bird species richness, diversity and abundance were negatively related to street density within 150 m of the stream. Brown-headed Cowbird (Molothrus ater) abundance was increasingly, negatively related to canopy cover as spatial scale increased. I used logistic regression to identify habitat and/or human-associated variables that predicted the occurrence of 32 species. The occurrence of four species (American Crow [Corvus brachyrhynchos], House Finch [Carpodacus mexicanus], Red-breasted Nuthatch [Sitta canadensis], and Vaux's Swift [Chaetura vauxi]) was positively, and five species (Black-headed Grosbeak [Pheucticus melanocephalus], Common Yellowthroat [Geothlypis trichas], Rufous Hummingbird [Selasphorus rufus], Steller's Jay [Cyanocitta setlleri], and Swainson's Thrush [Catharus ustulatus]) negatively related to human-associated variables. My results suggest that increasing urban canopy cover is the most valuable land management action for many breeding bird species. Preserving large undeveloped habitats and controlling urban sprawl may help prevent regional declines of NMB species. Close

• 40. [Article] Using remote sensing, in situ observations, and geographic information systems to map benthic habitats at Heceta Bank, Oregon

  Dramatic declines in many species of demersal fishes off the West Coast have resulted in the designation of nine commercially important species as being overfished. While the causes of those declines are ...

  Citation × Citation Citation Abstract Copy Title: Using remote sensing, in situ observations, and geographic information systems to map benthic habitats at Heceta Bank, Oregon Author: Whitmire, Curt E. Dramatic declines in many species of demersal fishes off the West Coast have resulted in the designation of nine commercially important species as being overfished. While the causes of those declines are not clearly understood, the fact remains that a paucity of life history and abundance data exists for many demersal species, also known as groundfish. Due to this uncertainty, only 21 of the 82 species of groundfish managed under the Groundfish Fishery Management Plan of the Pacific Fishery Management Council (PFMC) have been fully assessed. One challenge in designing a systematic survey of groundfish resources is that many species associate with heterogeneous substrate of varying relief. In many areas, the rugosity of the substrata precludes sampling by conventional techniques (e.g. bottom trawl gear). This has stimulated research that characterizes fish-habitat associations for use in design of new survey methodology. Using a combination of remote sensing, in situ observations, and spatial analytical techniques, four benthic habitat classes were mapped for a large rocky bank off the central Oregon coast known as Heceta Bank. Observational data from human-occupied submersible and remotely operated vehicle dives in the late 1980s, 2000 and 2001 were used to establish habitat classes with specific substrate characteristics that have been statistically shown to correlate with demersal fish distributions. The observational habitat data was then extrapolated over the extent of a multibeam sonar survey conducted in 1998 using quantitative parameters derived from high-resolution bathymetric and backscatter imagery of the seafloor. The resultant map predicts the locations of four habitat classes: Ridge-Gully, High-Relief Rock (boulders, cobbles), Unconsolidated Sediment 1 (muds), and Unconsolidated Sediment 2 (sands). The main utility of the habitat map developed as part of the current study is that it provides a context for analyses of a variety of spatial data. For instance, habitat data provides one additional spatial component besides depth and latitude that can be used to stratify catch per unit effort data from surveys and commercial logbooks. Also, essential fish habitat for many demersal species can now be identified in more detail. Finally, habitat data like those presented here can aid in the design of marine reserves and protected areas by providing a context for spatial analyses of data of ecological importance. Title: Using remote sensing, in situ observations, and geographic information systems to map benthic habitats at Heceta Bank, Oregon Author: Whitmire, Curt E. Dramatic declines in many species of demersal fishes off the West Coast have resulted in the designation of nine commercially important species as being overfished. While the causes of those declines are not clearly understood, the fact remains that a paucity of life history and abundance data exists for many demersal species, also known as groundfish. Due to this uncertainty, only 21 of the 82 species of groundfish managed under the Groundfish Fishery Management Plan of the Pacific Fishery Management Council (PFMC) have been fully assessed. One challenge in designing a systematic survey of groundfish resources is that many species associate with heterogeneous substrate of varying relief. In many areas, the rugosity of the substrata precludes sampling by conventional techniques (e.g. bottom trawl gear). This has stimulated research that characterizes fish-habitat associations for use in design of new survey methodology. Using a combination of remote sensing, in situ observations, and spatial analytical techniques, four benthic habitat classes were mapped for a large rocky bank off the central Oregon coast known as Heceta Bank. Observational data from human-occupied submersible and remotely operated vehicle dives in the late 1980s, 2000 and 2001 were used to establish habitat classes with specific substrate characteristics that have been statistically shown to correlate with demersal fish distributions. The observational habitat data was then extrapolated over the extent of a multibeam sonar survey conducted in 1998 using quantitative parameters derived from high-resolution bathymetric and backscatter imagery of the seafloor. The resultant map predicts the locations of four habitat classes: Ridge-Gully, High-Relief Rock (boulders, cobbles), Unconsolidated Sediment 1 (muds), and Unconsolidated Sediment 2 (sands). The main utility of the habitat map developed as part of the current study is that it provides a context for analyses of a variety of spatial data. For instance, habitat data provides one additional spatial component besides depth and latitude that can be used to stratify catch per unit effort data from surveys and commercial logbooks. Also, essential fish habitat for many demersal species can now be identified in more detail. Finally, habitat data like those presented here can aid in the design of marine reserves and protected areas by providing a context for spatial analyses of data of ecological importance. Close

• 41. [Article] Patch dynamics of desert fishes in the arid wetlands of western Utah

  The conservation of declining desert fish species requires the identification of relations between fish population dynamics and their environments. Dynamic occupancy modeling, an approach that requires ...

  Citation × Citation Citation Abstract Copy Title: Patch dynamics of desert fishes in the arid wetlands of western Utah Author: Sáenz, Jessica The conservation of declining desert fish species requires the identification of relations between fish population dynamics and their environments. Dynamic occupancy modeling, an approach that requires less information than traditional mark-recapture studies, may help identify important factors affecting population processes and aid desert fish conservation and restoration efforts. I used dynamic multi-season occupancy models for two analyses (multi-state and multi-species) to evaluate the influence of patch-level characteristics (patch percent open water, average patch depth, patch area), grazing damage, species interactions, population differences, patch connectivity and environmental variation (seasonal precipitation and temperature) on the patch dynamics (colonization, persistence, reproduction) of two desert chub species found in Snake Valley, UT. My results indicate that there was the strongest evidence according to model weights that patch dynamics in this system were influenced by patch-level characteristics (patch percent open water and average patch depth), grazing damage, population differences, biotic interactions, and winter precipitation rather than landscape level features such as connectivity. I observed positive effects of patch percent open water and average patch depth on least chub and Utah chub persistence. I also found that grazing damage increased their persistence at the medium damage level but decreased least chub and Utah chub colonization at the high grazing damage level. Least chub and Utah chub colonization varied between the two populations (study areas) with a higher probability of colonization at Bishop Springs than at Gandy Salt Marsh. In addition, I found some evidence that biotic interactions between least chub and Utah chub may be occurring in this system. Least chub were less likely to colonize patches previously occupied by Utah chub but surprisingly there was little evidence that these species interactions affected least chub persistence. Least chub reproduction increased with winter precipitation and was higher at Gandy Salt Marsh than Bishop Springs. The use of dynamic occupancy modeling in desert spring wetland complexes may provide a valuable tool for managers tasked with conserving at-risk desert fish species. Title: Patch dynamics of desert fishes in the arid wetlands of western Utah Author: Sáenz, Jessica The conservation of declining desert fish species requires the identification of relations between fish population dynamics and their environments. Dynamic occupancy modeling, an approach that requires less information than traditional mark-recapture studies, may help identify important factors affecting population processes and aid desert fish conservation and restoration efforts. I used dynamic multi-season occupancy models for two analyses (multi-state and multi-species) to evaluate the influence of patch-level characteristics (patch percent open water, average patch depth, patch area), grazing damage, species interactions, population differences, patch connectivity and environmental variation (seasonal precipitation and temperature) on the patch dynamics (colonization, persistence, reproduction) of two desert chub species found in Snake Valley, UT. My results indicate that there was the strongest evidence according to model weights that patch dynamics in this system were influenced by patch-level characteristics (patch percent open water and average patch depth), grazing damage, population differences, biotic interactions, and winter precipitation rather than landscape level features such as connectivity. I observed positive effects of patch percent open water and average patch depth on least chub and Utah chub persistence. I also found that grazing damage increased their persistence at the medium damage level but decreased least chub and Utah chub colonization at the high grazing damage level. Least chub and Utah chub colonization varied between the two populations (study areas) with a higher probability of colonization at Bishop Springs than at Gandy Salt Marsh. In addition, I found some evidence that biotic interactions between least chub and Utah chub may be occurring in this system. Least chub were less likely to colonize patches previously occupied by Utah chub but surprisingly there was little evidence that these species interactions affected least chub persistence. Least chub reproduction increased with winter precipitation and was higher at Gandy Salt Marsh than Bishop Springs. The use of dynamic occupancy modeling in desert spring wetland complexes may provide a valuable tool for managers tasked with conserving at-risk desert fish species. Close

• 42. [Article] Habitat selection by Greater Sage-Grouse during winter in southeastern Oregon

  This is the publisher’s final pdf. The published article is copyrighted by Brigham Young University and can be found at: https://ojs.lib.byu.edu/wnan/index.php/wnan/. To the best of our knowledge, one ...

  Citation × Citation Citation Abstract Copy Title: Habitat selection by Greater Sage-Grouse during winter in southeastern Oregon Author: Hagen, Christian A., Glenn, Elizabeth M., Anthony, Robert G., Willis, Mitchell J. This is the publisher’s final pdf. The published article is copyrighted by Brigham Young University and can be found at: https://ojs.lib.byu.edu/wnan/index.php/wnan/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Title: Habitat selection by Greater Sage-Grouse during winter in southeastern Oregon Author: Hagen, Christian A., Glenn, Elizabeth M., Anthony, Robert G., Willis, Mitchell J. This is the publisher’s final pdf. The published article is copyrighted by Brigham Young University and can be found at: https://ojs.lib.byu.edu/wnan/index.php/wnan/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Close

• 43. [Article] Habitat Selection by Greater Sage-Grouse During Winter in Southeastern Oregon

  This is the publisher’s final pdf. The published article is copyrighted by Brigham Young University, Monte L Bean Life Science Museau and can be found at: https://ojs.lib.byu.edu/spc/index.php/wnan

  Citation × Citation Citation Abstract Copy Title: Habitat Selection by Greater Sage-Grouse During Winter in Southeastern Oregon Author: Hagen, Christian A., Glenn, Elizabeth M., Anthony, Robert G., Willis, Mitchell J. This is the publisher’s final pdf. The published article is copyrighted by Brigham Young University, Monte L Bean Life Science Museau and can be found at: https://ojs.lib.byu.edu/spc/index.php/wnan Title: Habitat Selection by Greater Sage-Grouse During Winter in Southeastern Oregon Author: Hagen, Christian A., Glenn, Elizabeth M., Anthony, Robert G., Willis, Mitchell J. This is the publisher’s final pdf. The published article is copyrighted by Brigham Young University, Monte L Bean Life Science Museau and can be found at: https://ojs.lib.byu.edu/spc/index.php/wnan Close

• 44. [Article] Performance of Willamette Valley native plants following herbicide exposure

  Prairies were once the dominant vegetation type in Oregon's Willamette Valley. Land use conversion, fire suppression, succession, and invasive species have reduced Willamette Valley prairies to less than ...

  Citation × Citation Citation Abstract Copy Title: Performance of Willamette Valley native plants following herbicide exposure Author: Blakeley-Smith, Matthew R. Prairies were once the dominant vegetation type in Oregon's Willamette Valley. Land use conversion, fire suppression, succession, and invasive species have reduced Willamette Valley prairies to less than 1% of their historical area. The remnant prairies that persist today are small in size and are highly fragmented. Marginal strips of habitat along roadsides and agricultural fields play an important role as refugia for native species and provide important resources for wildlife. These seemingly insignificant habitat units may also play an important role in facilitating gene flow between disjunct populations of prairie plants, thus reducing the potential for the negative effects of inbreeding depression. Presently, much of the land area in the Willamette Valley is dedicated to commercial agricultural which is heavily reliant on herbicides for weed control and field preparation. Since herbicide applications are imprecise and prone to drift, there is potential to impact the native plants surrounding these agricultural fields. Current EPA methods for assessing the ecological effects of herbicides may not be robust enough to account for potential impacts on native plants since the suggested test species are ten annual agricultural crops. To address the need for improved phytotoxicity testing protocols, we incorporated non-crop plant species into the EPA vegetative vigor test methodology for use in determining effects of low concentrations of chemical herbicides on Willamette Valley terrestrial plants. A separate experiment was conducted in order to determine how herbicides might be used to restore Butterfly Meadows, a degraded Willamette Valley prairie. The specific objective of this study were to: 1.) determine which herbicide treatments were most effective at reducing dominance of an invasive species, Brachypodium sylvaticum, 2.) determine if native species declined following herbicide treatments, and 3.) describe the compositional changes in the plant communities over a four-year period. The EPA vegetative vigor test study showed that there was a wide variety of responses among 17 species (14 native and 3 introduced) to each herbicide tested (glyphosate, tribenuron, and fluazifop). For glyphosate, Potentilla gracilis was the most sensitive species based on an EC25 value of 0.012 x f.a.r. for dry weight; while Bromus carinatus, Clarkia amoena, Gilia capitata, and Lupinus albicaulis were tolerant to glyphosate as indicated by no effect on dry weight. Seven Willamette Valley forb species were sensitive to tribenuron based on EC25 values ranging from 0.001 to 0.012 x f.a.r.; Clarkia amoena, Collinsia grandflora, Leucanthemum vulgare, Potentilla gracilis, Prunella vulgaris, Ranunculus occidentalis and Sanquisorba occidentalis. Six grass species and Eriophyllum lanatum were resistant to tribenuron showing no reduction in dry weight. Fluazifop primarily affected grass species as expected due to the grass-specific activity for this herbicide. Two native grasses, Elymus trachycaulus and Danthonia californica were the most sensitive to fluazifop, based on low EC25 values of 0.002 to 0.010 x f.a.r. A native fescue grass, Festuca roemeri, and nearly all the forb species were resistant to fluazifop, showing no response at any herbicide rate applied. The results from this research will be useful as background information for evaluating potential modifications in the EPA's Vegetative Vigor Test to assess the risk of herbicides to non-target plants. Seven different herbicide combinations were effective at reducing the cover of Brachypodium sylvaticum in test plots at Butterfly Meadows one year after treatment. The reduction of B. sylvaticum was short lived however, since the cover of this grass species was not different from control plots during the second growing season. Native plant species were not negatively impacted by the herbicide treatments, as shown by MRPP analysis. Successional trajectories illustrate that control plots that were dominated by B. sylvaticum remained relatively unchanged over the course of four years. Some treatments exhibited a sharp decline in dominance by graminoids after the first year, a recovery the second year, but never returned exactly to their pretreatment community composition after the third year. The reduction of the dominant species after the first growing season was associated with colonization by a number of introduced species into the newly created open habitat. Over the same period there was no overall increase in native species cover, suggesting that the native species at this site may be recruitment limited. Future restoration activities at this site should include multiple years of B. sylvaticum control, with special attention to the seed bank and tolerant individuals. Seed additions of native species may help fill empty niches and afford resistance to invasion by introduced species. Title: Performance of Willamette Valley native plants following herbicide exposure Author: Blakeley-Smith, Matthew R. Prairies were once the dominant vegetation type in Oregon's Willamette Valley. Land use conversion, fire suppression, succession, and invasive species have reduced Willamette Valley prairies to less than 1% of their historical area. The remnant prairies that persist today are small in size and are highly fragmented. Marginal strips of habitat along roadsides and agricultural fields play an important role as refugia for native species and provide important resources for wildlife. These seemingly insignificant habitat units may also play an important role in facilitating gene flow between disjunct populations of prairie plants, thus reducing the potential for the negative effects of inbreeding depression. Presently, much of the land area in the Willamette Valley is dedicated to commercial agricultural which is heavily reliant on herbicides for weed control and field preparation. Since herbicide applications are imprecise and prone to drift, there is potential to impact the native plants surrounding these agricultural fields. Current EPA methods for assessing the ecological effects of herbicides may not be robust enough to account for potential impacts on native plants since the suggested test species are ten annual agricultural crops. To address the need for improved phytotoxicity testing protocols, we incorporated non-crop plant species into the EPA vegetative vigor test methodology for use in determining effects of low concentrations of chemical herbicides on Willamette Valley terrestrial plants. A separate experiment was conducted in order to determine how herbicides might be used to restore Butterfly Meadows, a degraded Willamette Valley prairie. The specific objective of this study were to: 1.) determine which herbicide treatments were most effective at reducing dominance of an invasive species, Brachypodium sylvaticum, 2.) determine if native species declined following herbicide treatments, and 3.) describe the compositional changes in the plant communities over a four-year period. The EPA vegetative vigor test study showed that there was a wide variety of responses among 17 species (14 native and 3 introduced) to each herbicide tested (glyphosate, tribenuron, and fluazifop). For glyphosate, Potentilla gracilis was the most sensitive species based on an EC25 value of 0.012 x f.a.r. for dry weight; while Bromus carinatus, Clarkia amoena, Gilia capitata, and Lupinus albicaulis were tolerant to glyphosate as indicated by no effect on dry weight. Seven Willamette Valley forb species were sensitive to tribenuron based on EC25 values ranging from 0.001 to 0.012 x f.a.r.; Clarkia amoena, Collinsia grandflora, Leucanthemum vulgare, Potentilla gracilis, Prunella vulgaris, Ranunculus occidentalis and Sanquisorba occidentalis. Six grass species and Eriophyllum lanatum were resistant to tribenuron showing no reduction in dry weight. Fluazifop primarily affected grass species as expected due to the grass-specific activity for this herbicide. Two native grasses, Elymus trachycaulus and Danthonia californica were the most sensitive to fluazifop, based on low EC25 values of 0.002 to 0.010 x f.a.r. A native fescue grass, Festuca roemeri, and nearly all the forb species were resistant to fluazifop, showing no response at any herbicide rate applied. The results from this research will be useful as background information for evaluating potential modifications in the EPA's Vegetative Vigor Test to assess the risk of herbicides to non-target plants. Seven different herbicide combinations were effective at reducing the cover of Brachypodium sylvaticum in test plots at Butterfly Meadows one year after treatment. The reduction of B. sylvaticum was short lived however, since the cover of this grass species was not different from control plots during the second growing season. Native plant species were not negatively impacted by the herbicide treatments, as shown by MRPP analysis. Successional trajectories illustrate that control plots that were dominated by B. sylvaticum remained relatively unchanged over the course of four years. Some treatments exhibited a sharp decline in dominance by graminoids after the first year, a recovery the second year, but never returned exactly to their pretreatment community composition after the third year. The reduction of the dominant species after the first growing season was associated with colonization by a number of introduced species into the newly created open habitat. Over the same period there was no overall increase in native species cover, suggesting that the native species at this site may be recruitment limited. Future restoration activities at this site should include multiple years of B. sylvaticum control, with special attention to the seed bank and tolerant individuals. Seed additions of native species may help fill empty niches and afford resistance to invasion by introduced species. Close

• 45. [Article] Contrasting distribution patterns of invasive and naturalized non-native species along environmental gradients in a semi-arid montane ecosystem

  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 International Association ...

  Citation × Citation Citation Abstract Copy Title: Contrasting distribution patterns of invasive and naturalized non-native species along environmental gradients in a semi-arid montane ecosystem Author: Andersen, Kelly M., Endress, Bryan A., Parks, Catherine G., Naylor, Bridgett 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 article is copyrighted by International Association for Vegetation Science and published by John Wiley & Sons, Ltd.. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291654-109X Title: Contrasting distribution patterns of invasive and naturalized non-native species along environmental gradients in a semi-arid montane ecosystem Author: Andersen, Kelly M., Endress, Bryan A., Parks, Catherine G., Naylor, Bridgett 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 article is copyrighted by International Association for Vegetation Science and published by John Wiley & Sons, Ltd.. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291654-109X Close

• 46. [Article] The roles of provenance and phylogeny in recruitment, community assembly, and species coexistence in invaded California grasslands

  Biological invasions pose one of the greatest threats to global biodiversity, but many naturalized invaders coexist with the native community. Community ecology theory provides a framework for understanding ...

  Citation × Citation Citation Abstract Copy Title: The roles of provenance and phylogeny in recruitment, community assembly, and species coexistence in invaded California grasslands Author: Brandt, Angela J. Biological invasions pose one of the greatest threats to global biodiversity, but many naturalized invaders coexist with the native community. Community ecology theory provides a framework for understanding the mechanisms by which invaders might coexist with native species or exclude them from the community, thus informing management practices to maximize their effectiveness at conserving native biodiversity. Differences in functional or phylogenetic similarity of invaders to native residents can affect invasion success and the probability they will coexist with natives. For example, functionally dissimilar species may not compete strongly and distantly related species may share fewer natural enemies. Furthermore, environmental heterogeneity can promote species coexistence by providing the opportunity for a greater number of coexistence mechanisms to operate, thereby mitigating the potential for species invasions to lead to native extinction. My thesis examines how provenance (i.e., native origin) and phylogenetic relatedness of plant species affect community dynamics and species interactions in the invaded California grasslands. To do this I have assembled two unique community data sets, one spanning 48 years across a 1000-ha site and one spanning 7 years along a 500-km latitudinal transect. I show that native and exotic species abundance and diversity is highly variable in both time and space, but these provenance group responses are rarely negatively correlated (Chapter 2). Thus, exotic species do not generally appear to exclude natives from communities. Long-term abundance patterns further suggest that the system remains in a state of transience, and populations of several native species are declining at local scales (Chapter 3). Recruitment limitation due to the build-up of plant litter associated with exotic grasses may be generally responsible for these declines, but habitat suitability, land-use history, and community composition also affect native recruitment. Across the grasslands, disturbance and resource supply can interact to affect both species and phylogenetic diversity (Chapter 4). Disturbance in particular can increase diversity, likely by increasing opportunities for colonization by removing plant litter that previously limited recruitment. Both phylogeny and provenance can also affect biotic interactions, such as with communities of soil organisms (Chapter 5). Thus, I have shown that spatio-temporal heterogeneity, alterations to the biotic environment mediated by exotic invasion, and phylogenetic relationships among species are all important considerations when evaluating impacts of invasion and designing management strategies to conserve native biodiversity, especially in light of anthropogenic influence on disturbance regimes and resource supply. Title: The roles of provenance and phylogeny in recruitment, community assembly, and species coexistence in invaded California grasslands Author: Brandt, Angela J. Biological invasions pose one of the greatest threats to global biodiversity, but many naturalized invaders coexist with the native community. Community ecology theory provides a framework for understanding the mechanisms by which invaders might coexist with native species or exclude them from the community, thus informing management practices to maximize their effectiveness at conserving native biodiversity. Differences in functional or phylogenetic similarity of invaders to native residents can affect invasion success and the probability they will coexist with natives. For example, functionally dissimilar species may not compete strongly and distantly related species may share fewer natural enemies. Furthermore, environmental heterogeneity can promote species coexistence by providing the opportunity for a greater number of coexistence mechanisms to operate, thereby mitigating the potential for species invasions to lead to native extinction. My thesis examines how provenance (i.e., native origin) and phylogenetic relatedness of plant species affect community dynamics and species interactions in the invaded California grasslands. To do this I have assembled two unique community data sets, one spanning 48 years across a 1000-ha site and one spanning 7 years along a 500-km latitudinal transect. I show that native and exotic species abundance and diversity is highly variable in both time and space, but these provenance group responses are rarely negatively correlated (Chapter 2). Thus, exotic species do not generally appear to exclude natives from communities. Long-term abundance patterns further suggest that the system remains in a state of transience, and populations of several native species are declining at local scales (Chapter 3). Recruitment limitation due to the build-up of plant litter associated with exotic grasses may be generally responsible for these declines, but habitat suitability, land-use history, and community composition also affect native recruitment. Across the grasslands, disturbance and resource supply can interact to affect both species and phylogenetic diversity (Chapter 4). Disturbance in particular can increase diversity, likely by increasing opportunities for colonization by removing plant litter that previously limited recruitment. Both phylogeny and provenance can also affect biotic interactions, such as with communities of soil organisms (Chapter 5). Thus, I have shown that spatio-temporal heterogeneity, alterations to the biotic environment mediated by exotic invasion, and phylogenetic relationships among species are all important considerations when evaluating impacts of invasion and designing management strategies to conserve native biodiversity, especially in light of anthropogenic influence on disturbance regimes and resource supply. Close

• 47. [Article] Rapid endangered species assessment : a novel approach to improve extinction risk assessments in poorly known species

  The number of endangered species is rapidly increasing while paucity of adequate information and resources delays establishment of conservation actions. The IUCN’s listing system is insufficient to determine ...

  Citation × Citation Citation Abstract Copy Title: Rapid endangered species assessment : a novel approach to improve extinction risk assessments in poorly known species Author: Bianchi, Carlos A. The number of endangered species is rapidly increasing while paucity of adequate information and resources delays establishment of conservation actions. The IUCN’s listing system is insufficient to determine conservation priorities and many species lack information even to be evaluated (i.e., “data deficient”). Here I proposed and tested the Rapid Endangered Species Assessment approach, combining methods including distribution modeling, landscape/habitat availability analysis and an evaluation of population spatial structure to improve information about species of concern and make future extinction risk assessments more attainable. I used the Pfrimer’s Parakeet (Pyrrhura pfrimeri) an endemic Brazilian species, as a case study. I modeled and validated the potential distribution of the species, known to occur in association with the tropical dry forests in central Brazil, using the Maxent method. The model predicted potential occurrence in three regions in central Brazil. Field surveys used to validate model found the species at 17 sites, all located in the dry forests of the Paranã River Basin. Modeling results set boundaries for the analysis of loss and fragmentation of the species’ habitat. Satellite imagery and remote sensing techniques were used to estimate deforestation trends over a large spatiotemporal scale (31 years). Results indicated a 66.3% decrease in forest extent, average annual deforestation rate of 2.1% and significant increase in fragmentation, suggesting that these forests may disappear in less than 20 years if current deforestation rates persist. The habitat availability analysis set boundaries for the investigation of spatial arrangement of local populations of Pfrimer’s Parakeets, which was carried out by collecting information on abundance, densities estimates, species home range, and habitat use. Twenty individuals were monitored with radio transmitters and home range estimates averaged between 195.7 ha (fixed kernel) and 261.8 ha (minimum convex polygons). Habitat use was estimated with behavioral observations of birds flying through a mosaic of forests and pastures. I found no evidence that the species used open areas farther than 300m from the forest edge. Systematic line transects and observations of parakeets per time effort produced estimates of population densities at 11.7 individuals/km2; indicating strong variation in abundance indices among areas, suggesting a population decline. The Rapid Endangered Species Assessment represents a broad and integrative approach carried out over a short term and was successfully used to produce relevant data about a poorly known species. Thus, I propose the use of this approach as a minimally ideal yet scientifically viable method to generate information for extinction risk assessment of species. Title: Rapid endangered species assessment : a novel approach to improve extinction risk assessments in poorly known species Author: Bianchi, Carlos A. The number of endangered species is rapidly increasing while paucity of adequate information and resources delays establishment of conservation actions. The IUCN’s listing system is insufficient to determine conservation priorities and many species lack information even to be evaluated (i.e., “data deficient”). Here I proposed and tested the Rapid Endangered Species Assessment approach, combining methods including distribution modeling, landscape/habitat availability analysis and an evaluation of population spatial structure to improve information about species of concern and make future extinction risk assessments more attainable. I used the Pfrimer’s Parakeet (Pyrrhura pfrimeri) an endemic Brazilian species, as a case study. I modeled and validated the potential distribution of the species, known to occur in association with the tropical dry forests in central Brazil, using the Maxent method. The model predicted potential occurrence in three regions in central Brazil. Field surveys used to validate model found the species at 17 sites, all located in the dry forests of the Paranã River Basin. Modeling results set boundaries for the analysis of loss and fragmentation of the species’ habitat. Satellite imagery and remote sensing techniques were used to estimate deforestation trends over a large spatiotemporal scale (31 years). Results indicated a 66.3% decrease in forest extent, average annual deforestation rate of 2.1% and significant increase in fragmentation, suggesting that these forests may disappear in less than 20 years if current deforestation rates persist. The habitat availability analysis set boundaries for the investigation of spatial arrangement of local populations of Pfrimer’s Parakeets, which was carried out by collecting information on abundance, densities estimates, species home range, and habitat use. Twenty individuals were monitored with radio transmitters and home range estimates averaged between 195.7 ha (fixed kernel) and 261.8 ha (minimum convex polygons). Habitat use was estimated with behavioral observations of birds flying through a mosaic of forests and pastures. I found no evidence that the species used open areas farther than 300m from the forest edge. Systematic line transects and observations of parakeets per time effort produced estimates of population densities at 11.7 individuals/km2; indicating strong variation in abundance indices among areas, suggesting a population decline. The Rapid Endangered Species Assessment represents a broad and integrative approach carried out over a short term and was successfully used to produce relevant data about a poorly known species. Thus, I propose the use of this approach as a minimally ideal yet scientifically viable method to generate information for extinction risk assessment of species. Close

• 48. [Article] Marine bird colony and at-sea distributions along the Oregon coast: Implications for marine spatial planning and information gap analysis

  Increasingly diverse interests in commercial and recreational use of marine resources are creating new challenges for coastal ocean management. One concern of increased offshore use and development off ...

  Citation × Citation Citation Abstract Copy Title: Marine bird colony and at-sea distributions along the Oregon coast: Implications for marine spatial planning and information gap analysis Author: Lowe, Roy W., Suryan, Robert M., Phillips, Elizabeth M., Zamon, Jeannette E., So, Khemarith, Stephensen, Shawn W. Increasingly diverse interests in commercial and recreational use of marine resources are creating new challenges for coastal ocean management. One concern of increased offshore use and development off the Oregon coast is the potential impact on marine bird populations. We summarized the primary surveys of seabird breeding colonies and at-sea distribution along the Oregon coast to describe spatial patterns in species distribution and identify gaps where additional data are needed. The abundance of breeding birds during the summer (over 1 million in total, primarily Common Murre Uria aalge and Leach’s Storm-Petrel Oceanodroma leucorhoa) is greatest in northern and southern Oregon due to the availability of breeding habitat on large offshore rocks and islands. While there are fewer breeding colonies along sandy shorelines, the adjacent coastal waters are still frequented by breeding birds and nonbreeding migrants, but generally in lower densities during summer. Seabird density, and likely potential interaction with offshore structures, is greatest nearshore and steadily declines to lowest levels beyond the outer continental shelf. Dynamic soaring species, however, which have a greater potential to interact with taller structures such as wind turbines, tend to be more common on the middle to outer shelf. Species composition also changes dramatically among seasons. Low flying (< 30 m above sea level) diving species dominate in most seasons, however, which has potential conservation implications for interactions with structures above and below the water’s surface. Given the abundance of storm-petrels, increased light pollution is also a concern for these and other nocturnal, phototactic species. Dramatic declines or redistributions have occurred at some breeding colonies, indicating long-term planning should consider changing habitat requirements. The greatest data needs currently include fall/winter/spring at-sea distribution, summer distribution off southern Oregon, and more accurate estimates and monitoring of burrow-nesting seabirds. Oregon’s coastal waters provide habitat for a large portion of breeding and nonbreeding marine birds along the U.S. west coast and a thorough knowledge of their spatial distribution, seasonal abundance, and migration corridors is critical for well-informed marine spatial planning. Title: Marine bird colony and at-sea distributions along the Oregon coast: Implications for marine spatial planning and information gap analysis Author: Lowe, Roy W., Suryan, Robert M., Phillips, Elizabeth M., Zamon, Jeannette E., So, Khemarith, Stephensen, Shawn W. Increasingly diverse interests in commercial and recreational use of marine resources are creating new challenges for coastal ocean management. One concern of increased offshore use and development off the Oregon coast is the potential impact on marine bird populations. We summarized the primary surveys of seabird breeding colonies and at-sea distribution along the Oregon coast to describe spatial patterns in species distribution and identify gaps where additional data are needed. The abundance of breeding birds during the summer (over 1 million in total, primarily Common Murre Uria aalge and Leach’s Storm-Petrel Oceanodroma leucorhoa) is greatest in northern and southern Oregon due to the availability of breeding habitat on large offshore rocks and islands. While there are fewer breeding colonies along sandy shorelines, the adjacent coastal waters are still frequented by breeding birds and nonbreeding migrants, but generally in lower densities during summer. Seabird density, and likely potential interaction with offshore structures, is greatest nearshore and steadily declines to lowest levels beyond the outer continental shelf. Dynamic soaring species, however, which have a greater potential to interact with taller structures such as wind turbines, tend to be more common on the middle to outer shelf. Species composition also changes dramatically among seasons. Low flying (< 30 m above sea level) diving species dominate in most seasons, however, which has potential conservation implications for interactions with structures above and below the water’s surface. Given the abundance of storm-petrels, increased light pollution is also a concern for these and other nocturnal, phototactic species. Dramatic declines or redistributions have occurred at some breeding colonies, indicating long-term planning should consider changing habitat requirements. The greatest data needs currently include fall/winter/spring at-sea distribution, summer distribution off southern Oregon, and more accurate estimates and monitoring of burrow-nesting seabirds. Oregon’s coastal waters provide habitat for a large portion of breeding and nonbreeding marine birds along the U.S. west coast and a thorough knowledge of their spatial distribution, seasonal abundance, and migration corridors is critical for well-informed marine spatial planning. Close

• 49. [Article] Vegetation response following thinning in young Douglas-fir forests of western Oregon : can thinning accelerate development of late-successional structure and composition?

  Across western Oregon, Washington, and British Columbia, forest management practices over the past century reduced the amount of late-successional forest while simultaneously increasing the amount of young ...

  Citation × Citation Citation Abstract Copy Title: Vegetation response following thinning in young Douglas-fir forests of western Oregon : can thinning accelerate development of late-successional structure and composition? Author: Beggs, Liane R. Across western Oregon, Washington, and British Columbia, forest management practices over the past century reduced the amount of late-successional forest while simultaneously increasing the amount of young (less than 80 years old), managed Douglas-fir (Pseudotsuga menziesii) dominated forests. Recently, concerns over loss of late-successional habitat pushed management objectives on public lands away from timber production and toward maintenance and restoration of late-successional habitat. In accordance with these new objectives, The Young Stand Thinning and Diversity Study (YSTDS) was developed to test if thinning could accelerate development of latesuccessional habitat in young managed Douglas-fir forests. Though the YSTDS examines several components of forest ecosystems, the goal of this study was to investigate short-term (5-7 years post-treatment) responses of vegetation to thinning treatments and to evaluate this response in relation to long-term objectives of late-successional development. The study is located on the western slope of the central Oregon Cascades. It consists of four replications of four thinning treatments (treatment areas average 30 ha each) in 30-50 year old second-growth Douglas-fir forest stands. Treatments include a control, heavy thin, light thin, and light thin with gaps. Unlike traditional thinning, the thinning treatments in this study sought to maintain and enhance overstory structural diversity by: (1) retaining species other than Douglas-fir, (2) simulating low densities that characterized development of some old-growth stands, and (3) adding canopy gaps to enhance spatial diversity. Following treatment completion, first, third, and fifth-year vegetation responses were measured Results for overstory vegetation indicate that heavy thinning may accelerate development of large trees, one important component of old-growth structure. This was evident by faster growth of the largest trees in the heavy thin than in the control. A heavy thin may also permit more time for understory development than a lighter thin because canopies of heavy thinned stands remained open longer than canopies of light thinned stands. Variation in overstory cover, which may promote heterogeneous understory development, was higher in the treatment that included canopy gaps than in other treatments including the control. Although accelerated development of a multi-layered canopy was not evident in any treatment, retention of non-dominant tree species prevented simplification of vertical canopy structure by retaining layers that are typically removed by a low thinning prescription. In addition, mortality of non-dominant species was not greater in thinned treatments than in the control. In the understory, results suggest that thinning can increase abundance of some vegetative layers without encouraging homogenization of the understory by clonal shrubs or exotic species. The thinnings resulted in initial declines of bryophytes, tall shrubs, and low shrubs followed by subsequent recovery and growth. While herbs displayed little initial response, a release of early-seral species was evident by 5-7 years post-treatment. Initial changes following thinning were likely due to harvesting damage and/or alteration of microclimate while subsequent changes were probably also related to increased resource availability. It is expected that eventually similarities and differences in overstory structure among thinned treatments will be reflected in the understory. For example, variation in canopy cover created by the addition of canopy gaps was already reflected in the understory, as plant assemblages differed across the gradient from gaps to the thinned forest matrix. Hence, although understory vegetation was similar among heavy and light thins in the short-term, early closure of the canopy following a light thin could preclude continuation of late-seral understory development. Finally, the effect of canopy gaps on the understory was more apparent at a within-stand scale than at a stand scale. Had the within-stand scale been ignored, relevant information regarding understory response would have been overlooked. This indicates that spatial scale should be considered when assessing ecological patterns. In conclusion, it is acknowledged that there are drawbacks to thinning (e.g., certain species decline following thinning) It is also acknowledged that the short-term nature of the data permits only speculation regarding long-term succession. While these limitations are recognized, current trends indicate that a moderate to heavy thinning in combination with gap formation can hasten development of late-successional features in thinned stands relative to unthinned stands. Thus, thinning similar to that used in this study can be one useful tool in the management of young Douglas-fir forests. Title: Vegetation response following thinning in young Douglas-fir forests of western Oregon : can thinning accelerate development of late-successional structure and composition? Author: Beggs, Liane R. Across western Oregon, Washington, and British Columbia, forest management practices over the past century reduced the amount of late-successional forest while simultaneously increasing the amount of young (less than 80 years old), managed Douglas-fir (Pseudotsuga menziesii) dominated forests. Recently, concerns over loss of late-successional habitat pushed management objectives on public lands away from timber production and toward maintenance and restoration of late-successional habitat. In accordance with these new objectives, The Young Stand Thinning and Diversity Study (YSTDS) was developed to test if thinning could accelerate development of latesuccessional habitat in young managed Douglas-fir forests. Though the YSTDS examines several components of forest ecosystems, the goal of this study was to investigate short-term (5-7 years post-treatment) responses of vegetation to thinning treatments and to evaluate this response in relation to long-term objectives of late-successional development. The study is located on the western slope of the central Oregon Cascades. It consists of four replications of four thinning treatments (treatment areas average 30 ha each) in 30-50 year old second-growth Douglas-fir forest stands. Treatments include a control, heavy thin, light thin, and light thin with gaps. Unlike traditional thinning, the thinning treatments in this study sought to maintain and enhance overstory structural diversity by: (1) retaining species other than Douglas-fir, (2) simulating low densities that characterized development of some old-growth stands, and (3) adding canopy gaps to enhance spatial diversity. Following treatment completion, first, third, and fifth-year vegetation responses were measured Results for overstory vegetation indicate that heavy thinning may accelerate development of large trees, one important component of old-growth structure. This was evident by faster growth of the largest trees in the heavy thin than in the control. A heavy thin may also permit more time for understory development than a lighter thin because canopies of heavy thinned stands remained open longer than canopies of light thinned stands. Variation in overstory cover, which may promote heterogeneous understory development, was higher in the treatment that included canopy gaps than in other treatments including the control. Although accelerated development of a multi-layered canopy was not evident in any treatment, retention of non-dominant tree species prevented simplification of vertical canopy structure by retaining layers that are typically removed by a low thinning prescription. In addition, mortality of non-dominant species was not greater in thinned treatments than in the control. In the understory, results suggest that thinning can increase abundance of some vegetative layers without encouraging homogenization of the understory by clonal shrubs or exotic species. The thinnings resulted in initial declines of bryophytes, tall shrubs, and low shrubs followed by subsequent recovery and growth. While herbs displayed little initial response, a release of early-seral species was evident by 5-7 years post-treatment. Initial changes following thinning were likely due to harvesting damage and/or alteration of microclimate while subsequent changes were probably also related to increased resource availability. It is expected that eventually similarities and differences in overstory structure among thinned treatments will be reflected in the understory. For example, variation in canopy cover created by the addition of canopy gaps was already reflected in the understory, as plant assemblages differed across the gradient from gaps to the thinned forest matrix. Hence, although understory vegetation was similar among heavy and light thins in the short-term, early closure of the canopy following a light thin could preclude continuation of late-seral understory development. Finally, the effect of canopy gaps on the understory was more apparent at a within-stand scale than at a stand scale. Had the within-stand scale been ignored, relevant information regarding understory response would have been overlooked. This indicates that spatial scale should be considered when assessing ecological patterns. In conclusion, it is acknowledged that there are drawbacks to thinning (e.g., certain species decline following thinning) It is also acknowledged that the short-term nature of the data permits only speculation regarding long-term succession. While these limitations are recognized, current trends indicate that a moderate to heavy thinning in combination with gap formation can hasten development of late-successional features in thinned stands relative to unthinned stands. Thus, thinning similar to that used in this study can be one useful tool in the management of young Douglas-fir forests. Close

• 50. [Article] The influence of prescribed fire on the rare endemic plant Delphinium pavonaceum (Peacock larkspur)

  In the wetland prairie of William L. Finley National Wildlife Refuge (FNWR) in western Oregon, we investigated the response of Delphinium pavonaceum Ewan (peacock larkspur, Ranunculaceae), an endangered ...

  Citation × Citation Citation Abstract Copy Title: The influence of prescribed fire on the rare endemic plant Delphinium pavonaceum (Peacock larkspur) Author: McKernan, Brie-Anne In the wetland prairie of William L. Finley National Wildlife Refuge (FNWR) in western Oregon, we investigated the response of Delphinium pavonaceum Ewan (peacock larkspur, Ranunculaceae), an endangered perennial forb, to four unreplicated dormant season fire regimes of 0, 2, 4, or 10 fires that were applied over a 12-year period. Additionally, an unexpected removal of woody plants by refuge staff within some portions of our control area offered an unplanned opportunity for study. In 2002 we measured the density and vigor of reproductive plants, and performed seed germination trials. In 2003 we repeated previous field measurements, sampled immature plant density, and recorded observations of the insects visiting D. pavonaceum in burned and unburned habitats. We hypothesized that this rare endemic species and its insect visitors would respond positively to prescribed burning or the removal of woody species. Low seedling density was found in the unburned and hand-removal areas, likely due to interference from litter and/or taller, shading plants. We also found low seedling density in sites burned the previous year, implying that fire consumes or damages unprotected seeds in the litter layer or exposed on the soil surface. Seedling density was greater in a site burned three seasons previously, suggesting that fire ultimately leads to the enhancement of seedling density following the replenishment of the seed bank. The largest density of recruits was detected in a subunit recently returned to fire management in 1999, and also burned in 2002 following our first field season. However, the other, more-frequently burned sites did not exhibit an increased density of recruits, possibly due to a reduction of the seed bank following repeated bums, and increased intraspecific competition with mature plants. The elevated density of seedlings and recruits we observed in some burned areas may lead to population growth, as we observed a greater density of reproductive plants in the two most-frequently burned subunits during both years of study. Our results also suggest that fewer plants enter summer dormancy in burned areas, and that increases in flowering plant density may decline after 3 years. Plants in the burned and hand-removal sites were shorter, likely resulting from water stress following the removal of shading plants and litter. Additionally, plants in unburned areas might have experienced greater stem elongation due to competition with tall and dense vegetation. Plants in the burned and hand-removal areas were generally similar to the unburned control site for flower and fruit production, fruit set, seed production and seed mass. However, plants in the burned and hand-removal areas produced more flowers per centimeter of height, indicating that they allocated more energy to reproduction than plants in the unburned area. We suggest that the decreased productivity we observed in some vigor traits is not problematic to D. pavonaceum conservation goals and may be ameliorated after 3 years. Bombus ca1ifornicus, B. appositus, and several large moths were the only insects we observed visiting D. pavonaceum during the two years of this study. We did not detect a difference in bumblebee abundance between a frequently burned and unburned study plot during the peak flowering time of D. pavonaceum. However, our small sample size requires that this result be cautiously interpreted and further studied, as it is possible that our visitation data would change appreciably with a broader range of observations. Our results indicate that the current FNWR fire management plan is not in conflict with D. pavonaceum conservation. The choice of fire-return interval seems to influence D. pavonaceum populations and plant vigor, but because the fire-schedule at FNWR was altered in 1997, our ability to recommend an appropriate fire-regime for this species is limited. Although not directly investigated, we suggest that annual fires, when applied for more than five consecutive years, might lead to population declines for this species because fire appears to consume the seed bank and reduce seedling density. If annual fires are returned to FNWR, the potential for this undesirable result should be investigated for at least 10 years by population monitoring. Title: The influence of prescribed fire on the rare endemic plant Delphinium pavonaceum (Peacock larkspur) Author: McKernan, Brie-Anne In the wetland prairie of William L. Finley National Wildlife Refuge (FNWR) in western Oregon, we investigated the response of Delphinium pavonaceum Ewan (peacock larkspur, Ranunculaceae), an endangered perennial forb, to four unreplicated dormant season fire regimes of 0, 2, 4, or 10 fires that were applied over a 12-year period. Additionally, an unexpected removal of woody plants by refuge staff within some portions of our control area offered an unplanned opportunity for study. In 2002 we measured the density and vigor of reproductive plants, and performed seed germination trials. In 2003 we repeated previous field measurements, sampled immature plant density, and recorded observations of the insects visiting D. pavonaceum in burned and unburned habitats. We hypothesized that this rare endemic species and its insect visitors would respond positively to prescribed burning or the removal of woody species. Low seedling density was found in the unburned and hand-removal areas, likely due to interference from litter and/or taller, shading plants. We also found low seedling density in sites burned the previous year, implying that fire consumes or damages unprotected seeds in the litter layer or exposed on the soil surface. Seedling density was greater in a site burned three seasons previously, suggesting that fire ultimately leads to the enhancement of seedling density following the replenishment of the seed bank. The largest density of recruits was detected in a subunit recently returned to fire management in 1999, and also burned in 2002 following our first field season. However, the other, more-frequently burned sites did not exhibit an increased density of recruits, possibly due to a reduction of the seed bank following repeated bums, and increased intraspecific competition with mature plants. The elevated density of seedlings and recruits we observed in some burned areas may lead to population growth, as we observed a greater density of reproductive plants in the two most-frequently burned subunits during both years of study. Our results also suggest that fewer plants enter summer dormancy in burned areas, and that increases in flowering plant density may decline after 3 years. Plants in the burned and hand-removal sites were shorter, likely resulting from water stress following the removal of shading plants and litter. Additionally, plants in unburned areas might have experienced greater stem elongation due to competition with tall and dense vegetation. Plants in the burned and hand-removal areas were generally similar to the unburned control site for flower and fruit production, fruit set, seed production and seed mass. However, plants in the burned and hand-removal areas produced more flowers per centimeter of height, indicating that they allocated more energy to reproduction than plants in the unburned area. We suggest that the decreased productivity we observed in some vigor traits is not problematic to D. pavonaceum conservation goals and may be ameliorated after 3 years. Bombus ca1ifornicus, B. appositus, and several large moths were the only insects we observed visiting D. pavonaceum during the two years of this study. We did not detect a difference in bumblebee abundance between a frequently burned and unburned study plot during the peak flowering time of D. pavonaceum. However, our small sample size requires that this result be cautiously interpreted and further studied, as it is possible that our visitation data would change appreciably with a broader range of observations. Our results indicate that the current FNWR fire management plan is not in conflict with D. pavonaceum conservation. The choice of fire-return interval seems to influence D. pavonaceum populations and plant vigor, but because the fire-schedule at FNWR was altered in 1997, our ability to recommend an appropriate fire-regime for this species is limited. Although not directly investigated, we suggest that annual fires, when applied for more than five consecutive years, might lead to population declines for this species because fire appears to consume the seed bank and reduce seedling density. If annual fires are returned to FNWR, the potential for this undesirable result should be investigated for at least 10 years by population monitoring. Close