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• 21. [Article] Avian population trends within the evolving agricultural landscape of the eastern and central United States

  State-level Breeding Bird Survey (1980-1998) and U.S. Department of Agriculture statistics were used to test the hypothesis that changes in agricultural land use within the eastern and central U.S. have ...

  Citation × Citation Citation Abstract Copy Title: Avian population trends within the evolving agricultural landscape of the eastern and central United States Author: Murphy, Michael T. Year: 2003 State-level Breeding Bird Survey (1980-1998) and U.S. Department of Agriculture statistics were used to test the hypothesis that changes in agricultural land use within the eastern and central U.S. have driven population trends of grassland and shrub habitat birds over the past two decades. The degree to which population trends differed between grassland and shrub habitats was evaluated with respect to migratory and nesting behavior. Grassland birds declined significantly between 1980 and 1999, but, on average, shrub habitat species did not. Grassland-breeding, long-distance migrants exhibited the strongest negative trends. Most species (78%; n = 63) exhibited at least one significant association between population trends and changes in agricultural land use, and in most, land use "explained" 25-30% of the variation in population trends among states. Changes in the farmland landscape accounted for more of the interstate variability of population trends of short-distance migrants than of both long-distance migrants and residents, and that variability was greater in grassland than shrub species. Declines in the area of rangeland and cover crops were followed by population declines and increases, respectively, by many species. Increases of land in the Conservation Reserve Program had negative associations with population trends of some shrub species. The results indicate that grassland birds have declined strongly over the past two decades, and that regardless of migratory behavior or nesting habits, avian population trends are linked strongly to changes in agricultural land use within North America. Title: Avian population trends within the evolving agricultural landscape of the eastern and central United States Author: Murphy, Michael T. Year: 2003 State-level Breeding Bird Survey (1980-1998) and U.S. Department of Agriculture statistics were used to test the hypothesis that changes in agricultural land use within the eastern and central U.S. have driven population trends of grassland and shrub habitat birds over the past two decades. The degree to which population trends differed between grassland and shrub habitats was evaluated with respect to migratory and nesting behavior. Grassland birds declined significantly between 1980 and 1999, but, on average, shrub habitat species did not. Grassland-breeding, long-distance migrants exhibited the strongest negative trends. Most species (78%; n = 63) exhibited at least one significant association between population trends and changes in agricultural land use, and in most, land use "explained" 25-30% of the variation in population trends among states. Changes in the farmland landscape accounted for more of the interstate variability of population trends of short-distance migrants than of both long-distance migrants and residents, and that variability was greater in grassland than shrub species. Declines in the area of rangeland and cover crops were followed by population declines and increases, respectively, by many species. Increases of land in the Conservation Reserve Program had negative associations with population trends of some shrub species. The results indicate that grassland birds have declined strongly over the past two decades, and that regardless of migratory behavior or nesting habits, avian population trends are linked strongly to changes in agricultural land use within North America. Close

• 22. [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

• 23. [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

• 24. [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

• 25. [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

• 26. [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

• 27. [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

• 28. [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

• 29. [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

• 30. [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

• 31. [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

• 32. [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

• 33. [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

• 34. [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

• 35. [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

• 36. [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

• 37. [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

• 38. [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

• 39. [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

• 40. [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