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Filtering by: Creator Blaustein, Andrew R. Remove constraint Creator: Blaustein, Andrew R. Degree Name Doctor of Philosophy (Ph.D.) Remove constraint Degree Name: Doctor of Philosophy (Ph.D.)

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  • The effects of pathogens, UV-B radiation, and introduced species on amphibians in the Pacific Northwest

    Creator:
    Kiesecker, Joseph Michael
    Abstract:
    I examined two amphibian communities to assess factors that may impact amphibian biodiversity. The results suggest that the potential factors which influence the maintenance of amphibian biodiversity are multi-faceted and thus, attempts to understand these factors must reflect these complexities. I investigated factors that influenced the susceptibility of western toad...
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    Dissertation
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    approved: Andrew R. Blaustein I examined two amphibian communities to assess factors that may

  • The effects of multiple pathogens on amphibians in the Pacific Northwest

    Creator:
    Romansic, John M.
    Abstract:
    The earth is undergoing a “biodiversity crisis” characterized by loss of populations, species, genetic diversity, and ecosystem services. Part of this crisis consists of population declines, extinctions, and increased incidence of deformities in amphibians. It is unknown whether deformities contribute to these declines. Many cases of population declines in amphibians...
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    Dissertation
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    : ________________________________________________________ Andrew R. Blaustein The earth is undergoing a “biodiversity crisis” characterized by

  • Ecological aspects of kin discriminating behavior with implications of functional value

    Creator:
    Hokit, D. Grant
    Abstract:
    To assess the context dependence of kin discriminating behavior, I examined kin-biased aggregation behavior in tadpoles of R. cascadae in different ecological conditions. I manipulated food distribution, predator presence, thermal heterogeneity, and relatedness in a multifactorial mesocosm experiment. All four factors interacted to influence tadpole dispersion. My results suggest that...
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    Dissertation
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    Behavior With Implications of Functional Value Abstract approved: Andrew R. Blaustein To assess the

  • The effects of an emerging pathogen on amphibian host behaviors and interactions

    Creator:
    Han, Barbara A.
    Abstract:
    Contemporary environmental change encompasses massive biodiversity loss and increasing numbers of emerging diseases worldwide. As part of a global biodiversity crisis, amphibians are disappearing at unprecedented rates. Batrachochytrium dendrobatidis is an emerging infectious pathogen prominently associated with many declines. Chapter 1 reviews the past decade of research on this system...
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    Dissertation
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    . Abstract approved: Andrew R. Blaustein Contemporary environmental change encompasses massive

  • Multiple stressors and amphibian population declines

    Creator:
    Hatch, Audrey C.
    Abstract:
    In the past decade, declines in amphibian populations have captured scientific and popular interest. The causes of the declines are likely to be complex and involve interactions between several environmental stressors. Using multifactorial experiments, I investigated the combined effects of several anthropogenic stressors on developing amphibians in Oregon, USA. In...
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    ACKNOWLEDGEMENTS My major professor, Dr. Andrew R. Blaustein, has been exceptionally supportive personally and

  • Ultraviolet radiation as an environmental stressor of amphibians

    Creator:
    Bancroft, Betsy A.
    Abstract:
    My thesis explored the effects of and potential mediating mechanisms for an important environmental stressor, ultraviolet-B (UVB) radiation. UVB radiation has negative effects on organisms in both terrestrial and aquatic systems. I used meta-analysis to quantify the effects of UVB radiation on a diversity of aquatic organisms (Chapter 2). UVB...
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    Abstract approved: Andrew R. Blaustein My thesis explored the effects of and potential mediating

  • Indirect effects of ultraviolet-B radiation on larval amphibians as mediated by food quality and trophic interactions

    Creator:
    Scheessele, Erin A.
    Abstract:
    Ultraviolet-B radiation (UVB) is an abiotic stressor in both terrestrial and aquatic systems. The stratospheric ozone layer, depleted due to anthropogenic activities and the cause of elevated UVB at earth's surface over the last four decades, is predicted to recover by 2065. However, UVB levels in aquatic systems may continue...
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    Dissertation
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    Food Quality and Trophic Interactions Abstract approved: Andrew R. Blaustein

  • The Effects of Host and Pathogen Variation on Infection Dynamics in the Amphibian-Chytrid System

    Creator:
    Dang, Trang D.
    Abstract:
    This dissertation uses manipulative experiments to explore amphibian-Bd infection dynamics. Although there has been almost two decades research since the discovery of Bd, many questions still remain regarding what conditions mediate chytridiomycosis virulence. My research shows how certain host and pathogen factors can influence disease virulence. Identifying how host and...
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    Dissertation
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    : ______________________________________________________ Andrew R. Blaustein This dissertation uses manipulative experiments to explore

  • Effects of Diversity on Emerging Infectious Diseases of Amphibians

    Creator:
    Snyder, Paul W.
    Abstract:
    Species declines and extinctions have been recorded across taxa as evidence of an ongoing global biodiversity crisis. Amphibians are at the forefront of these declines with nearly one third of amphibian species estimated to be at risk of extinction. While many factors contribute to population declines and extinctions, the role...
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    Dissertation
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    : ______________________________________________________ Andrew R. Blaustein Species declines and extinctions have been recorded across taxa

  • Environmental influences on host-pathogen dynamics of the amphibian chytrid fungus

    Creator:
    Buck, Julia C.
    Abstract:
    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...
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    Dissertation
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    : _____________________________________________________________________ Andrew R. Blaustein The causes of the global biodiversity crisis are varied and complex