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首页> 外文学位 >Fish fauna homogenization of the United States, life-history correlates of native extinctions and non-native invasions in the American Southwest, and the bi-directional impacts of dams in the American Southeast.
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Fish fauna homogenization of the United States, life-history correlates of native extinctions and non-native invasions in the American Southwest, and the bi-directional impacts of dams in the American Southeast.

机译：美国的鱼类动物同质化，美洲西南部自然灭绝和非本地入侵的生活史相关性以及美国东南部大坝的双向影响。

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摘要

The conservation of biodiversity and preservation of biological integrity are at the forefront of scientific thought and research. An important aspect of the current biodiversity crisis is the manner by which the compositions of biological communities are changing in time and space, and the specific mechanisms responsible for these changes.; In the first section of my doctoral dissertation I explore the process of biotic homogenization, by which formerly-distinct native communities become more similar as a result of native species extinctions and the establishment of cosmopolitan, nonnative species. I identify three forms of homogenization (genetic, taxonomic and functional) and explore the immediate and future impacts of each on ecological and evolutionary processes. Next, I present a conceptual model that describes a number of potential scenarios by which species invasions and/or extinctions can lead to various trajectories of biotic homogenization or differentiation (i.e., decreased community similarity). I use a simulation approach to explore the model's predictions and then validate the model using empirical data for freshwater fish faunas in the United States at three spatial scales: the entire continent, zoogeographic provinces in California, and watersheds within these provinces.; In the second section of my doctoral dissertation I examine the fish faunas of the Colorado River Basin, where environmental degradation and the proliferation of non-native fish species threaten the endemic, native faunas, making them especially susceptible to biotic homogenization. Using fish occurrence data for the past 160 years I quantify long-term changes in fish distributions and use a comprehensive suite of morphological, behavioural, physiological and life-history traits to identify specific life-histories strategies that are associated with the greatest loss of native species and spread of non-native species.; In the third section of my doctoral dissertation I report on research conducted in the Upper James River Basin that considers one of the primary causes of native extirpations and non-native introductions in aquatic systems; namely the regulation of rivers by dams and diversions. Specifically, I examine how environmental disturbance gradients that occur below a flood-control dam structure (i.e., altered flow regime, water temperatures, substrate composition, and macroinvertebrate biomass) influence the structure of downstream fish assemblages.
机译：保护生物多样性和保护生物完整性处于科学思想和研究的最前沿。当前生物多样性危机的一个重要方面是生物群落组成随时间和空间变化的方式以及造成这些变化的具体机制。在我的博士论文的第一部分中，我探讨了生物同质化的过程，由于原种的灭绝和世界性非本地物种的建立，原先与众不同的本土社区变得更加相似。我确定了同质化的三种形式（遗传，分类和功能），并探讨了每种同质化对生态和进化过程的直接和未来影响。接下来，我提出一个概念模型，该模型描述了物种入侵和/或灭绝可能导致生物同质化或分化的各种轨迹（即降低的社区相似性）的许多潜在情况。我使用一种模拟方法来探索模型的预测，然后使用经验数据对美国淡水鱼类动物群在三个空间尺度上进行验证：整个大陆，加利福尼亚的动物地理省以及这些省内的分水岭。在我的博士论文的第二部分中，我研究了科罗拉多河流域的鱼类动物群，那里的环境退化和非本地鱼类物种的扩散威胁着当地特有的动物群，使其特别容易受到生物同质化的影响。利用过去160年的鱼类发生数据，我对鱼类分布的长期变化进行了量化，并使用了一整套形态，行为，生理和生活史特征，以识别与原生动物损失最大相关的特定生活史策略物种和非本地物种的传播。在我的博士论文的第三部分中，我报告了在上詹姆士河流域进行的研究，该研究考虑了水生系统本地灭绝和非本地引进的主要原因之一。即通过水坝和引水来调节河流。具体来说，我研究了防洪大坝结构（即流态，水温，基质组成和无脊椎动物生物量的变化）下的环境扰动梯度如何影响下游鱼群的结构。

著录项

  • 作者

    Olden, Julian David.;

  • 作者单位

    Colorado State University.;

  • 授予单位 Colorado State University.;
  • 学科 Biology Ecology.; Agriculture Fisheries and Aquaculture.
  • 学位 Ph.D.
  • 年度 2004
  • 页码 324 p.
  • 总页数 324
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 生态学（生物生态学）;水产、渔业;
  • 关键词

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