Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
Anthropogenic impacts on the landscape can drive biotic homogenization whereby distinct biological communities become more similar to one another over time. Land-use change in the Southern Appalachian region of the United States is expected to result in homogenization of the highly diverse freshwater fish communities as in-stream habitat alterations favor widespread cosmopolitan species at the expense of more narrowly distributed highland endemic species. We compiled four datasets spanning 25 years to (1) evaluate the effects of environmental factors on relative abundance and richness of highland endemic vs. cosmopolitan species in this region and (2) test for taxonomic homogenization, measured as a change in beta diversity over time. We found that several environmental factors differentially affected highland endemic and cosmopolitan species, with the proportion of forested land cover in a watershed most strongly predicting higher relative abundance and richness of highland endemic species. Our analysis of beta diversity change, however, shows mixed evidence of taxonomic homogenization, depending on how common species are weighted. Shifts in community composition, with or without homogenization, may warrant attention in biodiversity conservation planning.

中文翻译：

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南阿巴拉契亚鱼类群落生物同质化的混合证据

加拿大渔业和水产科学杂志，提前印刷。
人为对景观的影响可以推动生物同质化，随着时间的推移，不同的生物群落变得更加相似。美国南部阿巴拉契亚地区的土地利用变化预计将导致高度多样化的淡水鱼类群落的同质化，因为河内栖息地的改变有利于广泛的世界性物种，而牺牲了分布更窄的高地特有物种。我们编制了跨越 25 年的四个数据集，以 (1) 评估环境因素对该地区高地特有物种与世界性物种的相对丰度和丰富度的影响，以及 (2) 测试分类同质化，测量为β多样性随时间的变化. 我们发现几个环境因素对高原地方性和世界性物种的影响不同，流域内林地覆盖的比例最强烈地预测了高地特有物种的相对丰度和丰富度。然而，我们对 beta 多样性变化的分析显示了分类同质化的混合证据，这取决于常见物种的加权方式。群落组成的变化，无论是否同质化，都可能需要关注生物多样性保护规划。