PDF(Pubmed)
Abstract：
Extensive distribution of widespread species and the loss of native species driven by anthropogenic disturbances modify community similarity, resulting in a decrease or increase in community distinctiveness. Data from four basins in the Wannan Mountains, China, were used to evaluate the effects of low-head dams on patterns of fish faunal homogenization and differentiation based on abundance data. We aimed to examine the spatial changes in taxonomic and functional similarities of fish assemblages driven by low-head dams and to examine whether the changes in the similarity of fish assemblages differed between taxonomic and functional components. We found that low-head dams significantly decreased the mean taxonomic similarity but increased the mean functional similarity of fish assemblages in impoundments using abundance-based approaches, suggesting that taxonomic differentiation accompanied functional homogenization in stream fish assemblages. These results show the importance of population abundance in structuring fish faunal homogenization and differentiation at small scales, especially when the major differences among assemblages are in species abundance ranks rather than species identities. Additionally, we also found only a weak positive correlation between changes in mean taxonomic and functional similarities, and partial pairs exhibited considerable variation in patterns of fish faunal homogenization and differentiation for taxonomic and functional components. In conclusion, this study highlighted that the observed taxonomic differentiation of current fish assemblages (short-term phenomenon) is probably an early warning sign of further homogenization in regions where native species are completely predominated and that changes in taxonomic similarity cannot be used to predict changes in functional similarity.
摘要：
广泛物种的广泛分布和人为干扰导致的本地物种的流失改变了群落的相似性，导致社区独特性的减少或增加。来自皖南山四个盆地的数据，中国,基于丰度数据，用于评估低水坝对鱼类动物区系均质化和分化模式的影响。我们旨在研究由低头水坝驱动的鱼类组合的分类学和功能相似性的空间变化，并研究鱼类组合的相似性变化是否在分类学和功能成分之间有所不同。我们发现，使用基于丰度的方法，低头水坝显着降低了平均分类学相似性，但增加了蓄水池中鱼类组合的平均功能相似性，表明在溪流鱼类组合中，分类学分化伴随着功能均质化。这些结果表明，种群丰度在小规模构建鱼类动物区系均质化和分化中的重要性，尤其是当组合之间的主要差异在于物种丰度等级而不是物种身份时。此外,我们还发现平均分类和功能相似性的变化之间只有微弱的正相关，和部分对在鱼类动物区系均质化和分类和功能成分分化的模式上表现出相当大的差异。总之,这项研究强调，观察到的当前鱼类组合的分类学差异（短期现象）可能是本地物种完全占主导地位的地区进一步同质化的预警信号，并且分类学相似性的变化不能用于预测功能相似性的变化。
