Historical climatic variability and geographical barriers as drivers of community composition in a biodiversity hotspot

Aim: To evaluate the roles of Quaternary (&lt; 2.6 Ma) climatic stability and geologic barriers (i.e. the Andes Mountains) in shaping the modern community composition and patterns of endemism in Neotropical dry forest bird communities. Location: Marañón Valley and Tumbes, north-western Peru. Methods: We recorded presence and abundance of species in six dry forest bird communities on either side of the Andes Mountains. We used the data to calculate the beta diversity and phylogenetic beta diversity across regional and local scales. We compared the observed results to randomly permuted communities to determine if the communities were significantly more or less similar than we would expect by chance. Mantel tests evaluated whether beta diversity and phylogenetic beta diversity measures were correlated and whether there was a correlation between spatial distance and community diversity. Results: Bird community composition, including abundance, is highly heterogeneous in north-western Peru, ...研究目的：评估第四纪（Quaternary，<2.6 Ma）气候稳定性与地质屏障（即安第斯山脉（Andes Mountains））在塑造新热带干燥森林鸟类群落（Neotropical dry forest bird communities）现代组成与特有性（endemism）格局中的作用。研究区域：秘鲁西北部的马拉尼翁河谷（Marañón Valley）与通贝斯（Tumbes）。研究方法：我们在安第斯山脉两侧的六个干燥森林鸟类群落中记录了物种的存在与多度情况；利用所得数据计算了区域及局域尺度下的β多样性（beta diversity）与系统发育β多样性（phylogenetic beta diversity）；将观测结果与随机置换的群落进行对比，以判断群落相似性是否显著偏离随机预期；通过曼特尔检验（Mantel tests）评估β多样性与系统发育β多样性的相关性，以及空间距离与群落多样性之间是否存在关联。研究结果：秘鲁西北部的鸟类群落组成（包括物种多度）呈现高度异质性，...