Partitioning beta diversity to untangle mechanisms underlying the assembly of bird communities in Mediterranean olive groves

Aim: We investigated taxonomic and functional beta diversity of bird communities inhabiting Mediterranean olive groves subject to either intensive or extensive management of the ground cover and located in landscapes with different degrees of complexity. Location: Andalusia, southern Spain. Methods: We partitioned taxonomic and functional beta diversity into its two additive components, turnover and nestedness. We also explored the contributions of single sites to overall beta diversity (LCBD) and separated the effects of species replacement (turnover) and richness difference (nestedness) in order to identify ecologically unique sites -keystone communities- within the metacommunity. In a further step, we employed abundance- and functional-based indicator species analyses to characterize bird assemblages. Results: Taxonomic beta diversity increased with landscape complexity. Although both taxonomic and functional differences among assemblages were driven mainly by species repla...研究目的：本研究针对地表覆盖采用集约化或粗放化经营模式、且所处景观复杂程度各异的地中海橄榄林内的鸟类群落，解析其分类学与功能β多样性。 研究区域：西班牙南部安达卢西亚（Andalusia）地区。 研究方法：本研究将分类学与功能β多样性拆分为周转（turnover）与嵌套性（nestedness）两个加性组分；同时探究单个样地对整体β多样性的贡献度（Local Contribution to Beta Diversity，LCBD），并区分物种替换（周转）与物种丰富度差异（嵌套性）的效应，以在集合群落（metacommunity）中识别具有生态独特性的样地——关键群落（keystone communities）。后续研究中，本研究采用基于多度与功能性状的指示物种分析方法，对鸟类群落组合进行特征表征。 研究结果：分类学β多样性随景观复杂程度提升而升高。尽管类群间的分类学与功能学差异主要由物种替换驱动，但……