Seasonal dynamics of waterbird assembly mechanisms revealed by phylogenetic and functional diversity in a subtropical wetland

Despite growing interest in phylogenetic and functional methods in ecological assembly, less attention has been paid to seasonal variation patterns of migrant species. Migrants can rapidly mediate influences of species interactions and environmental factors through seasonal movement, suggesting dynamical relative importance of different assembly mechanisms among seasons. Here we describe seasonal dynamics in phylogenetic and functional diversity of waterbirds in Mai Po Wetland, in a subtropical region with significant predictable temporal variation. Phylogenetic and functional structure of α diversity varied seasonally. Specifically, phylogenetic structures clustered in summer, while being over-dispersed in winter. However, phylogenetic structure in spring and autumn was intermediate with a transition to random. Functional structure was clustered in spring but showed over-dispersion in the other three seasons. For β diversity, summer and winter assemblages had two distinct groups, while...尽管当前学界对生态群落组装（ecological assembly）中的系统发育（phylogenetic）与功能方法的关注度与日俱增，但针对迁徙物种季节变化模式的研究却相对匮乏。迁徙物种可通过季节性迁徙快速介导物种相互作用与环境因子的影响效应，这表明不同群落组装机制的相对重要性会随季节发生动态变化。本研究针对位于亚热带、具有显著可预测时间变异特征的米埔湿地（Mai Po Wetland）内的水鸟群落，阐述其系统发育多样性与功能多样性的季节动态特征。α多样性（α diversity）的系统发育结构与功能结构均存在季节差异：具体而言，系统发育结构在夏季呈聚集状态，冬季则呈过度分散状态；春季与秋季的系统发育结构则处于中间水平，呈现向随机状态过渡的特征。功能结构在春季呈聚集状态，但在其余三个季节均表现为过度分散。就β多样性（β diversity）而言，夏季与冬季的群落样方可划分为两个截然不同的类群，而……