Data from: Effects of dispersal mode on the environmental and spatial correlates of nestedness and species turnover in pond communities

Advances in metacommunity theory have made a significant contribution to understanding the drivers of variation in biological communities. However, there has been limited empirical research exploring the expression of metacommunity theory for two fundamental components of beta diversity: nestedness and species turnover. In this paper, we examine the influence of local environmental and a range of spatial variables (hydrological connectivity, proximity and overall spatial structure) on total beta diversity and the nestedness and turnover components of beta diversity for the entire macroinvertebrate community and active and passively dispersing taxa within pond habitats. High beta diversity almost entirely reflects patterns of species turnover (replacement) rather than nestedness (differences in species richness) in our dataset. Local environmental variables were the main drivers of total beta diversity, nestedness and turnover when the entire community was considered and for both active and passively dispersing taxa. The influence of spatial processes on passively dispersing composition, total beta diversity and nestedness was significantly greater than for actively dispersing taxa. Our results suggest that species sorting (local environmental variables) operating through niche processes was the primary mechanism driving total beta diversity, nestedness and turnover for the entire community and active and passively dispersing taxa. In contrast, spatial factors (hydrological connectivity, proximity and spatial eigenvectors) only exerted a secondary influence on the nestedness and turnover components of beta diversity.

集合群落理论（metacommunity theory）的发展，为解析生物群落变异的驱动机制提供了重要支撑。然而，针对β多样性（beta diversity）的两个核心组分——嵌套性（nestedness）与物种周转（species turnover），探索集合群落理论具体表达模式的实证研究仍较为匮乏。本研究聚焦池塘生境中的大型底栖无脊椎动物（macroinvertebrate）群落，分别针对整体群落、主动扩散类群与被动扩散类群，解析局域环境因子及一系列空间变量（水文连通性、空间邻近性与整体空间结构）对总β多样性，以及β多样性的嵌套性与周转组分的影响。本数据集显示，较高的β多样性几乎完全由物种周转（物种替代）模式主导，而非嵌套性（物种丰富度差异）。针对整体群落、主动扩散类群与被动扩散类群而言，局域环境因子均是总β多样性、嵌套性与周转组分的主要驱动因素。空间过程对被动扩散类群的群落组成、总β多样性与嵌套性的影响，显著强于对主动扩散类群的影响。研究结果表明，基于生态位过程、由局域环境因子介导的物种分选，是调控整体群落、主动扩散类群与被动扩散类群的总β多样性、嵌套性与周转组分的核心机制。与之相对，空间因子（水文连通性、空间邻近性与空间特征向量（spatial eigenvectors））仅对β多样性的嵌套性与周转组分起到次要调控作用。