Data from: The assembly of ecological communities inferred from taxonomic and functional composition

Among-site variation in metacommunities (beta diversity) is typically correlated with the distance separating the sites (spatial lag). This distance decay in similarity pattern has been linked to both niche-based and dispersal-based community assembly hypotheses. Here we show that beta diversity patterns in community composition, when supplemented with functional-trait information, can be used to diagnose assembly processes. First, using simulated data, we show how the relationship between distance decay patterns in taxonomic and functional measures of community composition can be used to predict the influence of a given trait on community assembly. We then use the patterns generated by the simulation as a template to show that the sorting of benthic macroinvertebrate metacommunities in headwater streams is likely influenced by different sets of functional traits at regional and local scales. We suggest that functional-trait databases and spatially referenced taxonomic surveys can be used to predict the spatial scales at which different aspects of interspecific functional variation are involved in niche-based community assembly while accounting for the influence of dispersal-based community assembly processes.集合群落（metacommunity）的位点间变异（β多样性（beta diversity））通常与位点间的分隔距离（空间滞后（spatial lag））存在相关关系。这一相似性距离衰减模式，已被证实与基于生态位和基于扩散的两类群落构建假说均存在关联。本研究表明，结合功能性状（functional trait）信息后，群落组成的β多样性模式可用于诊断群落构建过程。首先，我们通过模拟数据证实，群落组成的分类学与功能学测度的距离衰减模式之间的关联，可用于预测某一特定性状对群落构建的影响。随后，我们以模拟生成的模式作为参照模板，证明源头溪流中的底栖大型无脊椎动物集合群落的环境筛选过程，在区域与局域尺度上，可能受到不同类别的功能性状的影响。本研究提出，可借助功能性状数据库与空间参考分类学调查，预测种间功能变异的不同维度参与基于生态位的群落构建的空间尺度，同时兼顾基于扩散的群落构建过程的影响。