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（metacommunities）内的生境间变异（即β多样性（beta diversity））通常与各生境间的空间距离（空间滞后（spatial lag））相关。这种相似性随距离衰减的分布格局，已被证实与基于生态位（niche-based）和基于扩散（dispersal-based）的两类群落组装假说均存在关联。本研究表明，若辅以功能性状（functional trait）信息，群落组成的β多样性格局可用于诊断群落组装过程。首先，我们通过模拟数据展示了：群落组成的分类学与功能学度量指标的距离衰减格局之间的关联，可如何用于预测某一特定性状对群落组装的影响程度。随后，我们以模拟生成的格局作为参照模板，证明了源头溪流（headwater streams）中的底栖大型无脊椎动物（benthic macroinvertebrate）集合群落，其组装过程在区域与局域尺度上，可能受到不同功能性状组合的调控。我们提出，可结合功能性状数据库与带空间参考信息的分类学调查，来预测种间功能变异的不同维度参与基于生态位的群落组装的空间尺度，同时考量基于扩散的群落组装过程的影响。