Data from a flexible framework to assess patterns and drivers of beta diversity across spatial scales

The patterns and underlying ecological (e.g., environmental filtering) and historical (e.g., priority effects) drivers of beta diversity are scale-dependent but generally difficult to distinguish and rarely explored with a sufficiently broad range of spatial scales. We propose a general scale-explicit framework to assess and contrast the patterns and drivers of beta diversity across hierarchical spatial scales ranging from within fine-scale ecoregion-scale to among broad-scale ecoregion-scale. By applying this framework to aquatic macroinvertebrate datasets, we show that beta diversity generally increases with spatial extent. With an increasing spatial extent, beta diversity shifts from being more influenced by environmental filtering to being more influenced by recent historical factors (i.e., past beta diversity). Such recent historical effects may result from past environmental variation rather than priority effects. We also found that the small-scale and large-scale environmental drivers act differently on beta diversity across spatial extents. Our research reveals a complex spatial-scale dependence in beta diversity patterns and their drivers and provides a more holistic understanding of beta diversity dynamics. Our framework represents a flexible way to unravel the internal structure of beta diversity across scales by partitioning of entire beta diversity variation into scale-specific differences and may have broad application in community ecology, landscape planning and biodiversity conservation.

β多样性（beta diversity）的格局及其潜在生态学驱动因子（如环境过滤（environmental filtering））与历史驱动因子（如优先效应（priority effects））具有尺度依赖性，但通常难以区分，且极少在足够广泛的空间尺度范围内开展相关研究。本研究提出一套通用的尺度显性框架，用于评估并对比从精细尺度生态区内到跨大尺度生态区的层级空间尺度（hierarchical spatial scales）下的β多样性格局及其驱动因子。将该框架应用于水生大型无脊椎动物（aquatic macroinvertebrate）数据集后，我们发现β多样性通常随空间幅度（spatial extent）的增加而升高。随着空间幅度扩大，β多样性的主导驱动因子从环境过滤逐渐转向近期历史因子（即过去的β多样性）。此类近期历史效应可能源于过去的环境变异，而非优先效应。本研究还发现，小尺度与大尺度的环境驱动因子在不同空间幅度下对β多样性的作用存在显著差异。本研究揭示了β多样性格局及其驱动因子复杂的空间尺度依赖性，为理解β多样性动态提供了更为全面的视角。我们提出的框架通过将整体β多样性变异拆解为尺度特异性差异，为解析不同尺度下β多样性的内在结构提供了一种灵活的方法，有望在群落生态学（community ecology）、景观规划（landscape planning）及生物多样性保护（biodiversity conservation）领域得到广泛应用。