Data from: Dispersal and diversity in experimental metacommunities: linking theory and practice

There has been a recent rise in the number of experiments investigating the effect of dispersal on diversity, with many of the predictions for these tests derived from metacommunity theory. Despite the promise of linking observed relationships between dispersal and diversity to underlying metacommunity processes, empirical studies have faced challenges in providing robust tests of theory. We review experimental studies that have tested how dispersal affects metacommunity diversity to determine why shortcomings emerge, and to provide a framework for empirical tests of theory that capture the processes structuring diversity in natural metacommunities. We first summarize recent experimental work to outline trends in results and to highlight common methods that cause a misalignment between empirical studies and the processes described by theory. We then identify the undesired implications of three widely used experimental methods that homogenize metacommunity structure or species traits, and present alternative methods that have been used to successfully integrate experiments and theory in a biologically relevant way. Finally, we present methodological and theoretical insights from three related ecological fields (coexistence, food web and priority effects theory) that, if integrated into metacommunity experiments, could help isolate the independent and joint effects of local interactions and dispersal on diversity, and reveal the mechanisms underlying observed dispersal–diversity patterns. Together, these methods can provide stronger tests of existing theory and stimulate new theoretical explorations.近年来，探究扩散对生物多样性影响的实验研究数量持续攀升，其中多数实验的预测均源自集合群落（metacommunity）理论。尽管有望将观测到的扩散与生物多样性间的关联，与底层集合群落过程相挂钩，但实证研究在为该理论提供稳健检验方面仍面临诸多挑战。我们对检验扩散如何影响集合群落生物多样性的实验研究展开综述，旨在剖析现存短板的成因，并构建一套可用于实证检验理论的框架，以捕捉自然集合群落中塑造生物多样性的核心过程。首先，我们梳理近期的实验研究成果，总结实验结果的整体趋势，并指出导致实证研究与理论描述的生态学过程出现偏差的常见方法缺陷。随后，我们阐明三种被广泛应用的实验方法的不良影响——这类方法会同质化集合群落结构或物种性状，并介绍已被成功用于以生物学相关方式整合实验与理论的替代方法。最后，我们介绍来自三个相关生态学领域（共存理论、食物网理论与优先效应理论）的方法论与理论进展，若将其融入集合群落实验研究中，将有助于分离局域相互作用与扩散对生物多样性的独立及联合效应，并揭示观测到的扩散-多样性模式背后的潜在机制。综上，这些方法可为现有理论提供更严谨的检验，并推动全新的理论探索。