Data from: Interactive effects of disturbance and dispersal on community assembly

The traditional debate on alternative community states has been over whether or not they exist. Studies of community assembly have examined the role of assembly history in driving community divergence, but the context in which assembly history becomes important is a continued topic of interest. In this study, we created communities of bacterivorous ciliated protists in laboratory microcosms and manipulated assembly history, disturbance frequency, and the presence of dispersal among local communities to investigate the mechanisms behind community divergence. Specifically, we sought to understand how the role of assembly history changed in response to disturbance, dispersal, and the combination of the two. Assembly history influenced the identity of the dominant species through priority effects, and dispersal and disturbance showed interactive effects on both alpha and beta diversity. Dispersal increased alpha diversity, but only in the absence of disturbance, and it reduced beta diversity, but not in the presence of low or mixed disturbance. These results demonstrate that the role of assembly history and the strength of priority effects depend on community context, suggesting that understanding the interactions between various factors shaping community assembly is important for understanding how ecological communities are structured.

关于替代群落状态的传统学术争论，始终聚焦于其是否真实存在这一核心问题。过往有关群落组装的研究已考察了组装历史在推动群落分化中的作用，但组装历史得以发挥重要作用的具体情境，仍是学界持续探讨的热点议题。本研究借助实验室微宇宙实验体系，构建食细菌纤毛原生生物群落，并对组装历史、干扰频率以及局地群落间的扩散过程进行操控，以此探究群落分化背后的作用机制。具体而言，本研究旨在明晰组装历史的作用如何随干扰、扩散以及二者的联合作用而发生改变。研究发现，组装历史通过优先效应影响优势物种的群落组成；扩散与干扰对α多样性和β多样性均存在交互调控效应：扩散可提升α多样性，但仅在无干扰的条件下有效；同时扩散能够降低β多样性，但在低干扰或混合干扰的情境下该效应并不显著。上述结果证实，组装历史的作用强度与优先效应的强弱均取决于群落背景，这提示我们，厘清塑造群落组装的各类因子间的相互作用，对于深入理解生态群落的构建机制具有重要意义。