School of Biology, University of Leeds, Leeds, LS2 9JT, UK.
Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK.
Oecologia. 2021 Mar;195(3):705-717. doi: 10.1007/s00442-020-04829-z. Epub 2021 Feb 8.
Tropical rainforest disturbance and conversion are critical drivers of biodiversity loss. A key knowledge gap is understanding the impacts of habitat modification on mechanisms of community assembly, which are predicted to respond differently between taxa and across spatial scales. We use a null model approach to detect trait assembly of species at local- and landscape-scales, and then subdivide communities with different habitat associations and foraging guilds to investigate whether the detection of assembly mechanisms varies between groups. We focus on two indicator taxa, dung beetles and birds, across a disturbance gradient of primary rainforest, selectively logged rainforest, and oil palm plantations in Borneo, Southeast Asia. Random community assembly was predominant for dung beetles across habitats, whereas trait convergence, indicative of environmental filtering, occurred across the disturbance gradient for birds. Assembly patterns at the two spatial scales were similar. Subdividing for habitat association and foraging guild revealed patterns hidden when focusing on the overall community. Dung beetle forest specialists and habitat generalists showed opposing assembly mechanisms in primary forest, community assembly of habitat generalists for both taxa differed with disturbance intensity, and insectivorous birds strongly influenced overall community assembly relative to other guilds. Our study reveals the sensitivity of community assembly mechanisms to anthropogenic disturbance via a shift in the relative contribution of stochastic and deterministic processes. This highlights the need for greater understanding of how habitat modification alters species interactions and the importance of incorporating species' traits within assessments.
热带雨林的干扰和转换是生物多样性丧失的关键驱动因素。一个关键的知识空白是了解生境变化对群落组装机制的影响，这些机制预计在分类群之间和不同空间尺度上会有不同的反应。我们使用零模型方法来检测本地和景观尺度上物种的特征组装，然后将具有不同生境关联和觅食习性的群落细分，以调查组装机制在不同群体之间是否存在差异。我们关注的是两种指示类群，即蜣螂和鸟类，它们分布在东南亚婆罗洲的原始雨林、选择性采伐的雨林和油棕种植园中一个干扰梯度上。对于蜣螂来说，在各种生境中，随机群落组装占主导地位，而对于鸟类来说，特征趋同（表明存在环境过滤）则发生在整个干扰梯度上。两个空间尺度上的组装模式相似。对于生境关联和觅食习性的细分揭示了在关注整个群落时隐藏的模式。在原始森林中，蜣螂的森林专化种和生境广适种表现出相反的组装机制，两种分类群的生境广适种的群落组装随干扰强度而不同，并且食虫鸟类相对于其他类群强烈影响整个群落的组装。我们的研究通过随机和确定性过程相对贡献的变化，揭示了群落组装机制对人为干扰的敏感性。这凸显了需要更好地了解生境变化如何改变物种相互作用，以及在评估中纳入物种特征的重要性。
