AIM: The two additive components of β‐diversity, namely turnover and nestedness, reflect the two basic mechanisms underlying the overall change in species identities across the landscape, the replacement of species or their loss, respectively. Analogously, functional turnover and nestedness express the replacement or loss of functional traits associated with variations in community composition. However, the extent to which patterns of compositional and functional nestedness and turnover may overlap, or diverge, is still uncertain in marine environments. Here, patterns of turnover and nestedness were quantified in marine benthic assemblages in order to assess their relative contribution to spatial patterns of compositional and functional ‐diversity. LOCATION: Mediterranean Sea, NE Ionian Sea, Ionian Archipelago. METHODS: In this study, we investigated patterns of dissimilarity in species and functional trait composition in subtidal macrobenthic assemblages from Mediterranean islands in order to quantify compositional and functional β‐diversity among islands, determine the relative contributions of turnover and nestedness, and compare β‐diversity patterns occurring in shallow and deeper reefs. RESULTS: We found a complex relationship between functional and compositional β‐diversity at varying depth. At 5 m, species and functional trait dissimilarity largely overlapped, with turnover being the dominant component in both cases. At 15 m, compositional β‐diversity was mostly due to turnover, with a negligible contribution of nestedness, whereas the opposite occurred for functional β‐diversity. Partitioning β‐diversity components revealed this discrepancy and the presence of functional hotspots, which would remain unnoticed analysing the overall compositional and functional β‐diversity. MAIN CONCLUSIONS: Our findings may have profound implications for the optimization of conservation planning, stressing the need for assessing habitat‐dependent idiosyncrasies in components of functional and compositional β‐diversity for a more comprehensive picture of possible protection scenarios that, besides structure, may also allow preserving the functioning of marine communities.

中文翻译：

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嵌套和周转揭示了海洋底栖生物不同深度的成分和功能β多样性的反向空间模式

目的：β多样性的两个相加成分，即周转和嵌套，分别反映了景观中物种身份整体变化、物种替换或丧失的两种基本机制。类似地，功能周转和嵌套表示与社区组成变化相关的功能特征的替换或丢失。然而，在海洋环境中，成分和功能嵌套和周转的模式可能重叠或发散的程度仍然不确定。在这里，在海洋底栖组合中量化了周转和嵌套的模式，以评估它们对组成和功能多样性的空间模式的相对贡献。位置：地中海，爱奥尼亚海东北部，爱奥尼亚群岛。方法：在本研究中，我们调查了地中海岛屿潮下带大型底栖生物群落物种和功能性状组成的差异模式，以量化岛屿之间的组成和功能 β 多样性，确定周转和嵌套的相对贡献，并比较浅层和海洋中发生的 β 多样性模式。更深的珊瑚礁。结果：我们发现不同深度的功能和成分 β 多样性之间存在复杂的关系。在 5 m 处，物种和功能性状的差异在很大程度上重叠，在这两种情况下，营业额都是主要组成部分。在 15 m 处，成分 β 多样性主要是由于周转，嵌套性的贡献可以忽略不计，而功能性 β 多样性则相反。划分β-多样性成分揭示了这种差异和功能热点的存在，在分析整体成分和功能性β-多样性时，这些热点将不会被注意到。主要结论：我们的发现可能对优化保护规划具有深远的意义，强调需要评估功能和组成 β 多样性组成部分中依赖栖息地的特性，以便更全面地了解可能的保护场景，除了结构之外，还可能允许保护海洋社区的功能。