Abstract Understanding how biodiversity is distributed across geographical and environmental gradients is a main goal of diversity sciences. However, since ecosystem processes are linked to variation in functional traits of the biota, examining functional beta diversity is particularly important. Our objective was to analyze the taxonomic and functional beta diversity patterns of saproxylic beetle assemblages in evergreen Quercus forest of Spain. We tested whether environmental or geographical distance had a greater influence on taxonomic and functional beta diversity, and if both measures of beta diversity were affected by the same environmental variables. We used 45 flight interception traps distributed in three protected areas over a 12-mo period to sample saproxylic beetles. We measured 13 environmental variables around each trap and the geographical distance between traps. For functional composition, we used 12 functional traits from four functional groups (morphological, phenological, trophic, and a surrogate of physiological). Our results showed that environmental differences between areas influenced the taxonomic and functional beta diversity components (replacement and loss/gain) but in different ways. While replacement components (higher for taxonomic composition) increased with environmental distance, the loss or gain components (higher for functional composition) remained constant, indicating that species replacement mostly involved functionally redundant species. Besides, environmental variables influencing both taxonomic and functional composition were strongly dependent on each area. In conclusion, in well-preserved Mediterranean forests, environmental filtering determines the taxonomic and functional composition of saproxylic beetle assemblages, by favoring species replacement but filtering species traits.

中文翻译：

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地中海森林中腐木甲虫的功能和分类 Beta 多样性：它们依赖于哪些因素？

摘要 了解生物多样性如何跨地理和环境梯度分布是多样性科学的主要目标。然而，由于生态系统过程与生物群功能性状的变化有关，因此检查功能性β多样性尤为重要。我们的目标是分析西班牙常绿栎树林中腐木甲虫组合的分类和功能β多样性模式。我们测试了环境或地理距离是否对分类和功能β多样性有更大的影响，以及β多样性的两种测量是否受到相同环境变量的影响。我们在 12 个月的时间里使用分布在三个保护区的 45 个飞行拦截陷阱来对腐木甲虫进行采样。我们测量了每个陷阱周围的 13 个环境变量以及陷阱之间的地理距离。对于功能组成，我们使用了来自四个功能组（形态学、物候学、营养学和生理学的替代品）的 12 个功能性状。我们的结果表明，地区之间的环境差异影响了分类学和功能性 beta 多样性组成部分（替换和损失/增加），但方式不同。虽然替换成分（分类组成更高）随着环境距离的增加而增加，但损失或增加成分（功能组成更高）保持不变，表明物种替换主要涉及功能冗余的物种。此外，影响分类和功能组成的环境变量强烈依赖于每个区域。综上所述，