Tropical species richness is threatened by habitat degradation associated with land‐use conversion, yet the consequences for functional diversity remain little understood. Progress has been hindered by difficulties in obtaining comprehensive species‐level trait information to characterize entire assemblages and insufficient appreciation that increasing land‐cover heterogeneity potentially compensates for species loss. We examined the impacts of tropical deforestation associated with land‐use heterogeneity on bird species richness, functional redundancy, functional diversity, and associated components (i.e., alpha diversity, species dissimilarity, and interaction strength of the relationship between abundance and functional dissimilarity). We analyzed over 200 georeferenced bird assemblages in the Atlantic Forest of Brazil. We characterized the functional role of the species of each assemblage and modeled biodiversity metrics as a function of forest cover and land‐cover heterogeneity. Replacement of native Atlantic Forest with a mosaic of land uses (e.g., agriculture, pastures, and urbanization) reduced bird species richness in a nonrandom way. Core forest species, or species considered sensitive to edges, tended to be absent in communities in heterogenous environments. Overall, functional diversity and functional redundancy of bird species were not affected by forest loss. However, birds in highly heterogenous habitats were functionally distinct from birds in forest, suggesting a shift in community composition toward mosaic‐exclusive species led by land‐cover heterogeneity. Threatened species of the Atlantic Forest did not seem to tolerate degraded and heterogeneous environments; they remained primarily in areas with large forest tracts. Our results shed light on the complex effects of native forest transformation to mosaics of anthropogenic landscapes and emphasize the importance of considering the effects of deforestation and land‐use heterogeneity when assessing deforestation effects on Neotropical biodiversity.

中文翻译：

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森林砍伐的巨型多样化热带森林中物种和功能的丧失

热带物种丰富度受到与土地利用转变相关的栖息地退化的威胁，但对功能多样性的影响仍知之甚少。由于难以获得全面的物种层面性状信息来描述整个组合的特征，以及对增加土地覆盖异质性可能补偿物种损失的认识不足，阻碍了进展。我们研究了与土地利用异质性相关的热带森林砍伐对鸟类物种丰富度、功能冗余、功能多样性和相关组成部分（即阿尔法多样性、物种差异性以及丰度与功能差异性之间关系的相互作用强度）的影响。我们分析了巴西大西洋森林中 200 多个地理参考鸟类组合。我们描述了每个组合物种的功能作用，并将生物多样性指标建模为森林覆盖和土地覆盖异质性的函数。用多种土地利用（例如农业、牧场和城市化）取代原生大西洋森林，以非随机方式降低了鸟类物种的丰富度。核心森林物种或被认为对边缘敏感的物种往往在异质环境中的群落中不存在。总体而言，鸟类的功能多样性和功能冗余并未受到森林损失的影响。然而，高度异质栖息地中的鸟类在功能上与森林中的鸟类不同，这表明由于土地覆盖异质性导致群落组成向马赛克独有物种转变。大西洋森林的受威胁物种似乎无法忍受退化和异质的环境；他们主要居住在拥有大片林地的地区。我们的研究结果揭示了原生森林转变为人类景观镶嵌体的复杂影响，并强调在评估森林砍伐对新热带生物多样性的影响时考虑森林砍伐和土地利用异质性影响的重要性。