Data from: Compensatory dynamics maintain bird phylogenetic diversity in fragmented tropical landscapes

1.Tropical forest loss can drive the extinction of forest-dependent species. Yet, non-forest species can proliferate in deforested landscapes, thus enabling community-level attributes (e.g., total abundance and richness) to be maintained in the remaining forest patches. Such compensatory dynamics have been, however, poorly investigated regarding the phylogenetic dimension of species diversity. Here, we assessed whether compensatory dynamics can stabilize the phylogenetic richness, divergence and structure of bird communities in response to forest loss in two regions in the Brazilian Atlantic forest, each under with different levels of land use intensification. 2.We surveyed birds in 40 forest sites, and assessed the response of five phylogenetic metrics to forest cover measured in local (600-m radius) landscapes. We separately assessed the entire community, forest-dependent and non-forest-dependent species and used information-theoretic criteria to assess the effect of forest cover on each response variable. In particular, we evaluated the plausibility of four models: a null model (no effect of forest cover), a linear model, a power law model (nonlinear effect), and an analysis of covariance model (to assess whether the effect of forest cover differed between regions). 3.Forest cover varied from 7% to 98%, and was positively related to the phylogenetic richness of forest-dependent species, but negatively related to the phylogenetic richness and divergence of non-forest birds, particularly in the more disturbed region. As consequence, the phylogenetic richness and divergence of the entire community were weakly related to forest cover. 4.Forest birds were less phylogenetically clustered in sites surrounded by lower forest cover, but the phylogenetic structure of non-forest birds was independent of forest cover. 5.Synthesis and applications. The phylogenetic impoverishment of forest-dependent birds is offset by the phylogenetic enrichment and divergence of non-forest-dependent birds in severely tropical deforested landscapes. These compensatory dynamics suggest that both bird groups are important for safeguarding bird evolutionary diversity in human-modified landscapes. Although deforested landscapes are reservoirs of bird phylogenetic diversity, suggesting that ecosystem functioning may be maintained in these sites, preventing further deforestation is urgently needed to preserve forest birds and their key ecological roles in the ecosystem.1. 热带森林丧失可引发依赖森林物种（forest-dependent species）的灭绝。然而，非森林物种（non-forest species）可在毁林景观中大量增殖，从而使剩余森林斑块中的群落级属性（如总个体丰度与物种丰富度）得以维持。不过，针对物种多样性的系统发生维度（phylogenetic dimension）的这类补偿动态，目前尚缺乏充分研究。本研究选取巴西大西洋森林的两个区域（二者土地利用强度水平各异），评估补偿动态是否能够稳定鸟类群落的系统发生丰富度（phylogenetic richness）、分歧度（phylogenetic divergence）与结构（phylogenetic structure），以响应森林丧失。 2. 我们在40处森林样地开展鸟类调查，评估了5项系统发生指标对局部（600米半径）景观中测得的森林覆盖度的响应。我们分别针对完整群落、依赖森林物种和非依赖森林物种进行分析，并采用信息论准则评估森林覆盖度对各响应变量的影响。具体而言，我们检验了4类模型的合理性：零模型（无森林覆盖度效应）、线性模型、幂律模型（非线性效应）以及协方差分析模型（用于验证森林覆盖度的效应在区域间是否存在差异）。 3. 本研究涉及的森林覆盖度介于7%至98%之间，其与依赖森林物种的系统发生丰富度呈正相关，但与非森林鸟类的系统发生丰富度及分歧度呈负相关，这一关联在受干扰程度更高的区域尤为显著。受此影响，完整群落的系统发生丰富度与分歧度与森林覆盖度仅存在微弱关联。 4. 在森林覆盖度较低的样地周边，森林鸟类的系统发生聚集程度更低，但非森林鸟类的系统发生结构与森林覆盖度并无关联。 5. 总结与应用。在受严重破坏的热带毁林景观中，依赖森林鸟类的系统发生贫乏可被非依赖森林鸟类的系统发生富集与分歧所抵消。这类补偿动态表明，两类鸟类群落在人为改造的景观中均对保护鸟类的进化多样性具有重要价值。尽管毁林景观是鸟类系统发生多样性的储存库，这提示这些样地的生态系统功能或可得以维持，但亟需阻止进一步的森林砍伐，以保护森林鸟类及其在生态系统中的关键生态功能。