We assessed the effects of global climate change as a driver of spatio-temporal biodiversity patterns in bird assemblages associated to Neotropical seasonally dry forests (NSDF). For this, we estimated the geographic distribution of 719 bird species under current and future climate (2050 and 2070) projections considering two dispersal ability assumptions (contiguous dispersal vs. no dispersal). Then, using Sørensen-based multiple-site dissimilarity and range-diversity plots analyses, we assessed the potential changes of range size and covariance in species composition, as well as in alpha and beta diversities across NSDF and within the current Protected Areas (PAs). Over 77% of species tended to reduce their potential distributional ranges for years 2050 and 2070 (regardless climate and dispersal scenarios), including several species extirpations from the NSDF. In fact, considering the contiguous dispersion, we observed that, on average, only ∼7% of species will be favored (increasing >10% their current distributional areas) by new climate conditions. We estimated a general decrease in local species richness and increase in Whittaker’s beta diversity across NSDF and PAs under future scenarios, which is indicative of biotic heterogeneity. This scenario suggests that NSDF’s avian assemblages could be prone to an uneven structural reorganization (likely decreasing the taxonomic similarity between sites) as a consequence of climate change. Such change in biodiversity patterns imply a threat for conservation of birds in this highly diverse and fragile ecosystem; however, the spatio-temporal patterns for the NSDF avifauna identified herein can be useful to guide new conservation efforts.

我们评估了全球气候变化对与新热带季节性干旱森林（NSDF）相关的鸟类组合时空生物多样性格局的驱动力。为此，考虑到两个扩散能力假设（连续扩散与无扩散），我们估算了当前和未来气候（2050和2070）预测下的719种鸟类的地理分布。然后，我们使用基于Sørensen的多站点异点和距离-多样性图分析，评估了物种组成以及NSDF和当前保护区内的α和β多样性的范围大小和协方差的潜在变化。 。在2050年和2070年间，超过77％的物种倾向于减少其潜在的分布范围（无论气候和扩散情况如何），包括NSDF的几种物种灭绝。实际上，考虑到连续分布，我们观察到平均而言，新的气候条件将仅对约7％的物种有利（其当前分布区域增加> 10％）。我们估计，在未来的情况下，NSDF和PA之间本地物种丰富度普遍下降，Whittaker的β多样性增加，这表明生物多样性。这种情况表明，由于气候变化，NSDF的禽类组合可能容易出现结构重组不均（可能降低站点之间的分类相似性）的情况。生物多样性模式的这种变化意味着在这个高度多样化和脆弱的生态系统中鸟类的保护受到威胁；然而，