LAUSR

Abstract 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 Sorensen-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.