Impacts of Climate Change on Alpha and Beta Diversity Patterns of Cerrado anurans.

Climate change poses a major threat to biodiversity, altering species distributions and reshaping ecological communities. In the Brazilian Cerrado, a highly threatened tropical savanna, future climate projections indicate increased temperatures and reduced precipitation, potentially driving significant shifts in anuran diversity. Here, we assess how climate change (2050, SSP585) affects alpha and beta diversity of 139 anuran species in the Cerrado and explore their relationships with two key climate dimensions: climate anomaly and climate change velocity. We used occurrence records and bioclimatic variables to build Species Distribution Models (SDMs) via Maxent, and using the binary maps generated by the SDMs, we calculated alpha and beta diversity and used spatially explicit regressions to investigate the associations of diversity metrics with climatic metrics. Our results indicate a strong reduction in species richness across most of the biome, with the southeast and southwest experiencing the highest losses of up to 40 species. Conversely, northern and northeastern regions show richness gains. Changes in community composition were mainly driven by species replacement, particularly in the northwest, west, and east. No significant relationship was detected between climatic anomalies and changes in species richness. Instead, higher velocity in the change of temperature extremes was associated with richness losses, while higher precipitation change velocity was linked to richness gains. Maximum temperature anomalies and precipitation change velocity were key predictors of community restructuring. These findings highlight the urgent need for regional conservation planning to mitigate biodiversity loss driven by climate change in the Cerrado.