Modelagem de distribuição da herpetofauna nos brejos de altitude do setor setentrional do semiárido brasileiro a partir do pleistoceno superior

Abstract

The Brazilian semi-arid region, which encompasses the Caatinga biome, is situated betweentwo humid biomes—the Amazon Rainforest and the Atlantic Forest—and is characterized bythe occurrence of isolated humid environments that constitute important habitats for the localherpetofauna. This region experienced climatic shifts during the Quaternary, which influencedthe spatial distribution of humid forests. The present study examined the distribution ofherpetofaunal species groups adapted to humid enclaves within the Brazilian semi-arid regionusing species distribution modeling, focusing on the Last Interglacial (~120 ka), the LastGlacial Maximum (~22 ka), and the Mid-Holocene (~6 ka). Paleoclimatic data obtained fromWorldClim 1.4 were employed in the analyses. The models demonstrated strong discriminatoryperformance for the variables associated with each taxonomic group (maximum temperatureof the warmest month for lizards and snakes, and annual precipitation for anurans), in additionto high rainfall totals, which were relevant for all groups. Amphibians exhibited a greaterdependence on humid ecosystems, with their distributions being markedly affected during drierperiods. Lizards and snakes, in contrast, showed higher ecological tolerance, resulting inbroader distributions under these drier climatic scenarios. Overall, species distributionscontracted by approximately 35% (lizards) to 61% (snakes) during the Last Interglacial,whereas amphibians experienced a reduction of 73% relative to their current distribution.