Impactos das mudanças climáticas sobre a distribuição de vertebrados terrestres em diferentes escalas espaciais

Abstract

Climate change is affecting many species around the world. Last year was the hottest year on record and forecasts point to even higher temperatures, further aggravating the risk of species extinction. One of the responses of species to climate change is dispersal. Indeed, species have changed their distribution latitudinally and altitudinally in search of climatically suitable areas to survive. One approach to identifying climatically suitable routes for species to disperse is to identify climate corridors. As population change will be observed over short time intervals, detecting annual corridors for species to disperse is essential, however, this has not yet been done. Contrary to the common expectation of negative impacts on biodiversity, some studies also point to positive projections for climate suitability and the extent of species occurrence in face of climate change. Nevertheless, the variability of these responses remains a gap in scientific understanding. The general aim of this thesis was to determine trends in the changes in the spatial distribution of non-flying terrestrial vertebrates - with an emphasis on anurans - as a result of both observed and projected climate change. To this end, we structured this study in three chapters. In the first chapter, we carried out an extensive global literature review that analyzed the climate changes observed, latitudinally and altitudinally, in non-flying terrestrial vertebrates, comparing ectotherms and endotherms. In the second, we carried out an ecological niche modeling study that determined, based on changes in climatic suitability and extent of occurrence, which characteristics of anurans are associated with their varying responses as a result of climate change projected for the future. In the third, we developed a spatial modeling study to identify climate corridors for anurans to disperse annually towards climatically suitable areas. Our results indicate that: (i) amphibians and reptiles (ectotherms) are changing their distribution more than mammals (endotherms) as a result of ongoing climate change; (ii) the direction of change is, in general, towards colder regions (higher altitudes and towards the poles); (iii) body size, habit (way of life) and characteristics linked to reproduction were more important than maximum altitude and extent of occurrence at present, for explaining variation in both future climatic suitability and extent of occurrence of species; (iv) larger, vegetation-dependent amphibians tend to experience a greater increase in climate suitability in the future; (v) all the anurans analyzed were able to occupy fewer areas each year due to predicted climate change; (vi) climate corridors are located in more priority cells for conservation than for restoration. These results can help guide conservation efforts since they indicate which species should receive greater attention considering the impact of climate change. In addition, we have shown that to enable the dispersal of species to climatically suitable areas, it is necessary to preserve areas with native vegetation, ensuring connectivity between forest fragments in the Atlantic Forest.