Traços funcionais como preditores da vulnerabilidade de plantas às mudanças climáticas: estudo de caso no semiárido brasileiro

Abstract

The ongoing global climate crisis will potentially affect the structure and functioning of ecosystems causing the extinction or reduction in the geographic range of many taxa. For the Brazilian semiarid region, an increase in temperature and a reduction in precipitation is expected, and, consequently, an increase in the water deficit in a region that has historically been subject to periods of drought. Understanding which species are most vulnerable to this increase in the severity of aridity is the first step in planning strategies that minimize the risks of extinction. Analyzes of niche modeling of species together with functional traits that are indicators of growth, water savings and dispersion capacity can be good indicators of vulnerability to climate change. In this sense, we analyzed two ecological niche models (current and future) for shrub-tree species in order to simulate the effects of climate change on their distribution. To build the species distribution models, we used data from the current climate, soil physical variables at various depths, taxon occurrence data and bioclimatic predictions from the Canadian Earth System Model for the pessimistic emission scenario (RCP8.5). To check the variation in the distribution area, we calculate the number of suitable pixels in the present and the future. Finally, we verified whether the functional attributes of water saving, dispersion and plant growth would be good predictors of the potential for expansion or retraction of the species. We found that the functional attributes can predict the vulnerability of plants in the Brazilian semiarid region. Species with a greater specific leaf area, greater leaf thickness and smaller seeds should lose more area due to climate change. These results serve as a basis for testing in future longterm studies the architecture, functioning and dynamics of populations.