História evolutiva em nascentes no sudeste do Brasil: passado, presente e futuro

Abstract

The way communities are structured, associated with their evolutionary history, is essential for understanding ecosystems and thus underpinning the planning of conservation measures. Springs are extremely important areas in relation to water supply. They harbor high biodiversity adapted to the conditions of these environments, and at the same time, are sensitive areas to anthropogenic action. Forests located in these areas play a fundamental role in regulating the hydrological cycle, carbon sequestration, and provide various essential environmental services for maintaining these ecosystems. Factors such as soil and climate act as environmental filters and can shape phylogenetic patterns in springs over time. Therefore, this study sought to understand the evolutionary history of forests in spring areas, located in the two main watersheds of southeastern Brazil, discussing the processes involved in the formation of these communities and in determining their phylogenetic diversity. The first part consisted of a theoretical framework discussing in general the topics addressed in this thesis. The second part comprises a scientific article aimed at evaluating the main predictors of phylogenetic diversity in headwater forests located in two major watersheds of southeastern Brazil (Rio Grande Basin and São Francisco River Basin). Correlations of past, current, and future climate, as well as the soil effect on headwater forests, located in two watersheds, within the Cerrado and Atlantic Forest domains, were observed. Given the scenarios of climate change, anthropogenic pressures on springs, and considering the diversity of species adapted to these sites, these areas may undergo changes in their phylogeny, posing a risk to the species occurring in these ecosystems. In this sense, given the ecological importance of these areas, it is expected that understanding the evolutionary history of headwater forests will help guide strategies for environmental restoration, management, and conservation of these environments, both in public and private areas, and promote the maintenance of phylogenetic diversity and assist in preserving springs in the face of future scenarios.