Anfíbios de um dos maiores remanescentes de Mata Atlântica do Brasil: fatores climáticos e da estrutura do habitat afetando a comunidade local

Abstract

A fundamental objective in community ecology is to understand which biotic and abiotic factors influence the set of species and community structures. In amphibian communities, different environmental factors (for example, climatic factors and changes in the landscape) can influence the parameters of the community structure, such as abundance, distribution, richness and species composition. The knowledge of the factors that influence the amphibian communities is a fundamental issue to understand functional parameters of the ecology of this group, complementing the basic information about the species richness, allowing a higher applicability in conservation when this information is related. Thus, we aim to study the amphibian community in one of the largest remnants of the Atlantic Forest (Reserva Natural Vale - RNV), evaluating some factors that influence the structuring of the community, as well as the factors that are most important for the occupancy and detectability of the species. This thesis is structured in seven chapters that pass through a set of learnings about the anuran community of RNV. First, we introduce the RNV amphibian community in terms of its composition, richness and abundance of species. Then, we present a review of studies on the abiotic factors that affect the detectability of amphibians and evaluate the activity and detectability of amphibians in RNV. Then, we present results on the effect of habitat heterogeneity on amphibian richness and occupancy. We also present three chapters that highlight the importance of climatic factors, especially precipitation, for the RNV amphibian community. Finally, we gather information about amphibians and other herpetofauna organisms and present recommendations for increasing the degree and effort of fauna conservation in RNV based on the lessons learned. In general, we conclude that the RNV amphibian community is rich in species, most of which are endemic to the Atlantic Forest. The species are mostly nocturnal and are distributed among the four different types of vegetation in the Reserve, presenting species with restricted occurrence to some phytophysiognomies. In terms of factors that influence amphibians, we demonstrate that habitat heterogeneity and several key vegetation structures are important for the occupation of different species. In addition, we have seen that climatic factors such as air humidity and precipitation are crucial for the abundance, richness and permanence of amphibian species in RNV and we have shown alarming results on the effect of drought on the amphibian community. It is crucial to encourage and promote the protection of ecosystems, as well as the restoration of springs to ensure the survival of amphibians. Furthermore, it is essential that long-term monitoring be carried out at RNV to monitor possible changes in the population dynamics of species and mitigate any impacts on species