Conservação de anfíbios em áreas agrícolas do sul do brasil

Abstract

Conservation initiatives in agricultural landscapes have become one of the priorities on the conservation agenda of amphibians, because l and use changes are associated with global declines. In this thesis, I tried to analyze the effects of agricultural fragmentation and intensification on anuran species richness and composition, in et lands of Pampa biome in Rio Grande do Sul. The thesis has three chapters. In the first one, I evaluated differences in anuran assemblages across natural areas, organic rice fields, and non-organic rice fields. In the second chapter, I investigated species co-occurrence and nested ness patterns in assemblages associated to natural areas and rice fields with different crop ages. In the last chapter, I examined the relationship between tadpole abundance and habitat features at 5 spatial scales, in southern half of Rio Grande do Sul state. In general, I conclude that amphibian conservation actions in agricultural areas need the management of different elements at multiple spatial scales. Different anuran species do not all respond to the same spatial scale or to historic differences across the areas. Therefore, to determine the extent of species-specific responses are an urgent steep toward workable conservation alternatives across agricultural landscapes in Pampa biome.