Small mammals in fragments of Atlantic Forest: species richness answering to field methods and environment

Response of small mammal species to landscape metrics in a highly fragmented area in the Atlantic forest of southern Brazil

The high rate of destruction of natural habitats has diminished fragments size, which negatively impacts small mammal community species richness and composition. We investigated the abundance of small non-flying mammal species in association with three landscape metrics: the size of the fragment (AREA); the shape index of the fragment (SHAPE); and the size of the central area of the fragment (CORE) in six forest fragments in a highly fragmented landscape of southern Brazil. Three rodent species (Akodon montensis, Oligoryzomys nigripes, Sooretamys angouya) and one marsupial species (Gracilinanus microtarsus) were captured in total. We used generalized linear models to test the influence of the landscape metrics on the abundance of the three most abundant species of small mammals captured (A. montensis, O. nigripes and S. angouya). Among the three species analyzed, A. montensis presented a significant negative association with the metric CORE; O. nigripes and S. angouya presented a positive association with the metric AREA and negative with the metric CORE. The negative association of A. montensis, O. nigripes and S. angouya with the core area of the fragments, and the absence of association of all species with the shape of the fragments indicate that these species might benefit from the effects of habitat fragmentation.