Implications of an agricultural mosaic in small mammal communities

Abstract

The ideas that larger fragments have greater species richness and abundance, when compared to smaller fragments and altered environments, and that assemblage composition is different, was tested in an agricultural mosaic using data on small mammals. To achieve this, we sampled ten forest fragments of different sizes, small and large, as well as five areas in a sugarcane matrix, through the capture-mark-recapture method. The study was conducted in a sugarcane plantation (Usina São José, Igarassu, Pernambuco, Brazil) from January to October 2016. There was a significant difference when comparing richness between small fragments (eight species) and the sugarcane matrix (four species). Abundance differed significantly between all areas, being influenced by fragment size and habitat type. We found that abundance was positively influenced by forested environments and, among them, larger fragments. The composition of assemblages in the forest fragments and the sugarcane matrix differed clearly for NMDS, MANOVA and SIMPER analyses. Between the habitats, assemblage parameters were also distinct. Lower abundance and richness were found in the sugarcane matrix, where the presence of rodents was associated with food availability and less competition; and higher abundance and richness was measured in forest fragments, where there was a strong association between marsupials and forest strata. The landscape configuration in an agricultural mosaic can compromise the level of interspecific interactions of small mammals, which negatively impacts the ecological processes of forested areas. In this case, the conservation of a matrix permeable to most species and the preservation of all fragments are necessary, since small and large fragments have different functions in the maintenance of species.