VEGETATION AND FLOOD PULSE EFFECTS IN SPATIAL DISTRIBUTION OF MARSUPIALS AND RODENTS IN NORTHERN PANTANAL

Resumo

Biotic and abiotic interactions and dispersion ability establish the limits for species distribution in habitats. Pantanal presents a mosaic of environments ranging from fields to forests subjected to varying levels of seasonal flooding. Thus, the local hydrology and vegetation cover should strongly affect the distribution of species in the landscape. The aim of this study was to understand how the topography, the flooding duration and vegetation cover influence the distribution of marsupials and small rodents in the Pantanal of Poconé, Mato Grosso. Terrestrial small mammals were sampled on a grid comprising 30 sampling sites, systematically distributed in the landscape. In total, four species of marsupials and six of rodents were registered throughout the study. The general analysis model was significant, being the stratification of vegetation the factor that most affected the distribution of species, considering habitat complexity increases availability of microhabitats. Analyses also indicated a positive relationship between species richness and environmental complexity.  Therefore, we did not find a direct effect of flooding upon populations of terrestrial small mammals, but instead, we found effect of the landscape, highlighting the importance of maintaining the mosaic system (with several types of savannas and forests) for the conservation of this fauna.