Seasonally flooded stepping stones: emerging diversity of small mammal assemblage in the Amazonia-Cerrado ecotone, central Brazil

Abstract

Seasonally flooded natural forest fragments, so-called ipucas, in the Araguaia alluvial plain of the state of Tocantins, central Brazil, represent a peculiar landscape that is poorly surveyed. This study considers the diversity in the small mammal assemblage and the zoogeographical patterns of this assemblage when compared to 30 other study sites in Brazil. Results: ‘Ipucas’ harbour species adapted to disturbed habitats that are common in fragmented landscapes and endemic species of the Cerrado. However, they also constitute the most central-eastern distribution limit of one typical Amazonian species. These fragments are closely related to the central-western region of Brazil, in the Amazonia-Cerrado ecotone, which lies in the so-called arc of deforestation. Conclusions: Our results reinforce the idea that the habitat mosaic found in the Araguaia alluvial plain has an important role in promoting the high biodiversity of this area and that natural forest fragments may act as a refuge and food resource for several species. These fragments may also constitute essential stepping stones for smallmammal species within agricultural landscapes. Further studies are essential to better understand small mammal communities inhabiting natural forest fragments in the Araguaia alluvial plain, and these will support in assessing the future of this fauna and, thereby, help to establish future conservation practices in this area.