Estrutura e heterogeneidade da paisagem de uma unidade de conservação no nordeste do Pantanal (RPPN SESC Pantanal), Mato Grosso, Brasil: efeitos sobre a distribuição e densidade de antas (Tapirus terrestris) e de cervos-do-pantanal (Blastocerus dichotomus)
The RPPN SESC-Pantanal (Private Reserve of the Natural Wealth, owned by the Social Service of Commerce) in Barão de Melgaço, state of Mato Grosso, Brazil, displays several features strongly associated to Cerrado physiognomies, featuring drier areas in comparison to southwestern Pantanal. Product of non-supervised satellite image classification, land cover maps identified 18 classes of land cover and 9 physiognomic domains which represent the distribution of landscape units inside the Reserve. Adequate elaboration of conservation and management strategies strongly relies on information regarding local fauna. Data regarding abundance, as well as information on the way local fauna occupies the surrounding environment, also shed some light on this setting. Tapir, Tapirus terrestris, and marsh deer, Blastocerus dichotomus, are both familiar elements to the landscape of the RPPN SESC-Pantanal.. Estimates of tapir population size was of 581 individuals. Density of tapirs in forest formations (0.71 ind./km2) was 92% higher than in grassland formations (0.37 ind./km2). Estimated marsh deer population size was of 135 individuals (0,44 ind./km2) during the dry period, and 157 (0,73 ind./km2) for the flooding period. According to the distribution models shown here, as well as Selection Index results and density estimates, one may infer on the quality of habitats available for these species. Forest with Acuri (Scheelea phalerata) are of high relevance for T.terrestris, although this species is widely distributed throughout the Reserve. The Pantanal shelters the largest population of B. dichotomus, yet inside the Reserve it is found in a peculiar situation: it occupies drier habitats than it normally would throughout most of its area of occurrence. Grassland habitats were favorably selected by this species. Spatial analysis at several scales was a crucial tool to demonstrate the relevance of water sources in predictive species occurrence: highest probability zones are represented by nuclei along the existing network of ponds at the central section of the RPPN, as well as along the lakes at the eastern portion of this Conservation Unit. These analyses demonstrated a hierarchy in habitat use for both T. terrestris and B. dichotomus which allowed for the identification of areas of high probability of species occurrence. This reflects a set of characteristics which are close to an optimal condition in the studied landscape for the species in question.