Composição e estrutura da comunidade arbórea de uma floresta estacional decidual sobre afloramento calcário no Brasil central

The Parana River basin (states of Goias and Tocantins, Brazil), with 5,940,382 ha, has a high diversity of phytophysiognomies, including the deciduous forest on limestone outcrops, which has not been studied yet in this region. In this paper we present the structure of an arboreal community in a deciduous forest on limestone outcrops (13o31'11" S and 46o29'48" W) in Sao Vicente Farm in the municipality of Sao Domingos, Goias, Brazil. Twenty-five plots of 20 m x 20 m (400 m2) were randomly allocated on lines set 100 m apart. Trees with at least 5 cm of diameter at breast height (DBH) were tagged, measured, and identified to the species level. A total of 51 tree species, belonging to 41 genera and 25 families were registered among the 860 individuals sampled. These values are higher than those found for two other limestone outcrops in this region, except for density, probably as a consequence of the improved conservational status of this area. The species with the highest importance value (IV) were: Pseudobombax tomentosum (36.39), Dilodendron bipinnatum (31.55), Tabebuia impetiginosa (26.66), Combretum duarteanum (18.38), Luehea divaricata (12.76), Cavanillesia arborea (12.52), Myracrodruon urundeuva (12.23), Chorisia pubiflora (12.21) and Acacia glomerosa (10.11), comprising together 57.6% of total. Diversity was greater than that found in other outcrop areas in the region.