Floristic composition and phytosociological structure of the grassland and cerrado areas in the Floresta Nacional de Silvânia, Goiás, Brazil

Abstract

The Cerrado is the savanna with largest floristic richness of planet and also one of the most fragmented and threatened regions of world. Therefore, inventory and know the diversity of plant species in the Cerrado is a very important initiative. This study was conducted at the Floresta Nacional de Silvânia, aiming to investigate the phytosociological structure of the “cerrado sensu stricto” (“cerrado s.r.”) and “campo sujo” vegetations. Sampling was performed in plots of 10 x 10 m, 15 in the “cerrado s.r.” and 10 in the “campo sujo”. Were sampled only woody individuals with a diameter equal to, or greater than 5 cm (30 cm from the soil). Results showed 60 species belonging to 28 families and 46 genera, 52 species in the “cerrado s.r.” and 27 in the “campo sujo’. The families with more species were Malpighiaceae (7), Fabaceae (6) and Vochysiaceae (5). The species with the highest importance values in the “cerrado s.r.” were Qualea grandiflora, Kielmeyera coriacea, and Styrax ferrugineus, on the other hand, in the “campo sujo” were S. ferrugineus, Piptocarpha rotundifolia e Erythroxylum deciduum. In the “cerrado s.r.”, density and basal area were 1125 individuals/ha and 5.32 m2/ha respectively. In the “campo sujo” were 730 indivíduos/ha and 1.96 m2/ha. The Shannon index (H') estimated for the “cerrado s.r.” was 3.48, and for the “campo sujo” 2.91. These values demonstrate a high diversity of species in the study area.