Abstract
Little is known about the structure and floristic composition of the highly fragmented northwestern Rio de Janeiro forests. Thus, this study aimed to address the following questions: What is the floristic composition and which species characterize it? Does the tree community show high species richness and diversity? What are the successional stages? Four fragments were selected. Five 20 m ×20 m plots were allocated in each fragment and all dead and alive trees ≥5 cm DBH were sampled. A total of 198 taxa belonging to 52 families was sampled. The most important species were Apuleia leiocarpa, Gallesia integrifolia, Dalbergia nigra and Guarea guidonia. The values of richness and species diversity (H’) in five different sample areas (0.2 ha) ranged from 33 to 89 and from 2.81 to 3.87, respectively. The forest fragments, although secondary and in a mid-successional stage, had a particular species composition, high diversity and richness, and seem to have floristic influence from both semideciduous and evergreen forests of southeastern Brazil. These characteristics are probably related to the geographic position of the region.
Key words:
floristic composition; tree diversity; forest fragments; northwestern Rio de Janeiro state