Composição florística e estrutura do componente arbóreo de um trecho de Mata Atlântica na Estação Ecológica Estadual do Paraíso, Cachoeiras de Macacu, Rio de Janeiro, Brasil

Abstract

A phytosociological survey of the tree component (DBH ≥ 5 cm) was carried out in an area of Atlantic Forest, in the Paraíso State Ecological Station, Cachoeiras de Macacu, RJ. The local climate is of type AAr, with annual mean temperature and precipitation of 23,0oC and 2.558,4 mm, respectively. Cambisoils predominate in the area. The point-centered quarter method was used for the phytosociological survey. In 150 points, 592 live trees were sampled, belonging to 42 families, 83 genera and 138 species; there were 8 dead trees. The 5 most important species are: Neoraputia magnifica var. magnifica, Euterpe edulis, Gallesia integrifolia, Chrysophyllum flexuosum and Calycorectes sellowianus. Myrtaceae has the greatest number of individuals (18,6% of the total) and species, with 27 (19,6%) from a total of 138. Families with the 5 highest IVs are: Sapotaceae, Myrtaceae, Rutaceae, Meliaceae and Palmae. The Shannon diversity index (H) is 4,20 and equability (J), 0,85. The forest has two almost continuous tree strata (1,8-18 m; 20-30 m), plus the emergent trees (to 45 m). Diameter (stem height of Euterpe edulis) distributions of the main species indicate abundant regeneration and stable population structure. This forest is probably at climax or at least approaching the final stage of succession.