Tree and shrub species of the Atlantic Forest on the slopes of Marambaia Island, Rio de Janeiro, Brazil

This study describes the tree and shrub component of the Atlantic Forest on the slopes of Marambaia Island, RJ. It further evaluates which species are found at threatened species lists and the similarity that the studied forest component has with other nearby locations with similar vegetation. Data gathering relied on the joint effort of arbitrary walks and sampling units known as Transect. The same sampling criterion was applied at both approaches (DBH greater than or equal to 5 cm). A similarity analysis, followed by a Cluster analysis, was used to compare the studied vegetation component. Similarity calculations were based in the Bray-Curtis coefficient. We detected a total of 235 species. These are divided in 134 genera and 52 families. The richest families are Myrtaceae (38 spp.), Fabaceae (20 spp.) and Rubiaceae (20 spp.). The richest genera are Eugenia (16 spp.), Myrcia (8 spp.) and Ocotea (6 spp.). Nineteen of the detected species are currently listed as threatened and the studied forest component is mostly resembled to the vegetation at Rio Bonito (RJ). Our evidence shows that the evaluated tree and shrub layer seems to be well preserved and represents an important area for conservational efforts. The results additionally indicate that this vegetation seems to have a greater floristic resemblance to drier and further locations, rather than to more humid and close ones.