Composition, diversity and geographical distribution of vascular plants of an Atlantic Rain Forest, Southeastern Brazil

Abstract

In the Montane and Submontane Rain Forest of the Carlos Botelho State Park - PECB (ca. 37,000 ha) the composition, richness and geographical distribution of native, vascular forest species was evaluated. The analysis of 1143 species of 140 families supported the pattern found for other forests of Eastern Brazil, showing high species richness of Myrtaceae (85 species), Orchidaceae (81), Fabaceae (57), Asteraceae, Melastomataceae (54), Lauraceae (53), Rubiaceae (51), Bromeliaceae (43), Piperaceae (30) and Solanaceae (25), besides ferns (123). The most species-rich genera were Eugenia (34), Ocotea (26), Leandra, Myrcia, Vriesea (18), Piper, Solanum (16), Miconia (14), Mollinedia (13), and Peperomia (12). The richness and composition varied greatly among life forms, as well as the number of families represented in each one of them (only Rubiaceae had species in all life forms, except parasites). Trees had the largest contribution of total richness (39.1%), a value that represented more than 20% of the species listed for the whole Atlantic Forest of Southeastern Brazil. Trees were followed by epiphytes (22.4%), herbs (18.4%), shrubs (10.1%), lianas (9.1%), and parasites (0.9%). The overall richness and composition of life forms was quite close to other neotropical forests (e.g. high contribution of ferns among epiphytes), although some life forms remain undersampled in the PECB (mainly herbs, lianas and epiphytes). The occurrence of species endemic to the Atlantic Forest was pronounced (65%), with a predominance of species restricted to the Southern Atlantic Forest (43%). Pantropical species were rare (2%), being more common among ferns. Myrtaceae and Melastomataceae were the families with greater number and proportion of endemic species.