Epífitas vasculares da Ilha Grande, Angra dos Reis, RJ

Abstract

The Atlantic Forest corresponds to one of the diversity centers for plants of epiphytic habit in the world and, despite its taxonomic and ecological importance in the environments, many areas still do not have floristic inventories of this community. The present study has the following objectives: to contribute to the knowledge of the vascular epiphyte flora of Ilha Grande, Angra dos Reis, RJ, to analyze the ecological parameters and state of conservation of the epiphytes of the restinga forest of the State Biological Reserve of Praia do Sul (RBEPS), suggest an alternative protocol for sampling the epiphytic community, and evaluate the effect of tree morphometry and spatial variation on species richness and composition. The floristic survey was based on consultations to collections of herbarium, the Flora Catalog of Rio de Janeiro, lists of species published for the study area and on fieldwork. We used the RAPELD plots, a method used to sample the biodiversity of Brazilian ecosystems, suitable for rapid inventories (RAP) and long term ecological projects (PELD). We demarcated 52 subplots of 100 m2 in the RAPELD permanent plots installed in the RBEPS restinga forest. We recorded all epiphytes and hemiepiphytes of trees with a diameter at breast height (DBH) greater than or equal to 45 cm in the subplots and measured the dendrometric data of the trees. We raised 213 species to Ilha Grande and, the RBEPS sampling resulted in 31 species and 10 new records for the island. The richest families of Ilha Grande were Orchidaceae and Bromeliaceae and in RBEPS were Araceae and Bromeliaceae. Most of the species are endemic to the Atlantic Forest, have an unknown conservation status and seven are listed in the Flora Red Book of Brazil. The species richness in the RBEPS was related to the spatial variation and to DBH and its composition, both with the spatial variation and the morphometric characteristics of the trees, except for the average top diameter. The suggested methodology is efficient and should be used for conducting quick inventories, as well as for collecting additional ecological information about the epiphytic community. Ilha Grande has one of the greatest riches in southern and southeastern Brazil and, therefore, can be considered an important area for the preservation of epiphytic biodiversity, it is necessary to sample other phytophysiognomies of the island and to develop ecological researches that may generate the necessary subsidies for the protection of species and ecosystems.