Structure and Composition of vascular epiphytes in a two vegetation formations in Ilha da Marambaia Mangaratiba, RJ / Estrutura e Composição de epífitas vasculares em duas formações vegetais na Ilha da Marambaia Mangaratiba, RJ

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The vascular epiphytes belong to a guild that occupies other plants (usually arboreous species) as support for fixing without parasiting them. This way of life have some disadvantages for the nutrients and water acquisition and therefore showed itself excessively sensitive to environmental variations in the forest. Having in view this aspect among others, the structures, composition and distribution of vascular epiphytes of two distinct vegetation formations (restinga and subspontaneous population of Elaeis guineensis Jacq.) and moreover, a floristic survey was conducted for all areas of the island. At each of the sampling units were allocated 50 parcels of 100 m, totaling 1 ha. At each sample, the epiphytes were counted in phorophytes with DBH ≥ 10 cm and the phorophytes were divided into height classes. In the restinga area were found 16 species belonging to 10 genera and five families, as well as new records for four species. At the area of subspontaneous population of Elaeis guineensis (Arecaceae) were found 24 species belonging to 22 genera and 15 families, with registration of five new species to the Island. For both areas it was found low richness with almost absence of the Orchidaceae family, considered one of the most abundant among the epiphytes. In general, there were no defined standards among the species distribution over the height classes of phorophytes. The morphometric variables tested by simple linear regression indicated that in general the phorophyte size directly influences the richness and abundance of epiphytes. The horizontal distribution was analyzed using the Morisitas index, indicating that most species presents an aggregated distribution, as well as anemochorous dispersion was the most recurrent among species. As the epiphytic flora of the island of Marambaia were listed 93 species, 53 genera and 21 families, indicating that low richness may be linked to the fact that the island of Marambaia be a region with a low rate of rainfall.

ASSUNTO(S)

conservação conservacao da natureza ecologia vegetal epiphytes epífitas plant ecology conservation

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