Biotemas (May 2004)
Species richness and floristic composition in a dune environment after 50 years of anthropic pressure: a study in the Boa Viagem beach, Recife, PE – Brazil
Abstract
The vegetation of sandy-coastal ecosystems is important to the fixing and maintenance of dunes in order to avoid the sand movement. In urban areas, however, the anthropic pressure may disrupt these ecosystems. In Recife, Brazil, we conducted a temporal analysis on changes of the dune vegetation related with the increasing anthropic pressure. Between November 1999 and May 2000, we sampled 6 km of the coastal plant community of Boa Viagem beach (8º06’02”S and 34º52’48”W) and compared the samples with those taken in a survey carried out by Andrade-Lima in 1951. We found 47 plant species, of which ten were halophytes, 34 were ruderals, and three were cultivated. Leguminosae and Poaceae were the richest families, and both consisted of nine species (19%). We found 18 species which were previously unknown, and ten species that no longer exist today. There are no significant differences in the species’ richness and in the proportion of ruderal species between the two surveys. On the other hand, the species composition shows a significant difference. It is reasonable to suppose that the changes in floristic composition are probably a consequence of the anthropic pressure, even though no significant changes were detected in the species’ richness and the proportion of ruderal species.
