DIVERSIDADE E SIMILARIDADE FLORÍSTICA EM ÁREAS SOB INFLUÊNCIA DE UMA USINA HIDRELÉTRICA NA AMAZÔNIA.

Current research evaluates the floristic diversity and similarity of tree species in two areas affected by a hydroelectric plant in the Amazon region, between the states of Amapá and Pará, Brazil. Continuous inventories were undertaken in two sampling modules, each with 5 permanent splits measuring 20 x 250 m (5.000 m2), equidistant 1 km. Shannon and Margalef diversity indexes and Pielou's equability were analyzed. Multivariate grouping techniques were employed in the case of floristic similarity. Further, 646 and 687 specimens were respectively detected distributed in sampling modules A and D. In module A, Shannon and Margalef diversity indexes and Pielou's equability were, respectively, 3.82 nats/ind, 8.04 and 0.87. In the case of module "D", they were, respectively, 3.47 nats/ind, 7.42 and 0.86. Indexes showed that areas had a relatively high diversity and species concentration with high uniformity within the vegetation community. Floristic diversity and composition between affected areas were similar, even though within different topographic conditions. [ABSTRACT FROM AUTHOR]