Riqueza, abundância e sazonalidade de comunidades de macroalgas em diferentes escalas espaciais em riachos da região centro-sul do estado do Paraná

Abstract

The structure and seasonality of benthic macroalgal communities of lotic ecosystems was evaluated at different spatial scales of observation in streams of the central-southern region of Paraná State. Samples were collected monthly from January to December 2007. We found 16 taxa (38% Cyanobacteria, 31% Chlorophyta, 19% Rhodophyta and 12% Heterokontophvta) without a confirmed seasonality pattern.The floristic composition varied at all spatial scales corroborated by low values of diversity index. The most significant differences were obtained for the drainage basin and shading scales, especially regarding the availability of light energy. Richness and abundance of species had seasonal patterns influenced by variables current velocity (mesohabitat) and irradiance (shading) respectively. Both variables have been widely described as determining factors on the community structure of lotic macroalgae.