Fitoplâncton de um lago de inundação amazônico (Lago Catalão, Amazonas Brasil): estrutura da comunidade, flutuações espaciais e temporais

Abstract

This study analyzed the attributes of the phytoplankton community (species richness, diversity, equitability, density, size structure and rate of community compositional change), associated with some physical and chemical characteristics of a floodplain lake from Central Amazon, Brazil, (Lake Catalão) during the low water (2006) and high (2007) periods , through four consecutive weeks in each period. The lake presented different limnological characteristics between the periods of high and low water. The phytoplankton was composed of 235 taxa, mainly nanoplanktonic algae, especially Chlorophyceae and Cyanobacteria. In both periods the functional group X1 was the most prominent association regarding density of organisms. The canonical correspondence analysis (CCA) demonstrated a separation between sample points in the low water period, determining a spatial pattern for this period. In the other hand, in the high water period, the highest differences were registered between the weeks. The CCA demonstrated also, a separation between the high and low water periods when considering the phytoplanktonic composition and the physical and chemical parameters of Catalão lake.