Phytoplankton community of floodplain lakes of the Araguaia River, Brazil, in the rainy and dry seasons

Abstract

This work analyses the attributes of the phytoplankton community (species richness, biovolume, diversity, equitability, abundance, dominance and size structure) associated with some physical, chemical and climatic variables of floodplain lakes of the Araguaia River, central Brazil, in the rainy and dry seasons of 2000 and 2001. The lakes in 2000 and 2001 presented different limnological characteristics between the periods of high and low water. The phytoplankton comprised 292 taxa, mainly Chlorophyceae and nanoplankton. In the dry seasons of both years, the functional group Υ (Cryptophyceae) was the most prominent association. In high-water periods, different functional groups dominated the lakes. The canonical correspondence analysis (CCA) demonstrated a separation between the rainy and dry seasons of both years. The high and low water presented different dynamics in 2 years due to the influence of the flood pulse. © The Author 2005. Published by Oxford University Press. All rights reserved.