Influence of environmental heterogeneity on the attributes of Chironomidae community in neotropical floodplain lakes

The environmental structure is an important factor influencing the communities distribution. In this context, physically more complex environments sustain higher species richness than those simpler. We aimed to evaluate the influence of environmental heterogeneity on the atributes of Chironomidae community, such that to determe their spatial distribution in different lakes from the Upper Paraná River floodplain. Samples were collected quarterly from March to December 2011 in six environments (three lakes with connection and three lakes without connection to main river). We determined the lacustrine heterogeneity, by the Environmental Score of each lake, which was calculated by summing of chemical, physical and biological features of the lakes. The correlations between the environmental heterogeneity with the richness, density and diversity of chironomid species were significant. These results suggest that the lakes with the greatest environmental heterogeneity (or highest Environmental Score) are more able to support a higher number of individuals and taxa.

Richness; granulometric texture; distribution of organisms