Odonata assemblages as indicators of stream condition - a test from northern Argentina

Abstract

The increasing consumption of natural resources due to population growth, and the expansion of agricultural activity have a major impact on freshwater ecosystems. The aim of this study was to verify if possible changes in habitat condition and physical-chemical variables due to different land uses are reflected by changes in Odonata assemblages. In order to do that, we evaluated the conservation status of the riparian zone and the physicochemical parameters of stream waters affected by different degrees of anthropogenic impact, and assessed richness and variation in species composition, testing for potential indicator species of habitat quality. The riparian index allowed the differentiation of three habitat condition categories: conserved, intermediate anddegraded. No significant differences were found in species richness between the three conservation states, but it was possible to discriminate between the communities present. Four species showed potential as habitat quality indicators that can serve as biomonitors in future strategies of stream management and conservation.