Influence of taxonomic resolution of stream macroinvertebrate
communities on the evaluation of different land uses
CORBI1, J.J. & TRIVINHO-STRIXINO1, S.
1 Laboratório de Entomologia Aquática, Departamento de Hidrobiologia, Universidade Federal de São Carlos, C. Postal 676, São Carlos, SP, Brasil.
e-mail: julianocorbi@yahoo.com.br
ABSTRACT: Stream macroinvertebrate communities have been widely used as indicators of water quality. The knowledge of the stream macroinvertebrates structure provides fundamental information about the response of this fauna to impacts of chemical and/or physical perturbations resulting from different land uses, as deforestation for agricultural activity or input of domestic and industrial effluents. In Brazil, many studies have been conducted using the macroinvertebrate fauna as bioindicator of land use. However, there is a little information about which is the more adequate taxonomic resolution level for the best biological evaluation of these impacts. In this study we analyze the influence of sugar cane cultivation, pasture and presence of riparian vegetation on the aquatic macroinvertebrate communities of 9 streams located on Cerrado areas of the State of São Paulo (Brazil). This fauna was analyzed using two taxonomic levels: macroinvertebrates families and chironomid species. The community indices applied to these two taxonomic levels show, in general, similarity of results, that is, higher values of richness and diversity, and lower dominance for the communities living on streams protected by the riparian vegetation. These results allow concluding that for streams of the studied region, the family level of taxonomic resolution was enough to evaluate the effect of the agricultural land use.
Key-words: stream macroinvertebrates, land uses, taxonomic resolution, bioindicators.