Uso de coleópteros aquáticos para caracterização de riachos conservados do cerrado brasileiro

Abstract

In landscapes that are under high anthropogenic pressure, like the Brazilian Cerrado, it is important to define the reference conditions that are present in the still existing pristine areas. The use of biological indicators allow to characterize these habitats, and furthermore can highlight early stages of degradation. In this study, we aim to investigate whether pristine streams from the Brazilian Cerrado could be characterized using aquatic beetles (Coleoptera), and whether early community’s responses could be evidenced for a low impairment. Field work was performed during the dry season of 2010 in the state of Goias, Brazil. Surber samples were taken from 48 streams located in two Watersheds: river Paraná and river Tocantins. A total of 4.194 individuals of aquatic Coleoptera were collected representing 42 taxa. The streams could be classified in five groups on the bases of the taxonomic structure and composition of the community. Conductivity and turbidity were the main driving variables. Stream impairment related to landscape degradation impacted the aquatic beetles communities, namely driving the morphological traits linked to respiration. This study evidenced that coleopteran can be used for characterization of pristine streams. Nevertheless, they are not appropriated for detecting early states of degradation, and for this an approach using a set of individuals from different Orders of aquatic macroinvertebrates is likely to be more efficient.