Influence Of Two Neotropical Ecoregions In The Community Of Benthic Macroinvertebrates

This study aimed to investigate the differences of the macroinvertebrate community in two neotropical ecoregions. In this regard were sampled in 12 low-order streams, biological samples (benthic macroinvertebrates), water samples to determine physical and chemical characteristics (pH, dissolved oxygen, altitude, water temperature, alkalinity, water hardness, total nitrogen and total phosphorus) and was evaluated of the substrate in the riverbed. To compare attributes between the two ecoregions, was used the ANOVA and for the analysis of the structure and its relation with the physiographic parameters, the data were summarized by Principal Component Analysis. In addition, were classified the functional groups and indicator groups for each ecoregion. There were no differences between the ecoregions for attributes, however, the structure was different according to the PCA. Functional groups had different percentages for each ecoregion. The indicator taxa for Ecoregion 'A' were Baetidae, Aeshnidae, Coenagrionidae, Chironomidae and Ceratopogonidae and for Ecoregion 'B', the indicator taxa were Leptohyphidae, Caenidae, Perlidae, Pleidae and Psephenidae. The presence of the sensible indicator taxa infers that Ecoregion 'B' shows better habitat condition, It is due to the structural difference in substrate types, alkalinity, dissolved oxigen and water temperature.