Spatial distribution of benthic macroinvertebrates in the Erhai basin of southwestern China

Abstract

The macroinvertebrate communities and relationships with environmental variables were characterized in the Erhai basin by sampling at 44 sites. Among the 76 taxa observed, Baetis sp., Tubificidae, Simulium sp., Eukiefferiella sp., Gammarus sp. and Parakiefferiella sp. were the dominant taxa. Canonical correspondence analysis indicated that seven environmental variables, namely altitude, Ca2+, chemical oxygen demand, NO3-N, total phosphorus, streambed width, and a qualitative habitat evaluation index (QHEI), were significantly related to the distribution of benthic macroinvertebrates. Two-way indicator species analysis divided total sampling sites into four groups. Weighted-averaging regression and crosscalibration produced strong models for predicting NO3-N, altitude, and QHEI, which enabled the selection of the following benthic taxa as potentially sensitive indicators of certain levels of NO3-N, altitude, and QHEI: Aracina, Atrichops morimotoi, Ceratopsyche sp., Guttilelopia sp., and Nemoura sp. for NO 3-N; Heptagenia sp. and Parakiefferiella sp. for altitude; and Aracina for QHEI. © 2012 Taylor & Francis.