Influence of microhabitat on diversity and distribution of Ephemeroptera, Plecoptera, and Trichoptera in subtropical forest streams

Abstract

ABSTRACT The distribution of aquatic insects is influenced by several environmental features, especially water quality and substrate. Diversity and distribution of the aquatic community and the distribution of the feeding functional groups (FFGs) of Ephemeroptera, Plecoptera and Trichoptera (EPT) in four microhabitats from low-order streams on a subtropical island were analyzed. Samples were taken with a Surber sampler and environmental descriptors – water temperature (°C), dissolved oxygen (mg/L−1), electrical conductivity (µS.cm−1), depth (cm) and organic matter – were recorded. The distribution of EPT genera was analyzed by a Canonical Analysis of Principal Coordinates, and the relationship of EPT genera and FFGs with the microhabitats was studied using Indicators Species Analysis. Environmental features were analyzed using Redundancy Analysis and BIO-ENV. Results showed that the EPT community structure and FFGs differed between microhabitats in summer and winter, and their occurrence was associated with physical structure habitat and water quality. During the winter, there was a greater abundance of EPT genera, and the community was clearly distinguished among the four microhabitats. Moreover, there was an association of specific genera with particular substrates along the streams. The present study indicated that habitat structure is an important determinant of the EPT composition insects in subtropical streams.