Community structure and distribution patterns of stream macroinvertebrates in the Huai River Basin in China

Damaged river ecosystems are increasing with rapid social and economic development. The community structure and spatial distribution pattern of stream macroinvertebrates reflect the health of river ecosystems because of their longevity, abundance in terms of taxa and quantities, sensitivity to environment stresses and amenability to surveying. In the present study, two field surveys for macroinvertebrate sampling were performed in August 2010 and May 2013. In all, 53 taxonomic groups from 24 families, belonging to 11 orders, 6 classes and 4 phyla, were recorded. The most widespread taxa were Tubificidae (Limnodrilus, Branchiura) and Chironomidae (Chironomus, Einfeldia), which were also the most abundant in the research area, occurring in more than 50% of sampling sites. Principal coordinate and clustering analyses partitioned the 59 sites into four groups, with similarities in their macroinvertebrate community structures. Moreover, indicator value (IndVal) analysis identified two indicator taxa each in Group 1 (Einfeldia spp. and Chironomus plumosus) and Group 4 (Tubificinae spp. and Limnodrilus claparedeianus), and one indicator taxon each in Group 2 (Branchiura sowerbyi) and Group 3 (Limnodrilus hoffmeisteri). Moreover, collector-gatherers and predators occurred primarily in Group 3, whereas collector-filterers, scrapers and shredders were primarily distributed in Group 2, indicating significant differences in the resources and habitats between Groups 2 and 3.