Ecological characteristics of macrobenthic communities and its relationships with enviromental factors in Hangzhou Xixi Wetland

Abstract

To explore the status of macrobenthic communities and their response to the ecological restoration in Xixi Wetland, we surveyed the diversity of macrobenthos at three areas between in August of 2009 and May of 2010. We recorded 45 species from 15 families, 8 classes and 3 phyla. Limnodrilus hoffmeisteri,Aulodrilus pluriseta and Bellamya purificata were the dominant species in Xixi Wetland. The density of Annelida of area I, which was carried out early, was lower than areaII and area III. However, the changes of density and biomass of Mollusca were different. Total density of macrobenthos in area I had no significant differences between area II and area III. But there were significant differences in the total biomass, number of species, Margalef abundance index and Shannon-Weaver index. These results suggested that the diversity of macrobenthos had been increased and the quality of environment had been improved by the restoration project in Xixi Wetland. ANOSIM showed that the structure of macrozoobenthic communities differed significantly between different areas and seasons, and the main contributing species were A. pluriseta and B. purificata. It indicated that the two dominant species were sensitive to the changing of environment in Xixi Wetland which could be indicator species in environmental assessment of Wetland. Using BIO-ENV (biota and environment analysis), we found that water temperature was the key factors affecting the macrozoobenthic communities in spring and summer, whereas water depth was the key factors affecting the macrozoobenthos in autumn and winter. The total phosphorus of sediment was related to the macrozoobenthic biomass and community structure.