Studies on macrozoobenthic community of Jiuduansha wetland in the Yangtze River estuary

Abstract:

Jiuduansha is a new shoal in the developing process in the Yangtze River estuary. Zoobenthic community is an important part of estuarine ecosystem, which determined many significant ecological processes in the estuarine ecosystem. From 2002 to 2003, we arrived at Jiuduansha three times. The macmzoobenthos were investigated, and the species composition, density and biomass were studied and the ecological characteristics were analyzed. The results showed that there were 27 species of macrozoobenthos on the tidal flat wetland of Jiuduansha. Mollusc and shellfish were the important species. The dominant species on Shangsha shoal were Hyoplax ningpeonsis Shen, llyrplax deschampsi and Stenothyra glabra. The dominant species on Zhongsha shoal were llyrplax deschampsi and Stenothyra glabra . The dominant species on Xiasha shoal were llyrplax deschampsi , Moerella iridescens Helice tridens tientsinensis, A. latericea and Stenothyra glabra. In the Jiuduansha shoal, there were significant differentiation in community structure and diversity of zoobenthos from saline algae zone, Scirpus mariqueter zone to reed community zone along elevational gradient of tidal flat , which reflected the succession process of zoobenthic community with the passage of time and the difference of its tolerance to environmental factors. Space ecological pattern of diversity also reflected the succession of zoonbenthic community of the new Jiuduansha shoal in time.