长江口九段沙湿地底栖动物群落研究

九段沙是长江口现代发育过程中的一个新生沙洲。于2002年5月、8月和2003年11月分三次上岛,调查了岛上的底栖动物资源,分析了底栖动物群落的种类组成、动态特征以及湿地生境变化与底栖动物群落结构空间格局变化的相互关系。结果表明,大型底栖动物27种,主要由软体动物和甲壳动物组成。上沙的优势种为宁波泥蟹(Hyoplax ningpeonsisShen)、谭氏泥蟹(Ilyrplax deschampsi)、彩虹明樱蛤(Moerella iridescens)、光滑狭口螺(Stenothyra glabra)等;中沙优势种为谭氏泥蟹(Ilyrplax deschampsi)、光滑狭口螺(Stenothyra glabra);下沙优势种为谭氏泥蟹(Ilyrplax deschampsi)、彩虹明樱蛤(Moerella iridescens)、天津厚蟹(Helice tridens tientsinensis)、绯拟沼螺(A.latericea)、光滑狭口螺(Stenothyra glabra)等。从光滩以软体动物为主的群落,到海三棱草(Scirpus mariqueter)、草带(Scirpus triqueter)以蟹类、软体动物为主的群落,发展到芦苇带(Phragmites australis)以蟹类为主的群落,趋势是生物多样性增高,群落结构趋于复杂,表现出明显的演替序列。

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

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.