杭州西溪湿地大型底栖动物群落特征及与环境因子的关系

Abstract

为揭示现阶段西溪湿地大型底栖动物群落现状及其对湿地生态保护工程的响应,于2009年8月至2010年5月对西溪湿地在3个不同时期建设的区域(Ⅰ区、Ⅱ区和Ⅲ区)中的大型底栖动物进行季度调查.共记录大型底栖动物3门8纲15科45种.霍甫水丝蚓(<em>Limnodrilus hoffmeisteri</em>)、多毛管水蚓(<em>Aulodrilus pluriseta</em>)和梨形环棱螺(<em>Bellamya purificata</em>)是现阶段西溪湿地大型底栖动物的优势种.最早建设的Ⅰ区的环节动物密度在各季节均低于建设较晚的Ⅱ区和Ⅲ区,而软体动物的密度和生物量的变化趋势则相反;Ⅰ区大型底栖动物的总密度虽然与Ⅱ区和Ⅲ区没有明显差异,但总生物量、物种数、Margalef物种丰富度指数和Shannon-Wiener多样性指数均显著上升.上述结果表明,西溪湿地生态保护工程早期建设区域的底栖动物多样性趋于增加,水生生态系统环境质量得以改善.ANOSIM分析显示,西溪湿地不同区域或季节间大型底栖动物群落结构均存在显著差异,且这些差异的主要贡献物种为多毛管水蚓(<em>Aulodrilus pluriseta</em>)和梨形环棱螺(<em>Bellamya purificata</em>),表明这两个优势物种对西溪湿地底栖环境变化反应敏感,可作为湿地环境评价的指示物种.BIO-ENV分析表明,水温是影响春季和夏季大型底栖动物群落结构的主要环境因子,水深是影响秋季和冬季大型底栖动物群落的主要因子,同时底泥总磷含量对解释大型底栖动物生物量和群落结构具有一定作用.;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. <em>Limnodrilus hoffmeisteri</em>,<em>Aulodrilus pluriseta </em>and <em>Bellamya purificata</em> were the dominant species in Xixi Wetland. The density of Annelida of area Ⅰ, which was carried out early, was lower than areaⅡand areaⅢ. However, the changes of density and biomass of Mollusca were different. Total density of macrobenthos in areaⅠhad no significant differences between areaⅡand areaⅢ. 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 <em>A.pluriseta</em> and <em>B.purificata</em>. 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.