江汉湖群基准环境与现代环境中的摇蚊属种组合变化

Comparison on chironomid compositions in the reference environment and modern environment of Jianghan floodplain lakes

了解湖泊生态系统基准环境和历史演变规律是进行湖泊生态环境保护和管理的关键.本文研究江汉湖群32个浅水湖泊现代环境和基准环境下的摇蚊组合特征,分析摇蚊组合变化的趋势和影响因素,并探讨了江汉湖群生态和营养参考值.研究发现Paratanytarsus penicillatus-type、Microchironomus tener-type、Cricotopus sylvestris-type、Polypedilum nubifertype、Dicrotendipes nervosus-type、Procladius等为基准环境下的摇蚊优势种.现代环境中Chironomus plumosus-type、Microchironomus tabarui-type、Procladius、Tanypus、Propsilocerus akamusi-type等富营养种明显增多.摇蚊组合CONISS聚类分析结果表明,32个湖泊主要分为3类,其中21个湖泊(第Ⅰ、Ⅱ类)的摇蚊属种与基准环境相比发生了显著变化,主要原因是流域营养盐输入和水生植被的破坏.本研究介绍了摇蚊古生态研究在重建湖泊基准环境方面的应用,并为湖泊管理和生态修复提供参考数据.

The reference condition and historical variability of aquatic ecosystems are key ecological characteristics for understanding the ecological environmental protection and lake ecosystem restoration. Based on chironomid records from 32 lakes in the Jianghan floodplain,this study aims to determine their ecological,chemical reference conditions and the historical variability and its controlling factors. Mesotrophic and macrophyte-related species Paratanytarsus penicillatus-type,Microchironomus tener-type,Cricotopus sylvestris-type,Polypedilum nubifer-type,Dicrotendipes nervosus-type,Procladius etc,were most abundant in the reference samples. Eutrophic-and pollution-tolerate species Chironomus plumosus-type,Microchironomus tabarui-type,Procladius,Propsilocerus akamusi-type,Tanypus etc,were more abundant in the modern samples. Cluster analysis of chironomid composition data from32 lakes based on eutrophication identified three clusters,21 out of the 32 lakes experienced significant change. Nutrient input from the catchment and destruction of aquatic vegetation were key factors that explained the significant species change. This study introduces the application of chironomid paleoecology techniques in reconstructing the historical,ecological characters of lake ecosystems,which will provide essential information for the management of wide ranges of wetland.