泛滥平原湿地位于河流与洪水淹没线之间，包括浅水湖泊、河漫滩等。泛滥平原湿地与河流的自由水文连通对维持生物多样性和生态健康至关重要。由于20世纪50至70年代的筑坝建闸，长江泛滥平原大部分湖泊与干流阻隔，导致生物多样性锐减、生物资源衰退。底栖动物可指示环境的长期变化，且对水文条件的改变反应敏感，研究该类群与水文连通度的关系对泛滥平原湿地管理和保护有重要意义。那么，底栖动物在水文连通梯度上的响应模式是怎样的呢？

近日，中国科学院水生生物研究所潘保柱、王海军、梁小民和王洪铸在底栖生物学领域重要刊物《北美底栖生物学会期刊》（Journal of the North American Benthological Society）(2011, 30(2): 589-602)发表论文“Macrozoobenthos in Yangtze floodplain lakes: patterns of density, biomass and production in relation to river connectivity”，回答了这一问题。

通过2003至2007年间对长江泛滥平原30余个阻隔湖泊、3个通江湖泊及10个长江干流江段的野外生态调查，该文揭示了长江泛滥平原湿地底栖动物群落特征与水文连通度的关系。结果显示，底栖动物的物种多样性在一定的江湖水文连通度下达到最大，且生物量和生产量也同时达到最大。这些结果不仅证实了国外关于在中等程度的水文连通度下生物多样性达到最大的理论，而且首次提出总体生物量也同时达到最大。结果表明，适度水文连通对维持泛滥平原湿地生态系统健康至关重要。

该研究受到国家自然科学基金委和中国科学院的联合资助。

原文出处：

Journal of the North American Benthological Society

Macrozoobenthos in Yangtze floodplain lakes: patterns of density, biomass, and production in relation to river connectivity

Bao-Zhu Pan, Hai-Jun Wang, Xiao-Min Liang, and Hong-Zhu Wang

A systematic investigation of macrozoobenthos was conducted in Yangtze floodplain waters to reveal patterns of density, biomass, and production in relation to river connectivity. In the Yangtze-connected lakes, 78 taxa belonging to 33 families and 62 genera were identified. Macrozoobenthos density was 327 individuals/m2, biomass was 1.40 g dry mass/m2, and production was 3.23 g dry mass m?2 y?1. The assemblages were characterized by high diversity, high production, and high bivalve-filterer abundance. The key factor determining the macrozoobenthic assemblages was river connectivity. As river connectivity increased, 3 types of response patterns were observed: 1) density, biomass, and production of collector-filterers (mainly Bivalvia), shredders (e.g., Stictochironomus), and predators (e.g., Dytiscidae) showed unimodal changes, i.e., first increased and then decreased; 2) density, biomass, and production of collector-gatherers (mainly Tubificidae and Chironomidae) decreased continuously; and 3) density of scrapers (mainly Gastropoda) decreased, whereas their biomass and production changed unimodally. At an intermediate level of river connectivity, biomass and production of total macrozoobenthos reached maxima, whereas density decreased with increasing river connectivity. Previous research showed that α diversity of zoobenthos also peaks at moderate connectivity with rivers. Therefore, to maintain high productivity as well as high biodiversity in the Yangtze floodplain, protecting the remnants of river-connected lakes and linking disconnected lakes freely with the mainstream are crucial.