Prevention of growth of potentially dense phytoplankton populations by zooplankton grazing, in the presence of zooplanktivorous fish, in a shallow wetland ecosystem
Prevention of growth of potentially dense phytoplankton populations by zooplankton grazing, in the presence of zooplanktivorous fish, in a shallow wetland ecosystem
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DOI：
10.4319/lo.1984.29.3.0472
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发表时间：
1984-05
影响因子：
4.5
通讯作者：
R. Timms;B. Moss
中科院分区：
文献类型：
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作者：
R. Timms;B. Moss
在两个相连的浅水淡水流域，浮游植物密度在夏季有很大的不同。哈德逊湾支持一个大的立场睡莲，和邻近的开放水域是明确的叶绿素a浓度一般100皮克 * 升。在生物测定中，哈德逊湾的水在夏季可以支持大量的浮游植物生长，在春季和秋季也是如此。期间的清水正好与存在的百合stand.Zoopancomatic轮虫和小型的枝角类在Hoveton大宽，但主要是枝角类，包括大型个体的plantassociated物种，在哈德逊湾。食虫鱼类存在，有证据表明，他们在两个盆地喂养。与鱼类的大，显然有效地放牧枝角类在哈德逊湾取决于白天的避难所提供的百合之间的枝角类，放牧是最大的在邻近的开放水域在夜间。放牧控制有助于水文制度，有利于小型和快速增长的植物，而不是不可食用的殖民地形式与缓慢的增长。杂草相关的食草动物可能是重要的，在浅水湖泊，否则将更迅速地成为浮游植物占主导地位的营养负荷增加，以维持水生植物的优势。
In two linked, shallow, freshwater basins, phytoplankton densities in summer were very different. Hudsons Bay supported a large stand of water lilies, and the adjacent open water was clear with chlorophyll a concentrations generally 100 pg*literl. Hudsons Bay water, in bioassays, could support great phytoplankton growth in summer and did so in spring and fall. The period of clear water coincided with the presence of the lily stand. Zooplankton populations were of rotifers and small-bodied Cladocera in Hoveton Great Broad, but mostly of Cladocera, including large-bodied individuals of plantassociated species, in Hudsons Bay. Zooplanktivorous fish were present and there was evidence of feeding by them in both basins. Coexistence with fish of the large, apparently efficiently grazing Cladocera in Hudsons Bay depended on provision of daytime refuges for the Cladocera among the lilies, and grazing was greatest in the adjacent open water at night. Grazing control was helped by a hydrological regime which favored small and rapidly growing phytoplankters, rather than inedible colonial forms with slow growth. Weed-associated grazers may be important in maintaining the dominance of aquatic plants in shallow lakes which would otherwise more rapidly become dominated by phytoplankton as nutrient loading increased.