Abstract: Several enclosure experiments, which combined various factors such as season, nutrient concentration, macrozooplankton species and density, were conducted to examine the control effect of macrozooplankton on excessive growth of phytop-lankton. At total P-concentrations between 0.039 and 0.119mg/L, total N-concentrations between 1.01 and 1.78mg/L, mega-herbivorous zooplankton such as Daphnia magna can effectively control the overgrowth of phytoplankton in summer and autumn (June-Oct.), resulting in improving of the water quality. Community response such as chlorophyll a concentration can be depressed by macrozooplankton. At the population level, not only the net growth rate of green algaespecies (such as Ankistrodesmus angustus Bern., Pediastrum simplex (Mey) Lemm., Selenastrum minutum(Nag.) Coll.and Scenedesmus) can be reduced by D magna, but also that of diatoms species (such as Melosira) and blue green algae species (eg.Merismopedia elegans A.Br.) can be decreased. Biomanipulation is regarded as an effective maethod to control excessive phytoplankton growth. Introducing mega-herbivorous zooplankton into lakes and(or) reducing grazing pressure of fishor producing shelters are proposed to achieve sufficient density of macrozooplankton.

Key words: macrozooplankton, phytoplankton, enclosure, biomanipulation

摘要： 本文通过受控生态系统试验研究了大型浮游动物对浮游植物的控制作用。试验结果表明，在适当的富营养条件下，通过合理的生物操纵，使得大型渴、平突船卵、等大型植食性浮游动物达到和维持足够的密度，浮游动物在夏秋季能够有效地控制浮游植物的过量生长，改善水质。

关键词: 大型浮游动物, 浮游植物, 围隔, 生物操纵