流速对浮游藻类生长和种群变化影响的模拟试验

Sci．(湖泊科学)，2015，27(1)：4449http：#www．jlakes．org．E—mail：jlakes@niglas．ac．cn@2015byJournalofSciences流速对浮游藻类生长和种群变化影响的模拟试验李飞鹏，高雅，张海平，肖宜华，陈玲(1：同济大学环境科学与工程学院，上海200092)(2：同济大学建筑设计研究院(集团)有限公司，上海200092)摘要：采集夏季崇明岛中心湖原水，在环形有机玻璃水槽开展了不同流速对浮游藻类生长和种群变化影响的研究．相对于静止水槽，实验前期不同的流速条件均对浮游藻类的生长产生了一定的抑制作用，实验后期浮游藻类叶绿素a含量均稳定在一定水平，且流动水槽中叶绿素a含量略大于静止水槽，这可能与静止围隔中出现大量枝角类浮游动物有关，而流动条件则抑制了浮游动物的生长，减轻了对浮游藻类的捕食压力．水体流动导致了浮游藻类种群的变化，蓝藻的迅速消失、绿藻和硅藻形成生长优势是主要特征，表明持续的流动条件是导致浮游植物种属减少和群落结构变化的直接原因．该研究可为调水引流在河道、湖泊和水库中的富营养化控制和水华防治提供基础依据．关键词：流速；浮游藻类；种群变化；模拟试验Simulationexperimentontheefectofflowvelocityonphytoplanktongrowthandcompo—sition、LIFeipeng，GAOYa，ZHANGHaiping，XIAOYihua＆CHENLing(1：CollegeofEnvironmentalScienceandEngineering，TongjiUniversity，Shanghai200092，P．R．China)(2：TongfiArchitecturalDesign(Group)Co．，Ltd．，Shanghai200092，P．R．China)Abstract：AnexperimentalsimulationstudywasconductedusingsurfacewaterfromZhongxinhuLakeofChongmingIslandinovalplexiglassenclosures．Theobjectofthestudywastoinvestigatetheefectofflowvelocityonphytoplanktongrowthandcompositiondynamics．Bothflowconditionshadinhibitionefectsonphytoplanktonbiomassinearlyexperimentcomparedwiththestillenclo—sureandinlateexperimentthephytoplanktonbiomassstabilizedinacertainlevelinallenclosures．Moreover，ahigherCh1．acon—eentrationwasfoundinbothflowenclosuresinthelateexperiment，implyingthatnumerousCladocerazooplanktonoccurredinthestillenclosuremightbethereasonthatinflowconditionstheturbulentflowsinhibitedthegrowthofzooplanktonandreducedthepredationpressureofphytoplankton．Theturbulentflowalsoresultedinthechangesofphytoplanktoncompositionwiththefeatureoftherapiddisappearanceofblue—greenalgaeandthedominationofgreenalgaeanddiatoms．Theresultindicatedthatthecontinu—OUSflowmaydirectlycausedthereducingspeciesandcompositiondynamicsofphytoplankton．Thestudycanprovidebasisoftheapplicationofwaterdivisionineutrophicationmanagementandalgaebloompreventionofrivers，lakesandreservoirs．Keywords：Flowvelocity；phytoplankton；speciesdynamics；simulationexperiment流速是水动力条件中最基本、最直观的参数，对浮游植物的生