简介：Multi-parameterstudies(stableisotopesincarbonateandorganicmatter,pigment,organiccarbonandnitrogencontents)froma660-yrcontinuoussedimentcorefromLakeCheng-hai,aclosed,eutropiclakeinsouthernChina,provideinformationonlakehistoricaleutrophi-cation.Duringthelast660years,greatchangeshavetakenplaceinproductivityandeutrophi-cationofLakeChenghaiinresponsetohumanactivities.In1690,theproductivityofthelakebegantoincreaseasLakeChenghaibecameclosedfromagricultureinthelake'swatershed.In1942,LakeChenghaievolvedtoeutrophicstate,markedbyanincreaseinorganiccarbon,ni-trogen,CaCO3,pigmentcontentsandobviousnegativevaluesofstableisotopes,whichismoreorlesssimultaneouswiththelarge-scalepopulationimmigrationduringtheperiod.In1984,in-tensivehumanactivitiesinducedmodernlacustrineproductivityandeutrophiclevel.Human-in-ducedtrophicchangesduringthepastfewdecadeshaveaffectedtheLakeChenghaiecosystemtosuchanextentthatithasneverexperiencedbeforeinthelast660years.