简介：Ｈｏｗ　ｔｈｅ　ｐｏｌｌｕｔｉｏｎ　ｓｔｒｅｓｓ　ａｃｔｉｎｇ　ｏｎ　ｔｈｅ　ｐｈｙｔｏｐｌａｎｋｔｏｎ　ｐｏｐｕｌａｔｉｏｎｓ　──ａｎ　ｏｂｓｅｒｖａｔｉｏｎ　ｂｙ　ｔｈｅ　ｅｘｐｅｒｉｍｅｎｔａｌ　ｅｎｃｌｏｓｅｄ　ｅｃｏｓｙｓｔｅｍＴａｎｇＳ...

简介：Effectsofnitrogen(N)andphosphorus(P)fromdifferentsourcesandatdifferentconcentrationsonthegrowthofLevanderinafissa(=Gyrodiniuminstriatum)werestudiedinlaboratoryconditions.ThefindingsmightexplaintherecurrentbloomsofthisspeciesinPearlRiverEstuary,China.ResultsshowedthatnutrientlimitationsignificantlyinhibitedthegrowthofL.fissa.Thevaluesofspecificgrowthrate(μmax)andhalf-saturationnutrientconcentration(KS)were0.37divisions/dand8.49μmolL?1forN,and0.39divisions/dand1.99μmolL?1forP,respectively.BasedonKSvalues,dissolvedinorganicNlevelinPREwassufficienttosupportthehighproliferationofL.fissa,whiledissolvedinorganicPconcentrationwasfarlowerthantheminimumrequirementforitseffectivegrowth.L.fissawasnotabletoutilizedissolvedorganicN(DON)compoundssuchasurea,aminoacids,anduricacid.However,itgrewwellbyusingawidevarietyofdissolvedorganicP(DOP)sourceslikenucleotides,glycerophosphate,and4-nitrophenylphosphate.TheresultsfromthisstudysuggestedthattheabilityinDOPutilizationofL.fissaoffersthisspeciesacompetitiveadvantageinphytoplanktoncommunities.ThehighlevelandcontinuoussupplyofDIN,enrichmentofDOP,togetherwithwarmclimateandlowsalinityinthePearlRiverEstuaryprovidedasuitablenutrientnicheforthegrowthofL.fissa,andresultedintherecurrentbloomsintheestuary.