简介:Floodingtimingandfrequencymayhavedifferenteffectsonthegrowthandcarbonmetabolismofplantsinwetlands.WetestedthishypothesisusingthreemarshplantsinSanjiangPlain,whichweregrowingindifferentfloodingtimingandfrequencyenvironmentsfor24days.Thethreemarshplantsindifferentelevationsalongawater-levelgradient,high-elevationspeciesCalamagrostisangustifolia,mid-elevationspeciesCarexlimosaandlow-elevationspeciesCarexlasiocarpa.Ourexperimentincluded6kindsoftreatments:control,longerfloodingtiming,medialfloodingtimingandfrequency(2treatments),andhigherfloodingfrequency(2treatments).LongerfloodingtimingandhigherfloodingfrequencytreatmentsledtosimilarreductionsinbiomassaccumulationandrelativegrowthrateofCalamagrostisangustifolia,whereasgrowthofCarexlimosawasnotaffectedbyeitherfloodingtimingorfrequency.However,biomassaccumulationandrelativegrowthrateofCarexlasiocarpawasonlyreducedbythehigherfloodingfrequency.StarchandsolublesugarcontentsofCalamagrostisangustifoliawerenegativelyaffectedbyfloodingfrequency.OnCarexlimosa,higherfloodingfrequencyresultedinhigherstarchcontent,butlongerfloodingtimingledtoaccumulatedstarchcontentinCarexlasiocarpa.SolublesugarcontentsofCarexlasiocarpaandCarexlimosawerenotaffectedbyeitherfloodingtimingorfloodingfrequency.Theseresultsindicatedthatgrowthresponsesofthethreemarshplantstofloodingtimingandfrequencywascloselyrelatedtothedifferentphysiologyofcarbohydratemetabolism.