简介：Background:Capturingtheresponseofforestecosystemstointer-annualclimatevariabilityisagreatchallenge.Inthisstudy,wetestedthecapabilityofanindividual-basedforestgapmodeltodisplaycarbonfluxesatyearlyanddailytimescales.Theforestmodelwasappliedtoaspruceforesttosimulatethegrossprimaryproduction(GPP),respirationandnetecosystemexchange(NEE).Weanalyzedhowthevariabilityinclimateaffectedsimulatedcarbonfluxesatthescaleoftheforestmodel.Results:Sixyearsweresimulatedatadailytimescaleandcomparedtotheobservededdycovariance(EC)data.Ingeneral,theseasonalcycleoftheindividualcarbonfluxeswascorrectlydescribedbytheforestmodel.However,theestimatedGPPdifferedfromtheobserveddataonthedaysofextremeclimaticconditions.Twonewparameterizationsweredeveloped:oneresultingfromanumericalcalibration,andtheotherresultingfromafilteringmethod.Wesuggestnewparametervaluesandevenanewfunctionforthetemperaturelimitationofphotosynthesis.Conclusions:Theforestmodelreproducedtheobservedcarbonfluxesofaforestecosystemquitewel.Ofthethreeparameterizations,thecalibratedmodelversionperformedbest.However,thefilteringapproachshowedthatcalibratedparametervaluesdonotnecessarilycorrectlydisplaytheindividualfunctionalrelations.TheconceptofsimulatingforestdynamicsattheindividualbaseisavaluabletoolforsimulatingtheNEE,GPPandrespirationofforestecosystems.