Background:Thelargepotentialofthesoilorganiccarbon(SOC)pooltosequesterCO2fromtheatmospherecouldgreatlyamelioratetheeffectoffutureclimatechange.However,thequantityofcarbonstoredinterrestrialsoilslargelydependsuponthemagnitudeofSOCmineralization.SOCmineralizationconstitutesanimportantpartofthecarboncycle,andisdrivenbymanybiophysicalvariables,suchastemperatureandmoisture.Methods:Soilsamplesofapineforest,anoakforest,andapineandoakmixedforestwereincubatedfor387daysunderconditionswithsixtemperaturesettings(5°C,10°C,15°C,20°C,25°C,30°C)andthreelevelsofsoilmoisturecontent(SMC,30%,60%,90%).TheinstantaneousrateofmineralizedSOCwasperiodicallyandautomaticallymeasuredusingaLi-CorCO2analyzer.BasedonthemeasuredamountofmineralizedSOC,carbonfractionswereestimatedseparatelyviafirst-orderkineticone-andtwo-compartmentmodels.Results:Duringthe387dayincubationexperiment,accumulativemineralizedcarbonrangedfrom22.89mgcarbon(C)·g-1SOCat30°Cand30%SMCforthemixedforestto109.20mgC·g-1SOCat15°Cand90%SMCfortheoakforest.Mineralizedrecalcitrantcarbonvariedfrom18.48mgC·g-1SOCat30°Cand30%SMCforthemixedforestto104.98mgC·g-1SOCat15°Cand90%SMCfortheoakforest,andcontributedatleast80%tototalmineralizedcarbon.Conclusions:Basedontheresultsofthisexperiment,thesoilorganicmatterofthepurebroadleavedforestismorevulnerabletosoilmicrobialdegradationinnorthernChina;mostoftheamountofthemineralizedSOCderivedfromtherecalcitrantcarbonpool.Labilecarbonfractionconstitutesonaverage0.4%ofSOCacrossthethreeforesttypesandwasrapidlydigestedbysoilmicrobesintheearlyincubationstage.SOCmineralizationmarkedlyincreasedwithsoilmoisturecontent,andcorrelatedparabolicallytotemperaturewiththehighestvalueat15°C.Nosignificantinteractionwasdetectedamongthese
