中科院科学家利用LGR二氧化碳同位素分析仪对土壤有机物的检测

LGR的二氧化碳同位素分析仪帮助ZG科学院的科学家监测“新鲜有机物的质量对土壤有机物的启动和微生物底物利用率模式的影响”

Qualityoffreshorganicmatteraffectsprimingofsoilorganicmatterandsubstrateutilizationpatternsofmicrobes

HuiWang1,2,ThomasW.Boutton3,WenhuaXu1,GuoqingHu1,2,PingJiang1,EdithBai1

Abstract

Changesinbiogeochemicalcyclesandtheclimatesystemduetohumanactivitiesareexpectedtochangethequantityandqualityofplantlitterinputstosoils.Howchangingqualityoffreshorganicmatter(FOM)mightinfluencetheprimingeffect(PE)onsoilorganicmatter(SOM)mineralizationisstillunderdebate.HerewedeterminedthePEinducedbytwo 13C-labeledFOMswithcontrastingnutritionalquality(leafvs.stalkof Zeamays L.).Soilsfromtwodifferentforesttypesyieldedconsistentresults:soilsamendedwithleaftissueswitchedfasterfromnegativePEtopositivePEduetogreatermicrobialgrowthcomparedtosoilsamendedwithstalks.However,after16dofincubation,soilsamendedwithstalkshadahigherPEthanthoseamendedwithleaf.Phospholipidfattyacid(PLFA)resultssuggestedthatmicrobialdemandforcarbonandothernutrientswasoneofthemajordeterminantsofthePEobserved.Therefore,considerationofbothmicrobialdemandsfornutrientsandFOMsupplysimultaneouslyisessentialtounderstandtheunderlyingmechanismsofPE.OurstudyprovidedevidencethatchangesinFOMqualitycouldaffectmicrobialutilizationofsubstrateandPEonSOMmineralization,whichmayexacerbateglobalwarmingproblemsunderfutureclimatechange.