摘要
Background:Coarsewoodydebris(CWD)isveryimportantforforestecosystems,particularlyforbiodiversityandcarbonstorage.Itsrelevanceasapossiblereservoirandsourceofnutrientsislessclear,especiallyincentralEurope.Methods:Basedonachronosequenceofknownagesoflogs,weanalyzedthenutrientsstoredinCWDofFagussylvatica,Piceaabies,andPinussylvestrisatdifferentsitesinGermany.Toquantifynutrientconcentrations,weassessedtheuseofNearInfraredReflectanceSpectroscopy(NIRS)todeterminethechemicalpropertiesofCWD.Results:NIRSmodelsweresuitabletopredictconcentrationsofC,N,P,ligninandextractives.Concentrationsofmostnutrientsincreasedwithmassloss,withtheexceptionofpotassium,whichdecreasedforbeechandpineandremainedrelativelyconstantforspruce.Thehighestnutrientconcentrations(N,P,S,CaandMn,exceptMgandK)weregenerallyobservedinhighlydecomposedsprucelogs.TheneteffectofdecreasingCWDmassandincreasingnutrientconcentrationswaseitheradecreasing(N,PandKinbeech;P,Mg,KandMninpine),constant(S,CaandMginbeech;N,SandCainpine)orincreasingamountofnutrients(N,P,SandCainspruce;Mninbeech)inthelogsoverthecourseofdecomposition.TheC/Nratiodecreasedforalltreespecies,mostmarkedlyforsprucefromca.1000atthebeginningofthedecompositionprocessto180at36years.TheN/Pratioconvergedtoavalueofabout30forallthreespecies.Ligninconcentrationsincreasedforspruceandbeechandremainedconstantforpine.Conclusions:OurresultsindicatethatmostnutrientsremaininCWDforlongperiods.NutrientsmaybeusedandcycledbymicroorganismswithinCWD,butwiththeexceptionofP(inbeech),Mg(inpine)andK(inbeechandpine),thereappearstobelittlenetnutrientexportuntiltwothirdsofthemassislost.Instead,N,P,SandCawereaccumulatedinsprucelogs,indicatingthatCWDbecameanetsinkratherthananetsourceofsomenutrientsforsevera
出版日期
2018年03月13日（中国期刊网平台首次上网日期，不代表论文的发表时间）
