Determinantsofsoilcarbonandnitrogenhydrolyzingenzymes.docx

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1、EnvironmentalScienceandPollutionResearchhttpsdoi.org10.17sll356-021-16817-8RESEARCHARTICLEDeterminantsofsoilcarbon-andnitrogen-hydrolyzingenzymeswithindiferentaforestedlandsincentralChinaQianxiLi国 Xiaoli Chengxlcheng Hubei Provincial Academy of Eco-environmental Sciences (Hubei Eco-environmental Eng

2、ineering Assessment Center), Wuhan 430079, Peoples Republic of China* Schl of Environmental Studies. China University of Geosciences, Wuhan 430074, Peoples Republic of ChinaYiranDong2QianZhang, Key Laboratorjf of Soil Ecology and Health in Universities OfYunnan Province. School of Ecology and Enviro

3、nmental Science, Yunnan University, Kunming 650091, Peoples Republic of ChinaWeiJia Key Laboratory of Aquatic Botany and Watershed Ecology. Wuhan Botanical Garden, Chinese Academy of Sciences (CAS), Wuhan 430074, Peoples Republic of ChinaXiaoIiCheng3Received:27May2021/Accepted:25September2021TheAuth

4、or(s),underedusivelicencetoSpringer-VerlagGmbHGermany,partofSpringerNature2021AbstractSoilorganicmatter(SOM)decompositionisregulatedbyacomplexsetofenzymes.However,theinfuencesofbioticandabioticfactorsonspatialvariationsofsoilenzymeactivity(EA)withinecosystemsremainunresolved.Here,wemeasuredEAatdifer

5、entlocationswithintwoaforestedlands(coniferouswoodlandandleguminousshrubland),andsimultaneouslycollecteddataonsoilphysico-chemical,vegetation-related,andmicrobialpropertiestoidentifythedeterminantsofEAspatialpatterns.TheresultsshowedthatsoilorganicCandtotalNcontentswerethepredominantabioticfactorsin

6、regulatingabsoluteEA(EAperunitofoven-drysoilmass)inbothaforestedlands,whilesoilpHwasthepredominantfactorinregulatingspecifcEA(EAperunitofmicrobialbiomass(MB).However,thepredominantbioticfactorsvariedwiththeaforestedtype:therootbiomassandMBwerethedeterminantsofEAintheshrubland,whereasthetreedistribut

7、ion,litterandrootbiomass,andbacterialbiomasswerethedeterminantsinthewoodland.Vegetation-relatedfactors(i.e.,litterandrootbiomass)indirectlyinfuencedsoilEAbyregulatingthesoilabioticfactors.ComparedwiththeMB,microbialcommunitycompositionhadaminorimpactonEA.ThevarianceofspecifcEA(EAperunitofMBorSOM)exp

8、lainedbyselectedfactorswasmuchlowerthanthatofabsoluteEA.Inaddition,theenzymaticC/Nratiowithinecosystemsdidnotfollowageneralpattern(1:1)observedataglobalscale.Ourresultsprovidenovelexperimentalinsightintoecosystem-levelspatialvariabilityofCandNcyclingviaenzymes,suggestingthatsoilabioticfactorsaremore

9、reliablethanbioticfactorstorefectEAspatialpatternsacrossaforestedsystems.KeywordsSoilenzymeactivitySpatialvariationAforestationEnzymestoichiometryVariationpartitioningpublishedonline:26october2021ResponsibleEditor:RobertDuranIntroductionGiventhatsoilscontainthelargestreservoiroforganiccarbon(C)andni

10、trogen(N)inthebiosphere(Lal2004;LehmannandKleber2015),soilorganicmatter(SOM)mineralizationcouldpotentiallyregulateglobalCandNcycling.Meanwhile,soilenzymesareregardedasproximateagentsofSOMmineralizationbecausetheyreducetheactivationenergyofrate-limitingreactionsandspeedupthebreakdownofpolymericmacrom

11、oleculesintolowmolecules(Nannipierietal.2012;Bumsetal.2013;Maoetal.2015).Therefore,accuratepredictionofsoilenzymeactivity(EA)canprovideusefulinformationaboutSOMturnoveraswellasitsresponsetoanthropogenicdisturbancesandenvironmentalchanges(Hanetal.2019).However,thepredictionofsoilEAiscomplicatedsincee

12、nzymesarenotevenlydistributedintheenvironment(Baldrian2014).RelativelyhighspatialvariabilityofsoilEAhasbeenobservedevenwithinasinglefeldbecausesoilEAareregulatedbymultiplebioticfactors(e.g.,vegetationandmicrobialcommunitycomposition)andabioticfactors(e.g.,soilphysico-chemicalpropertiesandmicroclimat

13、e).Inrecentdecades,anumberofstudieshavebeenconductedtoexplorethespatialvariationsofsoilEAandtheirdeterminantsataglobalorregionalscale.Basedonthesestudies,soilpHandSOMcontentwereidentifedasthemostimportantabioticfactorsafectingsoilEA,especiallyforsoilhydrolaseactivity(Sinsabaughetal.2008;KivlinandTre

14、seder2014;Xuetal.2020).However,thespatialvariabilityofsoilEAwithinecosystemshasbeenlargelyneglected(Banerjeeetal.2016;Stursovaetal.2016).Whetherobse,ationsatlargescalescouldapplytoasingleecosystemisstillanopenquestion.AlthoughafewstudieshaveinvestigatedthespatialheterogeneityofsoilEAwithinecosystems

15、andthedeterminants,theseconclusionsareindebate.Forexample,Boeddinghausetal.(2015)reportedthatsoilpHwasanimportantdeterminantofspatialdistributionofEAinagrasslandecosystem,whilestudiesconductedinforestecosystemsandinagrassland-woodlandecotonefoundthatsoilpHwasnotspatiallyconnectedwithsoilEAbecauseoft

16、heverylowvariationsofpHobservedinthesestudies(Banerjeeetal.2016;tursovaetal.2016).Mayoretal.(2016)investigatedthespatialdiferencesinsoilEAlevelsbetweenvegetationpatchesandinter-patchesinashrublandecosystem,andfoundthatvegetationcanopycouldafectsoilEApatternsthroughrhizosphereefectsandsubstrateinputbyIitterfall(Dornbush2007;Brzosteketal.2013;Fengetal.2019).Bycontrast,vegetationpropertiesdidnotSignifcantlyinf