長白山森林土壤剖面氨基糖的分布(英文).docx

1、第25卷第5期中國科學(xué)院研究生院學(xué)報Vol.25No.52008年9月JournaloftheGraduateSchooloftheChineseAcademyofSciencesSeptember2008ArticleID：1002-1175(2008)05-0657-08DistributionofaminosugarsinforestsoilprofilesoftheChangbaiMountainsupportedbyKeyProjectofNationalNaturalScienceFoumlation(40535028)tcorresjwndingauthor,E-mail：xdz

2、hangDistributionofaminosugarsinforestsoilprofilesoftheChangbaiMountainsupportedbyKeyProjectofNationalNaturalScienceFoumlation(40535028)tcorresjwndingauthor,E-mail：xdzhangXIEHong-Tu1LIWei-Fu1,2BAIZhen12HEHong-Bo1ZHANGXu-Dong'”(IKeyLaboratoryofTerrestrialEcologicalProcessInsliliUeAppliedEcology,Ch

3、ineseAcademyofSciences,Shenyang110016China;2GraduateUnursiiyoftheChineseAtwiemyofScience«BeijingJ00049.China;3NationalFieldResearchStationofShenyangAgroet'asystenu,Shenyang110016,China)(Received12January2007;Revised7January2008)XieHT.LiVVF,BaiZ,etal.Distributionofaminosugarsinforestsoilprof

4、ilesoftheChanagbaiMountain.JournaloftheGraduateSchooloftheChineseAcademyofSciences,2008,25(5)：657664AbstractTheverticaldistributionofthreeaminosugarsandthecontributiontoorganicmatterpoolsinthesoilprofilesoftheChangl>aiMountainwerediscussed.Thecompositesamplesoforganiclayersandmineralhorizonswerec

5、ollectedalthreesites(altitude,600m,1680mand2580m)onthenorthernslopeofthemountain.Thecontributionofthreeaminosugarstothetotalamountsofaminosugarswasintheorderglucosamine(GIucN)>galactosamine(GalN)>muramicacid(MurAc).Thecontentsofaminosugarsandtheproportionofaminosugarstosoilorganicmatterinthepr

6、ofilesincreasedfromthetoporganiclayeruntilAhorizons,buttheyvariedamongthesubsoilhorizons.TheratiosofGlucN/MurAcandGlucN/GalNinthesoilhorizonsatdifferentaltitudesindicatedthattheymightoriginatefromdifferentmicrobialcommunities.Keywordsaminosugars,verticaldistribution,microbe,soilorganicmatterCLCS154.

7、2IntroductionSoilisanimportantcomponentinforestecosystems.Thedynamicsandturnoverprocessofsoilorganicmatter(SOM)inforestsoilplaysanimportantroleintermsofglobalcarboncycling.DuringSOMtransformation,microbesbuiltuptheircell-wallconstituents,whicharebelievedasthemainpoolofinherentSOM.Intheshortterm,SOMt

8、ransformationsarethuslinkedtofluctuationsinlivinganddeadmicrobialbiomass.Severalmethodscanbeusedtoassesslivingsoilbiota,butveryfewaresuitableforthedeterminationofmicrobialCandNresiduesinsoil.Amongthem,analysesofaminosugars(AS)arehelpfulintheassessmentoftheoriginofdifferentmicrobialCandNresiduesinsoi

9、l.Aminosugarsconstitute5%to10%oftotalnitrogeninsoils'1.Theimportantaminosugarsinsoilareglucosamine,galactosamineandmuramicacid,althoughavarietyofotheraminosugarsalsoexist2.Forsoilstudies,SowdenandIvarson"foundthatlittleGIucNwassynthesizedduringafungi-inocuiated-incubation.Chantigriy,etal.l4

10、alsosuccessfullyusedMurAcandGiucNtodifferentiatebetweenbacterialandfungalcontributiontosoilaggregation.AminosugaranalysesarcsuitableforthedeterminationofmicrobialCandNresiduesinsoil,whereasconvenlionalmethodsofbiomassestimationsuchasfumigation-extraction,substrate-inducedrespiration,ormicrobial-dive

11、rsityindicatorssuchasphospholipidsorergosterolareusedtoassesslivingsoilbiotawhichshowedbigseasonalfluctuations.Aminosugaranalyses,ontheotherhand,havesuccessfullybeenappliedtotheelucidationofland-usechangesintemperateandtropicalenvironments”.However,fewareknownsofarofhowaminosugarpatternisinmountains

12、oils.TheverticaldistributionpatternofforestvegetationsandsoilfromthefoottothetopoftheChangbaiMountainaretypical.ResearchonpedogenesisandvariationofsoilpropertiesoftheMountainhavebeencarriedoutlargely61,butlittlewasdoneontheturnoverprocessofCandN,especiallythecontributionofmicroorganismstotheturnover

13、offorestlitterandtheaccumulationofSOMinsubsoilhorizonsofdepthprofiles.Inordertounderstandsomeaspectsintheturnoverprrxress,itwasnecessarytolookinsightinlothemechanismofCcyclingandsequestration.Ourobjectivewastoinvestigatethedecompositionprocessofmicrobialresiduesfromlittertosoilhorizonsbyanalyzingthe

14、verticaldistributionpatternofaminosugarsinthreesoilprofilesatdifferentaltitudes.1 MaterialsandmethodsSitedescriptionandsamplingTheChangbaiMountainissituatedinthesoutheastofJilinProvince»peakingat2691m(126°55z129°E;4°23'42°36'N).There,representativetopographyofthemoun

15、luiniscindercone,piedmontslopebasalticplateau(altitude11001800m)andpiedmontplatform(altitude<1100m).PrecipitationconcentratesinJulyandAugust.Soilsampleswerecollectedat3sitesinthenorthernslopeoftheChangbaiMountainatthealtitudeof600m(128°6'E,42°24'N),1680m(128°04'E,42

16、6;05'N)and2580m(128°06'E,42°0TN),correspondingtopiedmontplatform,piedmontplateauandcinderconerespectively.Themainforestspeciespresentarc：PurplebloomMaple(Acerpseudo-sieboldianum(PAX)kom.),KoreanPine(PinuskoraiensisSieb.EtZucc.),BlackFalseHellebore(VeralrumnigrumL.)andMongolianoak(Q

17、uercusmongolicusFisch.)ataltitudeof600m;ErmansBirch(Betulaermaniicham.).Yeddospruce(PiceajezoensisCarr.)at1680m;andmoss,lichen,rhododendron(RhododendronchrysanthumPall.)at2580m.Meanannualtemperature(MAT)is2.6勾，-2.9%and-7.7%,respectivelyandmeanannualprecipitation(MAP)is708mm,1031mmand1321mmatsite600i

18、n,1680mand2580m,respectively(datafromtheChangbaiMountainexperimentalstation,1980).Wecollectedcompositesoilsurfacesamplesfromatleast5subsites,butthedepthsamplesweretakenfromdifferentpointsinthesamehorizon.Depthsamplesatsites1680mand2580mwerecollectedfromAhorizonuntilpermafrostlayer.Thesoilsampleswere

19、airdriedandpassedthrougha2mmanda0.25mmsieve.SomephysicalchemicalpropertiesareshowninTable1.Table1SomephysicalchemicalpropertiesofsoilhorizonsintheChangbaiMountain注一mainlycomposedofsandandgravel.Notdetected.Altitude/mHorizonDepth/cmP"(H:O)CEC/(cmol*kg'1)Sand(2000-20pm)/(%)Sih(20-2pm)/(%)Clay

20、(<2Mm)/(%)600Ah0-134.085.6031.9443.7024.36E13-373.752.2038.8145.7315.46Bgl37-723.355.5425.7848.5625.66Bg272-1103.325.3327.8447.0825.081680Ah0-103.793.3462.3123.4414.25Cl10-404.420.5978.3815.925.70C240-654.560.4983.1713.982.852580Ahl043.652.51Ah24-124.520.94B-C12-224.700.88第5期XIEHong-Tutetal:Distr

21、ibutionofaminosugarsinforestsoilprofilesoftheChangbaiMountain659AnalyticalmethodsTheaminosugarsGlucNGalN,andMurAcwereextractedfromwholesoilaccordingtothemethodofZhangandAinelung.Soilsamples(<0.25mm)wereheatedwith6mol/LHC1containing50/xgofinternal(myo-inositol)inaclosedhydrolysisflaskfor8hat105.Af

22、tercooling,thehydrolysatewasfilteredthroughglassfiberfiltersandtheGhratewasdriedcompletelybyarotaryevaporatorat40勾invacuum.Thentheresiduewasdissolvedwith20mLofwater,andpHwasadjustedto6.66.8witha0.4mol/LKOHsolution.Theprecipitatewasremovedbycentrifugation(2000gforlOmin)andtheclearsupeniatantwasfreeze

23、-driedtodrynessagain.Theresiduewasdissolvedwith3mLofdrymethanolandcentrifuged(2000gforlOmin)toremovethesalts.Theaminosugarfractionwastransferredtoareactivialof5mL,anddriedbyusingN2gasat45X.Finally,theresiduewasdriedcompletelyinavacuum.Thedcrivatisationreagent(0.3mL),i.c.aldononitrilederivativesconta

24、ining32mghydroxylaminehydrochloridemL'and40mg4-(dimethylaniino)pyridinemL'1inpyridine-methanol(u/“)(4：1)wasaddedtoareactivial(5mL)containingthedrysample.Aftercappingthevialandshakingforafewseconds,thesolutionwashealedfor30rninal7080T(duringheating,thevialwasshakenoncemore).Thenthevialwascool

25、edtoroomtemperature,andImLofaceticanhydridewasadded.Thevialwasclosed,shakenagain,andreheatedfor20min.Afterc(x)ling,1.5mLofdichloromethanewasadded.Excessdcrivatisationreagentswereremovedbytwowashingsteps.Firstly,afterImLofImol/LHCIwasaddedandstronglyshakenfor30s,theupperaqueousphasewasremoved.Secondl

26、y,inthesamemanner,theorganicphasewasextracted3timeswithdistilledwater(1mLeach),inthelastwashingstep,thewaterwasremovedascompletelyaspossible.ThefinalorganicphasewasdriedwithN2at45筆,andfinally,dissolvedin200/xLofethylacetate-hexane(1：1).GCanalysiswascarriedoutonaModel-6890g.c.(Agilent,U.S.A)equippedw

27、ithaflameionizationdetector(FID).Weuseda30mx0.32mmID(0.25/nn)column(HP-5)toseparateaminosugarsderivativeswithasplitratioof25U.SoilorganicCandtotalNweredeterminedwithaC/N/H/S-analyzer(Elcmcnta/,Germany),andthepH(H20)wasdeterminedin1：2.5soil:water(w/v)suspensionusingapHmeter.Cation-exchaiige-capacily(

28、CEC)wasdeterminedwith1mol/LNH4OAc(pH7.0)accordingtoHendershot*.Soiltexturedctciminationwasmodifiedbythepipettemethod9j.1.1 StatisticalanalysisThreereplicationswereappliedforallanalysisbyanalysisofvariance(ANOVA)andmultiplecomparisonsusingsoftwarepackageSPSS10.0.IfthemaineffectsweresignificantatP<

29、0.05,aposthocseparationofmeanswasdonebyunivariateleastsignificancedifference(LSD)test.2 Resultsanddiscussion3.1DistributionofCandNinsoilprofilesTable2showstheresultsofsoiloianicC(SOC)andtotalNcontentsinthethreetypicalsoilprofiles.Significantdifferenceswerefound(/><0.05)indifferenthorizons.Ther

30、ein,thehighestvalueoforganicCoccurredinorganichorizonL,while,thelowestvalueoforganicCinthedeepestsoilhorizons.ThechangeoforganicCandtotalNcontentsshowedadecliningtrendalongthesoildepth(P<0.05).TheratiosofCtoNwereregardedasakeyindicatorofSOMcliaractersanditreflectedthedegreeofSOMturnovertosomeexte

31、nt.Inthethreeprofiles,theC/Nratiosweredifferentalongthedepth(P<0.05),thatconfirmedthedecompositiondegreesofSOMweredifferentalongthesoildepth.Table2SOC,NandC/NratiosinthreesoildepthprofilesoftheChangbaiMountain注：a.b.c.d.e.f.gHhowstheMgnificantdiffrrrnc-eofthedifferentdepth(P<0.05).Altitude/mHur

32、iunDep<h/vinS(X：(Sample)/(g*kg'1)TohilN(Sample)/(kg-1)C/N600i.5.5-4451.50aII.92a37.88“Of4-2432.30b16.91b25.56bOh2-0324.90e25.23c12.88cAh01358.67d5.61d10.46<lE13-376.76rl.05«6.44eBgl37-722.33f0.74f3.l5fBg272-110183g0.7lg2.58g16801.43461.60a17.52a26.35aOf3-0.5415.50bI7.8II>23.33bOh0.

33、5-0132.00c13.56c9.73cAh01046.38d3.94dll.77dCl10-404.31。0.66r6.53eC240-653.42f0.59f5.80f2580L54425.00a9.85a43.15u()40140.20b6.5lb21.54bAhl0-494.28c4.92c19.16cAh24-1226.08J1.814I4.4ldBC12-2218.05妙1.59ell.35eAlthoughitwasfoundthatSOMintheforestsoilaccumulatedmostlyinsoilsurface,decliningsharplyasthedep

34、thincreased,accumulationmechanismsoforganicCinthethreetypicalprofilesweredifferent.AccumulationofSOCatsites600rnand1680mresultedmainlyfromrichlitterinput,whileatsite2580mSOMdecomposedmoreslowlythantheothertwositesduetoshorterfrostlessseasonandlowertemperature.Acconlingtothefindingsaboveitcouldl)econ

35、cludedthattemperaturewasakeyfactordeterminingthedecompositionandpropertiesofSOMintheChangbaiMountain.Nevertheless,thedecornpositionofforestlitterandSOMisabiochemicalprocesscontrolledbymicroorganisms.Therefore,aminosugarsasanindicatorofmicrobialprocessescouldreflectmoreclearlythemicrobialcontribution

36、toSOMturnoverandaccumulationI：,.3.2Thecontentofaminosugars(soil)(mg,kg_1)inthesoilprofilesAminosugarcontentsbasedonsampleweight(soil)(mg,kg1)indicateabsoluteaccumulationofaminosugarinforestsoil(Table3).Thecontentsofaminosugarsit)diflerenthorizonsintheChangbaiMountainincreasedfromtoptoIxHtoniintheorg

37、aniclayer,however,itdeclinedasthedepthincreasedgenerallyinsoilmineralhorizon.TheaminosugarcontentwasrelativelylowintheLlayeroftheorganiclayerwherefreshplantdebrishadaccumulated.ThelowcontentofaminosugarintheLlayerofallsiteswasascribedtothefactthattheplantdebriswasstillfresh.Therefore,theplantdebriso

38、ftheLhorizonwasnotattackedeasilyl>ymicroorganismsU1.Aminosugarcontentsweremuchhigherinorganiclayerthanthoseinthemineralhorizons.Ixjwe1141foundthatthecontentofaminosugarsincreasedashumificationproceedsinforestsoils.Wcalsofoundthataccumulationofaminosugarsincreasedastheorganicmatterdecomposed.Thisf

39、indingisinlinewiththetrendofC/Nratios,thusiliscorrespondingIothedifferenthumificationdegreesoforganicuiallcraslhesamereportbyDai151.Hence,aminosugarcontentscouldindicatethe(lecomfx)sitioridegreeoforganicmatterinorganiclayers.第5期XIEHong-Tu.Wal:DistributionofaminosugarsinforestsoilprofilesoftheChangl&

40、gt;aiMountain661Table3AminosugarcontentsandpatternsinsoildepthprofilesoftheChangbaiMountainAllitiuieHorizon/mDepthClucNMurAcGalNTotalASTotalAS(JIucN/GlueN/cm(9oil)/(mg*kg*1)(SOC)/(g-kg»)(；alNMurAc600L5.5-4906.5409.51316.0a2.9a2.2Of424214.9205.51738.56268.0b14.5a2.420.5Oh2-09574.8543.53453.71369

41、0.3c42.1b2.817.6Ah0-133869.6203.21965.16118.0l>104.3c2.019.0E13-37351.987.3439.2d65.0<l4.1Bgl37-7250620.Od266.le5.816.2Bg272-110364.225.972.4462.5d252.7e5.314.216801.432435.6783.03218.7a7.0a3.1(M3-0.53752.3201.42129.26082.9b14.6b1.818.7Oh0.5-02857.8223.91238.84320.6c32.7c2.312.8Ah01

42、02743.6185.81123.24052.M87.4d2.414.8Cl10-40207.766.9274.7e63.7e3.2C2406562.527.489.9(26.3f2.32580L5-4832.6243.31075.9a2.5a3.504-01287.7388.01675.6b12.0b3.4Ahl041684.2794.92479.1c26.3c2.1Ah24-12405.0177.2582.2d22.3d2.3B-C12-22368.4184.4552.8d30.6r2.0注：ab.<*Iliecharacterrrpm»rntr<ithesignif

43、icantdifFcrvnce«ofthesanirgrouptiarainP<0.05level;reprv»cntcdaminosugarcontent*belowthedetectinglimit(orc'annotbecalculated).Thecontentsofaminosugars(soil)(mg,kg'1)insoilmineralhorizonsdecreasedrapidlygenerallyasthedepthincreased,from6118.0mg,kg-1to462.5mg*kg"1soilforattitu

44、de600m,4052.6mgkg"1to89.9mgwkg'1for1680mand2479.1mg*kg"1to552.8mg*kg"1for2580m(P<0.05,Table3)duetolowinputsoforganicmatterindeepmineralhorizons.Indeephorizons,soilaerationmaybeakeyfactortothemicrobialactivities.However,atthesiteof600m,muchmoreaminosugarsaccumulatedinthehorizonB

45、gl(3772cm)andtheBg2(72110cm)probablyduetotheeluvialdepositofclayandaco-precipitationofaniinosugars-containingorganiccompounds.SimilarresultswerealsoreportedbyAmelung.Amelung,etal.l，7>suggestedthataminosugarsinsoilparticlefractionpoolsincreasedsignificantlywhenthesoilmineralparticlebecamefiner.Thi

46、ssuggestedthataminosugarswerestronglyprotectedbyfineparticlesinthetwohorizons.Atsite2580m,thecontentsofaminosugarsindeepsoilhorizonwerehigherrelatively(soil)(588.2552.8mgkg1)thanthoseattheothertwosites.Thedifferencemighthaveresultedfromtemperatureandmoisture,butbadaerationduetolong-termfrozencoverag

47、eatsite2580mcouldalsoinhibitthedecompositionofaminosugarsformerlysynthesizedbymicrobe,i.e.depletionratewasslowerthanthesynthesisrate.3.3 RelativeaccumulationofaminosugarsinSOM(g,kg1)TheproportionofaminosugarstoSOM(g,kg'1)inthethreedepthprofilesshow<*<lasimilartrendastheaminosugarcontents(s

48、oil)(mg,kg1)didfromlayerLtohorizonA.ThisconfirmedthedifferentdecompositiondegreesofSOMamongtheorganiclayersandmineralhorizons.Moreandmoreaminosugarswereenrichedinthemicrobially-alteredorganicmatter(P<0.05.Table3).Thehigharninosugarsconcentrationintheforestfloorlayersindicatedastabilizationofamino

49、sugarsintheSOM.AminosugarsinhorizonAinthethreeprofilesshowedsignificantdifferences(Table3).ThechangesintherelativecontentofaminosugarscharacterizeddifTerentcontributionofmicrobestoorganicCsequestration.Themicrobialactivitieswereaffectedbymanyfactors,suchaswettinganddryingcyclesaswellasfluctuationint

50、emperature,and,inturn,microbialactivitiesinfluencedaminosugarsaccumulationinSOMpools.TemperaturealdifferentsiteswasconsideredasthekeyfactortoaffecttheabilityofCsequestration.ClimaticfactorsweremorefluctuantastheelevationincreasingintheCharigbaiMountain.Thehighertheelevationwas,thelowerthemeanannulte

51、mperature(MAT)occurred.Lowtemperatureinhibitedmicrobialactivities,andthenaffectedtheaccumulationofaminosugars.Aminosugarssynthesisbymicrobedeclinedorthedecompositionofformerlysynthesizedaminosugarswasacceleratedastheprofiledepthincreasedupwards(Table3)orprobablybothprocessoccurredsimultaneously.Ther

52、efore,aminosugarsproportionsinSOMpresenteddeclinetrends.Whereas,aminosugarcontents(SOM)(g,kg1)inthebottomhorizonssignificantlyincreased(P<0.05)againataltitude600m,andtherewasnosigniGcantdifferencebetweenhorizonBglandBg2wasfound.Asmentionedabove,aminosugarcontents(soil)(g*kg-1)werehighinthetwoclay

53、eluvialdepositionhorizonsandherewefoundalsothattheSOMwasaffectedlargelybysoilmicrobesinfinesoilseparate,i.e.thecontributionofmicrobestoSOMpoolwasgreaterthanthatintheupperhorizons.Weconcludedthatfineclaymineralcouldprotectthemicrobialresidues»aminosugarsfn)mmicrobialattackagain.Thisshouldbethere

54、asonthataminosugarswereenrichedinthedeepSOMpoolataltitude600m.Similarly,aminosugarproportion(SOM)(g*kg-1)atsite2580rnincreasedsignificantlyfromhorizonAh2toB-C(P<0.05,Table3).However,iftherelativeaccumulationofaminosugarsinhorizonBandC(permafrost)wascausedbyinhibitioninthemicrobialactivitiesneedsf

55、urtherresearch.3.4 AminosugarconstituentsandratiosinthesoilprofilesTable3showsthatinthethreeprofiles,thecontentsofglucosaminevaried(soil)from62.5rng,kg'1to9574.8mgkg-',galactosamine(soil)from27.4mg,kg"'to3453.7mg,kg'1,andthemurarnicacidranged(soil)from25.9nig,kg'1to543.5mg,k

56、g'1.Hence,thecontributionoftheaminosugarsinthesoilincreasedintheorder：glucosamine>galactosamine>murarnicacid(P<0.001).TheresultswereinlinewiththeresultsofAmelung10andZhang,elal.l，：forNorthAmericansoils.Glucosamineisfoundinmostfungalcellwallsandininvertebrateexoskeletonsuchaschitin"

57、'.SowdenandIvarson'demonstratedthatverylittlegalactosaminewassynthesizedduringfungal-in<x:ulatedincubation.Hence,theratioofglucosaminetogalactosamine(GlucN:GalN)hasbeensuccessfullyusedtoevaluatetherelativecontributionsoffungiandbacteriatoSOMturnoverandaccumulationl0,H,171.Moreover,sincemu

58、ramieaciduniquelyoriginatesfrombacteria16,theratioofglucosaminetomurarnicacid(GlucN:MurAc)hasalsobeenusedtoevaluatethefateofbacteria-derivedaminosugarsinsoilundertemperateenvironmentl0*1,1.TheGlucN/GalNratio,whichcandifferentiatebetweenthebacterialandfungalcontribution,increasedfromhorizonAhtoEatsite600mandfromhorizonAhtoClatsite1680m.i.