简介：INTRODUCTIONSoilacidificationduetoaciddepositionhasbeenoneofthemajorenvironmentalprob-lemsconcernedbysoilscientistsandecologistsfortherecent20years(vanBreemen,1990).SoilacidificationwithamarkedpHdecreaseofforestsoilswithinvarioustimeintervalshasbeenreportedinGermany,Sweden,theNetherlands,AustraliaandtheUnitedStates(van

简介：AchangeintheEuropeanUnionenergypolicyhasmarkedlypromotedtheexpansionofbiogasproduction.Consequently,largeamountsofnutrient-richresiduesarebeingusedasorganicfertilizers.Inthisstudy,apotexperimentwasconductedtosimulatethehigh-risksituationofenhancedgreenhousegas(GHG)emissionsfollowingorganicfertilizerapplicationinenergymaizecultivation.WehypothesizedthatcattleslurryapplicationenhancedCO_2andN_2Ofluxescomparedtobiogasdigestatebecauseoftheoverallhighercarbon(C)andnitrogen(N)input,andthathigherlevelsofCO_2andN_2OemissionscouldbeexpectedbyincreasingsoilorganicC(SOC)andNcontents.Biogasdigestateandcattleslurry,atarateof150kgNH_4~+-Nha~(-1),wereincorporatedinto3soiltypeswithlow,medium,andhighSOCcontents(Cambisol,MollicGleysol,andSapricHistosol,termedClow,Cmedium,andChigh,respectively).TheGHGexchange(CO_2,CH_4,andN_2O)wasmeasuredon5replicatesoveraperiodof22dusingtheclosedchambertechnique.TheapplicationofcattleslurryresultedinsignificantlyhigherCO_2andN_2Ofluxescomparedtotheapplicationofbiogasdigestate.NodifferenceswereobservedinCH_4exchange,whichwasclosetozeroforalltreatments.SignificantlyhigherCO_2emissionswereobservedinChighcomparedtotheothertwosoiltypes,whereasthehighestN_2OemissionswereobservedinCmedium.Thus,theresultsdemonstratetheimportanceofsoiltype-adaptedfertilizationwithrespecttochangingsoilphysicalandenvironmentalconditions.

简介：Theannualseriesofδ13CweremeasuredintreeringsofthreeCryptomeriafortuneidisks(CF-1,CF-2,andCF-3)collectedfromWestTianmuMountain,ZhejiangProvince,China,accordingtocross-datingtreeringages.Therewasnoobviousdecreasingtrendoftheδ13CannualtimeseriesofCF-2before1835.However,from1835to1982thethreetreeringδ13Cannualseriesexhibitedsimilardecreasingtrendsthatweresignificantly(P≤0.001)correlated.Thedistributioncharacteristicsofascatterdiagrambetweenestimatedδ13CseriesofCF-2frommodelingandtheatmosphericCO2concentrationextractedfromtheLawDomeicecorefrom1840to1978wereanalyzedandacurvilinearregressionequationforreconstructingatmosphericCO2concentrationwasestablishedwithR2=0.98.Also,atestofindependentsamplesindicatedthatbetween1685and1839thereconstructedatmosphericCO2concentrationusingtheδ13CseriesofCF-2hadacloserelationshipwiththeLawDomeandSipleicecores,withastandarddeviationof1.98.ThegeneralincreasingtrendofthereconstructedatmosphericCO2concentrationcloselyreflectedthelong-termvariationofatmosphericCO2concentrationrecordedbothbeforeandaftertheIndustrialRevolution.Between1685and1840theevaluatedatmosphericCO2concentrationwasstable,butafter1840itexhibitedarapidincrease.Givenalongerδ13Cannualtimeseriesoftreerings,itwasfeasibletorebuildarepresentativetimeseriestodescribetheatmosphericCO2concentrationforanearlierperiodandforyearsthatwerenotintheicecorerecord.