简介：

简介：降水在半干旱、干旱的区域是生态系统函数和进程的主要驱动程序。在如此的水有限生态系统，搏动了水输入直接通过弄干的一系列土壤和重新弄湿的周期控制地下的过程。在土壤CO2流出上调查水的分散的增加的效果，一个人工的降水事件(3公里)在亩被用于一个荒芜的灌木生态系统我们在中国的Ordos高原的沙土地。土壤呼吸率在在这块地里增加水以后立即增加了2.84.1次，然后它在48h以内回到了背景水平。在实验期间，土壤CO2生产在2047.0和7383.0mgm之间?2。在灌木陆地，土壤呼吸回答显示出空间变化，有在比在interplant空格的灌木下面的更强壮的脉搏效果。土壤呼吸回答的空间变化仔细与土壤底层可获得性的异质被联系。除了降水，玷污器官的碳和全部的氮水池也在荒芜的生态系统作为土壤CO2损失的决定因素被识别。

简介：

简介：Elevatedatmosphericnitrogen(N)depositionhasbeendetectedinmanyregionsofChina,butitseffectsonsoilNtransformationintemperateforestecosystemsarenotwellknown.WethereforesimulatedNdepositionwithfourlevelsofNadditionrate(N0,N30,N60,andN120)for6yearsinanold-growthtemperateforestinXiaoxing’anMountainsinNortheasternChina.WemeasuredgrossNtransformationratesinthelaboratoryusing15NtracingtechnologytoexploretheeffectsofNdepositiononsoilgrossNtransformationstakingadvantageofNdepositionsoils.NosignificantdifferencesingrosssoilNtransformationrateswereobservedafter6yearsofNdepositionwithvariouslevelsofNadditionrate.ForallNdepositionsoils,thegrossNH4+immobilizationrateswereconsistentlylowerthanthegrossNmineralizationrates,leadingtonetNmineralization.Nitrate(NO3-)wasprimarilyproducedviaoxidationofNH4+(i.e.,autotrophicnitrification),whereasoxidationoforganicN(i.e.,heterotrophicnitrification)wasnegligible.Differencesbetweenthequantityofammonia-oxidizingbacteriaandammonia-oxidizingarchaeawerenotsignificantforanytreatment,whichlikelyexplainsthelackofasignificanteffectongrossnitrificationrates.GrossnitrificationratesweremuchhigherthanthetotalNO3-consumptionrates,resultinginabuild-upofNO3-,whichhighlightsthehighriskofNlossesviaNO3-leachingorgaseousNemissionsfromsoils.ThisresponseisoppositethatoftypicalN-limitedtemperateforestssufferingfromNdeposition,suggestingthattheinvestigatedold-growthtemperateforestecosystemislikelytoapproachNsaturation.

简介：Theclosed-jarincubationmethodiswidelyusedtoestimatethemineralizationofsoilorganicC.TherearetwoCpools(i.e.,organicandinorganicC)incalcareoussoil.ToevaluatetheeffectofadditionalcarbonatesonCO2emissionfromcalcareoussoilduringclosed-jarincubation,threeincubationexperimentswereconductedbyaddingdifferenttypes(CaCO3andMgCO3)andamountsofcarbonatetothesoil.TheadditionofcarbonatessignificantlyincreasedCO2emissionfromthesoil;theincreaserangedfrom12.0%intheCaCO3amendedsoilto460%intheMgCO3amendedsoilduringa100-dincubation.CumulativeCO2productionattheendoftheincubationwasthreetimesgreaterintheMgCO3amendedsoilcomparedtotheCaCO3amendedone.TheCO2emissionincreasedwiththeamountofCaCO3addedtothesoil.Incontrast,CO2emissiondecreasedastheamountofMgCO3addedtothesoilincreased.Ourresultsconfirmedthattheclosed-jarincubationmethodcouldleadtoanoverestimateoforganicCmineralizationincalcareoussoils.BecauseofitseffectonsoilpHandthedissolutionofcarbonates,HgCl2shouldnotbeusedtosterilizecalcareoussoiliftheexperimentincludesthemeasurementofsoilCO2production.

简介：Inthecontextofglobalcarboncyclemanagement,accurateknowledgeofcarboncontentinforestsisarelevantissueincontemporaryforestecology.Wemeasuredtheabove-groundandsoilcarbonpoolsinthedarkconiferousborealtaiga.Wecomparedmeasuredcarbonpoolstothosecalculatedfromtheforestinventoryrecordscontainingvolumestockandspeciescompositiondata.Theinventorydataheavilyunderestimatedthepoolsinthestudyarea(StolbyStateNatureReserve,centralKrasnoyarskTerritory,RussianFederation).Thecarbonpoolestimatedfromtheforestinventorydatavariedfrom25(tha-1)(low-densitystands)to73(tha-1)(highlystockedstands).Ourestimatesrangedfrom59(tha-1)(lowdensitystands)to147(tha-1)(highlystockedstands).Ourvaluesincludedlivingtrees,standingdeadwood,livingcover,brushwoodandlitter.Wefoundthattheproportionofbiomasscarbon(livingtrees):soilcarbonvariedfrom99:1to8:2forfullystockedandlow-densityforeststands,respectively.Thiscontradictsthecommonunderstandingthatthebiomassintheborealforestsrepresentsonly16–20%ofthetotalcarbonpool,withthebalancebeingthesoilcarbonpool.

简介：在地中海盆的半干旱的区域，一个降雨事件能导致释放大量土壤二氧化碳的呼吸脉搏(公司2)进空气；这脉搏能显著地贡献年度生态系统碳(C)平衡。常规耕种和二不同盖子庄稼，居民植被和BromuscatharticusL.的影响，在土壤公司2上，流出在VitisviniferaL被评估。在LaRioja的葡萄园，西班牙。土壤公司2流出，gravimetric水内容，和温度在降雨降水事件以后在0-5厘米的深度被监视近似，在到2012年7月27日，盖子在期间收割的从5月17日的时期的每10d凋谢了。在2012年6月10日，另外玷污器官的C，微生物引起的生物资源C，和-glucosidase活动在0-2.5，2.5-5，5-15，和15-25厘米的土壤深度被决定。土壤公司2搏动的结果表演与土壤水内容追随者降水事件的增加有关。比作常规耕种处理，更高有的两个盖子庄稼处理在降水事件以后玷污公司2流出。更高有的两个盖子庄稼处理比常规耕种处理在土壤表面(0-2.5厘米)玷污器官的C，微生物引起的生物资源C，和-glucosidase活动。公司2的每脉搏与表面土壤性质有关。因此，这研究建议在在盖子庄稼下面的土壤表面的器官的C和microbiological性质可以增加的土壤的改进在旱季期间在降水事件以后立即相对常规耕种玷污公司2流出。

简介：Fivehumicfractionswereobtainedfromauniformly^15N-labelledsoilbyextractionwith0.1molL^-1Na4P2O7,0.1molL^-1NaOH,andHF/HCl-0.1molL^-1NaOH,consecutively,andanalyzedby^13Cand^15NCPMASNMR(crosspolarizationandmagicanglespinningnuclearmagneticresonace).Comparedwiththoseofnativesoilshumicfractionsstudiedasawholecontainedmorealkyls,methoxylsandO-alkyls,being27%-36%,17%-21%and36%-40%,respectively,butfeweraromaticsandcarboxyls(bein14%-20%and13%-90%,respectively),Amongthosehumicfractions,thehumicacid(HA)andfulvicacid(FA)extractedby0.1molL^-1Na4P2O7containedslightlymorecarboxylsthancorrespondinghumicfractionsextractedby0.1molL^-1NaOH,andtheHAextactedby0.1molL^-1NaOHaftertreatmentwithHF/HClcontainedtheleastaromaticsandcarboxyls.Thedistributionofnitrogenfunctionalgroupsofsoilhumicfractionsstudiedwasquitesimilartoeachotherandalsoquitesimilartothatofhumicfractionfromnativesoils.Morethan75%oftotalNineachfractionwasinamidefrom,with9%-13%presentasaromaticand/oraliphaticaminesandtheremainderasheerocyclicN.

简介：陆地使用变化影响地下的生态系统。在过去几十年期间，在东北中国的陆地使用更加变化了，并且稻地的区域从高地很快增加了。在这研究，土壤特征和土壤，有大米耕作的不同的年的稻地里的关於生命的社区被测量在土壤上从高地检验土地使用变化的效果到稻地微食物的网。当控制和微生物引起的社区作文用phospholipid被描绘，高地玉米领域被选择丰满的酸(PLFA)分析。微生物引起的生物资源(全部的PLFA)，细菌生物资源，和真菌生物资源在20-40-year是更高的(迟了阶段)比1-10-year(早阶段)稻领域。许多总数线虫和bacterivores是更低的在比迟了阶段的稻地早阶段。许多草食动物在早阶段的稻领域里是最高的，但是不偏食的人食肉动物的在迟了阶段的稻领域里是最高的。结构的方程模型显示那张土壤食物网在20以后被发展并且组织稻耕作的年。我们的结果建议了微食物的网可以是的那土壤为土壤开发和稻的稳定的好指示物回答后面的土地使用变化。

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：Bt玉米叶垃圾的化学作文上的基因修正的非计划中的效果可以在它的分解上有影响。在在南非的很农业的系统，玉米垃圾是任何一个留在土壤表面上或在耕种期间合并了到土壤。用三个玉米混血儿(DKC80-12B，DKC80-10和DKC6-125)的叶垃圾，一个litterbag实验在堡垒兔研究农场的大学被执行，南非，为了在玉米叶的分解上决定基因修正的效果，乱丢东西什么时候在在7月和11月之间的地条件下面留在土壤表面上，正常休闲时期，在2008。另一个litterbag实验在堡垒兔研究农场的大学被进行，使用南非遗传上与cry1Ab修改了的二个玉米混血儿的叶垃圾并且Zanyokwe灌溉计划，基因(MON810)，DKC75-15B和PAN6Q-308B，和他们的相应近的isolines，CRN3505和PAN6Q-121。在崽的Cry1Ab蛋白质的降级，适用表面、合并土壤，也被调查。当在表面上适用时并且当合并了到土壤时，Bt玉米垃圾的分解类似于non-Bt玉米垃圾的。合并土壤的垃圾，以及它的Cry1Ab蛋白质，比在表面上适用的快分解了。叶崽C:PAN6Q-308B和PAN6Q-121的N比率在整个学习是类似的，而那些在一个12星期的时期期间由类似的数量DKC75-15B和CRN3505衰退了。这些调查结果建议与MON810事件，Bt玉米的叶垃圾的那分解没被玉米影响基因修正，并且Cry1Ab蛋白质不管崽是否在土壤表面上被使用或合并了到土壤在冬季休闲期间和植物叶垃圾垮掉。

简介：Itisgloballyacceptedthatsoilcarbon(C)dynamicsareatthecoreofinterlinkedenvironmentalproblems,deterioratingsoilqualityandchangingclimate.Itsmanagementremainsacomplexenigmaforthescientificcommunityduetoitsintricaterelationshipwithsoilnitrogen(N)availabilityandmoisture-temperatureinteractions.ThisarticlereviewsthemanagementaspectsofsoilCdynamicsinlightofrecentadvances,particularlyinrelationtotheavailabilityofinorganicNpoolsandassociatedmicrobialprocessesunderchangingclimate.Globally,drasticalterationsinsoilCdynamicsunderchanginglanduseandmanagementpracticeshavebeenprimarilyattributedtothevariationinsoilNavailability,resultinginahigherdecompositionrateandaconsiderabledeclineinsoilorganicC(SOC)levelsduetoincreasedsoilCO_2emissions,degradedsoilquality,andincreasedatmosphericCO_2concentrations,leadingtoclimatewarming.PredictedclimatewarmingisproposedtoenhanceSOCdecomposition,whichmayfurtherincreasesoilNavailability,leadingtohighersoilCO_2efflux.However,aliteraturesurveyrevealedthatsoilmayalsoactasapotentialCsink,ifwecouldmanagesoilinorganicNpoolsandlinkmicrobialprocessesproperly.Studiesalsoindicatedthattherelative,ratherthantheabsolute,availabilityofinorganicNpoolsmightbeofkeyimportanceunderchangingclimate,astheseNpoolsarevariablyaffectedbymoisture-temperatureinteractions,andtheyhavevariableimpactsonSOCturnover.Therefore,multi-factorialstudiesarerequiredtounderstandhowtherelativeavailabilityofinorganicNpoolsandassociatedmicrobialprocessesmaydetermineSOCdynamicsforimprovedsoilCmanagement.

简介：Apotexperimentwasconductedtoinvestigatetheeffectsofnitrogencontent[N1(nofertilizer),N2(0.15g?kg–1),andN3(0.3g?kg–1)]onthegrowthandthehydrauliccharacteristicsofpeachseedlingsunderdifferentsoilmoistureconditions(W1,W2andW3,inwhichthesoilwatercontentwas45%to55%,60%to70%,and75%to80%ofthefieldwatercapacity,respectively)byusingaspecializedhighpressureflowmeterwitharootchamberandacoupling,whichwasconnectedtoplantorgans.Leafareaandleafhydraulicconductivity(KL)increasedsignificantlyintheseedlingsbecauseofincreasedsoilmoistureandNcontent.KLincreasedwithleafarea.AlinearcorrelationwasdocumentedbetweenKLandleafarea.KLwashigherinthemorningandbegantodeclinesharplyafter16:00,atwhichKLdeclinedafteraninitialincrease.SoilmoistureandNcontentenhancedshoot(Ks)androot(Kr)hydraulicconductivities,therebyimprovingthelowsoilmoistureconditiontoalargeextent.KsandKroftheseedlingswerereducedby32%and27%respectivelyinN1,andby14.7%and9.4%,respectivelyinN2,andbothinW1,comparedwiththecontroltreatment.N3hadnosignificanteffectonKsandKrundersimilarconditions.LinearnegativecorrelationswereobservedbetweenKrandtheexcisedrootdiameteraswellasbetweenKsandtheshootstemdiameter.Theshoot-to-rootratioincreasedwithincreaseinNcontent.Theshoot-to-rootratioinN3wasincreasedby14.37%,comparedwithN1inW1aswellasby12%and4.39%inW2andW3,respectively.KnowledgeoftheeffectsofsoilmoistureandNfertilizeronhydrauliccharacteristicsandgrowthisimportant.Ourresultsprovidebasicguidelinesfortheimplementationofwater-savingirrigationandfertilizationmanagementofnurserystock.

简介：PhysiographyandsoilinMaeRimwatershed,ChiangMaiProvince,Thailandwereinvestigatedbyusingaerialphotographsandsatelliteimageinconjunctionwithfieldwork,andsoilinfiltrationrateandsoilshearresistanceweremeasuredinfield.ManyfactorsaffectingrunoffwereanalyzedusigtheIntegratedLandandWaterInformaitonSystem(ILWIS).Asaresult,amodeldeterminingfloodhazarwassetup.Threempsincludingrunoffcurvenumbermap,runoffcoefficentmap,andfloodinumdationmapwerecreated,Inaddition,thetimeofconcentrationwaspredicted.