学科分类
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24 个结果
  • 简介:Thedynamicsofrhizospheremicrobialcommunitiesisimportantforplanthealthandproductivity,andcanbeinfluencedbysoiltype,plantspeciesorgenotype,andplantgrowthstage.ApotexperimentwascarriedouttoexaminethedynamicsofmicrobialcommunitiesintherhizosphereoftwosoybeangenotypesgrowninablacksoilinNortheastChinawithalonghistoryofsoybeancultivation.Thetwosoybeangenotypes,Beifeng11andHai9731,differinginproductivityweregrowninamixtureofblacksoilandsiliceoussand.Thebacterialcommunitieswerecomparedatthreezonelocationsincludingrhizoplane,rhizosphere,andbulksoilatthethirdnode(V3),earlyflowering(R1),andearlypod(R3)stagesusingpolymerasechainreaction-denaturinggradientgelelectrophoresis(PCR-DGGE)of16SrDNA.Theresultsofprincipalcomponentanalyses(PCA)showedthatthebacterialcommunitystructurechangedwithgrowthstage.Spatially,thebacterialcommunitiesintherhizoplaneandrhizosphereweresignificantlydifferentfromthoseinthebulksoil.Nevertheless,thebacterialcommunitiesintherhizoplaneweredistinctfromthoseintherhizosphereattheV3stage,whilenoobviousdifferenceswerefoundattheR1andR3stages.Forthetwogenotypes,thebacterialcommunitystructurewassimilarattheV3stage,butdifferedattheR1andR3stages.Inotherwords,somebacterialpopulationsbecamedominantandsomeothersrecessiveatthetwolaterstages,whichcontributedtothevariationofthebacterialcommunitybetweenthetwogenotypes.Theseresultssuggestthatsoybeanplantscanmodifytherhizospherebacterialcommunitiesintheblacksoil,andthereexistedgenotype-specificbacterialpopulationsintherhizosphere,whichmayberelatedtosoybeanproductivity.

  • 标签: 群落动态 细菌生长 基因型 黑土 空间 根际
  • 简介:Background:Ecologistsareinterestedinassessingthespatialandtemporalvariationinecologicalsurveysrepeatedovertime.Thispapercomparesthe1985and2015surveysoftheBarroColoradoForestDynamicsplot(BCI),Panama,dividedinto1250(20m×20m)quadrats.Methods,spatialanalysis:TotalbetadiversitywasmeasuredasthetotalvarianceoftheHellinger-transformedcommunitydatathroughouttheBCIplot.Totalbetawaspartitionedintocontributionsofindividualsites(LCBDindices),whichweretestedforsignificanceandmapped.Results,spatialanalysis:LCBDindicesindicatedthesiteswithexceptionalcommunitycomposition.In1985,theyweremostlyfoundintheswamphabitat.Inthe2015survey,noneoftheswampquadratshadsignificantLCBDs.Whathappenedtothetreecommunityintheinterval?Methods,temporalanalysis:Thedissimilarityincommunitycompositionineachquadratwasmeasuredbetweentime1(1985)andtime2(2015).TemporalBetaIndices(TBI)werecomputedfromabundanceandpresence-absencedataandtestedforsignificance.TBIindicescanbedecomposedintoB=species(orabundances-per-species)lossesandC=species(orabundances-per-species)gains.B-Cplotswereproduced;theydisplayvisuallytherelativeimportanceofthelossandgaincomponents,throughtime,acrossthesites.Results,temporalanalysis:InBCI,quadratswithsignificantTBIindiceswerefoundintheswamparea,whichisshrinkinginimportanceduetochangestothelocalclimate.ApublishedhabitatclassificationdividedtheBCIforestplotintosixhabitatzones.GraphsoftheBandCcomponentswereproducedforeachhabitatgroup.Group4(theswamp)wasdominatedbyspecies(andabundances-per-species)gainswhereasthefiveotherhabitatgroupsweredominatedbylosses,somegroupsmorethanothers.Conclusions:WeidentifiedthespeciesthathadchangedthemostinabundancesintheswampbetweenT1andT2.Thisanalysissupportedthehypothesisthattheswampisdryingoutandisinvadedbyspeciesfr

  • 标签: BETA DIVERSITY B-C PLOTS BCI forest
  • 简介:Duetothegrowingconcernabouttheagriculturalphosphorus(P)lossespollution,anin-depthunderstandingofPinpaddysoilsofChinawouldbehelpfulinprovidinganationalperspectiveoftheenvironmentalimpactofPcyclingandfertilityonChina'sfarms.Inthisstudy,weevaluatedthePstorageandthePdensityofpaddysoilsinChina,characterizedthespatialvariationsofPamongthesubgroupsofpaddysoilsandsoilregionsinChina,andevaluatedthePdatausingGIS-basedanalysis,whichincludedanewlycompiled1:1000000digitalsoilmapofChina,andusing1490soilprofiles.TheavailableandtotalPdensitiesofpaddysoilswere6.7and698.5gm-3,respectively.OverallinChina,thetotalPstoragewithin1mofpaddysoilswasestimatedtobe330.2Tg.ThePdensityofpaddysoilsvariedsubstantiallywithsubgroupsduetothedifferentsoilwaterregimessuchasgroundwatertableandsoildrainage.ThePavailabilityinpaddysoils,especiallyinsurfacelayer,washigherinhightemperatureandprecipitationareas.Furtherresearchisneededtoexaminemoreanthropogenicimpactfactors,suchasincreasinguseofchemicalfertilizer.

  • 标签: 中国地区 空间变化 水稻土 土壤磷 存储 地理信息系统
  • 简介:Background:Europeanforestsareconsideredacrucialresourceforsupplyingbiomasstoagrowingbio-economyinEurope.ThisstudyaimedtoassessthepotentialavailabilityofforestbiomassfromEuropeanforestsanditsspatialdistribution.Wetriedtoanswerthequestions(i)howisthepotentialforestbiomassavailabilityspatiallydistributedacrossEuropeand(ii)wherearehotspotsofpotentialforestbiomassavailabilitylocated?Methods:Thespatialdistributionofwoodybiomasspotentialswasassessedfor2020forstemwood,residues(branchesandharvestlosses)andstumpsfor39Europeancountries.UsingtheEuropeanForestInformationSCENario(EFISCEN)modelandinternationalforeststatistics,weestimatedthetheoreticalamountofbiomassthatcouldbeavailablebasedonthecurrentandfuturedevelopmentoftheforestage-structure,growingstockandincrementandforestmanagementregimes.Wecombinedtheseestimateswithasetofenvironmental(siteproductivity,soilandwaterprotectionandbiodiversityprotection)andtechnical(recoveryrate,soilbearingcapacity)constraints,whichreducedtheamountofwoodybiomassthatcouldpotentiallybeavailable.Wemappedthepotentialbiomassavailabilityatthelevelofadministrativeunitsandatthe10km×10kmgridleveltogaininsightintothespatialdistributionofthewoodybiomasspotentials.Results:Accordingtoourresults,thetotalavailabilityofforestbiomassrangesbetween357and551Tgdrymatterperyear.ThelargestpotentialsupplyofwoodybiomassperunitoflandcanbefoundinnorthernEurope(southernFinlandandSweden,EstoniaandLatvia),centralEurope(Austria,CzechRepublic,andsouthernGermany),Slovenia,southwestFranceandPortugal.However,largepartsofthesepotentialsarealreadyusedtoproducematerialsandenergy.Thedistributionofbiomasspotentialsthatarecurrentlyunusedonlypartiallycoincideswithregionsthatcurrentlyhavehighlevelsofwoodproduction.Conclusions:Ourstudyshowshowthefo

  • 标签: FOREST BIOMASS EFISCEN EUROPE POTENTIAL supply
  • 简介:ConsumptionofriceisthemainsourceofmicronutrientstohumaninAsia.Apaddyfieldwithunknownanthro-pogeniccontaminationinDeqingCounty,ZhejiangProvince,Chinawasselectedtocharacterizethespatialvariabilityanddistributionofmicronutrientsinricegrainandsoil.Atotalof96pairedsoilandricegrainsampleswerecollectedatharvest.Themicronutrientsinthesoilsampleswereextractedbydiethylenetriaminepentaaceticacid(DTPA).Themeanmicronutrientconcentrationsinricegrainwere3.85μgCug-1,11.6μgFeg-1,39.7μgMng-1,and26.0μgZng-1.Themeanconcentrationswere2.54μgg-1forDTPA-Cu,133.5μgg-1forDTPA-Fe,30.6μgg-1forDTPA-Mn,and0.84μgg-1forDTPA-Zn.Semivariogramsshowedthatmeasuredmicronutrientsinricegrainweremoderatelydependent,witharangedistanceofabout110m.TheconcentrationsoftheDTPA-extractablemicronutrientsalldisplayedstrongspatialdependency,witharangedistanceofabout60m.TherewassomeresemblanceofspatialstructurebetweensoilpHandthegrainCu,Fe,Mn,andZn.Byanalogy,similarspatialvariationwasobservedbetweensoilorganicmatter(SOM)andDTPA-extractablemicronutrientsinthesoil.Krigingestimatedmapsoftheattributesshowedthespatialdistributionsofthevariablesinthefield,whichisbeneficialforbetterunderstandingthespatialvariationofmicronutrientsandforpotentiallyrefiningagriculturalmanagementpracticesatafieldscale.

  • 标签: 空间变异性 微量元素 水稻土 稻米
  • 简介:Inordertocomprehendtemporalpatternofthelarvaepopulationoftheyellowriceborer,Tryporyzaincertulas,andprovidevaluableinformationforitsforecastmodel,thedataseriesofthepopulationforeachgenerationandtheover-winteredlarvaefrom1960to1990inDingchengDistrict,ChangdeCity,HunanProvince,wereanalyzedwithgeostatistics.Thedataseriesoftotalnumber,the1stgeneration,the3rdgenerationandtheover-winteredlarvaeyeartoyeardisplayedratherbetterautocorrelationandprediction.Thedataseriesofgenerationtogeneration,the2ndgenerationandthe4thgenerationyeartoyear,however,demonstratedpoorautocorrelation,especiallyforthe4thgeneration,whoseautocorrelationdegreewaszero.Thepopulationdynamicsoftheyellowriceborerwasobviouslyintermittent.Aremarkablecycleoffourgenerations,oneyear,wasobservedinthepopulationofgenerationtogeneration.Omittingthecertaingenerationorinterposingtheover-winteredlarvaeonlyresultedinalessorslightchangeofautocorrelationofthewholedataseriesgenerationtogeneration.Cropsystem,food,climateandnaturalenemies,therefore,playedmoreimportantrolesinregulatingthepopulationdynamicsthanbasenumberofthelarvae.Thebasictechniquesofgeostatisticsappliedinanalyzingtemporalpopulationdynamicswereoutlined.

  • 标签: 水稻 分子动力学 分子标记 球形模型
  • 简介:ToaidinmanagementofCunninghamialanceolata,themaintimberspeciesinSouthernChina,itsvariationofspatialdistributionpatternwasanalyzed.ThreepermanentplotsofC.lanceolataplantationswithapproximatelythesamesiteconditions,setbyChinacontinuousforestinventoryinShunchang,Fujian,wereselected.C.lanceolatagrowthwasdividedintotwostages:youngtrees(5cm≤diameteratbreastheight(DBH)<10cm)andmaturetrees(DBH≥10cm).TheDBHandcoordinatesofeverytree(DBH≥5cm)inthepermanentplotswererecordedin2003and2008.ThefunctionL(r),improvementofRipley’sK(r),thepaircorrelationfunctiong(r),andtheuniformangleindex(W_i)wereusedtoanalyzethespatio-temporalvariationofspatialdistributionpatterns.Thethreepermanentplotshadmeanuniformangleindex(W)between0.494-0.578atlowaltitudes,0.465-0.477atmediumaltitudes,and0.426-0.601athighaltitudes.Resultsshowedthataltitudedidnotaffectthespatialdistributionpattern.TheL(r)andg(r)functioncurvesofmaturetreesweregenerallylowerthanyoungtrees’,i.e.tendtobemorerandomoruniformdistribution.Soregardlessoftheinitialdistributionofyoungormaturetrees,withthepassageoftime,therewasatendencyfortheaggregateddistributiontochangetoarandomdistribution,andarandomdistributiontochangetoauniformdistribution.

  • 标签: FOREST ECOLOGY Cunninghamia lanceolata SPATIAL distribution
  • 简介:ThecanopyrainfallinterceptionmodeilinkedtoenvironmentalconditionsandbiologicalfeaturesisestablishedonthebasisofstationaryobservationandmeasurementsinChina.UpscalingfromsiteobservationtoregionalIevelestimationofcanopyrainfallinterceptionhasbeenmade.ThepotentialinterceptionvalueofforestsduringtherainfallseasoninChinaaccordingtorainfallrecordsofMay,JulyandSeptemberintheyear1982,hasbeensimulatedandmappedundertheGISsoftwarepackageIdris...

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  • 简介:Climateisadominantenvironmentalfactorinbuildingecosystemstructureanddrivingbioticdynamicswithtopographicdependenceonspatialdistribution.Thispaperdemonstratestheapplicationofinterpolationtechniquetodescribespatialclimatedistribution.Adigitalelevationmodel(DEM)inresolutionof0.01degreeoflatitudeandlongitudehasbeendevelopedbecausetheincorporationofspatialdependenceontopographyiscrucialtoaccuracyofinterpolation.Climatedatafromsparseanddiscr...

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  • 简介:Theobjectivesofthepresentstudyweretoexaminethespatialpatternsofswarddrymatter(DM)andnitrogen(N)yieldsinagrasssilagefieldatfirst,second,andthirdcutsovera3-yearperiod;quantifytheirtemporalstabilitieswithtemporalstabilitymaps;andassessthepotentialforsite-specificmanagementineachpasture-growingperiodusingclassifiedmanagementmaps.Atcut1,thespatialpatternsofDMandNyieldsprovedtobewelldefinedandtemporallystableandwerelikelytobeduetodifferencesinthenetNmineralizationratesacrossthefieldduringspring.Incontrast,atcut2,thepatternsofDMproductionwerepatchyandtemporallyunstable.Itwasconcludedthat,inprinciple,asimplesite-specificapproachtoNfertilizationwouldbepossibleinthisfieldduringspringatcut1.Atlaterharvests,therationaleforasite-specificapproachtofertilizermanagementwaslessclearwithlogisticsappearingtobemorecomplexandlessfeasible.

  • 标签: 草原 空间变异性 精细农业 土壤
  • 简介:Informationonricephenologyisessentialforyieldestimationandcropmanagement.Totesttheabilityofremotesensingindetectingmultiplephenologicalstages,paddyricecanopyspectrumwasmeasuredbyahand-heldradiometer.Normalizeddifferencevegetationindex(NDVI)wascalculatedfromspectrum,andtheslopeofNDVIwasobtainedasitsdifference.WeevaluatedtheresponseofNDVIanditsslopetoricegrowthwithacomparisonoftwolate-seasonricecultivars.TheresultsshowedthatNDVIanditsslopecurveshaddistinctvariationcorrespondingtoricedevelopmentandtheycouldbeusedascultivar-independentphenologicalindicators.Thedatesoffloodingandtransplanting,tillering,panicledevelopment,headingandflowering,maturity,harveststages,andevenfieldmanagementpractices,couldbededucedfromtheseindicators.‘NDVI≤0'couldbeusedasasinglethresholdforthedetectionoffloodingandtransplanting.ThelargestspikeinthecurveoftheNDVIslopeindicatedthedurationoftilleringstage.Thenextspikecorrespondedtopanicledevelopment.TheheadingandfloweringstagewascharacterizedbythemaximumNDVIandthechangeofNDVIslopefrompositivetonegative.Atthematuritystage,NDVIdecreasedcontinuously,anditsslopefluctuatedjustbelowzero.Whenricegrainswerecompletelymatureandreadyforharvest,NDVIdeclinewasaccelerated.Atharvest,NDVIslopereacheditsminimumvalue.Thedistinctionbetweenheadingandmaturitystageswasobscure,mostlikelyduetoNDVIsaturationathighbiomass.Thestudymightprovidereferencesforpaddyricephenologydeterminationthroughremotesensingimages.

  • 标签: 冠层光谱 物候期 水稻 检测 NDVI 归一化植被指数
  • 简介:Bytakingtheurbangreenlandastestingobjective,theGeoEye-1fusionimageasbackground,andusingMoran’sindex,thecorrelativityofgreenlandunitshasbeenmeasured.Then,thepresamplingwasconductedbasedonthemeasuredcorrelativity,thesystematicsamplingdesignhasbeencarriedoutattheprecision95%and85%.ByusingofKriginginterpolationmethod,theweightofdifferenttypeofgreenlandhasbeendividedintothestratifications.Throughthestratifiedsampling,theestimationofgreenlandcoveragehasbeenobtained.Theresultsshowthattheurbangreenlandcoverageareais14.81km~2,accountingfor27.73%ofallurbanlandareas.Comparedwiththecommonsamplingmethod,theprecisionofthatincreasedabout3%.Thismethodcanalsobeutilizedinmonitoringdynamicvariationofurbangreenlandwiththerealtimeimages.

  • 标签: URBAN GREENLAND AUTOCORRELATION ANALYSIS SPATIAL STRATIFIED
  • 简介:Background:Estimationoftreediversityatbroaderscaleisimportantforconservationplanning.Treediversityshouldbemeasuredandunderstoodintermsofdiversityandevenness,twointegralcomponentstodescribethestructureofabiologicalcommunity.Variationofthetreediversityandevennesswithelevation,topographicrelief,aspect,terrainshape,slope,soilnutrient,solarradiationetc.arewelldocumented.Methods:Presentstudyexploresthevariationoftreediversity(measuredasShannondiversityandevennessindices)ofMajellaNationalPark,Italywithfiveavailableforesttypesnamelyevergreenoakwoods,deciduousoakwoods,black/aleppopinestands,hop-hornbeamforestandbeechforest,usingsatellite,environmentalandfielddata.Results:Hop-hornbeamforestwasfoundtobemostdiverseandevenwhileevergreenOakwoodswasthelowestdiverseandeven.Diversityandevennessofforesttypeswereconcurrenttoeachotheri.e.foresttypewhichwasmorediversewasalsomoreeven.Asabroadpattern,majorityportionofthestudyareabelongedtomediumdiversityandhighevennessclass.Conclusions:SateliteimagesandotherGISdataprovedusefultoolsinmonitoringvariationoftreediversityandevennessacrossvariousforesttypes.PresentstudyfindingsmayhaveimplicationsinprioritizingconservationzonesofhightreediversityatMajela.

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  • 简介:为简洁的原因,最通常使用的水文学模型基于土壤保存服务曲线数字(SCS-CN)当模特儿,它可能是为中国的黄土高原上的流量的评价的一种好选择;然而,高空间的异质,主要在土壤类型由碎裂的地形和变化引起了,可以限制它的适用性到这个区域。因此,到一个小分水岭的SCS-CN模型的适用性,高原上的Liudaogou,被评估,在模型的最适当的起始的抽象比率(Ia/S)价值被反的方法确定。结果证明标准SCS-CN模型对在Liudaogou分水岭的流量的评价适用,模型表演根据相对错误和Nash-Sutcliffe效率的价值是可接受的。因为,为分水岭的最适当的Ia/S值是0.22与这修改Ia/S值,模型性能稍微被改进。当一个重降雨事件(50.1公里)没被考虑时,模型表演不对Ia/S价值的修正敏感,它暗示模型用标准Ia/S价值,因为很少超过50公里的单个降雨事件发生在那个区域,能为Liudaogou分水岭被推荐。流量数量由SCS-CN模型为Liudaogou分水岭预言了,用修改Ia/S价值,当降雨价值比50公里低时,与增加降雨逐渐地增加了,而当降雨超过了50公里时,预言的数量很快增加了。这些调查结果可能在在中国的黄土高原上解决严肃的土壤和水损失的问题是有用的。

  • 标签: 小流域径流 空间异质性 水文模型 SCS CN 中国黄土高原
  • 简介:Saturatedhydraulicconductivity(Ks)isanimportantsoilhydraulicparameterforcharacteringtherateofwaterflowacrossthesoilsandismainlyrelatedtoitshighspatialvariability.Inasmallwatershedwiththeareaof0.27km2intheLoessPlateau,Ksof197soilsamplesunderdifferentvegetationsandlandformsweremeasured.Kshadamoderatevariabilityfortotalsamples.TheforestlandhadhighKswithlowcoefficientofvariation(CV),butthegrasslandinthewatershedbottomhadlowKswit...

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  • 简介:AccordingtotheunificationprincipleofsystemstructureandsystemfunctionoftheWaterResourceConservationForests,sevenfactorswereselectedfromstandspatialstructure,treesstructureandhealthyofwoods,themultifunctionmanagementoptimizationmodeltargetwasconfirmedbyusingnonlinearitymulti-objectiveprogrammingapproach,andthetargetfunction-standspatialstructurehomogeneityindexwasdefinedtoestablishspatialoptimizationmodelswithrestrainingconditionssetupindiversityofstandstructureandspatialstructure.ThespatialstructureofavailabletypicalstandinthewetlandareainsouthernDontingLakewasoptimizedbymeansofselectivecuttingandreinforcementplanting.Theresultsshowedthatthespatialstructurewasimprovedobviouslyandtreesdiversityandstandhealthwerenotweakened.It’ssuggestedthattheestablishedoptimizationmodelcaneffectivelyguidemultifunctionmanagement,standstructureoptimizationandthesteadinessofecologicalecosystemanditisconvenientandoperableinpractice,andit’sveryimportanttoprotectandrecoverecosystemofWaterResourceConservationForests.

  • 标签: water resource CONSERVATION FOREST southern Dongting
  • 简介:Soilsalinityandhydrologicdatasetswereassembledtoanalyzethespatio-temporalvariabilityofsalinizationinFengqiuCounty,HenanProvince,China,inthealluvialplainofthelowerreachesoftheYellowRiver.Thesalinesoilandgroundwaterdepthdataofthecountyin1981wereobtainedtoserveasahistoricalreference.Electricalconductivity(EC)of293surfacesoilsamplestakenfrom2km×2kmgridsin2007and40soilprofilesacquiredin2008wasanalyzedandusedforcomparativemapping.OrdinarykrigingwasappliedtopredictECatunobservedlocationstoderivethehorizontalandverticaldistributionpatternsandvariationofsoilsalinity.Groundwatertabledatafrom22observationwellsin2008werecollectedandusedasinputforregressionkrigingtopredictthemaximumgroundwaterdepthofthecountyin2008.ChangesinthegroundwaterlevelofFengqiuCountyin27yearsfrom1981to2008wascalculated.Twoquantitativecriteria,themeanerrororbias(ME)andthemeansquarederror(MSE),werecomputedtoassesstheestimationaccuracyofthekrigingpredictions.Theresultsdemonstratedthatthesoilsalinityintheuppersoillayersdecreaseddramaticallyandthetaxonomicallydefinedsalinesoilswerepresentonlyinafewmicro-landscapesafter27years.Presently,thesoilswithrelativelyelevatedsaltcontentweremainlydistributedindepressionsalongtheYellowRiverbed.Thereductioninsurfacesoilsalinitycorrespondedtothelocationswithdeepenedmaximumgroundwaterdepth.Itcouldbeconcludedthatgroundwatertablerecessionallowedwatertomovedeeperintothesoilprofile,transportingsaltswithit,andthusplayedanimportantroleinreducingsoilsalinityinthisregion.Accumulationofsaltsinthesoilprofilesatvariousdepthsbelowthesurfaceindicatedthatsecondarysoilsalinizationwouldoccurwhenthegroundwaterwasnotcontrolledatasafedepth.

  • 标签: 土壤盐渍化 冲积平原 黄河下游 时空变异 普通克里格法 土壤盐碱化
  • 简介:很多个基于过程的模型为确定被开发了在agro生态系统的碳(C)隐遁。DeNitrification分解(DNDC)模型被用来模仿并且确定长期(1980–2008)玷污器官的碳(SOC)在重要的生产大米的省的动力学,江苏,中国。在SOC存储的变化从在空间分辨率不同的二个土壤数据库被估计:由68个多角形和土壤组成的一个县数据库为在江苏的稻田的所有3.7Mha的701个多角形的基于补丁的数据库。分别地,当那与好决定估计数据库是201.6和216.2时,有粗糙的决定县数据库的模仿的SOC存储在2008在1980和170.3–305.1TgC在131.0–320.6TgC之间变化了在1980和2008的TgC分别地。建模,土壤数据库在空间分辨率不同的结果显示用土壤输入,有更高的分辨率的数据实质地增加了建模的结果的精确性;并且当缺乏详细土壤数据集时,DNDC模型,有最敏感的因素(MSF)的parameterized应付属性无常的方法,尽管,能仍然生产可接受的结果与为在这份报纸报导的案例研究的多达60%的偏差。

  • 标签: 土壤数据库 空间分辨率 数据库建模 水稻生产 江苏省 土动力学
  • 简介:Basedonlongtermandstationaryresearch,thetemporalandspatialpatternsanddynamiclawsofsoilwatercontentinMinqindesertareawerestudied.Someresultsareasfollows:(1)ThechangeofsoilwatercontentindifferentyearsisnotobviouslyinshrubsandduneofNitrariasibiricaandTamarixramosissima,butitwasgreatinshiftingsanddune,themaximumis2.538%;(2)Theseasondynamicscanbedividedintothreestages:accumulating,consumingandstable;(3)Theverticalchangeofsoilwa...

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  • 简介:AfieldexperimentwasconductedatKezuohouqiCounty,InnerMongoliaAutonomousRegionofChina,whichwaslocatedonthesoutheasternedgeoftheHorqinSandyLand,tostudythespatialvariabilityofsoilnutrientsforasmallscale,nutrient-poor,sandysiteinasemi-aridregionofnorthernChina;toinvestigatewhetherornottherewere'islandsoffertility'attheexperimentalsite;andtodeterminethekeynutrientelementsthatsustainedecosystemstability.Resultsobtainedfromgeostatisticalanalysisindicatedthatthespatialdistributionpatternofsoiltotalnitrogen(STN)wasfardifferentfromthoseofsoilorganicmatter(SOM),totalphosphorus(STP),andtotalpotassium(STK).ComparedtoSOM,STP,andSTK,STNhadalowerstructuralheterogeneityratioandalongerrange,whileotherelementswereallsimilar.Inaddition,STNhadanisotropicspatialstructure,whereastheothershadananisotropicspatialstructure.Thespatialstructurepatternsofherbagespecies,cover,andheightalsodiffered,indicatingthatspatialvariabilitywassubjectedtodifferentecologicalfactors.Differencesinthespatialvariabilitypatternsamongsoilnutrientsandvegetationpropertiesshowedthatsoilnutrientsforasmall-scalewerenottheprimarylimitingfactorsthatinfluencedherbagespatialdistributionpatterns.Incorporatingspatialdistributionpatternsoftreespecies,namely,Pinussylvestrisvar.mongolicaLitv.andshrubLespedezabicolorTurcz.inaresearchplotandusingfractaldimension,SOM,STP,andSTKwereshowntocontributetothe'islandsoffertility'phenomenon,howeverSTNwasnot,possiblymeaningthatnitrogenwasakeylimitingelement.Therefore,duringrestorationofsimilarecosystemsmoreattentionshouldbegiventosoilnitrogen.

  • 标签: 土壤化学 土壤成分 空间变异性