简介:TobuildarapidandaccuratemethodforgreenhousevegetablelandinformationextractionusinganindexmodelderivedfromTMdigitaldataofQingzhouCity,ShandongProvince,basedonasystematicanalysisofthespectralcharacteristicsofdifferentlandusetypesinthestudyarea,asubsetoftheimagewasfirstmadetoeliminatethemountainousregionnotassociatedwithvegetabledistribution,andthenwaterbodypixelsweremasked.WiththistheV1indexmodelforgreenhousevegetablelandextractionwasdeveloped.TheindexmodelindicatedgreenhousevegetablelandforQingzhouinApril2002wasconcentratedinthesoutheastandaroundruralresidentialareas.Fielddatausedforanaccuracyevaluationshowedthatgreenhousehectaresdeterminedwithremotesensingwere95.9%accurate,andaccuracyforthespatialdistributionofgreenhousevegetablelandcrosscheckedwitharandomsamplewas96.3%.Therefore,thisapproachprovidedaneffectivemethodforgreenhousevegetablelandinformationextractionandhaspotentialsignificanceformanagementofgreenhousevegetableproductioninthestudyarea,aswellasNorthChina.
简介:比较方法和录象带录音机被使用以防为记录二个组操作符的操作表演的学习。时间跨度是7个月,从9月到三月。在9月的操作的表演作为参考书被拿。测试调查和数据分析的结果证明掉落树的手术效率被冷天气影响,适当地减少了18.5%在里面平均。
简介:VILLAGEFORESTRYSTATIONSPERFORMANIMPORTANTROLEINCHINA’SSOCIALFORESTRYDEVELOPMENTByZhuTue;WangLiping;ShiWenkaiTheRelationshipBe...
简介:Availablewaterandfertilizerhavebeenthemainlimitingfactorsforyieldsofspringwheat,whichoccupiesalargeareaoftheblacksoilzoneinnortheastChina;thus,theneedtosetupappropriatemodelsforscenarioanalysisofcroppingsystemmodelshasbeenincreasing.ThecapabilityofCropSyst,acroppingsystemsimulationmodel,tosimulatespringwheatgrowthofawidelygrownspringcultivar,'Longmai19',intheblacksoilzoneinnortheastChinaunderdifferentwaterandnitrogenregimeswasevaluated.Fielddatacollectedfromarotationexperimentofthreegrowingseasons(1992-1994)wereusedtocalibrateandvalidatethemodel.Themodelwasrunfor3yearsbyprovidinginitialconditionsatthebeginningoftherotationwithoutreinitializingthemodelinlateryearsintherotationsequence.CropinputparametersweresetbasedonmeasureddataortakenfromCropSystmanual.Afewcultivar-specificparameterswereadjustedwithinareasonablerangeoffluctuation.TheresultsdemonstratedtherobustnessofCropSystforsimulatingevapotranspiration,abovegroundbiomass,andgrainyieldof'Longmai19'springwheatwiththerootmeansquareerrorsbeing7%,13%and13%oftheobservedmeansforevapotranspiration(ET),grainyieldandabovegroundbiomass,respectively.AlthoughCropSystwasabletosimulatespringproductionreasonablywell,furtherevaluationandimprovementofthemodelwithamoredetailedfielddatabasewasdesirableforagriculturalsystemsinnortheastChina.
简介:Becauseofthedistinctionofsoilpropertyandhumuscontent,soilwatercontentisnotidealtoindicatewhetheritissuitabletothegrowthofplant.MainlybasedonthePF-anumericalvaluedenotingthewaterregimeofsoilandconnectedwiththegrowthofplant,thestudycombinedthemoisturepercentageofsoilwithPFtoresearchinquantitytheinterrelationbetweenthemoisturepercentageandPFindifferentsuccessionphasesofsubalpinedarkconiferousforestinGonggaMountain.Theresultsshowedthat:(1)InthesamePFvalue,themoisturepercentageinhumushorizonincreasedgraduallywiththedevelopmentofthesuccessionofthedarkconiferousforest;Themoisturepercentageofover-matureforestwasthehighestand>matureforest>half-matureforest>younggrowthforest;(2)Withtheincreaseofsoildepth,thesoilbulkdensityincreasedandthemoisturepercentagedecreased,butthedifferenceinthepercentageofmoisturewasnotnotableindifferentsuccessionphases.(3)Indifferentsuccessionseries,thevegetationaffectedthesoilwatercharacteristicsbyincreasingthesoilorganicmatter,improvingthesoilconstruction,recedingthesoilbulkdensityandenhancingthesoilporosity;(4)Thehumushorizonofthedarkconiferousforestsoilhasthehighestwaterholdingcapabilityinthisregion.
简介:TheplantationoccupiesgreatproportioninurbanforestinmanycitiesinChina.Thedesignandmanagementforurbanforestsupplementseachother.Thedesigndecidestheorientationofmanagement,whilethemanagementalsoaffectsthelandscapeeffectsandecologicalbenefitsofthedesigninreverse.Therearemanyissuesondesignandmanagementofurbanforest.Forexample,somedesignsonlyemphasizethevisualimpressionwhileignoringtheecologicalbenefits,theproblemsofsimplifyingtheforestlayerstructureandpurifyingitsspeciescompositionareubiquitous,Itisshortofcomprehensiveanalysisoflocalenvironmentconditions,thephenomenaareveryoutstandinginlearningforeignorothercity'smodelbycopyingmechanically.Themanagementmodelisnotonlymonotonous,butalsobehindthestepofurbandevelopmentandthehumandemandforreturningtonature.Theseunreasonabledesignsandmanagementsareoneofthemainreasonsforlowerecologicalbenefits,andalsocausedsomeotherbadaftereffects,suchaslowerbiodiversityandhighcostofmanagement,etc.Sothethoughtofclose-to-naturedesignandmanagementinurbanforestisproposedanditsfeasibilityandmethodsarediscussedinthepaper.
简介:Abstract:FortyspeciesofBasidiomycotafrom21generain15families,collectedfromLiuxiheNationalForestPark,Guangzhou,China,havevaluesforusebylocalpeople.Morethanhalfofthespeciescollectedareedible,andsome(Lactariusdeliciosus,Boletusspp.)aregatheredforcommercialconsumptioninSouthChina.Tenspecieshavemedicinalproperties,andincludeDictyophora,Ganoderma,PisolithusandScleroderma.Over60%species(26taxa)areectomycorrhizalinvolving12ediblefungi.ThemostabundantfamiliesweretheAmanitaceae,BoletaceaeandSclerodermataceae,whichformimportantectomycorrhizalassociationswithconiferousandmixedbroad-leafedtreesinthePark.Prospectiveusesofthesemacrofungiarediscussed.
简介:Fourvegetationtypes,namelyconiferousandbroadleavedmixedforest,secondarydeciduousbroadleavedforest,openshrubsandmeadow,withdwarfbamboo(Indocalamuswilsoni)arecomparedontheirfloristiccomposition,lifeform,communitystructure,andsurvivorshipofbamboos.Disturbanceofconifer-loggingtwodecadesagopromotedthespeciesdi-versity,butnegativelyinfluencedthesurvivorshipofdwarfbamboowhichisdominateontheforestfloor.Openshrubsbearmorespeciesdiversityandmoregeophytesinitslife-formspectrumthanitsbackgroundvegetationsubalpinemeadow,how-ever,dwarfbambooisgrowingmuchbetterintheopenshrubsthaninthemeadow.Itseemsdwarfbambooprobablyfavor-itestooccurinthevegetationatgentleslopeswithamediatecanopycover.Itsmassfloweringinthesecondarydeciduousforestsuggeststhatasimultaneousfloweringandfollowingdiebackmaybeirruptintherecentlycomingyearsoverthesubal-pineShennongjiainChina,whichwillbenotonlyalterthefloristiccompositionandcommunitystructureoftheoldbamboostands,butalsoinfluencethesurvivorshipofthisrarespecies.
简介:Landusechangescangreatlyinfluencesoilphosphorus(P)dynamics,especiallywhenconvertingnativeforeststoagriculturalland.SoilsinXishuangbanna,whichisoneofsouthwestChina'stropicalareasthatmaintainfragmentsofprimaryforests,werestudiedtoa)evaluatetheeffectoftwocommonlandusechanges,conversionofforeststoagriculturallandorrubbertreeplantation,onthedynamicsofavailablePandtotalPinbulksoilsaswellastotalPinparticlesizefractions;b)assesstherelationshipbetweensoilPdynamicsandsoilorganiccarbon(SOC);andc)elucidatetherelationshipbetweensoilPcontentandsoilpropertiessuchaspHandtexture.Clearingsecondaryforestswithsubsequentshiftingcultivationandestablishmentofrubbertreeplantationcausedsignificantdecreases(P<0.05)inavailablePat0-20cmsoildepths,whereasfortotalPtherewasasignificantdecrease(P<0.05)whenconvertingtoshiftingcultivation,rubbertreeplantation,orfallowfieldatboth0-20and20-40cmdepths.Abandonmentoffieldsusedforshiftingcultivationledtosignificantincreases(P<0.05)inavailablePat20-40cmdepth.Inaddition,therewasasignificantpositiverelationshipbetweensoilorganiccarbonandsoilPcontent.Comparedtosecondaryforests,theratiooforganiccarbontototalPinsurfacesoils(0-20cm)ofshiftingcultivationandrubbertreeplantationwassignificantlylower(P<0.05).
简介:FixedammoniumcontentsandNH4^+fixationcapacitiesofsomerepresentativecultivatedsoliscollectedfrom16provincesofChinawerestudied.Resultsshowedthatthecontentsoffixedammoniuminsoilsrangedfrom35to573mgNkg^-1,withanaverageof198mgNkg^-1.Thecontentoffixedammoniumcorrelatedverysignificantlywithmicacontentfortropicalandsubtropicalsoils,whereasthiswasnotthecaseforsoilsinthetemperatezone.AttheendofK-exhaustingexperimentthefixedammoniumcontentincreasedinmostsoilsstudied.However,itdecreasedinsmomtemperatesoils.Generally,fixationofaddedNH4^+couldnotbefoundeitherbeforeorafterK-exhaustingexperimentforhighlyweatheredsoils,includingtropicalsoilsandsoilsderivedfromgranite-gneissorQuaternaryredclaysinthesubtropiczone,whileformostsoilsintheYangtzeRiverdaltatheNH4^+fixationcapacitywasratherhighandincreasedsignificantlyintheK-exhaustedsoils.
简介:ThiscasestudyoutlinestheproblemsfacedbythepeoplesoftheHexiCorridor.Theseproblemsareseriousandurgent,andarerepresentativeofthosefacedbyothercommunitiesrightacrosswesternChina.Therootcausesareoutlinedandsomeremediesaresuggested.ThepracticalmeasuresproposedunderChina'sNationalActionPlantoCombatDesertificationaredescribedanddiscussed.
简介:Basedoninvestigationof53gapsand25quadrats(15m×15meach)ofnon-gapclosedstandinanold-growthtropicalmontanerainforestofHainanIsland,China,canopydisturbanceregimesandgapregenerationwerestudied.Gapswereellipticalinhorizontalform,theratiooflongaxis/shortaxiswasabout1.4.Percentageofexpandedgaps(EG)andcanopygaps(CG)areainthelandscapewere53.5%and25.2%respectively.EGrangedfrom31.4m2to488.2m2andCG/rom14.9m2to354.2m2,theiraveragesizes...
简介:TheexcessiveexploitationandharvestingofforestresourcesduetoChina’seconomicconstructiondemandshavemadeitsforestresourcefallingintostructuralcrisis.Overthelastthreedecades,theareaofChina’snaturalforestsdecreasedby11millionha.Theareaofmaturedforestshasdecreasedfrom12millionhainearly50sto5.6millionhaatp
简介:ThefloraandcommunityphysiognomyofdegradedplantationecosystemsonpurplesoilwereinvestigatedinNinghuaCountyofFujianProvince,Chinatounderstandtherelationshipbetweenplantdiversityandecosystemprocesses..Fourdifferentrestorationcommunities(labeledasecologicalrestorationtreatmentI,II,IllandIV)wereselectedbyspace-timereplacementmethodaccordingtotheerosionintensityindegradedpurplesoilecosystem.Theresultsshowedthatthereweretotally86plantspeciesbelongingto78generaand43familiesinthedegradedpurplesoilecosystem.Ofthe15typesofdistributionareainspermatophytegenus,12typeswerefoundinthepurplesoilecosystem.Alongrestorationgradientfromlowtohigh,plantgrowthtypeandlifeformspectrabecameabundantmoreandmore,andthespermatophytegeneraforeachdistributionareatypeandgeneranumbersfordifferentfoliagecharactersincreasedaswell.Itisconcludedthattheplantfloraandphysiognomyinecologicalrestorationprocessbecomemorecomplexanddiverse,indicatingthattheforestecosystemonpurplesoiltendstobemorestable.
简介:SongRong(i.e.Matsutake,Tricholomamatsutake)isthemostfavoriteediblemushroominJapanandrestrictedlydistributesinforestsinEastAsia.TheyieldofSongRong,however,hasbeenextremelydroppingsince1940'sintheregionduetochangesofenvironmentalecologyofnatureforests.Asacompensationforconsumption,JapanimportedproductsofT.matsutakefromKoreaandChina,andT.magnivelarefromNorthAmericasincemid-1970s,butT.matsutakestiliaccountsforalargeportionofthe...
简介:分析了中国东北小兴安岭林区红松种群的生活史过程及其影响因素,对红松生活史的4个阶段进行了分析,并讨论了其进化和保护对策.红松的传粉和受精主要受天气条件的影响.林冠下的光照是控制红松幼苗生长和存活的主要因素.红松种子生产的周期性波动会引起有关动物种群的相应变化.动物是阔叶红松林生态系统中不可缺少的组成成分,松鼠在红松种群的天然更新中起着非常重要的作用.了解森林生态系统中物种的协同进化关系对于我们保护森林生物多样性和生态系统的完整性有着重要的意义.在红松的保护中,我们不仅要保护树木本身,而且还应当保护与红松相关的动物、生境乃至整个生态系统.