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简介：TobuildarapidandaccuratemethodforgreenhousevegetablelandinformationextractionusinganindexmodelderivedfromTMdigitaldataofQingzhouCity,ShandongProvince,basedonasystematicanalysisofthespectralcharacteristicsofdifferentlandusetypesinthestudyarea,asubsetoftheimagewasfirstmadetoeliminatethemountainousregionnotassociatedwithvegetabledistribution,andthenwaterbodypixelsweremasked.WiththistheV1indexmodelforgreenhousevegetablelandextractionwasdeveloped.TheindexmodelindicatedgreenhousevegetablelandforQingzhouinApril2002wasconcentratedinthesoutheastandaroundruralresidentialareas.Fielddatausedforanaccuracyevaluationshowedthatgreenhousehectaresdeterminedwithremotesensingwere95.9%accurate,andaccuracyforthespatialdistributionofgreenhousevegetablelandcrosscheckedwitharandomsamplewas96.3%.Therefore,thisapproachprovidedaneffectivemethodforgreenhousevegetablelandinformationextractionandhaspotentialsignificanceformanagementofgreenhousevegetableproductioninthestudyarea,aswellasNorthChina.

简介：从在到喂转动的木头的水库的木材仓库的木头漂流技术被模型测试学习。模型测试与引力类似和110的比率的规则被参加。主要参数象拖船船，水疗院加速器和喂转动的结构的数量一样，是坚定的。更合适的漂流过程被提出，设计的可靠基础被供应。

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.

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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：Sanjiang平原是冲积泛滥平原的一个广阔区域；在东北Heilongjiang省的低山。因为在过去的过多的陆地开垦，整个森林区域；质量减少了。在持续开发的看法，这篇论文以开发潜力为非木材福雷斯特产品分析了可能性，市场，社会效果；在Sanjiang平原的几个县的NTFP的地位。结果显示出那，活跃开发；为NTFP的管理是到怎么平衡沼泽地保存的一种乐观选择；持续经济开发。

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．