简介：Basedonmeteorological,hydrological,forest,andgrasslanddatacollectedbylocationobservation,remotesensing,fieldsurveysandrelevantliteratureduring1956to2009,theecologicalenvironmentchangeinnorthernslopeoftheQilianshanMountainswasanalyzedsyntheticallyusingregressionandcorrelationanalyses.Theresultsshowedthatthetemperaturehadanannualvariationrateof0.0334℃·a-1innorthernslopeoftheQilianshanMountainssince1960,andexhibitedaraisingtrend,especiallysince1987.Theannualvariationrateofannualprecipitationwas0.5702mm·a-1,indicatingthattheprecipitationtendedtoincrease.Theclimatehadchangedfromaridtohumidinthisregionsince1976.From1956to2006,theglacierareaofsixinlandriverbasin（Shiyangheriver,Heiheriver,Beidaheriver,Shuleheriver,DangheriverandHalternheriver）andDatongheriverbasininnorthernslopeofQilianshanmountainsdecreasedby17.7%.Thicknessoftheglacierreducedabout5-20m,andthesnowlineroseabout100-140m.TheGlaciericereservesininlandriverbasinofHexidecreasedby11.4%.From1972to2007,27glaciersintheeasternsectionoftheQilianshanMountainsdisappeared.From1956to2009,therunoffchangeinthenorthernslopeoftheQilianshanMountainswasdifferentindifferentregions.TherunoffwasreducedsignificantlyinShiyangheriverbasin,increasedslightlyinHeiheriverbasin,andincreasedobviouslyinShuleheriverbasin.From1958to1988,theareaofdeforestationandfarmingwasmorethan10.0millionha,andtheforestareawasreduced0.6millionha.SincetheQilianshanMountainNatureReservewasestablishedin1989,theforestwasrestoringgraduallybecauseofcontinualprotectionandcultivating,andtheforestareawasincreased9.4millionhafrom1989to2008.Duetohumaninterference,especiallyover-grazingimpact,thequalityofthewood-land,shrub-landandgrass-landinnorthernslopeoftheQilianshanMountainswereinadegradedcondition,whichre

简介：Inrecentyears,especiallyinthesummerof2002,themostseriousforestfiresoccurredintheDaxinganMountainofHeilongjiangprovinceandInnerMongolia.TherehasbeenlongtimeseriousforestfireenvironmentinsummerinDaxinganMountain.Thegrassintheforestisscorchedforlongtimedroughtandthemoisturecontentoflitterandturflayerdecreaserapidly.Theaccumulationanddrynessoffuelbuildthesummerforestfireenvironment,whicharemajorcausedbyMeteorologicalenvironment....

简介：EcosystemdegradationoccursinparallelwithdesertificationprocessinsandyareasofNorthChina.ThevastsandyareasinNorthChinaarecharacterizedwithflexibleenvironmentsandfragileecosystemsaswellasintensivehumanactivities.DuetotheannualprecipitationgradientdecreasesfromeasttowestinNorthChina,thewholesandyregionfallsinto3mainclimaticzones:add,semi-addanddrysub-humidzones.Theecosystemsineachtypeofclimaticzonesaredifferentinclimaticconditions,humanactivities,culturaldimensions,vegetationcovers,landscapes,andcausesandprocessesofecosystemdegradation.Therefore,themosteffectiverehabilitationmeasuresofdegradedecosystemsindifferenttypesoftheclimaticzonesarealsodifferent.Forthearidsandyareas,vegetationrehabilitationofdegradedecosystemsneedstobecompletelyclosed,assistingwithartificialmeasures,suchasplantation,irrigationorothers.Forsemi-addsandyareas,theeffectivemeasuresofvegetationrehabilitationofdegradedecosystemsincludeincreasingofproportionofforestsandrangelandsandlimitationofreclamation;reducingthecarryingcapacityoflivestockonunitareaofrangelandsandgrowthoffodderplants;andplantationonthelowlandsbetweensanddunes.Forthedrysub-humidareas,themosteffectivemeasureisenclosureofdegradedecosystemscombinedwithplantation,andinsomecases,juststopusesbygrazingorreclamation.

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：ＣｏｎｔｏｕｒＰｌａｎｔｉｎｇ－ＡＳｏｃｉａｌＦｏｒｅｓｔｒｙＭｏｄｅｌｏｆＣｏｍｐｒｅｈｅｎｓｉｖｅＤｅｖｅｌｏｐｍｅｎｔｏｆＡｒｉｄＭｏｕｎｔａｉｎＲｅｇｉｏｎｓｉｎＮｏｒｔｈＣｈｉｎａＢｙＦｅｎｇＸｉａｏｊｕｎＩｎｔｈｅａｒｉｄ，ｍｏｕｎｔａｉ...

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简介：Inaspectofthescaleofworks,theThreeNorthShelterbeltProgramisuptonowthemostmagnificentprojectofforestryecologicalconstructionintheworld.Attheendof2000,the1st,2nd,and3rdperiodsofconstructioninthe1stphase(1978-2000)hadbeencompleted.Basedonfuzzycomprehensiveevaluationmethod,thepaperisabouttheresearchesonpost-evaluationinthe1stphaseaimsoftheThreeNorthShelterbeltProgram.Theconclusionobtainedisthattheaimsarepartlysuccessful.

简介：Background:Themainobjectiveofthisstudywastoexaminetheclimaticsensitivityoftheradialgrowthresponseof13easternwhitepine(PinusstrobusL.)provenancesplantedatseventestsitesthroughoutthenorthernpartofthespecies’nativedistributionineasternNorthAmerica.Methods:Thetestsites(i.e.,Wabeno,Wisconsin,USA;Manistique,Michigan,USA;PineRiver,Michigan,USA;Newaygo,Michigan,USA;TurkeyPoint,Ontario,Canada;Ganaraska,Ontario,Canada;andOrono,Maine,USA)examinedinthisstudywerepartofarange-widewhitepineprovenancetrialestablishedintheearly1960sintheeasternUnitedStatesandCanada.Principalcomponentsanalysis(PCA)wasusedtoexaminethemainmodesofvariation[first(PC1)andsecond(PC2)principalcomponentaxes]inthestandardizedradialgrowthindicesoftheprovenancesateachtestsite.TheyearscoresforPC1andPC2wereexaminedinrelationtoanarrayoftestsiteclimatevariablesusingmultipleregressionanalysistoexaminethecommonalityofgrowthresponseacrossallprovenancestotheclimateofeachtestsite.ProvenanceloadingsonPC1andPC2werecorrelatedwithgeographicparameters(i.e.,latitude,longitude,elevation)andasuiteofbiophysicalparametersassociatedwithprovenanceoriginlocation.Results:TheamountofvariationinradialgrowthexplainedbyPC1andPC2rangedfrom43.4%to89.6%.Dendroclimaticmodelsrevealedthatwhitepineradialgrowthresponsestoclimatewerecomplexanddifferedamongsites.Thekeydendroclimaticrelationshipsobservedincludedsensitivitytohightemperatureinwinterandsummer,coldtemperatureinthespringandfal(i.e.,beginningandendofthegrowingseason),summermoisturestress,potentialsensitivitytostorminduceddamageinspringandfal,andbothpositiveandnegativeeffectsofhigherwintersnowfal.Separationoftheloadingsofprovenancesonprincipalcomponentaxeswasmainlyassociatedwithtemperature-relatedbioclimaticparametersofprovenanceoriginat5ofth