简介：Thetreesinurbanlandscapes,independentofwhethertheyareinurbanforestsorstandalone,canimproveenvironmentquality,enhanceindividualandcommunitywell-being,provideawiderangeofservicestoindividualsandcommunities,andproduceamorehealthfulandcomfortableenvironmentforthevastmajorityofthepopulation.Knowledgeofthepotentialsignificanceoftreesinurbanlandscapesisexpandingrapidlyasresearchcontinuestodocumenttheimportantrolethaturbanforestsandtreescanplayinimprovingthequalityofurbanlife.Theenvironmentalconditionsinurbanlandscapesare,however,verydifferentfromthenaturalconditionsthatthetreespeciesareadaptedto.Thisposesbigchallengestotheurbanforestryinitseffortstocreatehealthyandvaluabletreesinurbanlandscapes.Onlythroughimplementingsomeimportantmeasureswecanensurehighsurvivalrateofsaplingsandwell-beingandlongevityofurbantrees.

简介：n2000,theauthorscollectedagreatquantityofrelevantdatabyinvestigatingmorethan50naturereserves.BasedontheanalysisofdevelopmentandmanagementsituationoftheprotectedareasinChina,themainproblemswereputforward,suchas,nounifiedmanagementforincomeandmanagingactivities,lackofspecialguidelineandeffectivesupervision,lackofincomeandinvestment,investingfinancialdifferenceindifferentprovinces.Alltheseproblemscausedthelackoffundsforconstruction,aswellasthedamageofresourcesandenvironment.Furthermoretheconservingactivitieshavetotransmittotheprofitsinmanyprotectedareas.Combinedwiththeseproblems,theprimarysolutionprogrammersalsowereputforward.

简介：Buildingaforestcityrequiressufficientareaofurbanforestsandanexpeditewatercirculatingsystem.TakingShanghaiasanexample,itisproposedthatChinashoulddevelopitsurbanforestrythroughnetworkingofforestsandwaterareasduetohighdensityofpopulation,limitedlandresourcesandpoorwatercirculatingsystem.InordertodevelopaconceptionofurbanforestwithChinesecharacteristics,thispaperelaboratesimplications,foundation,evolutionanddevelopmentofthenewconceptionthroughcomparativestudiesofurbanforestdevelopmentinsideandoutsideChina.

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：AimingatnaturalenvironmentconditionsinChina’swesternregions,theStateCouncilhasdecidedtoimplementnaturalenvironmentprotectionanddevelopmentwithmaincomponentsofnaturalforestprotection,afforestationandgrassgrowingonsuitablewastelandandsystematicallyreturningcultivatedlandtoforest(grass),thisisanimporta

简介：

简介：Remote-sensingdataforprotectedareasinnorthernTogo,obtainedinthreedifferentyears(2007,2000,and1987),wereusedtoassessandmapchangesinlandcoverandlanduseforthisdroughtpronezone.Thenormalizeddifferencevegetationindex(NDVI)wasappliedtotheimagestomapchangesinvegetation.Anunsupervisedclassification,followedbyclassesrecoding,filtering,identifications,areacomputingandpost-classificationprocesswereappliedtothecompositeofthethreeyearsofNDVIimages.Maximumlikelihoodclassificationwasappliedtothe2007image(ETM+2007)usingasupervisedclassificationprocess.Sevenvegetationclassesweredefinedfromtrainingdatasets.Thesevenclassesincludedthefollowingbiomes:riparianforest,dryforest,floodedvegetation,woodedsavanna,fallows,parkland,andwater.Fortheseclasses,theoverallaccuracyandtheoverallkappastatisticfortheclassifiedmapwere72.5%and0.67,respectively.Dataanalysesindicatedagreatchangeinlandresources;especiallybetween1987and2000probablyduetotheimpactofdemocratizationprocesssocial,economic,andpoliticaldisorderfrom1990.Wide-scalelossofvegetationoccurredduringthisperiod.However,areasofvegetationclearingandregrowthweremorevisiblebetween2000and2007.Themainsourceofconfusioninthecontingencymatrixwasduetoheterogeneitywithincertainclasses.Itcouldalsobeduetospectralhomogeneityamongtheclasses.Thisresearchprovidesabaselineforfutureecologicallandscaperesearchandforthenextmanagementprograminthearea.

简介：Inthisresearch,fiveNitrariasibiricaprovenancessuchasDayiluwereselectedtodoexperimentofsalt-resistance,combiningfixedplotstestwithtypicalplotinvestigation,measuringsurvivalrateandgrowthasmainindicators.TheexperimentsofmainculturaltechnologyweredoneonNitrariasibiricain4typesofsitepreparation,3typesofplanting,3designsforplantingdensity.TheNitrariasibiricaexperimentsfortheeffectsofcurbingsaltandimprovingsoilweredonebytestingsoilnutrients,saltcontent,soilphysicalpropertiesasfocalpointsintypicalsiteof3-4yearswoods.TheexperimentresultsshowedthattheNitrariasibiricacouldsurvivewellwithsoilsaltcontentof0.6%,andthatsurvivalratedeclineddistinctivelyassoilsaltcontentexceeded0.8%.However,highsoilsaltcontentdidnotinfluencegrowthintheyearofplanting.Therewereobviousdifferencesinsalt-toleranceamongNitrariasibiricaprovenances;Dayiluwasthebestonsalt-tolerance,theother4provenanceshadnodifferences,andobviouslyinferiortoDayilu.Thedifferenttypesofsitepreparationclearlyinfluencedplantingsurvivalrate,conservingrateandgrowth.Themethodoftwo-ploughing-two-harrowingwasthebestamongall4typesofsitepreparation.Seedforestationwaslargelylimited,bared-rootedseedlingforestationmaybepopularisedwhensoilsaltcontentwaslessthan1%andsoilmoisturecontentwasbetterinspring.Forestationwithcontainerseedlingwassuitedtocoastalsalinesoilinrainyseason.TheoptimumplantingdensityofNitrariasibiricawas2505/haintheYellowRiverDeltaareainviewofcoveragerate,yieldoffruitsandcostofplanting.Generallyspeaking,Nitrariasibiricacouldeffectivelyrefrainsoilfromaccumulationofsaltinthesurfacesoil,decreasesaltcontentandincreasesoilnutrient,andheightensoilcapillaryporerate.

简介：我们比较了在处于Karnataka的状态种区域的三棵宽广柚木从三个种子生产区域(矿泉)和柚木(TectonagrandisL.f)的三个相应未耕过的看台(UIS)获得的子孙的词法、基因的属性，印度。一般来说，播种象种子重量，种子尺寸和种子空虚那样的词法参数在与UIS相比的矿泉是显著地优异的。种子萌芽百分比在从矿泉的种子也是更高的。在二每月的间隔测量六个月的幼苗性能被观察在在比较的三个区域中的二个的矿泉优异。尽管矿泉的子孙的基因差异根本比UIS低区域，价值中等高。当差异索引否定地每种子与水果重量，水果直径和核重量被相关时，萌芽百分比断然每种子与水果重量和核重量被相关。矿泉没有对未来种植园的基因差异的严重威胁作为中等改进的种的材料的来源证明重要。