简介:Gummosisisthemostseriousdiseaseofmangoallaroundtheworld,whichisbecomingepidemicindifferentregionsofthesecountries,caninfectalmostallthecommercialandindigenousvarietiesofmango,andhasbeenregardedasanewseriousthreatofmangotreesatanalarmingratio.Thisarticlereviewedcausalorganisms,currentstatus,futureprospects,andmanagementpracticesofmangogummosisdisease.
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简介:Chemicalmodificationandindustrialutilizationofligninbasedonitsstructurewerereviewedinthispaper.Anditseconomicvalueandsignificanceforthesocietyandenvironmentalprotectionwerealsoevaluated.
简介:Salt-affectedsoilsextensivelydistributeontheearth.Althoughthecausesarevarious,generallyspeakingsalinizationoccurrenceresultsfromtheaccumulationoffreesaltstoanextentthatcausesdegradationofvegetationandsoils.Besides,irrationalhumanpracticeshaveincreasedsoilsalinitybyallowingexcessrechargingofgroundwatertochangethenaturalbalanceofthewatercycleinthelandscape.Thisreducesthesuitabilitytoplantgrowthandincreasesthepotentialforotherformsofland...
简介:Urbanforestryisunderstoodtobethemanagementoftreesandforestsinurbanareas.Ityieldsmanyenvironmentalandmaterialbenefits.InSabah,theenvironmentalservicesofurbanforestryaremoreimportantthanmaterialproducts.Thepotentialofpractisingurbanforestryinvariouszonesandunderdifferentlandownershipisevaluated.AsurbanisationhasoccurredrecentlyinSabah,urbanforestryhasonlybeenpractisedtoalimitedextent.Tourismisaneconomicsectorwhichhasgainedprominenceinrecentyearsandhashugegrowthpotential.Withthenumerousenvironmentalservicesprovidedbyurbanforestrytomakeurbanareasmoreinhabitable,theincreasingtourismactivitiesnecessitateintensificationofurbanforestryactivities.Themainurbancentrescontainmanytouristattractions,andarealsothegatewaystomanyotherecotouristdestinationslocatedthroughoutSabah.WithtourismhighonthedevelopmentagendainSabah,urbanforestryneedstobepromotedsothatbothlocalsandvisitorscanenjoythenumeroussocial,environmentalandeconomicbenefits.
简介:ChineseForestEcosystemResearchNetwork,estabfishedinlate1950'sanddirectlyconstructedandadministeredbytheScienceandTechnologyDepartmentofStateForestryAdministrationofChina,isalargeecologyresearchnetworkfocusesonlong-termecosystemfixed-observation.Itembodies15sitesthatrepresentdiverseecosystemsandresearchpriorities,including6state-levelsites.CFERNOfficecoordinatescommunications,networkpublications,andresearch-planningactivities.CFERNusestheadvancedgroundandspatialobservationtechnologiessuchasRS,GPS,GIStostudythestructure,functionallawsandfeedbackmechanismofChineseforestecosystem,aswellasitseffectsonChina'ssocialandeconomicdevelopment.ThemaintaskscarriedoutbyCFERNare:(1)constructionofthedatabaseonthestructureandfunctionsofChineseforestecosystemanditsecologicalenvironmentalfactors;(2)thedatabaseconstructionofforestresources,ecologicalenvironment,waterresourcesandrelatedsocialeconomyinbothregionalandnationalscales;(3)theestablishmentofanevaluationsystemofforestecologicaleffectsinChina'smaindrainageareas;(4)theestabfishmentofaforestenvironmentmonitoringnetworkandadynamicpredictionandalarmsystem.
简介:Globalwarmingisoneofthehottestenvironmentproblems.OneofthereasonsisthesharpincreaseofCO2inatmosphere.Soilrespirationinforestecosystemsaccountsto60%-90%oftotalecosystemrespirationandisthereforeoneofthekeycomponentsoftheglobalCcycle.Thispapersummarizeddifferentresponsesofsoilrespirationtoforestmanagementmeasures,anddescribedtherelevantresearchesathomeandabroadontheeffectofmanagementmeasureslikeharvesting,forestfertilization,soilimproving(Liming),litterremoval,andprescribedburningonsoilrespiration.
简介:ThispaperestablishedanintegratedstandgrowthmodelofMongolianoak(ISGM_oak)usingthedatafrom61permanentsampleplotsmeasuredin1997and2007.ISGM_oakisagroupofnonlinearsimultaneousequations.Themethodofnonlinearerror-in-variablesimultaneousequationsisusedtoestimatetheparametersofISGMoakwiththestatisticalsoftwareForstat2.0,sotheparameterestimationofthegroupofcorrelatedequationsinISGMoakisunbiasedandtheequationsarecompatible.Modelvalidationusingbootstrapmethodshowedthatboththeaveragerelativeerrorandsquareerrorarelessthan15percent.TheISGM_oakmodelcanbeusedtosimulatethestandgrowthwithdifferentvaluesofsiteindex,standdensityandtodrawstanddensitymanagementdiagramfordecision-making.
简介:LanddegradationisoneofthesignificantenvironmentalproblemsinbothChinaandCanada,whichseriouslythreatensthesustainabledevelopmentofnationaleconomyandsocietyofbothcountries.Thispaperintroducedsomepolicies,regulationsanddepartmentcoordinationmechanismsoflandresourcemanagement,restoration/rehabilitationofdegradedland,forestresourcesmanagement,agriculturalenvironmentalprotectionandmineralarealandreclamationinCanada.Somepractices,experiencesandeffectsinlanddegradationcontrolofCanadawerelistedandanalyzed.Finally,itwassuggestedthatthesuccessfulexperiencesofCanadaintechnology,policyandmanagementforlanddegradationcontrolshouldbelearnedforimprovingefficiencyoflanddegradationinChina’swesternregion.
简介:Thepaperelaboratesindetailscertificationmechanismforsustainableforestmanagement,includingthedefinition,contents,objectives,costs,benefits,characteristics,proceduresandimpactsofcertificationaswellasmaincertificationsystems.ItalsointroducesindetailsthelatestprogressanddevelopmentperspectivesofcertificationinChinaandaroundtheworld.Certificationisamarket-basedmechanism,whichaimsatenhancingandstrengtheningthereasonableutilizationofforests.Itusua...
简介:Successionrulesofsoilacidityqualityoflarchplantationsinfirstrotationatdifferentdevelopmentstages,successionrulesofsoilacidityqualityofyoungstandoflarchplantationsinsecondrotationandtherelationshipbetweensoilacidityandvariousformsoforganicphosphorusandinorganicphosphoruswerestudiedinmountainousareaofeasternpartofNortheasternChina.Theresultsshowedthatactiveacidity(pHvalue)inrhizospheresoildecreasedcontinuallywithstandageincreasingfromyoungstand,half-maturestand,nearmaturestandtomaturestand,butactiveacidity(pHvalue)innon-rhizospheresoil,exchangeacidity,exchangeablealuminium,totalhydrolyticacidity,andtheratioofexchangeacidityandtotalhydrolyticacidityinrhizospheresoilandinnon-rhizospheresoilincreasedapparently;totalorganicP,moderatelyresistantorganicP,andhighlyresistantorganicPinsoildecreasedatallagestagesinlarchplantationswhensoilacidityadded.Forrhizospheresoilofallstandsoflarchplantationsatdifferentdevelopmentstages,therewaspositivecorrelationbetweenCa-P(exceptinyoungstand),Al-P(exceptinhalf-maturestand),Fe-P(exceptinnearmaturestandandmaturestand),O-P(exceptinyoungstand),andsoilactiveacidity,respectively;Forrhizospheresoil,therewasnegativecorrelationbetweenCa-P(exceptinhalf-maturestand),Al-P(exceptinyoungstand),O-P,andexchangeacidity,exchangeablealuminium,therewasalsonegativecorrelationbetweenCa-P,Al-P(exceptinyoungstandandhalf-maturestand),Fe-P,O-P,andtotalhydrolyticacidityrespectively.Forrhizospheresoil,thecorrelationcoefficientbetweenCa-P,O-Pandtotalhydrolyticaciditydecreased,respectively,asstandagesupandthatbetweenFe-Pandexchangeacidity,exchangeablealuminiumincreased,respectively,asstandagesgrew.Fornon-rhizospheresoil,therewasnotsignificantcorrelationbetweensoilacidityandvariousformsofinorganicphosphorusandorganicphosphorus,respective
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:Theroleandpositionofforestryinresponsetotheissueofclimatechangehavebeenincreasinglyconcernedbymoreandmorecountriesandtheinternationalcommunity.Thecostincurredinforestcarbonsequestrationislowerthanotheroptionstomitigateclimatechange.However,thefund’sgapbecomesthemainbarriertoreducingcarbonemissionscausedbydeforestationandforestdegradation(REDD)andenhancingcarbonstorageinforests(REDD+)andalsobecomestheconcernsofgovernments,academiccommunityandenterprises.Basedonthecomparativeanalysisofoverseasforestcarbonfinancingmodels,thepaperpinpointedtheirdevelopmenttrendandproposedsolutionstofinancingforforestcarbonsinkinChina.
简介:Nitratereductaseactivity(NRA)indifferentplantorgansandleavesindifferentpositionsofCamptothecaacuminataseedlingswasdeterminedbyanInvivoassay,thediurnalvariationrhythmofNRAinleavesofdifferentpositionswasobserved,andthecorrelationsbetweenleafNRA,leafareaandlaminamassperunitarea(LMA)werealsoexamined.TheresultsshowedthatNRAintheleafwassignificantlyhighest,comparedwiththatinotherorganssuchasroots,stemsandleaves.Inthisexperiment,the10leaveswereselectedfromtheapextothebaseoftheseedlingsinorder.ThedifferentNRAoccurredobviouslyinleavesofdifferentpositionsofC.acuminataseedlingsfromtheapextothebase,andNRAwashigherinthe4th-6thleaves.ThediurnalchangerhythmofleafNRAshowedaonepeakcurve,andmaximumNRAvalueappearedataboutmidday(at12:30orso).NoobviouscorrelationsbetweenNRAandleafareaorlaminamassperunitareawereobserved.ThisstudyofferedscientificfoundationforthefurtherresearchonnitrogenmetabolismofC.acuminata.