简介:从1999年8至10月,2000年的4至6月,2002年8月至2003年9月,在平均树高为26米的长白山阔叶红松林内,用红外气体分析仪(2250D,LI-CORInc.和LI-COR,820)测定了不同高度的二氧化碳浓度。根据测定的数据,分析了阔叶红松林二氧化碳廓线的日变化和季节变化动态。结果表明:CO2浓度的垂直分布在白天和夜间是不同的,在接近地面处CO2浓度始终最大。从季节CO2廓线看出,在植物生长季节林冠处CO2浓度有明显的成层现象,不同高度(60~2.5m)的CO2浓度3月份变化较小差值为10mmol穖ol-1,而在7月份变化较大,差值为60mmol穖ol-1。7月份林冠处(22,26,32m)CO2浓度梯度较大,浓度差为8mmol穖ol-1。计算位于涡度相关仪器之下的40米高空气柱中CO2贮存状况表明,年际贮存是负值,但对NEE的贡献很小。图4参11。
简介:TheimpactsofelevatedtemperatureandCO2onyoungsilverbirch(BetulapendulaRoth)saplingsafter0,25,50or75%artificialdefoliationwereassessedbymeasuringplantheightanddrymassofabovegroundcompartmentsandrootsandvariousmorphologicalandphysiologicalvariables.Defoliationeitherincreasedordecreasedplantgrowthdependingontheseverityofdamageandtheclimatictreatment.At21Cand400mgL-1CO2,defoliatedplantswerenotabletocompensateforthelostfoliage,butgrowthcompensationandadaptationtothechangedconditionsweregreater;growthofyoungdefoliatedsilverbirchsaplingsincreased,whichledtoincreasedheightandatendencytoenhancefinalabovegroundandrootbiomassandleafnitrogenandcarboncontentcomparedtothenondefoliatedcontrols.Nevertheless,theshort-termeffectofthedifferentclimaticconditionsdidnotresultinasignificantovergrowthofdefoliatedplants.AslightincreaseintemperatureandCO2werethemostacceptableconditionsfordefoliatedplants;however,a4CincreasewithcorrespondinglyhigherCO2wasmorestressfulasshownbylessgrowthinheightandbiomassallocationtoleaves,stemsandroots.Thefindingsfromthepilotexperimentaremoreapplicabletoyoungbirchtrees,butstressonyoungtreesmaybereflectedinfuturetreegrowth.
简介:Background:Thispaperexploredthelong-term,ceteris-paribuseffectsofpotentialCO,fertilizationontheglobalforestsector.BasedonthefindingsofNorbyetal.(PNAS2005,102(50))aboutforestresponsetoelevated[CO_2].Methods:ForestproductivitywasincreasedintheGlobalForestProductsModel(GFPM)inproportiontotherising[CO.,]projectedintheIPCCscenarioA1B,A2,andB2.Projectionsoftheforestareaandforeststockandoftheproduction,consumption,prices,andtradeofproductsrangingfromfuelwoodtopaperandpaperboardwereobtainedwiththeGFPMforeachscenario,withandwithoutCO_2fertilizationbeginningin2011andupto2065.Results:C02fertilizationincreasedwoodsupply,leadingtolowerwoodpriceswhichinturninducedmodestlowerpricesofendproductsandhigherglobalconsumption.However,productionandvalueaddedinindustriesdecreasedinsomeregionsduetotherelativecompetitiveadvantagesandtothevaryingregionaleffectsofCO_2fertilization.Conclusion:ThemaineffectofCO,fertilizationwastoraisetheleveloftheworldforeststockin2065by9to10%forscenariosA2andB2andby20%forscenarioA1B.Theriseinforeststockinducedbyfertilizationwasinpartcounteractedbyitsstimulationofthewoodsupplywhichresultedinlowerwoodpricesandincreasedharvests.
简介:LocatedontheDaxing'anlingforestregionofChina'sfrontier,theDaxing'anlingForestryGroupCo.isoneofthe500nationallargesizeenterprisegroupswithatotalmanagementareaof8.225millionha.Thereare10forestrybureausunderitsjurisdiction,93000in-servicestaffandapopulationof358000.Thenetvalueoffixedassetis3.58billionyuan,Accumulativetotaloutputoftimberhasamountedto110millionm3duringthepast38years.ItsprofitsandtaxturnedovertotheStatehast...
简介:Co-managementisanewmanagingpatternofthedevelopmentofnaturereserve.Itrelievestheconflictsofresourceutilizationbetweennaturereserveandcommunity,encouragesvillagerstoparticipateintheprotectionofnaturereservebio-diversity,attemptstoimprovetheconditionsofcommunityproductionandliving,andelevatesthelivings
简介:KafangTownship,XinxianCountyofHenanProvinceislocatedinthehinterlandoftheDabieMountainborderingHenanandHubeiprovinces.Thistown...