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.
简介:Background:Replacementoffossilfuelbasedenergywithbiochar-basedbioenergyproductioncanhelpreducegreenhousegasemissionswhilemitigatingtheadverseimpactsofclimatechangeandglobalwarming.However,theproductionofbiochar-basedbioenergydependsonasustainablesupplyofbiomass.Although,NorthwesternOntariohasarichandsustainablesupplyofwoodybiomass,acomprehensivelifecyclecostandeconomicassessmentofbiochar-basedbioenergyproductiontechnologyhasnotbeendonesofarintheregion.Methods:Inthispaper,weconductedathoroughlifecyclecostassessment(LCCA)ofbiochar-basedbioenergyproductionanditslandapplicationunderfourdifferentscenarios:1)biocharproductionwithlowfeedstockavailability;2)biocharproductionwithhighfeedstockavailability;3)biocharproductionwithlowfeedstockavailabilityanditslandapplication;and4)biocharproductionwithhighfeedstockavailabilityanditslandapplication-usingSimaPro~,EIOLCA~softwareandspreadsheetmodeling.BasedontheLCCAresults,wefurtherconductedaneconomicassessmentforthebreak-evenandviabilityofthistechnologyovertheprojectperiod.Results:Itwasfoundthattheeconomicviabilityofbiochar-basedbioenergyproductionsystemwithinthelifecycleanalysissystemboundarybasedonstudyassumptionsisdirectlydependentoncostsofpyrolysis,feedstockprocessing(drying,grindingandpelletization)andcollectiononsiteandthevalueoftotalcarbonoffsetprovidedbythesystem.SensitivityanalysisoftransportationdistanceanddifferentvaluesofCoffsetshowedthatthesystemisprofitableincaseofhighbiomassavailabilitywithin200kmandwhenthecostofcarbonsequestrationexceedsCAD$60pertonneofequivalentcarbon(CO_2e).Conclusions:Biochar-basedbioenergysystemiseconomicallyviablewhenlifecyclecostsandenvironmentalassumptionsareaccountedfor.Thisstudyprovidesamediumscaleslow-pyrolysisplantscenarioandwerecommendsimilarexperimentswithlarge-scale