简介:Biocharcouldhelptostabilizesoilorganic(SOM)matter,thussequesteringcarbon(C)intothesoil.Theaimofthisworkwastodetermineaneasymethodi)toestimatetheeffectsoftheadditionofbiocharandnutrientsontheorganicmatter(SOM)mineralizationinanartificialsoil,proposedbytheOrganizationforEconomicCo-operationandDevelopment(OECD),amendedwithglucoseandii)tomeasuretheamountoflabileorganicmatter(glucose)thatcanbesorbedandthusbepartiallyprotectedinthesamesoil,amendedornotamendedwithbiochar.Afactorialexperimentwasdesignedtochecktheeffectsofthreesinglefactors(biochar,nutrients,andglucose)andtheirinteractionsonwholeSOMmineralization.Soilsampleswereinoculatedwithamicrobialinoculumandpreincubatedtoensurethattheirbiologicalactivitieswerenotlimitedbyasmallamountofmicrobialbiomass,andthentheywereincubatedinthedarkat21℃for619d.PeriodicalmeasurementsofCmineralizedtocarbondioxide(CO_2)werecarriedoutthroughoutthe619-dincubationtoallowthemineralizationofbothactiveandsloworganicmatterpools.Theamountofsorbedglucosewascalculatedasthedifferencebetweenthetotalandremainingamountsofglucoseaddedinasoilextract.Twodifferentmodels,theFreundlichandLangmuirmodels,wereselectedtoassesstheequilibriumisothermsofglucosesorption.TheCO_2-Creleasestronglydependedonthepresenceofnutrientsonlywhennobiocharwasaddedtothesoil.ThemineralizationoforganicmatterinthesoilamendedwithbothbiocharandglucosewasequaltothesumofthemineralizationofthetwoCsourcesseparately.Furthermore,asignificantamountofglucosecanbesorbedonthebiochar-amendedsoil,suggestingtheinvolvementofphysico-chemicalmechanismsinlabileorganicmatterprotection.
简介:Throughthemethodsofcorrelationanalysisandmainfactoranalysis,therelationshipbetweenthepoplarINAbacterialcankerandcircumstanceswasanalyzedand9mainfactorsforaffectingthediseasewereselected.Basedonthecomprehensiveanalysisofmainfactorsandinducedfactors,thestandardforriskgradesofthisdiseasewaspromotedandnortheastregionofChinawasdividedinto4districtswithdifferentriskgrades:seriouslyoccurringdistrict,commonlyoccurringdistrict,occasionallyoccurringdistrict,andun-occurringdistrict.NonlinearregressionanalysisforsixmodelcurvesshowedthattheRichardgrowthmodelwassuitablefordescribingthetemporaldynamicsofpoplarINAbacterialcanker.Bystepwisevariableselectionmethod,themulti-variablelinearregressionforecastingequationwassetuptopredictthenextyear'sdiseaseindex,andtheGM(1,1)modelwasalsosetupbygreymethodtosubmitmiddleorlongperiodforecast.
简介:Background:Climatechangetriggeredmanystudiesshowingthattrendsandeventsofenvironmentalconditionscanreducebutalsoaccelerategrowthatthestandandindividualtreelevel.However,itisstillratherunknownhowclimatechangemodifiesthegrowthpartitioningbetweenthetreesinforeststands.Methods:Basedonlong-termgirth-tapemeasurementsinmaturemonospecificandmixed-speciesstandsofNorwayspruce(Piceaabies(L.)Karst.)andEuropeanbeech(FagussylvaticaL.)wetracedtheeffectoftheseveredroughtsin2003and2015fromthestand-downtothetreelevel.Results:StandgrowthofNorwaysprucedecreasedbyabout30%intheonce-in-a-centurydrought2015,whileEuropeanbeechwasmuchmoredroughtresistant.Wateravailabilitygenerallyamplifiedsize-asymmetricgrowthpartitioning.EspeciallyincaseofNorwaysprucewateravailabilityprimarilyfosteredthegrowthofpredominanttrees,whereasdroughtfavouredthegrowthofsmalltreesattheexpenseofthepredominantones.Wecouldnotdetectsignificantdifferencesbetweenmixedandmonospecificstandsinthisregard.Conclusions:Thedrought-inducedreallocationofgrowthinfavourofsmalltreesincaseofsprucemayresultfromitsisohydriccharacter.Wehypothesizethatassmalltreesareshaded,theycanbenefitfromthereducedwaterconsumptionoftheirsun-exposedtallerneighbours.Incaseofbeech,asananisohydricspecies,talltreessufferlessandsmallertreesbenefitlessunderdrought.Thediscussionelaboratestheconsequencesofthewaterdependentgrowthallocationforforestmonitoring,growthmodelling,andsilviculture.
简介:Inthecontextofglobalcarboncyclemanagement,accurateknowledgeofcarboncontentinforestsisarelevantissueincontemporaryforestecology.Wemeasuredtheabove-groundandsoilcarbonpoolsinthedarkconiferousborealtaiga.Wecomparedmeasuredcarbonpoolstothosecalculatedfromtheforestinventoryrecordscontainingvolumestockandspeciescompositiondata.Theinventorydataheavilyunderestimatedthepoolsinthestudyarea(StolbyStateNatureReserve,centralKrasnoyarskTerritory,RussianFederation).Thecarbonpoolestimatedfromtheforestinventorydatavariedfrom25(tha-1)(low-densitystands)to73(tha-1)(highlystockedstands).Ourestimatesrangedfrom59(tha-1)(lowdensitystands)to147(tha-1)(highlystockedstands).Ourvaluesincludedlivingtrees,standingdeadwood,livingcover,brushwoodandlitter.Wefoundthattheproportionofbiomasscarbon(livingtrees):soilcarbonvariedfrom99:1to8:2forfullystockedandlow-densityforeststands,respectively.Thiscontradictsthecommonunderstandingthatthebiomassintheborealforestsrepresentsonly16–20%ofthetotalcarbonpool,withthebalancebeingthesoilcarbonpool.
简介:典型地物数据库是通过计算机自动分类来识别地物信息的。然而传统的以中低空间分辨率遥感数据建立的典型地物数据库由于同物异谱,同谱异物,单一指标信息等原因无法很好地区分相近目标。因此本文利用WorldView数据为典型地物影像建立数据库,可以加大遥感影像中的信息量,同时拟采用非监督分类、聚类分析的方法,以及多种指标信息对地物进行分类(如纹理信息、光谱信息等),可显著地提高识别精度,有助于更加快速、精确的识别地物类型,从而实现对地物的分类,增强遥感图像的识别,提高最终的地物分类精度以及此实验的分类效率与工作效率的提高,有着十分重要的现实意义。
简介:机载激光雷达(LiDAR)是一种新型数据获取手段,目前在林业资源管理、森林防火、林木砍伐等方面已广泛应用,但尚未形成完整的、实用的林业LiDAR数据分析与处理系统。通过分析已有LiDAR数据应用于林业资源管理方面的理论和方法,以目前开源LiDAR点云数据处理技术、海量点云数据可视化技术,以及GIS相关分析技术为基础,结合林业资源管理需求,设计并研发了基于LiDAR数据的林业资源数据分析与处理系统。系统实现了Li-DAR点云数据的管理与可视化、数字高程模型生成、数字地表模型生成、冠高模型生成、平均树高估计等功能,为基于LiDAR数据的林业资源管理提供统一的平台。