简介：Elevatedatmosphericnitrogen(N)depositionhasbeendetectedinmanyregionsofChina,butitseffectsonsoilNtransformationintemperateforestecosystemsarenotwellknown.WethereforesimulatedNdepositionwithfourlevelsofNadditionrate(N0,N30,N60,andN120)for6yearsinanold-growthtemperateforestinXiaoxing’anMountainsinNortheasternChina.WemeasuredgrossNtransformationratesinthelaboratoryusing15NtracingtechnologytoexploretheeffectsofNdepositiononsoilgrossNtransformationstakingadvantageofNdepositionsoils.NosignificantdifferencesingrosssoilNtransformationrateswereobservedafter6yearsofNdepositionwithvariouslevelsofNadditionrate.ForallNdepositionsoils,thegrossNH4+immobilizationrateswereconsistentlylowerthanthegrossNmineralizationrates,leadingtonetNmineralization.Nitrate(NO3-)wasprimarilyproducedviaoxidationofNH4+(i.e.,autotrophicnitrification),whereasoxidationoforganicN(i.e.,heterotrophicnitrification)wasnegligible.Differencesbetweenthequantityofammonia-oxidizingbacteriaandammonia-oxidizingarchaeawerenotsignificantforanytreatment,whichlikelyexplainsthelackofasignificanteffectongrossnitrificationrates.GrossnitrificationratesweremuchhigherthanthetotalNO3-consumptionrates,resultinginabuild-upofNO3-,whichhighlightsthehighriskofNlossesviaNO3-leachingorgaseousNemissionsfromsoils.ThisresponseisoppositethatoftypicalN-limitedtemperateforestssufferingfromNdeposition,suggestingthattheinvestigatedold-growthtemperateforestecosystemislikelytoapproachNsaturation.

简介：ThispaperhighlightstheresearchanddevelopmentactivitiesbeingdoneonurbanforestryinthePhilippines.TherolethatR&Dplaysinurbanforestryislikewisediscussedintheintroduction.Recommendedtreespeciesforurbanplantingarepresentedincludingtheircharacteristicsanddistribution.Researchesrelatedtourbanforestrybeingconductedarelistedwithashortdescriptionofeachproject.Developmentactivitiesonurbanforestryarelikewisediscussed.Finally,recommendedR&DagendaandresearchableareasbasedonthePhilippineAgenda21andtheDepartmentofEnvironmentandNaturalResources(DENR)R&DFrameworkarepresented.

简介：温室条件下,向盆栽山毛榉幼苗中施加192g.m·^-2^15N示踪物,研究连续两个生长季沉积氮在森林土壤（含森林地被物）、沥出物、以及地上和地下部分生物量的分配。模拟了四种处理（栽培和非栽培）下的NH4^＋和NO3^-沉积情况,每种处理各自标记为^15N-NH4^＋或者^15N-NO3^-。在整个体系中施加15N的总回收率分别是,盆栽处理的^15N-NH4^＋为67.3%～74.9%,非盆栽处理的^15N-NO3^-为85.3%～88.1%。两种^15N示踪物主要沉积在森林土壤（包括森林地被物）中,其中盆栽处理的森里土壤中^15N-NH4^＋为34.6%～33.7%,^15N-NO3^-为13.1%～9.0%,说明异养微生物有很强的固氮作用。森林土壤微生物对^15N-NH4^＋的固定能力比^15N-NO3^-的固定能力强三倍。^15N-NH4^＋的优先异养利用造成土壤中^15N-NH4^＋的沉积量是植物体保存量的两倍而土壤中^15N-NO3^-的沉积量却低于植物体的。总之,植被-土壤系统中15N-NH4＋的沉积量比^15N-NO3^-的沉积高了60%,说明了沉积氮的形式在森林生态系统中氮保存中的重要性。

简介：Background:Monitoringforesthealthandbiomassforchangesovertimeintheglobalenvironmentrequirestheprovisionofcontinuoussatelliteimages.However,opticalimagesoflandsurfacesaregenerallycontaminatedwhencloudsarepresentorrainoccurs.Methods:Toestimatetheactualreflectanceoflandsurfacesmaskedbycloudsandpotentialrain,3DsimulationsbytheRAPIDradiativetransfermodelwereproposedandconductedonaforestfarmdominatedbybirchandlarchinGenheCity,DaXing’AnLingMountaininInnerMongolia,China.Thecanopyheightmodel(CHM)fromlidardatawereusedtoextractindividualtreestructures(location,height,crownwidth).Fieldmeasurementsrelatedtreeheighttodiameterofbreastheight(DBH),lowestbranchheightandleafareaindex(LAI).SeriesofLandsatimageswereusedtoclassifytreespeciesandlandcover.MODISLAIproductswereusedtoestimatetheLAIofindividualtrees.CombiningalltheseinputvariablestodriveRAPID,high-resolutionopticalremotesensingimagesweresimulatedandvalidatedwithavailablesatelliteimages.Results:Evaluationsonspatialtexture,spectralvaluesanddirectionalreflectancewereconductedtoshowcomparableresults.Conclusions:Thestudyprovidesaproof-of-conceptapproachtolinklidarandMODISdataintheparameterizationofRAPIDmodelsforhightemporalandspatialresolutionsofimagereconstructioninforestdominatedareas.

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简介：为探究杭州西湖景区园林绿化废弃物粉碎后直接进行堆肥处置的可行性,设置不同C/N(T125:1、T215:1、T310:1、CK32:1)处理的试验,并且对堆肥过程的几个重要指标变化情况进行分析。结果表明:园林绿化废弃物不同C/N堆肥试验中,T1堆肥过程中堆体能达到71.6℃高温,且堆体连续超高55℃的天数为10天,是所有处理中温度最高持续时间最长的;T1堆肥腐熟后堆体pH值为弱碱性,其余处理为弱酸性,仅有CK和T1处理EC值符合作为绿化种植土使用的国家城镇建设行业标准;T1处理C/N降低幅度最大,达到完全腐熟要求。调控合适的C/N(25:1)有利于堆体温度升高,延长高温持续时间,促使堆体pH值的升高,同时增加腐熟后堆体中有机物质矿化速率,提高堆肥矿质养分含量,利于微生物在堆体内的快速繁殖加快堆肥腐熟,缩短堆肥周期。

简介：从纯carrageenans获得的Oligo-carrageenans(OC)从海洋的红水藻提取了由在烟草植物和桉树类树提高光合作用和基础新陈代谢刺激生长。另外，OC刺激第二等的新陈代谢，增加涉及对病原体的防卫的代谢物的水平。在这个工作，我们在高度的增加以后分析了OCkappa的效果，在涉及碳，氮和硫吸收的基础新陈代谢酶的活动，ribulose1,5biphosphatecarboxylase/oxygenase(rubisco)，glutamate脱氢酶(GDH)和O-acetylserinethiol-lyase(OASTL)，并且在支持生长的荷尔蒙，植物生长素吲哚醋酸(IAA)和在松(Pinusradiata)的赤霉素GA3,的水平，树在1和5的集中与OC对待kappa?mg?mL在1点与OCkappa对待的松?mg?mL1在高度显示出类似的增加，但是显示一更高比在5点与OCkappa对待的那些在IAA和GA3的全部的叶绿素，rubisco的活动，GDH和OASTL和水平增加了?mg?mL1。因此，OCkappa刺激生长和基础新陈代谢并且在松树上增加支持生长的荷尔蒙的水平，主要在1点?mg?mL1。

简介：Settingmonitoringtransectinthemiddleandshallowwaterarea(altitude156-172m)inThreeGorgesreservoirhydro-fluctuationbelttoresearchthechangingcharacteristicsofthecontentsofN,P,K,pHandorganicmatterofthesoilwhichexperiencedtheinfluenceoffluctuationthefirsttime.Theresultsshowedthatbytheinfluenceofwaterlevelfluctuating,contentsofsoilN,P,K,pHandorganicmatterhadreducedindifferentsoillayersinhydro-fluctuationbelt.TheavailableNdecreasedby41.53%-59.87%,availablePdecreasedby5.26%-36.76%,availableKdecreasedby3.55%-45.56%,totalNdecreasedby9.52%-40.00%,totalPhadnochangegenerally,totalKhaddecreasedalittle,contentoforganicmaterialdecreasedby7.62%-37.83%%,pHvalueturnedtoneutral,changedby1.73%-9.58%.

简介：采用封闭罩-气相色谱法观测研究了干旱胁迫对长白山阔叶红松林的几种优势树种-红松(Pinuskoraiensis)、水曲柳(Fraxinusmandshurica)、胡桃楸(Juglansmandshurica)、椴树(Tiliaamurensis)和蒙古栎(Quercusmongolica)叶片N2O排放,并同步测定5种树木叶片净光合速率、呼吸速率和气孔导度.结果表明:土壤水分胁迫明显降低树木叶片气孔导度、净光合速率和N2O排放速率,叶片气孔是树木N2O排放的主要通道.树木N2O排放以白天为主,在相同的水分条件下,不同的苗木有不同的N2O排放速率,同种苗木的N2O排放随干旱胁迫的加重而减少,在受到不同干旱胁迫时,针叶树红松N2O的排放速率降至正常水分条件下的34.43%和100.6%、阔叶树种N2O排放平均降至31.93%和86.35%.不同干旱胁迫的红松、水曲柳、胡逃楸、椴树和蒙古栎幼树叶片N2O排放速率为34.43、14.44、33.02、16.48和32.33ngN2O.g-1DW.h-1.图1表1参12.

简介：Themodernizationandinformatizationmanagementofancientandfamoustrees’managementisanimportantstandardwithwhichthemunicipalpublicresourcemanagementlevelofaregionorcitycanbemeasured.Designanddevelopmentofancientandfamoustrees’three-dimensionalmanagementinformationsystemwasrealizedbasedonvirtualplantbyusingintegratedtechniquesofvirtualplantsandGeographicInformationSystem.Thesystemarchitecturedesignwasdevelopedonthebasisoffunctionalrequirements,andthepracticalsystemwasachievedinVisualStudio2008developmenttoolsandOpenGLgraphicsstandards.Thesystemhasfunctionofancienttreesarchivesmanagement,three-dimensionalreconstructionofthetreessurroundingenvironment,individualtreeinformationinquiryinthree-dimensionalscene,etc.Applicationanddisseminationofthissystemwillgreatlypromotethemanagementandprotectionofancientandfamoustreesstandardization,informalizationandvisualization