简介：森林碳汇在应对气候变化中的重要作用越来越突显.用可计算一般均衡模型（CGE）分析碳汇政策能够为政策的制订提供强有力的依据,构建CGE模型的前提需要构建基于林业部门的社会核算矩阵（SAM）.SAM中的林业产出和投入各账户、林产品供给和需求各账户,以及隐含的相对价格可以用来模拟碳汇政策对林业的影响.基于《2007年中国投入产出表》并结合其他统计数据,编制了基于林业部门的2007年中国社会核算矩阵.该表的特点是对涉及林业的账户进行了核算,对统计年鉴中没有的数据进行了合理的估算.编制的SAM为CGE模型的构建与应用提供了数据基础.

简介：ThehistoricaltransitionoftimberdistributionpatterninChinawaspresentedfirstlywithmainpartsoftimberflowsinChina,whichincludedtimbermarkets,timbertransportsystemandregulationsoftimbertransport.BasedontheoverviewontropicaltimberflowsinChina,thetradeflowsoftropicaltimberfromproductionandimportsoftropicaltimbertoexportoftropicaltimberproductswereanalyzedbyvividillustrations.Atthesametime,problemsintimbertradeflowsinChinawereanalysedintheend.

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简介：Inaviewofnaturalconditionsofestablishingnaturereserve,anindexsystemwaspreparedforquantitativeassessmentonstatusofendangeredspecies,andthusdegreeofendangeredspeciesinTibetwasevaluated.Takingasub-ecozoneasbasicunit,top5animalsand1plantwithhighEaswellasthenumberofspeciesineachunitwereenumerated;andthedegreeoflandutilizationwasfiguredout.Afterward,weselected6coefficients,assignedweight,andframedformulatoreckonproportionofnaturereserve,thusanareaofnaturereserveineachsub-ecozonewasobtained.In5schemesofweightassignment,aschemewithmediumareaofnaturereservewasselected.Allsub-ecozoneswereclassifiedinto4gradespriorconservation,1wasingradeA,2ingradeB,2ingradeC,and11ingradeD.Totalplannedareawasapproximately365135km2,about48834km2smallerthantheactualareaof413969km2,ratioofnaturereserveinTibetdiminishesfrom34.4%to30.38%.Basedon3factorsofhumandisturbance,ratioofbuffer-experimentalzoneinproposednaturereservewascalculated.Itwasdemonstratedthatexistingsizeofnaturereservesisexcessiveonthewhole,andtheirdistributionisnotreasonableentirely.Thesizeofnaturereservesin3sub-ecozonesofnorthernChangtangshoulddecrease,anddecrementofareaisapportionedamongother13sub-ecozoneswhichshouldincreasenaturereserve.HeterogeneityofregionaldistributionofrarespeciesinTibetisquiteobvious,soproposedareadistributionofnaturereservesismorescatteredthantheexisting.

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简介：在P下面在P缺乏的allophanic土壤在磷(P)部分变化。在壶用扫帚(CytisusscopariusL.)和毒麦(Loliummultiflorum)种的radiata幼苗被学习在以在根围决定导出施肥料的P的命运的·g−1,玷污的0，50，和100μg的率的三倍的过磷酸钙的申请以后的14个月。Pfertiliser的申请增加了NaOH-Pi,NaOH-Po,和H2那么4-P在土壤的i集中，但是减少residual-P集中。resin-Pi集中，在这土壤极其低，1～3μg·g−1),仍然是一样。增加的fertiliserP的多数然而在NaOH-Pi部分(40%49%)。这由于在这土壤(92%)的高P固定。第二最高的P恢复在NaOH-Po部分(7%19%)。在以0μg·g−1,的率的P缺乏的状况或增加下面NaOH-P在radiata根围土壤的i集中在体积土壤和草根围土壤是比那低的。这可能在释放了一些在根围修理到土壤的P的P缺乏的条件下面由于由根和mycorrhiza的更高的盐生产，它需要在未来研究被测试。

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：TheratesofsoilNmineralizationatsoildepthsof0-15,15-30,30-45and45-0cmandmoistureregimesweremeasuredatthreesand-fixationplantationsofPinussylve.strisvar.mongolicabylaboratoryaerobicincubationmethod.TheresultsshowedthataverageratesofsoilnetN-mineralizationacrosssoildepthvariedfrom1.06to7.52mg~kg1.monthqatsoildepthsfrom0to60cm.Statisticalanalysesindicatedthattheeffectsofdifferentsoildepths,moisturesandtheirinteractionsonnetN-mineralizationratesweresignificant(P<0.05).ThenetN-mineralizationratessignificantlydecreasedwithincreasingsoildepthsandatdepth0-15cmaccountedfor60.52%ofthatatdepthof0-50cm.TherewasnodifferenceinsoilnetN-mineralizationratesbetweenhalfandfully-saturatedwatertreatments,howevertheseratesweresubstantiallyhigherthanthatwithoutwatertreatment(P<0.05).ThefactorsinfluencingNmineralizationprocesshavetobestudiedfurtherinthesesemiaridpineecosystems.