欢迎来到天天文库
浏览记录
ID:33007812
大小:2.14 MB
页数:52页
时间:2019-02-19
《东北落叶阔叶林土壤呼吸与林冠层co2浓度的时空变异》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、AbstractForestisamaincontributortoterrestrialCarbon(C)sink.Itisimportanttogetinsightintothecarboncyclinginforestecosystemsforevaluatingtheforestssink/sourcefunctionandunderstandingthefeedbackbetweenterrestrialecosystemandatmosphere.AsamajorpathbywhichsoilCfixedviaphotosynthesisretumtoatmospher
2、e,soilrespirationisclosedrelatedtoC02concentration(【C02】)withinforestcanopy.TheC02derivedfromRsnotonlydirectlyinfluencestheatmosphere【C02】incanopy,butalsocanserveasthesubstratesupplyforphotosynthesis.AlthoughthetemperatebroadleaveddeciduousforestaccountsfortwothirdsareaoftheforestinNortheastCh
3、ina,thespatio—temporalvariationsinC02concentration(【C02】)havenotbeenquantifiedexactly.Therefore,itisessentialtoexplorethespatiotemporalvariationsinRsand【C02】inordertogetinsightintocarboncyclingprocessinforestecosystems.OurpurposesweretoquantifytheseasonalandspatialvariationsofRs,anddiurnalands
4、easonalvariationsandverticalgradientsofthe【C02】inarepresentativetemperatebroadleaveddeciduousforestinthisregion,andtoexploretheircontrollingfactorsbasedonaninfraredgasanalyzer(LI—COR6400,Li—CorInc.,Lincoln,NE,USA)equippedwithaportablechamber(LI.6400.9,Li.CorInc.,USA),an8-level【C02】profile,andr
5、elatedmicrometeorologicalmeasurements.(1)Theinter-plotandintra-plotvariationsofRs,RH,andtheircorresponding乃and%allexhibiteddistinctseasonalpatterns.Theintra—plotvariationsofRs,RH,temperaturesensitivityofRsandRH,W5,totalsoilorganiccarboncontentandthesoilorganiccarboncontentatAhorizon,leaf-litte
6、randtotallitterfall,finerootbiomass(ROandnecromass,andmaximumleafareaindex(LAIm)werehigherthanthoseforinter—plot,withthesoilbulkdensity,乃,andsoilorganiccarboncontentatAohorizon(CAo)intheoppositesituation.Atlocalscale,cumulativeRsWassignificantlyrelatedtoCAOandRtacrosstheeightplots.nebaseRHat0。
7、C(R0h)hadasignificantrelation谢nlCAO.LAImwascloselyrelatedtocumulative(gC’m。)andmeanRH(1上molC02·m-2·S-1),andRoh.thedifferencebetweenthecumulativeRsforⅡlegrowingseasonestimatedbytotalregressionmodel(pooledalltheeightplots,718.25gC‘m_),plo
此文档下载收益归作者所有