Biomass and carbon storage of Eucalyptus and Acacia plantations in the Pearl

桉树

BiomassandcarbonstorageofEucalyptusandAcaciaplantationsinthePearlRiverDelta,SouthChina

HuiZhanga,b,DongShengGuana,b, ,MingWeiSongc

a

DepartmentofEnvironmentalScience,SchoolofEnvironmentalScienceandEngineering,SunYat-senUniversity,Guangzhou510275,Guangdong,ChinaGuangdongProvincialKeyLaboratoryofEnvironmentalPollutionControlandRemediationTechnology,Guangzhou510275,Chinac

CollegeofResourcesandEnvironment,HuazhongAgriculturalUniversity,Wuhan430070,Hubei,China

b

articleinfoabstract

Forestplantationsrepresentanimportantcarbonsink.InthePearlRiverDelta(PRD)inSouthernChina,fast-growingEucalyptusandAcaciaarefavouredplantationspecies,butlittleisknownregardingtheiref ciencywithrespecttobiomassproduction,partitioninganddynamicswithstandage,orthecontri-butionmadebytheunderstory,litterandcoarsewoodydebris(CWD)tothevolumeofbiomassand xedcarbon.Here,asetof21plantationsofvariousagesweremonitoredforthepatternofbiomassaccumu-lationandpartitioning.Acontinuousbiomassexpansionfactor(BEF)methodwasappliedtoasetoffor-estinventorydata(FID)overtheperiods1989–2003toestimatebiomassaccumulation,carbonstorageanditspatternofchangeovertime.Theaccumulationofbiomassincreasedwithstandage,reaching,respectively,207.45and189.35thaÀ1inmatureEucalyptusandAcaciaplantations.Thecontributionofsecondarybiomassfromtheunderstory,litterlayerandCWDaccountedfor,respectively,upto10.2%and20.3%ofthetotalbiomassinthetwotypesofplantation,highlightingthesigni canceofsecondarybiomass.Atasimilargrowthstage,therankingofthecontributiontosecondarybiomassintheEucalyptusplantationswaslitter>herbaceousplants>shrubs>CWD,whileintheAcaciaplantations,itwaslitter>CWD>shrubs>herbaceousplants.TheEucalyptusandAcaciaplantationsinthePRDaccumulatedsome2.66–7.84Mtofbiomassandsequestered1.33–3.92Mtofcarbon.Forbothspecies,thebulkoftheplantations(Eucalyptus82.1%,Acacia89.3%)wereattheyoungtomiddle-agedstage.TheAcaciaplanta-tionsgeneratedahigherbiomassdensitythantheEucalyptusplantations.Forestmanagementintensi -cationandreforestationprogrammes,especiallytargetingAcaciaormixedEucalyptus/Acaciaforests,offergoodpotentialforfuturecarbonsequestration.

Ó2012ElsevierB.V.Allrightsreserved.

Articlehistory:

Received11January2012

Receivedinrevisedform11April2012Accepted12April2012

Availableonline15May2012Keywords:EucalyptusAcacia

Plantations

Secondarybiomass

Continuousbiomassexpansionfactormethod(BEFmethod)

Biomassandcarbonstorage

1.Introduction

Plantedforests(plantations)areseenasamitigatingmeasureagainstthepredictedriseinatmosphericcarbondioxideconcen-tration,sincetreesareef cientsequesterersofcarbon(Sandsetal.,1999;Hunter,2001;Kurzetal.,2009).Agrowingforestryre-searchpriority,notleastinChina,istheneedtomeasurethevol-umeofcarbonsequesteredinplantations(Brown,2002;Huangetal.,2012).TheareaofsuchplantationsinChina(5.33Mha)ac-countsfor30%ofthenation’sforestedarea,and29%oftheglobalplantationarea(FAO,2007).Mostoftheseplantationsarestillimmature,andsoretainasubstantialcapacityforcarbonseques-tration(PregitzerandEuskirchen,2004;ZhaoandZhou,2005;Kauppietal.,2006;Xuetal.,2010).SouthernChinaaccountsfor>65%ofthenationalcarbonsink(Piaoetal.,2009),butinthePearlCorrespondingauthorat:DepartmentofEnvironmentalScience,SchoolofEnvironmentalScienceandEngineering,SunYat-senUniversity,Guangzhou510275,Guangdong,China.Tel.:+8613642647676;fax:+862084110267.

E-mailaddress:eesgds@mail.sysu.edu.cn(D.Guan).

0378-1127/$-seefrontmatterÓ2012ElsevierB.V.Allrightsreserved.doc.guandang.net

RiverDelta(PRD),coveragebyevergreenbroadleafprimaryforestiscurrently<1.5%oftheforestedarea(WenandHuang,2006).Inthe1980s,therefore,theprovincialGuangdonggovernmentinsti-gatedareforestationprogrammefeaturingmainlyEucalyptusandAcaciaspp.,andtargetingareaswherethesoilshadbecomebadlydegraded.ThisefforthassucceededinraisingtheareaoccupiedbyforestinGuangdongprovincefrom26.2%in1979to50.1%in1998and57.0%in2010,whilethe2010 gureforthePRDis49.5%.ThelocalsuccessofanumberofEucalyptus(Eucalyptusurophylla,Euca-lyptuscitriodora,Eucalyptusexserta,EucalyptustereticornisandEucalyptuscamaldulensis)aswellasAcacia(Acaciamangium,AcaciaauriculaeformisandAcaciaconfusa)spp.re ectstheirtoleranceofpoorsoilsandtheirrapidgrowthrate(Yangetal.,2009a;Chenetal.,2011).

Currently,thedominanttreespeciesusedinPRDplantationsareEucalyptusandAcacia,butneitherthemeanstoassesstheircapacitytosequesterbiomassandcarbon,noraproperunder-standingofhowthisbiomassandcarbonstorageisin uencedbytheagestructureoftheplantation,arecurrentlyavailable.Thegreatestpotentialforabove-groundbiomassandcarbonstorage