Nitrogen deposition and its ecological impact in C

ThisarticleappearedinajournalpublishedbyElsevier.Theattachedcopyisfurnishedtotheauthorforinternalnon-commercialresearchandeducationuse,includingforinstructionattheauthorsinstitutionandsharingwithcolleagues.Otheruses,includingreproductionanddistribution,orsellingorlicensingcopies,orpostingtopersonal,institutionalorthirdpartywebsitesareprohibited.Inmostcasesauthorsarepermittedtoposttheirversionofthearticle(e.g.inWordorTexform)totheirpersonalwebsiteorinstitutionalrepository.AuthorsrequiringfurtherinformationregardingElsevier’sarchivingandmanuscriptpoliciesareencouragedtovisit::AnoverviewqXuejunLiua,e,*,LeiDuanb,JiangmingMoc,EnzaiDud,JianlinShena,XiankaiLuc,YingZhanga,XiaobingZhoue,ChuneHef,FusuoZhangaaCollegeofResourcesandEnvironmentalSciences,ChinaAgriculturalUniversity,Beijing100193,ChinabDepartmentofEnvironmentalScienceandEngineering,TsinghuaUniversity,Beijing100084,ChinacSouthChinaBotanicalGarden,ChineseAcademyofSciences,Guangzhou510650,ChinadCollegeofUrbanandEnvironmentalSciences,PekingUniversity,Beijing100871,ChinaeXinjiangInstituteofEcologyandGeography,ChineseAcademyofSciences,Urumqi830011,ChinafInstituteofGeographicSciencesandNaturalResourcesResearch,ChineseAcademyofSciences,Beijing100101,ChinaarticleinfoArticlehistory:Received20April2010Receivedinrevisedform31July2010Accepted5August2010Keywords:AtmosphericpollutionNemissionanddepositionCriticalloadsEcologicalimpactabstractNitrogen(N)depositionisanimportantcomponentintheglobalNcyclethathasinducedlargeimpactsonthehealthandservicesofterrestrialandaquaticecosystemsworldwide.AnthropogenicreactiveN(Nr)emissionstotheatmospherehaveincreaseddramaticallyinChinaduetorapidagricultural,industrialandurbandevelopment.ThereforeincreasingNdepositioninChinaanditsecologicalimpactsareofgreatconcernsincethe1980s.ThispapersynthesizesthedatafromvariouspublishedpaperstoassessthestatusoftheanthropogenicNremissionsandNdepositionaswellastheirimpactsondifferentecosystems,includingempiricalcriticalloadsfordifferentecosystems.ResearchchallengesandpolicyimplicationsonatmosphericNpollutionanddepositionarealsodiscussed.ChinaurgentlyneedstoestablishnationalnetworksforNdepositionmonitoringandcross-siteNadditionexperimentsingrasslands,forestsandaquaticecosystems.CriticalloadsandmodelingtoolswillbefurtherusedinNrregulation.
2010PublishedbyElsevierLtd.1.IntroductionNitrogen(N)depositionhasbeenanimportantcomponentintheglobalNcyclewithincreasinganthropogenicreactiveN(Nr)emis-sionssincetheindustrialrevolution(Vitouseketal.,1997;Gallowayetal.,2008).ExcessNdepositionhasarousedconcernsaboutitsnegativeimpactsonecosystemhealthandservicessuchaslossofbiodiversity(Salaetal.,2000;Stevensetal.,2004),eutrophicationandNsaturation(Aberetal.,1998),soilacidification(RichterandMarkewitz,2001),andincreasedsusceptibilitytosecondarystresses(AertsandBobbink,1999;WitzellandShevtsova,2004).RatesofNdepositionhaveleveledofforstabilizedintheUSandEuropesincethelate1980sorearly1990swiththeimplementationofstricterlegislationtolimitatmosphericpollution(e.g.Gouldingetal.,1998;NADP,2000).Incontrast,emissionsofNrspeciesinChinahavebeenincreasingcontinuouslysincethe1980smainlyduetogrowingagriculturalandindustrialactivities(Klimontetal.,2001;Zhangetal.,2007,2009a).TheseincreasedNremissionstotheatmospherehavearousedwidespreadconcernonairpollutioninChina(Richteretal.,2005).AlthoughtherehavebeenseveralNdepositionmonitoringprogramsandNdepositionsimulationexperimentssincethelate1990s(e.g.Wangetal.,2004;Liuetal.,2006;Moetal.,2006),therearestilllargegapsinknowledgeofthemagnitudeandpotentialimpactsofatmosphericNdepositionondifferentecosystemsacrossChina.InthisreviewpaperwesummarizeallthepublisheddatafromNdepositionmonitoringandmodeling,criticalloads,andtheeffectsonecosystemsinorderto:1)identifythemagnitudeandspatio-temporalvariabilityofNdepo-sition;2)summarizethemajorimpactsofNdepositiononterrestrialandaquaticecosystems;3)analyzethepotentialcriticalloadsofNdepositiontomajorChineseecosystems;4)comeupwithrecom-mendationsforresearchonregulatorystrategiesformitigationofatmosphericNrpollutionanddepositioninChina.2.EmissionsandatmosphericconcentrationsofNrpollutantsinChina2.1.TrendsinNremissionstotheatmosphereTherehavebeenanumberofstudiesonbothreducedandoxidizedNemissionsinChina(e.g.KatoandAkimoto,1992;SunandWang,1997;Tianetal.,2001;Streetsetal.,2003;YamajiqAlltheco-authorscontributedequallytothiswork.*Correspondingauthor.E-mailaddress:[e-mail](X.Liu).ContentslistsavailableatScienceDirectEnvironmentalPollutionjournalhomepage:
2010PublishedbyElsevierLtd.doi:10.1016/j.envpol.2010.08.002EnvironmentalPollution159(2011)2251e2264Author'spersonalcopyetal.,2004;Oharaetal.,2007;Wangetal.,2009a;Zhangetal.,2009a).Despitethevariationamongstudies,NH3andNOxemis-sionshaveshownsubstantialincreasessincetheearly1980s(Fig.1a,b).Comparedwith1980,NH3emissions(13.7TgNyr
1)haddoubledandNOxe