Ecosystemservicevalueassessmentforconstructedwetla

ANALYSISEcosystemservicevalueassessmentforconstructedwetlands:AcasestudyinHangzhou,ChinaWuYanga,JieChanga,⁎,BinXub,ChanghuiPengc,a,YingGea,⁎aCollegeofLifeSciences,ZhejiangUniversity,Hangzhou310058,PRChinabDepartmentofPublicAdministration,ZhejiangGongshangUniversity,Hangzhou310018,PRChinacInstitutdessciencesdel'environnement,Départementdessciencesbiologiques,UniversitéduQuebecàMontréal,Casepostale8888,SuccursaleCentre-Ville,Montréal,QC,CanadaH3C3P8ARTICLEINFOABSTRACTArticlehistory:Received30September2007Receivedinrevisedform10February2008Accepted10February2008Availableonline14March2008Basedonacomprehensiveanalysisofvariousclassificationsofnaturalresourcevalues,wesummarizedanecologicaleconomicvaluesystemofconstructedwetland(CW)ecosystemsfortreatingeutrophicwater.UsingtheCWlocatedattheHangzhouBotanicalGardenasanexample,thecontingentvaluationmethod(CVM)andshadowprojectapproach(SPA)wereappliedtoestimatetheeconomicvaluesofCWsystemecosystemservices.TheCVMestimatedavalueof800,000yuan(yuan:ChineseCurrency,7.6yuan=1USDasofAugust,2007)asthetotaleconomicvalueoftheCWinatwentyyearperiod.Meanwhile,theSPAcalculatedavalueof23.04millionyuanasthetotaleconomicvalueoftheCWinatwentyyearperiod.ItisdeterminedthatcomparedtotheCVM,theSPAprovidesamoreapproximatevalueofthetruemonetaryvalueoftheHangzhouBotanicalGardenCW.ThisstudycouldfillthegapofknowledgeandprovideabenchmarkwhenevaluatingconstructedecosystemservicesandhelppolicymakerstopromotethedevelopmentofconstructedwetlandsinChina.©2008PublishedbyElsevierB.V.Keywords:ContingentvaluationmethodCost-benefitanalysisEconomicvaluationShadowpriceShadowprojectapproachWillingnesstopay1.IntroductionEcosystemservicesrepresentthebenefitsthatpeopleobtaindirectlyorindirectlyfromecosystems(Costanzaetal.,1997;MA,2003).Assessingtheeconomicvaluesofecosystemservicesplayvariousandimportantrolesinlinkinghumanactivityandnaturalsystems.Asaspecificinterdisciplinaryfieldofpractice,theremarkableworkofDaily(1997)andCostanzaetal.(1997)hasmadeabreakthroughinecosystemservicesvaluation.Todate,mostrecentstudies(Alberinietal.,2005;Heetal.,2005;Spashetal.,inpress;Hougneretal.,2006;Branderetal.,2007;Costanzaetal.,2007;Sattoutetal.,2007),however,stillfocustheirattentiononestimatingthevalueofnaturalecosystemservices;onlyfew(BolundandHunham-mar,1999;TianandCai,2004;Shenetal.,2005)attempttoestimatethevalueofconstructed(orartificial)ecosystemservices.Fromourpointsofview,constructedecosystemservicesaresimilartonaturalecosystemservicesinessence,however,differinthefollowingmainaspects:1)enhancementofcertainservicesanddeclineofmostotherservicesinconstructedecosystemscomparingtonaturalecosystems(Foleyetal.,2005).Likehuman-dominatedecosystemsservicesandunlikenaturalecosystemsservices,certainconstructedecosystemsservicesareusuallydesignedinten-tionally;2)higherdirectusevalues(e.g.,foodproduction,recreation)thanindirectusevaluesareusuallyestimatedECOLOGICALECONOMICS68(2008)116–125⁎Correspondingauthors.Tel./fax:[phone].E-mailaddresses:[e-mail](J.Chang),[e-mail](Y.Ge).0921-8009/$–seefrontmatter©2008PublishedbyElsevierB.V.doi:10.1016/j.ecolecon.2008.02.008availableat(mainlyfoodproduction),whileatinyindirectusevalue;3)theassessmentscaleofconstructedecosystemservicesisexplicitthannaturalecosystemservices,sinceboundariesoftheconstructedecosystemareusuallymoredistinctthanthenaturalecosystem.Theconstructedwetland(CW),atypicalconstructedecosystem,wasinitiallydevelopedapproximatelyfortyyearsagoinEuropeandNorthAmericatoexploitandimprovethebiodegradationabilityofplants(Shutes,2001).Possessingtheadvantagesoflowconstructionandoperatingcostsaswellasitsabilitytobeusedonitsownorincombinationwithothersystems,CWisespeciallysuitableforsmallcommunitiesindevelopingcountrieswherepotentialhealthbenefitsfrompathogenremovalareconsiderable(Cooperetal.,1996;Shutes,2001).InChina,thefirstCWstudyforwastewatertreatmentwaslaunchedasearlyastheperiodofthe“7thFive-YearPlan”(1986–1990)(LiandZheng,1993).Thefirstreedbedwetlandappearedin1987andthefirstfull-scaleCWemergedin1990(DingandShen,2006).Since1999,ChinahasbeenmakingagreatprogressintheareaofCWapplication,reachingapeakwith127researchreportsin2004(Gao,2006).Theproblem,however,thaturbanwastewatertreatmentratesoperateatonly46%asof2004mustnowbeaddressed(whitepaperonChinaEnvironmentProtection,1996–2005).MostsmalltownsinChinatodaystillreleasedailywastewater,withexcessiveamountsofeutrophicmaterialscontainingnitrogenandphosphorus,directlyintowatersystemswithouttreatment(Jinetal.,2005).Thisisoneofthemajorcausesofwaterpollution,especiallyeutrophicationpollution,inChina.WhenitcomestotheeconomicvaluationofconstructedecosystemsinChina,fewstudieshavebeenconducteduptothispoint.TianandCai(2004)evaluatedecosystemservicesofconstructedlandscapesinBeijing;however,theirstudymerelyreferredtonaturalecosystemdataf