NetecosystemservicesvalueofwetlandEnvironmentaleco

Netecosystemservicesvalueofwetland:EnvironmentaleconomicaccountZ.M.Chena,G.Q.Chena,*,B.Chenb,J.B.Zhoua,Z.F.Yangb,Y.ZhoucaCollegeofEngineering,PekingUniversity,Beijing100871,ChinabSchoolofEnvironment,BeijingNormalUniversity,Beijing100875,ChinacTransformEco-environmentSolutionLtd.,Beijing100078,ChinaarticleinfoArticlehistory:Received15April2007Receivedinrevisedform24December2007Accepted25January2008Availableonline21May2008PACS:89.60.k89.75.kKeywords:EcosystemservicesConstructedwetlandEcologicalengineeringabstractFordecisionmakingintermsofenvironmentaleconomicsforwetlandconstruction,resto-rationandpreservation,netecosystemservicesvaluesofconstructed,human-interferedandnaturalwetlandsareexploredinthepresentworkasacomparativestudy.Theecosys-temservicesvaluesofapilotconstructedwetlandinBeijing,Chinaindifferentdiscountratesandtimehorizonsareaccountedandcomparedwiththoseofthenaturalwetlandsallovertheworldasameanandofatypicalhuman-interferedwetlandinWenzhou,China.Resultsshowthatinbothfiniteandinfinitetimehorizonsconsidered,theconstructedwet-landhasthelargestnetservicesvalueinareasonablediscountrate.2008ElsevierB.V.Allrightsreserved.1.IntroductionEcosystemservicesaretheprofitspeopleobtainfromecosystemfunctionsassomeintrinsiccharacteristicsofthestruc-tureandprocessesofanecosystemtosatisfytheirneed.Whenaccountedaspartofhumanwelfare[1],ecosystemservicesvalue(ESV)isactuallyconsideredasthespecificpriceofecosystemservices.Owingtotherisingconcernonecosystemdegradationandtheincreasingneedfordecisionmakingtoconserveandre-storeecosystem,comprehensiveevaluationsonESVhavebeenemerged[2],sincetheproblemofmarketfailurefor‘‘freeservices”wasputforwardbyKrutilla[3].Inparticularly,wetlandasonekindofthemostimportantecosystemsintheworldhasattractedmanystudiesonESVevaluationinthepastdecades[4–12].Asthesynthesesofabovestudies,meta-analyseshavealsobeencarriedoutbyBrouweretal.[13],WoodwardandWui[14],Branderetal.[15]andGhermandietal.[16].Indecisionmakingofanecologicalengineering,whatmattersisnottheESVitselfbutthenetvalueofecosystemservices(NVES)asthedifferencebetweenESVandecosystemservicescost(ESC),i.e.NVES¼ESVESC;whereESC¼CcþCoþCvwithCcstandingfortheconstructioncost,Cotheoperationandmaintenancecost,andCvthevirtualcost.Asaninitialinvest-ment,Ccisneededwhenpeoplewanttoconstructanewecosystemormodifyanoriginalecosystemforcertainuse.Theade-quateinputofCoiscrucialtomaintainstableecosystemservicesfromsomeartificialecosystems.Theconceptofvirtualcostisbroughtforwardtorepresentthecostswhichdonothappeninpracticalprocessbutshouldbeaccountedbecauseoftheexis-1007-5704/$-seefrontmatter2008ElsevierB.V.Allrightsreserved.doi:10.1016/j.cnsns.2008.01.021*Correspondingauthor.E-mailaddress:[e-mail](G.Q.Chen).CommunNonlinearSciNumerSimulat14(2009)2837–2843ContentslistsavailableatScienceDirectCommunNonlinearSciNumerSimulatjournalhomepage:[17].Inthiscircumstance,ESVandESCshouldbediscounted.Discountingiscommonlyusedtoex-pressfuturegainorcostintermofpresentvaluebytheuseofadiscountrate.Tomakethedecisionproceduresimpleandvis-ible,thedynamicperformancesofbenefitandcostareusuallytransformedintopresentvaluebyusingdiscountrateinmanystudiesby,amongothers,Costanzaetal.[4],Grenetal.[6],Kosz[18],Leschineetal.[19],Turneretal.[20],GutrichandHit-zhusen[21]andKoetal.[22].ThediscountedNVESisreferredtoasthenetpresentvalueofecosystemservices(NPVES).Presentedinthispaperisanenvironmentaleconomiccost–benefitanalysisforaconstructedwetlandinBeijing(Beijingwetland).BasedonTongetal.[12]andCostanzaetal.[1],valuationsforatypicalhuman-interferedwetlandinSanyang,Wenzhou,China(Sanyangwetland)andforthenaturalwetlandsallovertheworldasamean(meanwetland)areprovidedforacomparison.2.Typicalwetlands2.1.BeijingwetlandTheLongdaoRiverwithadailydischargeof16,000m3flowsacrossthecountrysideofBeijing.Theriverwaterwasheavilypollutedbythesewagereceivedfromtheupstreamresidentialareaandtheriverecosystemwasseverelydestroyedbythepollution.Thewastewaterhasaverageloadingrateofabout47,23and5.0mg/lforBOD5,NH3-Nandtotal-P.Nearbyresi-dentssufferthesmellyodorletofffromtherivereverysummerandcomplainalot.Torestoretheriverecosystemandtreatthepollutedwater,webuiltaverticalsubsurface-flowconstructedwetland,theBeijingwetlandneartheestuaryoftheLongdaoRiverin2004asa