Ecosystem Service Function Value Of Coastal Wetlands In Hainan

Evaluation of ecosystem service function makes the value of ecosystem service functions measurable and visible by economic monetization methods.We estimated the ecosystem service function values of coastal natural wetlands of Dongzhaigang Mangrove Reserve and the Hainan main-island.The wetlands of Dongzhaigang Mangrove Reserve contains 4 types of wetland: mangroves,mudflats,ponds and estuarines;and the Hainan main-island coastal wetlands contains 10 types of wetland: shallow waters,sandy coast,rocky coast,tidal water layer,coral reefs,mangroves,estuaries,mudflats,deltas（Sand Island）and salt lakes,according to the most updated Hainan second wetland resources survey,Hainan Province Statistical Yearbook（2013）and the interpretation of 2013 LandsatTM remote sensing image.The paper studies carbon storage and value of Dongzhaigang Mangrove ecosystem;and carbon storage and value of coastal wetlands,tidal water born layer,mangrove and estuarine waters,muddy beach,delta and coastal saltwater lake in Hainan Province.The ecosystem service function evaluation system of the coastal wetland included the value of tree volume production,fishing and aquaculture,wave dissipation and water storage,water purification,air conditioning,carbon sequestration,pest control,biological diversity maintainance,epeirogenic sedimentation and soil nutrients maintainance,recreation,scientific research and education.Market valuation method,production valuation method,project-substituting method,expense method and carbon tax method were used to evaluate the ecosystem services functions.The main results are as follows:（1）For Dongzhaigang Mangroves Reserve,the vegetation carbon density was 95.97 t·hm^-2 and the vegetation carbon storage was 148658.12 t.The soil carbon density was 170.4 t·hm^-2 and the soil carbon storage was 276770.23 t.The total carbon density is 262.03 t·hm^-2 and the total carbon storage was 425428.35 t.The total carbon storage value was 403.30 million yuan a^-1;（2）For Hainan main-land coastal natural wetlands,the vegetation carbon storage was 296390.61 t.The soil carbon density of 207.72 t·hm^-2 and soil carbon storage was 4347152.65 t.The total carbon density of vegetation and soil was 221.89 t·hm^-2 and total carbon storage was 4643543.26 t.The total carbon storage value was 4.4 billion yuan a^-1;（3）The total wetland ecosystem service value of the Dongzhaigang Mangroves Reserve was 471.36 milliom yuan·a^-1.The dominant services were wave dissipation and water storage(157.54 milliom yuan·a^-1),epeirogenic sedimentation and soil nutrient maintainance(99.75 milliom yuan·a^-1)and recreation(52.97 milliom yuan·a^-1),accounting for 33.42%,21.16%,11.24% of the total value,respectively;（4）The total ecosystem value of the Hainan main-island coastal wetlands was 9.69 billion yuan a^-1.The dominant services were recreation(2.98 billion yuan a^-1),farming and fishing(1.81 billion yuan a^-1),wave dissipation and water storage(for 1.58 billion yuan a^-1),scientific research and education(1.43 billion yuan a^-1)and biodiversity maintainance(983.58 mmillion yuan a^-1),accounting for 30.79%,18.71%,16.26%,14.77%,10.15% of the total value,respectively.By comparing the ecosystem service function values of Dongzhaigang Mangrove reserve and Hainan main-land,we found their dominant services,which,will help policy makers and wetland reserve managers in managing wetland reserves and also help the public to understand the functions and values of coastal wetland ecosystems.Moreover,By evaluating the carbon storage value and ecosystem service functions of coastal natural wetlands in Hainan province,this study filled the void and demonstrated the primary ecosystem service functions of the coastal wetlands of Hainan province,which can be used as the reference data for the ecological compensation mechanism.