Valuation Of Ecosystem Services Of The Yellow River Delta Wetland

The Yellow River Delta Wetland (YRDW) is one of the most complete, largest and youngest primitive wetland ecosystems in the warm temperate regions of China. The landscape pattern and ecosystem services of YRDW have been damaged due to the long-term human activities and natural changes. However it is still not clear how much are these damages. This paper aimed to reveal the long-term change of landscape pattern of YRDW and identify and evaluate the effects of these changes on their ecosystem services. Suggestions to improve YRDW management were drafted.The studied area was manily on the coastal region of YRDW, covering the coastal land and nearby shallow waters. By using ArcGIS, 4 pieces of Landsat TM images in 1992, 1996, 2000 and 2004 were applied to analyze the changes of wetland landscape of YRDW and their driving factors were identified. The total area of the YRDW increased from 3,745.38 km2 in 1992 to 3872.66 km2 in 2004. The intertidal zone and reed grassland still kept dominant in 8 types of landscape of YRDW in the same time period. The transfer patterns among landscape types were complex, which reflected the complex driving stress from both natural changes and human activities.Following Chen's classification system on marine ecosystem services, the YRDW has 14 kinds of ecosystem services belonging to 4 groups. The current utilization of ecosystem services in this wetland was analyzed and 9 main kinds of ecosystem services were selected to be valuated. The ecosystem service value of the YRDW was totally 2,866 million CNY and 764,900 CNY per km2 in 2006 year. Among these services, food supply and climate regulation ranked the first, i.e. 633 million CNY for both. Then oxygen production and wastewater purification ranked the second, i.e. 596 and 558 million CNY respectively. Biodiversity maintenance and raw material supply were 230 and 131 million CNY respectively. Recreation, scientific service and disturbance regulation were the least, i.e. 35, 35 and 14 million CNY respectively.Based on the landscape changes of YRDW in 4 periods from 1992 to 2006, the ecosystem services of YRDW were valuated accordingly. Total service value of YRDW ecosystem was 2,585, 2,136, 2,353, 2,866 million CNY in 1992, 1996, 2000 and 2006 respectively. The spatial distribution maps of ecosystem service value of YRDW showed that the service value of YRDW ecosystem increased at the direction from land to seawater, and reed grassland had the highest value of ecosystem services from 1992 to 2006.Based on ecosystem service theories, the ecosystem management measures were proposed in order to achieve the sustainable provision of ecosystem services and maintain the health of the YRDW ecosystem.