CRITICAL EXAMINATION OF WETLANDS ECOSYSTEM SERVICE IN SHANGHAI, CHINA

Wetlands provide many important services to human society, but are at the same time ecologically sensitive and adaptive systems, and are under heavy pressure. As a wetland city, Shanghai city has various types of natural wetlands (chiefly, includes coastal, riverine, lacustrine, and reservoir and pond wetlands), which account for 23.5% of total areas. Meanwhile, Shanghai is a metropolitan city, being confronted with the pressure of port expansion and urban and industrial sprawl, just like the other megalopolises in the world. Based on our earlier study on estimating the ecological service values of wetlands in Shanghai, this paper analyzed the ecological functions of the wetland city, such as nutrient cycling, water regulation and supply, food supply, disturbance control, water treatment, habitats and refugia, aesthetic, education and culture, tidal flats and potential land resources. Unfortunately, the wetland function was being degraded and the ecosystem service was discounted accordingly because of over-reclamation, over-fishing, water pollution, and rapid urbanization in the city. It's therefore recommended that, to improve the environment of Shanghai ciry, and make the ecosystems sustainable function appropriately, the effective wetland management strategies should be taken.