北京湿地生态系统重要服务功能及其价值评估

论文基于北京市湿地资源调查数据,重点评估了湿地调蓄洪水、供给水源、净化水质、蒸发降温和维护生境等重要生态服务功能及其价值。结果表明,2014年北京市湿地面积5.14×10⁴ hm²,其中46%为自然湿地,并集中分布在密云、房山和门头沟等远郊区。北京市湿地生态系统年均调蓄洪水20.75×10⁸ m³、供给水源9.44×10⁸ m³、净化水体污染物（COD）4.22×10⁴ t、蒸发吸热3.03×10¹² kJ,并维护着较高质量生境0.96×10⁴ hm²,其经济价值分别为158.95×10⁸、11.89×10⁸、1.69×10⁸、4.21×10⁸和10.84×10⁸元。虽然这些重要生态系统服务的78%来自于北京市远郊区的湖库与河流湿地,但是主城区湿地同样提供着重要的生态服务功能,且受益人群数量较高,因而更需重点保护。

The Key Ecological Services and Their Values of Wetland Ecosystems in Beijing

With increasing urbanization and agricultural expansion, there is rapid loss, conversion, and degradation of global wetlands. Quantifying the key ecosystem services and elucidating the main providers of wetland can help implement sustainable and diverse wetland utilization strategies. This study estimates the economic values and dominant contributors of five key ecosystem services (i.e. flood regulation, water provision, water purification, cooling effect and habit maintenance) of wetlands in Beijing using the economic valuation methods with the wetland inventory data in 2014. There are 5.14×10⁴ hm² wetlands in Beijing, 46% of which are natural wetlands and mainly distribute in outer suburban districts of Beijing, such as Miyun, Fangshan and Mentougou. These wetlands can annually regulate 20.75×10⁸ m³ of flood, supply 9.44×10⁸ m³ of water, purify 4.22×10⁴ t of COD from surface water, absorb 3.03 PJ of heat by evaporation, and maintain 0.96×10⁴ hm² super-quality habit. The economic values of the 5 key ecosystem services are 1.59×10¹⁰, 1.18×10⁹, 1.69×10⁸, 4.21×10⁸ and 1.08×10⁹ yuan, respectively. In addition, the reservoirs and rivers in Miyun, Yanqing, Fangshan, Huairou and Mentougou provide 78% of wetland ecosystem services, whereas the urban wetland resources in Xicheng, Dongcheng, Shijingshan, Chaoyang and Haidian also take important roles. The study highlights the economic values and the dominate contributors of wetland ecosystem services in Beijing, and provides basis for wetland protection policy when developing new urban areas.