土地覆盖变化对盐城海岸带湿地生态系统服务价值的影响

Effects of Land Cover Change on the Ecosystem Services Values in Yancheng Coastal Wetlands

应用Costanza的生态服务价值计算方法,参考中国陆地生态系统单位面积服务价值表,依据当地市场价格,参考海岸带湿地生态服务价值已有文献确定各生态服务价值系数,并结合野外实地调查结果和遥感提取的盐城海岸带湿地两期土地覆被数据,分析盐城海岸带湿地土地覆盖变化以及由此引起的生态系统服务价值的变化。结果表明:1992-2008年研究区土地覆盖发生了显著变化。自然湿地大量转化为生产用地,水产养殖塘和弃耕地面积变化最明显;自然湿地中芦苇和盐地碱蓬滩面积减少了75.27%和72.83%,而互花米草滩面积增加了369.09%。1992-2008年研究区生态服务价值增加了25.349亿元,水产养殖塘的扩建是生态服务价值增加的主要原因;生态系统单项生态服务功能中,大气组分调节、水分调节、污染物降解、科考旅游及生物多样性保护价值均大幅减少。各种土地覆盖类型中,水产养殖塘及互花米草滩的生态服务价值显著增加,而芦苇和盐地碱蓬滩的生态服务价值则大幅减少。自然湿地大量转化为生产用地以及互花米草的大范围入侵是导致不同土地覆盖类型生态服务价值发生变化的主要原因。

Using Costanza＇s ecosystem services value computing formula and Chinese land ecosystem services value per unit area of coefficients, according to the local market price, based on the existing literatures of coastal wetland ecosystem service value to determine the value of coefficient of ecosystem services, and combined with field survey resuits and two-period land cover dynamic data from remote sensing image of Yancheng coastal wetland, this paper analyzed change in land use and cover and subsequent loss of ecosystem services value. The results showed that： from 1992 to 2008, this wetland＇s land cover has experienced significant changes. A large number of natural wetlands transform into productive land, aquaculture ponds and farmland area change is most obvious, Phragmites cornmunis and Suaeda salsa area reduced 75. 27% and 72.83% respectively in the natural wetlands, while Spartina alterniflora area increased 369. 09%. Total ecosystem service values of study area increased 2. 534 9×10^9 Yuan in period 1992--2008, aquaculture pond＇s expansion is the primary reasons for the ecosystem services value increased. Atmospheric composition regulation, water regulation, pollutant degradation, recreation, cultural and biodiversity conservation vaiues were significantly reduced. Among the various land cover types, aquaculture ponds and Spartina alterniflora were increased in the val ue of ecosystem services, while the Phragrnites cornmunis and Suaeda salsa were substantially reduced. Nu merous natural wetland transformed into productive land and large-scale Spartina alterniflora invasion were the mainly reasons which led different land cover type＇s ecosystem service value to change.