陕北长城沿线地区生态系统服务价值变化研究

Values of ecosystem services and their change in the regions along the Great wall in north Shaanxi Province

以水土流失严重,土地沙化强烈,生态环境脆弱的陕北长城沿线风沙过渡区作为一个研究对象,通过近14年土地利用变化分析计算了区域生态服务价值的动态变化,反映了土地利用变化的区域环境效应,结果表明:在近14年,土地利用结构发生了明显变化,土地利用类型以农业用地为主,建设用地和园地的增长幅度加大。通过生态系统服务价值核算,本区1992年的生态服务价值为138.94亿元,2002年生态服务价值为146.92亿元,增加了7.98亿元,生态服务价值在增加,这表明该区生态环境质量整体在提高。以土地利用变化为切入点,对土地生态系统服务价值的计算,以货币的形式反映生态系统所发挥的重要作用,即把隐性的、公益性的生态系统作用定量化,它使我们认识到生态系统服务价值在脆弱地域生态系统发挥着重要作用,在追求经济效益的同时,要更多地考虑生态效益,准确地把握人与自然的关系,达到人与自然的和谐发展。

The study area covers 150 townships and towns in 6 counties and districts, its total area is 33972 km^2, and its total population is 1. 895 × 10^6, among whom the non - agricultural population is 3. 472 × 10^5 and occupies 19.34% of the total. The study area belongs to a farming-pasturing ecotone, thus the diversity, complexity and vulnerability of ecological environment form. Moreover, the regional environment is degenerated and the land degradation becomes more serious due to the climatic fluctuation and the increase of human activities. Based on the 14-year data of land use change, this paper analyzes the dynamic change of the values of regional ecological services in the regions along Great Wall in north Shaanxl Province, where the soil erosion and land desertiflcation are serious and the ecological environment is vulnerable. The results show that the land use structure has been significantly changed since recent 14 years, the land use types are dominated by farmlands, and the proportions of the lands used for construction and original lands are significantly increased. The calculated results reveal that the values of ecosystem services in the study area were 1. 389 4 × 10^10 Yuan RMB and 1.4692 × 10^10 Yuan in 1992 and 2002 respectively, and the value of ecosystem services was increased by 7. 98× 10^8 Yuan in 2002 than that in 1992, which reveals that the ecological environment quality is currently iimproved in general. The quantitative calculation of the value of ecosystem services based on land use change makes us understand the important role of the value of ecosystem services in the regions with vulnerable ecology and further consider the ecological benefits while developing the local economy so as to achieve the nature-human harmonious development.