摘要
为研究陕西省延安市退耕还林工程的实施效果,选取退耕还林前的1995年、退耕还林初期的2000年以及退耕还林后期的2007年作为研究时点,采用USLE模型测算退耕还林前后延安市的土壤侵蚀量变化,并运用生态系统服务功能价值评估方法从不同时点、不同土地利用类型2个方面对土壤保持服务功能价值进行对比分析。主要结论如下:1)从1995—2007年,延安市的土壤保持总量呈先减少后增加的态势;2)1995、2000、2007年延安市农林牧业土壤保持功能价值总量分别为1 076.84亿、911.04亿、1 341.59亿元,在此3期的价值量评估中,土壤肥力保持的价值量占总价值量的98%以上;3)1995—2007年的10余年中,延安市耕地和草地的土壤保持功能价值量互为消长,疏林地(包括灌木林地)的土壤保持功能价值较平缓,而有林地的土壤保持功能价值在1995—2000年较为平缓,2000—2007年则大幅提高;4)有林地单位面积的土壤保持功能价值量最大,其次是疏林地、草地,最小的是耕地。上述结果表明,退耕还林工程带来的土地利用变化对增强研究区土壤保持功能起到了明显作用,促进了研究区环境的改善。
The Grain for Green Project （GFGP） of ecological restoration has been implemented in China for more than ten years. To evaluate the effects and benefits of GFGP up to now, we have carried out a comparative study in Yan＇an City, the central area of the Loess Plateau in northwestern China and one of the main initiation areas of the GFGP, through choosing three special time points, i.e. the years of 1995, 2000 and 2007 （dynamically representing the before, the early and the later stages of the project, respectively）. The USLE model and the method for evaluating ecological services on soil conservation function were used in the study from the aspects of land use type and time change. The results showed that ： 1 ） From 1995 to 2007, the quantity of soil conservation benefit by the project reduced slightly first and then increased very much later on. 2） The estimated total economic benefits of soil conservation in the study area was valued at 107. 684 billion CNY in 1995, 91. 104 billion CNY in 2000, and 134. 159 billion CNY in 2007, in which the value from protection of soil fertility accounted for more than 98%. 3） From 1995 to 2007, the benefits of soil conservation from the farmland and the grassland accounted by money value were mutually interrelated, showing a trade-off in between. Meanwhile, the benefits of the same aspect from the open forest （shrub） land did not change very much; whereas that from the forestland changed slightly from 1995 to 2000, and sharply increased from 2000 to 2007. 4） The highest benefit of soil conservation per unit area, counted by economic value, was from the forestland, followedby the open forest （shrub） land and then the grassland, while the lowest one came from the farmland. The results of the research imply that the land use change initialized by GFGP has greatly enhanced the local ecosystems＇ function, especially in soil conservation aspect, and thus contributed to the better-off on local environment.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2013年第6期67-73,共7页
Journal of Beijing Forestry University
基金
国家自然科学基金项目(41271059)
"973"国家重点基础研究发展计划项目(2007CB106807)
关键词
延安市
退耕还林工程
土壤保持服务功能价值
通用土壤流失方程
Yan＇ an City
Grain for Green Project
ecological service of soil conservation
universal soil loss equation
