生态政策对库布齐沙漠土地利用格局及生态系统服务价值的影响

为了探讨生态政策对库布齐沙漠土地利用格局及生态系统服务价值的影响，以内蒙古自治区杭锦旗为例，运用CA-Markov模型及生态系统服务价值评估法预测了非政策干预情景下的土地利用格局及生态系统服务价值，并与政策干预情景下的值进行了对比。结果显示:与非政策干预情景相比，政策干预后耕地面积降低了0.95万hm²，林地面积提高了9.26万hm²；生态系统服务价值增加了21.49亿元，其中气体调节功能、土壤形成与保护功能的生态系统服务价值分别增加了7.85亿元和7.59亿元，林地对生态系统服务价值的贡献率提高了13.41%。以上表明生态政策通过降低耕地增长速度、加快林地增长速度等途径优化了土地利用结构，促进了杭锦旗的生态系统服务价值增长及生态恢复。但实施生态政策后，仍存在生态效益空间分布不均匀及水域退化等问题，有待进一步解决。

Effects of Ecological Policies on Land Use Types and Ecosystem Service Values in Hobq Desert

To study the effects of ecological policies on land use and ecosystem service values in Hobq Desert, a case study of Hangjinqi, Inner Mongolia Autonomous Region was carried out. The CA-Markov model and the assessment method of ecosystem service value were integrated to predict the land use types and ecosystem service values without implementing ecological policies, then the predicted land use types and ecosystem service values without implementing ecological policies were contrasted with actual conditions with implementing ecological policies. The results showed that compared with the predicted land use types and ecosystem service value without implementing ecological policies, the actual area of farmland decreased 9 500 hm², while the actual area of woodland increased 92 600 hm²; besides, the actual ecosystem service value increased 2.15×10⁹ yuan, among which the actual values of gas regulation function and soil formation and protection function increased 785 million yuan and 759 million yuan, respectively, which made a great sense to the fragile ecosystem of Hangjinqi; furthermore, the actual contribution rate of the woodland increased by 13.41%. Thus, all of the results could demonstrate that implementing ecological policies could optimize the land use structure by decreasing the growth rate of farmland while increasing the growth rate of woodland, meanwhile it could promote the growth of ecosystem service values and ecological restoration process. Nevertheless, after implementing ecological policies there are still some problems to be solved, such as the unbalanced distribution of the benefit of ecological policies and the degradation of water bodies.