2000—2019年中国重大生态工程生态效益遥感评估

本文提出了重大生态工程实施生态效益评估理论框架,在选取生态系统宏观结构、生态系统质量和生态系统服务3大类、6个一级指标和9个二级指标的基础上,利用地面和遥感数据,结合模型模拟,生成了2000—2019年长时间序列评估指标参数数据集,定量评估了中国重大生态工程实施20年后的生态效益。结果表明：生态恢复程度中等、较高和高的区域面积分别占全国国土面积的24.1%、11.9%和1.7%,生态工程实施数量越多的地区,生态恢复程度越高,生态恢复程度较高和高的区域主要集中在黄土高原、北方农牧交错带、东北平原、川滇黔渝湘结合部等地区;气候因素和生态工程对植被净初级生产力变化的贡献率分别为85.4%和14.6%,对水蚀模数变化的贡献率分别为69.5%和30.5%;中国植被覆盖度有20%的恢复潜力,森林植被覆盖度恢复潜力为6.4%,草地植被覆盖度恢复潜力为23%;气候条件是生态恢复的重要限制因素,生态恢复程度较高和高的区域主要分布在年均温大于0 ℃和年降水量大于300 mm的地区。因此,重大生态工程的部署,应充分考虑气候条件的限制性,避免实施单一生态工程或单一生态恢复措施,充分发挥生态工程组合措施的综合效应,提高生态投入资金的最大效益。

Assessment of ecological benefits of key national ecological projects in China in 2000-2019 using remote sensing

We propose a theoretical framework for assessing the ecological benefits provided by national key ecological projects in China over the past 20 years. A dataset consisting of six primary indicators and nine secondary indicators of ecosystem structure, ecosystem quality, and ecosystem services for the period 2000-2019 was generated using ground survey and remote sensing data. Ecological benefits were quantitatively evaluated following the implementation of national key ecological projects in China. Areas with medium, relatively high, and high degrees of ecological restoration accounted for 24.1%, 11.9%, and 1.7% of the national land area, respectively. Degrees of ecological restoration were higher in areas with a greater number of ecological projects. Areas with relatively high and high degrees of ecological restoration were mainly concentrated in the Loess Plateau, the farming-pastoral zone of northern China, the Northeast China Plain, and an area spanning the border areas of Sichuan, Yunnan, Guizhou, Chongqing, and Hunan. The relative contributions of climatic factors and ecological projects to changes in vegetation net primary productivity were 85.4% and 14.6%, respectively, and the relative contributions of climatic factors and ecological projects to changes in water erosion modulus were 69.5% and 30.5%, respectively. The restoration potential of national vegetation coverage was 20%, and the restoration potential percentages of forest and grassland vegetation coverage were 6.4% and 23%, respectively. Climatic conditions can inhibit ecological restoration. Areas with relatively high and high degrees of ecological restoration were mainly distributed in areas with an annual average temperature greater than 0 ℃ and annual precipitation greater than 300 mm. Therefore, the limitations associated with climate conditions should be considered during the implementation of national ecological projects. The implementation of single ecological projects or single ecological restoration measures should be avoided, the use of combined measures should be emphasized, and the benefits of ecological investment funds should be maximized.