陕北黄土高原区生态服务价值对土地利用变化的响应

为了给陕北黄土高原区生态恢复工程的经济效益评估提供科学数据和参考依据,基于遥感图像解译的土地利用变化数据,运用单位面积价值当量法,剖析了区域的生态系统服务价值对土地利用变化的响应。结果表明:(1)1997—2018年,土地利用格局的变化主要表现为农田向林木和草地转化,未利用地向草地、林木和农田转化; 这些转化同时促使研究区生态系统服务价值增加357.56亿元,增幅33.28%,其中榆林市增量最大,铜川市最小; 除食物生产功能价值量有所减少外,其他服务价值均在增加; 调节服务价值增加量最大,文化服务价值增幅最大。(2)研究区32.93%的区域生态服务价值增加,主要集中退耕还林区和防风治沙区; 农田向林木和草地的转化是价值增加的主要驱动力,促使服务价值增加363.64亿元,占总增加量的95.68%; 未利用地的转化是服务价值增加的另一贡献因子,促使价值量增加16.42亿元,占比4.32%。研究区5.92%区域生态服务价值减少,集中在西部风沙区和南部残塬区; 大型集中农场的修建导致林木和草地向农田转换,促使服务价值损失70.17亿元,占总损失量的93.08%。(3)榆林市辖区43.24%的区域生态服务价值在增加,延安市23.37%增加,铜川市仅11.51%。(4)在不同地物类型中,林木的生态服务价值增加最大,草地次之; 农田生态系统服务价值减少最多。以上监测结果说明,研究区生态恢复工程的实施使其土地利用结构发生变化,随之促使生态服务价值显著增加,生态恢复工程取得了一定的经济效益。

Response of Ecological Service Value and Quality to Land Use Change in China's Loess Plateau

In order to provide scientific data and reference basis for the assessment of the economic benefits of ecological restoration projects in the Loess Plateau region of northern Shaanxi, the response of the regional ecosystem service values to land use changes was profiled based on the land use change data interpreted from remote sensing images, using the per unit area value method. The results showed that:(1)from 1997 to 2018, the changes in land use patterns were mainly manifested by the transformation of farmland to forest and grassland, and unused to grassland, forest and farmland; these transformations simultaneously contributed to an increase of 35.756 billion yuan or 33.28% in the ecosystem service value in the study area, with the largest increment in Yulin and the smallest in Tongchuan, respectively; all service value was increasing, except for the value of food production function, which was decreasing; the value of regulating services was increasing the most, and the value of cultural services was increasing the most;(2)the increase in ecosystem service value in 32.93% of the study area mainly concentrated in the areas of returning farmland to forest and wind and sand control in the Loess Plateau area; the conversion of farmland to forest and grassland was the main driver of the increase in value, prompting an increase in service value of 36.364 billion yuan, accounting for 95.68% of the total increase; the conversion of unused land was another contributing factor to the increase in service value, prompting an increase in value volume of 1.642 billion yuan, accounting for 4.32%; the decrease of ecosystem service value in 5.92% of the study area concentrated in the western wind and sand area and the southern residual loess area; the conversion of forest and grassland to farmland due to the construction of large centralized farms contributed to the loss of service value of 7.017 billion yuan, accounting for 93.08% of the total loss;(3)the ecosystem service value was increasing in 43.24% of the areas under the jurisdiction of Yulin, 23.37% in Yan'an, and only 11.51% in Tongchuan;(4)among the different feature types, the ecosystem service value of forest increased the most, followed by grassland; the service value of farmland ecosystems decreased the most. The above monitoring results indicate that the implementation of the ecological restoration project in the study area has led to changes in its land use structure and subsequently prompted a significant increase in ecological service values, and the ecological restoration project has achieved certain economic benefits.