Impact of land use evolution on the value of ecosystem services in the returned farmland area of the Loess Plateau in northern Shaanxi

The Grain-for-Green Program (GGP) has been contributing to changes in the nationwide use of land and vegetation, further changing ecosystem services (ESs). However, the influence of GGP on ESs, in terms of land use evolution remains elusive. This study is conducted based on a dataset collected every five years for the past 30 years. This dataset includes land use statistics and is obtained from Landsat images and the random forest algorithm. Land use evolution in the Loess Plateau in northern Shaanxi from 1990 to 2020 is systematically analyzed. The interest transfer method is adopted to compute the ecosystem service value (ESV), and the willingness and economic affordability are included in the evaluation model. Finally, a cross-sensitivity coefficient is specified to reveal the effects of land use evolution on the ESV in the studied area. The results are as follows: (1) Land use changes mainly occurred on farmland, forest, and orchards. In the past 30 years, the area of cultivated land showed a decreasing trend, whereas the land areas used for other purposes increased. (2) In the same period, the ESV of the investigated plateau continued to rise, increasing by 5.12 billion USD in total. Additionally, the ESV provided by secondary services increases in the following order: regulating services > supporting services > provisioning services > cultural services. (3) The cross-sensitivity coefficient showed that the net transition among forest, grassland, orchard, and unused land in the studied region is relatively sensitive, and a larger transition span of land utilization leads to a stronger effect on the ESV. This study offers crucial data for the compensation of interregional ecology and provides model cases for other regions for ecosystem management.