Ecological benefits assessment of land degradation control in the Three-North Shelterbelt Program region

Land degradation has become a major global environmental challenge, threatening ecosystem security and sustainable development. It reduces land productivity and biodiversity, exacerbates carbon emissions through the loss of soil organic matter, and disrupts climate regulation and soil functions. These ecological risks warrant close attention. In this study, taking the Three-North Shelterbelt Program (TNSP) region as the study area, a comprehensive assessment framework was established based on meteorological, topographic, soil and remote sensing data from 1985 to 2024, using five ecosystem indicators including vegetation cover, water conservation, biodiversity, soil conservation, and wind erosion control to evaluate the ecological benefits of land degradation control. The results showed that (1) overall, ecosystem service functions in the study area exhibits an increasing trend, indicating that land degradation has been partially mitigated across most regions. (2) Temporally, ecological benefits increase rapidly since 1995, with significant improvements observed in multiple indicators. However, since 2015, pressures such as increasing aridity and forest stand aging have slowed the rate of ecological improvement in some areas, with localized signs of degradation re-emerging. (3) Spatially, ecosystem service functions display a clear southeast-to-northwest gradient, with more effective restoration in the wetter southeastern and southern regions, while recovery in the arid central and western areas has been slower and land degradation risks remain high. The findings provide a scientific foundation and technical support for optimizing future ecological programs in the TNSP region and guiding sustainable ecological management in similar areas.