Modulating shrub-grassland proportion to improve ecosystem services and advance SDGs in the Alpine Basin of Central Asia

Current understanding of the direct impacts of shrub encroachment on grassland ecosystem services (GESs) and their indirect effects on social, economic, and environmental sustainable development goals (SDGs) remains limited. Using the alpine shrub-encroached grasslands in Central Asia as a case study, we first derived the spatiotemporal dynamics of shrub encroachment from 1994 to 2023 using Landsat 5/7 and Sentinel-2 imagery. We then evaluated the effects of shrub encroachment on three GES categories: provisioning, regulating, and cultural services. Finally, an innovative GESs-SDGs-Bayesian Network (BBN) conceptual framework was developed to investigate the causal relationships among shrub encroachment, GESs, and SDGs. The results indicated an obvious intensification of shrub encroachment over the 30-year period, with the most severely affected area expanding by up to 45.54%. This process enhanced regulating services such as carbon storage, soil conservation, and nutrient cycling, while concurrently reducing provisioning and cultural services. Given this trade-off identified by the GESs-SDGs-BBN conceptual framework, we proposed a management strategy focused on restricting severe shrub encroachment and maintaining moderate encroachment levels to best balance environmental, economic, and social SDG benefits. This work bridges the divide between conservation theory and practice, reconciling ecological sustainability with pastoral well-being to advance shrubland restoration.