Greening–Function Decoupling and Land Degradation Risks in the Mongolian Plateau

ABSTRACT Vegetation greening in drylands does not always translate into ecological recovery. However, most existing assessments rely solely on greenness metrics such as NDVI, which fail to capture whether greening is accompanied by improvements in key ecosystem functions like productivity, water balance, or thermal regulation. To address this gap, we developed an Ecological Greening Coordination Index (EGCI) that integrates NDVI with net primary productivity, evapotranspiration, and land surface temperature to assess the synchrony between vegetation growth and ecosystem functioning on the Mongolian Plateau. Results from 2012 to 2022 show that non‐greening areas dominated (average 61.6%), while coordinated greening peaked at 33.2% in 2016 and decoupled greening reached 19.6% in 2012. Urbanization pressure, measured by nighttime lights, had limited impact in natural areas but produced ring‐like correlation patterns around urban zones. By combining EGCI and NDVI trends, four ecological synchronization zones were identified, reflecting distinct pathways of recovery or degradation. EGCI provides a practical tool for distinguishing genuine ecological restoration from apparent greening, supporting land degradation risk assessment, restoration evaluation, and progress toward land degradation neutrality in arid and semi‐arid regions.