Two decades of vegetation productivity change shaped by water availability and human activity in northern China’s arid–semi-arid transition

Northern foothills of the Yinshan Mountains in Inner Mongolia (NFYM), China (arid-semi-arid transition) This study examined how and why vegetation net primary productivity (NPP) changed in the NFYM region from 2001 to 2020. We used trend analysis, persistence modeling, and spatial attribution approaches (Optimal Parameter Geodetector and partial derivatives) to characterize spatiotemporal variation and its driving mechanisms, and to quantify the relative contributions of climate and human activities. Results indicate that NPP increased on average by 2.08 gC⋅m −2 ⋅a −1 over the study period. However, a low Hurst index (mean = 0.44) suggests that these gains are unlikely to persist. Moisture-related drivers—especially evapotranspiration and precipitation—explained more variation than temperature, while interactions between climate and human activity (e.g., evapotranspiration and economic development) had the strongest explanatory power. On average, human activities contributed more to NPP change than climate. Gains were widespread across the region, while declines were rare and spatially clustered. These results underscore the combined influence of biophysical and anthropogenic drivers on dryland vegetation dynamics and support targeted ecological interventions to promote resilience in water-limited regions. • NPP increased by 2.08 gC⋅m −2 ⋅a −1 (2001–2020); 65 % of area greened significantly. • Moisture-related factors (ET, Pre) explained more variation in NPP than temperature. • Human activities explained more than two-thirds of NPP change. • The strongest interaction (ET & GDP) shows strong climate-human synergy on NPP. • 82.8 % area showed anti-persistent greening, risking future reversal.