Quantitative contribution of climate change and vegetation restoration to ecosystem services in the Inner Mongolia under ecological restoration projects

• Dynamic changes in ecosystem services in ecological engineering area were quantified. • The vegetation restoration index driven by human activities was constructed. • Vegetation restoration explained 63.23% of the dynamic changes in ecosystem services. • NDVI exerts a constraint effect on total ecosystem services with a threshold of 0.79. In the context of ongoing ecological restoration efforts, understanding the impacts of vegetation restoration on ecosystem services (ESs) is critical for sustainable ecosystem management. However, the quantitative contributions of vegetation restoration and climate change to ESs, as well as the relationship between vegetation restoration and ESs, remain insufficiently explored. This study focuses on the Inner Mongolia Section of the Beijing-Tianjin Sandstorm Source Control Project Area (IM-BTSSCPA) to address these gaps. The temporal and spatial dynamics of total ecosystem services (TES) in the IM-BTSSCPA from 2001 to 2020 were evaluated. The contributions of climate and Human Appropriation of NDVI (HANDVI) to TES were quantified, and the nonlinear constraint thresholds of NDVI on TES were identified. Key findings include: (1) TES improved significantly from 2001 to 2020, with a spatial trend of increasing from the northwest to the southeast; (2) HANDVI was identified as the primary driver of TES improvement, contributing 63.23%; and (3) NDVI exhibited nonlinear constraint effects on sand fixation, water yield, and TES, with respective thresholds of 0.32, 0.49, and 0.79. These findings suggest the need for multi-scale eco-spatial management and planning strategies, and offering valuable guidance for the implementation of sustainable ecological restoration projects.