Does the Ecological Conservation Redline Policy Enhance Multidimensional Ecosystem Services? A Causal Assessment of Mechanisms and Governance Pathways

This paper develops a dynamic multidimensional ecosystem service value index for 280 prefecture-level cities in China from 2000 to 2023. The index is constructed by integrating remote sensing, GIS, and ecological–economic indicators, with machine learning used as a data-driven tool to aggregate multidimensional ecological information. Building on this measurement framework, the paper applies a staggered Difference-in-Differences (DID) model to evaluate the impact of the ecological conservation redline policy on regional ecosystem service value. The results show that the policy significantly increases urban ecosystem service value and that the effect is cumulative over time. Mechanism analysis suggests that the policy mainly works through three channels: ecological benefit improvement, ecological spatial reconstruction, and community public participation. Heterogeneity analysis further shows that the effect is stronger in early pilot cities and in high-ecological-function zones. In addition, policy coordination and local governance capacity significantly strengthen policy effectiveness. By combining multidimensional ecosystem service measurement with causal policy evaluation, this study extends existing research on ecological conservation redline and provides empirical evidence for improving land spatial governance and ecological protection policy design in China.