Stage-Lagged, Spatially Embedded, and Regionally Heterogeneous Land-Use Responses to China’s Grain for Green Program: Evidence from Sichuan, 1985–2024

The Grain for Green Program is one of China’s major long-term ecological restoration policies, but its land-use response should not be interpreted as a one-off shock or a simple increase in ecological land. Using Sichuan, an early-pilot and internally heterogeneous western province, and prefecture-level land-use panel data from 1985 to 2024, this study examines stage-lagged, spatially embedded, and regionally heterogeneous land-use ecological transition under the program. The analysis defines 1985–1998 as the pre-policy reference period and compares three post-policy stages: early implementation (1999–2006), achievement consolidation (2007–2013), and new-round key-area governance (2014–2024). Baseline cropland share in 1985 is used as a proxy for potential policy exposure because it reflects pre-policy pressure for cropland conversion, rather than official project implementation intensity. Ecological land share is measured as the proportion of forest, shrubland, grassland, water bodies, and wetlands in total land area. Improvements did not fully emerge immediately after policy initiation but became most pronounced in 2014–2024. Ecological land change also formed spatial clustering and was embedded in shared terrain, watershed linkages, sloping cropland distribution, and governance tasks. Most prefecture-level units experienced increases, whereas areas with high initial ecological endowments had limited proportional growth. The findings suggest that long-term ecological restoration should be evaluated through policy stages, spatial relations, and regional conditions rather than a single ecological outcome.