Cropland reclamation versus cropland restoration: Which is more conducive to China's food security and ecological conservation?

To meet food demand, China has reclaimed marginal land for cropland in recent decades while converting cropland to ecological land via ecological retirement and agricultural restructuring, yet the rationality of this dual practice remains unevaluated. This study first analyzed the spatiotemporal patterns of cropland reclamation and ecological loss in China from 1990 to 2024, then employed the XGBoost-SHAP model to identify their underlying drivers. It also used the MaxEnt model to assess cropland suitability and the substitution potential of cropland restoration for reclamation, and quantified effects on grain production and ecosystem services via GAEZ-PCA-RF and InVEST models. Results showed cropland reclamation and ecological loss accounted for 26.25% and 22.46% of the base-period cropland area, respectively, with net reclamation concentrated in Northwest and Northeast China, and the two processes had opposing drivers. Ecologically lost cropland had 1.14 times higher suitability than reclaimed cropland, with the former’s suitability rising and the latter’s falling. Notably, 50.12% (25.95 Mha) of planned new reclamation could be substituted by cropland restoration, mainly in the Middle and Lower reaches of the Yangtze River drainage basin and South China (90.11%). This substitution would boost national grain production by 3.07% (23.26 Mt, 74.87% from Southern China) and raise the integrated ecosystem service index by 0.65%. These findings suggest that China should place greater emphasis on the importance of cropland restoration in the future to maintain stable cropland area, an approach that would better balance food security and ecological conservation.