Projecting the future impacts of China's cropland balance policy on ecosystem services under the shared socioeconomic pathways

摘要

China has implemented a strict policy of cropland balance to reduce the impacts of built-up land expansion on food production. However, this policy only alleviates the quantitative loss of cropland, while exerting unexpected damages to ecosystem services. Given that China's built-up land will continue to expand in the foreseeable future, the evaluation of potential ecological cost of obtaining a cropland balance is important to help seeking a sustainable strategy for cropland protection. To address this issue, this study develops a cellular automaton model to conduct multiple scenario simulations under the assumptions of shared socioeconomic pathways. The results reveal the inferior physical condition of the reclaimed cropland for compensation. Despite the quantity balance achieved, the lost productivity is compensated by only 28-31%. If the lost productivity is intended to be fully offset, however, the amounts of reclaimed cropland should be more than double, leading to substantial declines in ecosystem services. These findings suggest the failure of the current cropland balance policy, because either the lost cropland or productivity had to be compensated at a high cost of ecological declines. The results also imply that upgrading the quality of remaining cropland is more important than maintaining the quantity balance. (C) 2019 Elsevier Ltd. All rights reserved.