Impact of Cereal Production Displacement from Urban Expansion on Ecosystem Service Values in China: Based on Three Cropland Supplement Strategies

The acceleration of global urban expansion constantly occupies high-quality cropland and affects regional food security. The implementation of cropland protection policies has alleviated the pressure of cropland loss worldwide, and thus keeping a dynamic balance of cereal production. Such a displacement of cereal production from the lost cropland to the supplemented cropland has resulted in the massive losses of natural habitats (such as forests, grasslands, and wetlands) as well as ecosystem service values. However, the impact of cereal production displacement caused by different cropland supplement strategies has not been concerned. Therefore, taking China (mainland) as a case, this study used the LANDSCAPE model to simulate cereal production displacement caused by urban expansion and cropland supplement between 2020 and 2040, based on three scales of the Chinese administration system (i.e., the national level, the provincial level, and the municipal level). The natural habitat loss and corresponding ecosystem service value (ESV) loss were assessed. The results show that the national-scale cereal displacement will lead to a large reclamation of cropland in North China, causing the most natural habitat loss (5090 km(2)), and the least ESV loss (46.53 billion yuan). Cereal production displacement at the provincial and municipal scales will lead to fewer natural habitat losses (4696 km(2) and 4954 km(2), respectively), but more ESV losses (54.16 billion yuan and 54.02 billion yuan, respectively). Based on the national food security and ecological conservation in China, this study discussed the reasons for the ecological effects of cereal production displacement, direct and indirect natural habitat loss of urban expansion, and cropland protection policies in China. We suggest that China's cropland protection policy should emphasize avoiding large-scale cropland displacement and occupation of natural habitat with high ESV for cropland supplement.