Influencing factors of the supply-demand relationships of carbon sequestration and grain provision in China: Does land use matter the most?

The provision of ecosystem services (ESs) such as carbon sequestration and grain provision are critical components to sustainable development. Reaching carbon neutrality generally requires the growing carbon sequestration of forest land, and feeding a growing population needs an expansion of cultivated land. However, limited land resources may lead to a contradiction between the carbon sequestration and grain provision. China has proposed long-term and large-scale land use programs, and exploring whether these land use policies are effective for ES sustainable provision would be instructive for future policy implications. This study integrated multi-source data in the socioecological dimension to determine the extent by which land use and land use change influence the supply-demand mismatches of carbon (carbon sequestration and emission) and grain (grain provision and consumption) in China at the provincial level. The result showed that the total quantity of carbon emissions surpassed carbon sequestration and the grain provision could cover the consumption from 2000 to 2015. Spatially, southeastern coastal provinces had higher grain deficits and northeast provinces had higher carbon deficits. This study further detected the influencing factors of the mismatches between the supply and demand of the two ESs. Excluding land use factors, our results showed that social factors contributed 38% and 47% to the supply-demand mismatches of carbon and grain, respectively, and natural factors contributed 39% and 15%, respectively. During 2000-2005, 2005-2010, and 2010-2015, cropland changes significantly affected grain balance, while forest land changes did not significantly affect carbon balance. These results indicated that cropland protections are vital to food safety, and carbon emission reductions should be the focus for carbon balance. Finally, this study makes policy suggestions for land use and ecosystem management, and a future research framework was proposed to help mitigate ES supply-demand imbalance.