Impacts of cropland expansion on carbon storage: A case study in Hubei, China

When cropland expansion encroaches on ecological land (e.g., forest, grassland, wetland), it seriously affects carbon storage which plays an important role in global climate change. Taking Hubei as the study area, this study explored the effects of cropland expansion on carbon storage in both 2000-2010 and 2010-2030 in different scenarios by using the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model and the LAND System Cellular Automata model for Potential Effects (LANDSCAPE). The results showed that cropland expansion led to a massive loss of carbon storage (1.76 Tg C) during 2000-2010, which is expected to continue during 2010-2030 in different scenarios. The loss is predicted to be 3.70 Tg C in the Business-As-Usual scenario and be 0.88 Tg C in the Requisition-Compensation Balance of Cropland Policy scenario. Noticeably, the loss of carbon storage due to cropland expansion was 1.12 times more than that due to urban expansion during 2000-2010. For the period of 2010-2030, the loss of carbon storage caused by cropland expansion is predicted to be 3.89 times more than that caused by urban expansion in the Business-As-Usual scenario, while the losses caused by cropland expansion and urban expansion are predicted to be almost equal in the Requisition-Compensation Balance of Cropland Policy scenario. The main cause of carbon storage loss due to cropland expansion is that it leads to the considerable loss of forest and wetland. This study highlights the importance of considering the loss of carbon storage caused by cropland expansion when conducting cropland protection policies and land use planning.