Land Use Transitions and the Associated Impacts on Carbon Storage in the Poyang Lake Basin, China

Carbon storage plays an important role in the global carbon cycle and climate change mitigation. Understanding the relationship between land use change and carbon storage can significantly contribute to carbon neutrality and sustainable development. However, most previous studies only analyze the carbon storage change due to land use change, while few studies quantitatively evaluate the contributions of various land use transitions (LUTs) to carbon storage change, which cannot provide enough information for land use management. In the context of rapid urbanization and ecological conservation, the Poyang Lake basin (PYLB) has experienced dramatic land use change, which has significantly affected local carbon storage. Therefore, this study used the InVEST model to evaluate carbon storage in the PYLB from 1990 to 2020. Then, the Geo-information Tupu method was used to quantify the contributions of various LUTs to carbon storage change and identify the key LUTs. The results showed that carbon storage in PYLB decreased by 17.26 Tg from 1990 to 2020. The carbon gain was mainly attributed to transitions from ‘farmland to forestland’ (36.87%), ‘grassland to forestland’ (22.58%), and ‘farmland to water’ (15.89%). In contrast, the transitions from ‘farmland to built-up land’, ‘forestland to built-up land’, and ‘forestland to grassland’ contributed 39.94%, 28.06%, and 13.25% to carbon loss, respectively. Massive carbon loss caused by built-up land expansion should attract attention. This study can provide references for the formulation and optimization of land use policies to achieve carbon neutrality and sustainable development in the PYLB.