Spatio-temporal Heterogeneity of Carbon Storage in Coastal Jiangsu Province Based on the Coupled InVEST-CA-Markov Multi-model Approach

Land use/cover change (LUCC) is a key driver of terrestrial ecosystem carbon storage. By altering vegetation cover, soil organic matter decomposition, and biomass allocation, LUCC regulates carbon cycling processes at regional to global scales. This study investigated the spatio-temporal evolution characteristics of land use and carbon storage under various development scenarios in the coastal region of Jiangsu Province, based on its land use status from 1987 to 2023. We employed a coupled approach integrating the carbon storage module of the InVEST model with the CA-Markov model. The key findings are as follows: (1) Land Use Dynamics (1987-2023): Land use changes in coastal Jiangsu were mainly characterized by the rapid expansion of built-up land and decreases in agricultural land and forest land, while aquaculture ponds and natural water bodies increased slightly. (2) Carbon Storage Changes (1987-2023): Land use type conversions drove significant changes in coastal carbon storage. Yancheng exhibited the highest carbon storage, followed by Nantong, with Lianyungang recording the lowest. Overall, carbon storage displayed a declining trend, decreasing from 71.85×10⁶ t in 1987 to 68.07×10⁶ t in 2023. This represents a cumulative loss of 3.78×10⁶t, amounting to a decrease of approximately 5.26%. (3) Multi-Scenario Projections (2035 & 2050): Simulation results under three distinct development scenarios consistently predicted a continued decline in ecosystem carbon storage for both 2035 and 2050. The high-speed development scenario projected the most significant carbon storage attenuation. Crucially, the ecological protection scenario, which incorporates stringent ecological management measures, demonstrated the capacity to effectively mitigate the rate of carbon storage loss compared with the inertial development scenario. By the end of the planning period (2050), this scenario is projected to maintain regional carbon storage at a level of approximately 67.01×10⁶ t. These findings could not only help to improve the monitoring and assessment of carbon storage dynamics in coastal Jiangsu, but also provide a scientific basis for land use planning and ecological conservation policies, thereby supporting environmental protection and sustainable development in the region.