Quantifying spatiotemporal dynamics and driving factors of carbon stock with integrated model in Bohai Bay, China

The contradiction between rapid urbanization and ecological protection leads to the aggravation of carbon sink function differentiation in coastal areas. In this study, a framework of "historical assessment-future prediction-mechanism analysis" was constructed, and InVEST, PLUS, SEM, and OPGD models were integratedto study the dynamics of carbon storage and its driving mechanisms in three rapidly urbanizing coastal areas (Beidaihe, Caofeidian and Huanghua) in the Bohai Rim region of China. The main results showed that: (1) carbon storage showed the characteristics of periodic change-the expansion of low-carbon land led to the decline of carbon storage (2000-2010), and then Caofeidian achieved 1.50 × 10⁶ tons of carbon storage restoration through ecological restoration (2010-2020). (2) Carbon stocks are expected to increase in all four scenarios in 2030, with the largest increase in the Cultivated Land Protection (CP) scenario, with a peak of 3.00 × 10⁷ tons. (3)The analysis of the driving mechanism showed that population density was the main driving factor (q = 0.2126-0.2129), and there was a significant nonlinear interaction with socio-economic factors, which jointly shaped the spatial pattern. This analysis reveals the spatiotemporal heterogeneity and core driving factors of carbon storage changes in coastal areas, emphasizes the key role of human activities under urbanization and ecological conflicts, and provides a scientific basis for the implementation of differentiated low-carbon spatial planning in rapidly developing coastal areas.