Spatio-temporal Evolution and Prediction of Mangrove Carbon Storage in Hainan Island

Background As a critical component of coastal wetland ecosystems, mangrove forests play a pivotal role in blue carbon sequestration within coastal zones. Investigating the spatiotemporal evolution of mangrove carbon stocks in Hainan Island and the underlying driving mechanisms holds significant scientific value for enhancing mangrove wetland conservation strategies and promoting regional sustainable development.Methods In this study, we integrated the PLUS (Patch-generating Land Use Simulation) model and the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model to systematically analyze the evolution of landscape patterns in mangrove wetlands and the spatiotemporal dynamics of carbon stocks in Hainan Island between 2000 and 2020. Furthermore, we simulated and predicted carbon stock dynamics under three scenarios—natural development, economic priority, and ecological protection—for the year 2030. Using a geographic detector model, the driving factors of carbon storage differences within wetland areas were identified. Results : 1) the mangrove area exhibited a significant growth trend during the study period, with a net increase of 1,329.84 hectares; the proportion of mangrove carbon stocks continued to rise, while carbon stocks in other woodland types showed a declining trend; 2) mangrove ecosystems are the primary contributors to wetland carbon stocks. Scenario simulations revealed that, compared to the 2020 baseline, carbon stocks under the natural/t/nscenario decreased by 3.6%, whereas those under the economic priority and ecological protection scenarios increased by 4.4% and 7.6%, respectively;(3) geographic factors (elevation, slope, and aspect) and climatic factors (mean annual temperature and precipitation) significantly explained the spatial heterogeneity of carbon stocks. Notably, economic factors (distance from government sites and GDP density) significantly enhanced their influence on carbon stocks through interactions with natural factors. Conclusion From 2000 to 2020, the area and carbon storage of mangroves in Hainan Island increased significantly, making them the dominant contributor to wetland carbon sinks. Scenario predictions show that compared with natural development, ecological protection policies will significantly enhance carbon storage in 2030. The spatial variation in mangrove carbon storage is primarily driven by physical geography and climatic factors, while economic factors exert significant influences through interactions with natural factors. This study provides a quantitative foundation for the scientific management of tropical mangrove wetlands and nature based climate solutions.