Ecosystem stability trajectories identify mangrove conservation priorities in China

Assessing mangrove ecosystem stability across space and time remains challenging due to the multidimensional nature of ecological structure and function and the lack of integrative indicators. Here, we developed a Mangrove Ecosystem Stability Index (MESI) based on multiple remote sensing indicators to quantify the spatiotemporal dynamics of mangroves across China from 2000 to 2021. During this period, mangrove forests expanded by 38.5%, largely through the conversion of aquaculture ponds and water bodies under active restoration programs, while the mean MESI increased from 0.49 to 0.55. Bayesian models revealed scale-dependent drivers of stability, with soil organic carbon dominating at the national scale and urbanization intensity and population density shaping patterns at provincial and reserve scales. Spatiotemporal trajectory analysis showed that over 55% of China's mangroves remained stable, with positive changes (23%) slightly exceeding declines (22%). Integrating stability trajectories with spatial prioritization identified 32% of mangroves outside current reserves as high-priority conservation areas, particularly in Guangxi, the Guangdong-Hong Kong-Macau Greater Bay Area, and Hainan. These findings provide a scalable framework for linking ecosystem stability assessment with conservation planning to support adaptive mangrove management under increasing climatic and anthropogenic pressures.