China’s Mangrove Stability (2000-2021) and Conservation Priorities

Mangroves are critical coastal ecosystems that sustain biodiversity, sequester carbon, and buffer coastlines, yet they face mounting pressures from urbanization and climate change. 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. Moreover, the spatiotemporal trajectories and driving mechanisms of mangrove ecosystem stability that underpin conservation prioritization in China remain poorly understood.Here, we developed a Mangrove Ecosystem Stability Index (MESI) by integrating four remote sensing indicators (fractional vegetation cover, biodiversity index, remote sensing ecological index, and gross primary productivity) to quantify spatiotemporal dynamics of mangroves across China from 2000 to 2021.Over this period, mangrove forests expanded by 38.5%, primarily through the conversion of aquaculture ponds and water bodies under active restoration programs, with the mean MESIrising from 0.49 to 0.55. National protected mangroves exhibited higher MESIthan non-protected areas. Bayesian generalized linear mixed models revealed scale-dependent drivers: soil organic carbon dominated national-level stability, whereas urbanization intensity and population density were primary factors at provincial and reserve scales. MESI-based spatiotemporal trajectory analyses revealed that over 55% of China’s mangroves remained stable from 2000 to 2021, with positive changes (23%) slightly exceeding declines (22%). Integrating MESI trajectories with the Marxan optimization model, spatial prioritization identified 32% of mangroves outside current natural reserves as high-priority for conservation, particularly in Guangxi, the Guangdong-Hong Kong-MacauGreater Bay Area, and Hainan. By linking ecosystem stability assessment with spatial conservation planning, this study provides a scalable and transferable framework for adaptive management of mangrove ecosystems under intensifying climatic and anthropogenic pressures.