Abstract
<title>Abstract</title> <p>The potential to enhance blue carbon in coastal wetlands is shaped not only by local habitat conditions but by anthropogenic pressures transmitted from upstream watersheds through the land-ocean aquatic continuum. Yet regional assessments remain constrained by discontinuous optical remote-sensing observations in tidally inundated zones and by insufficient representation of upstream-downstream linkages. To address these limitations, we develop a transferable, mechanism-based framework that integrates upstream anthropogenic pressure, estimated productivity responses, and habitat suitability to reconstruct spatially continuous enhancement potential, while propagating uncertainty to support risk-aware prioritization. Applied to the Guangdong-Hong Kong-Macao Greater Bay Area, the framework reveals community-specific responses to upstream pressure: salt marshes and mixed wetlands are the most negatively affected, mangroves exhibit modest but consistent negative sensitivity, whereas tidal flats show negative sensitivity in enclosed inner-estuarine settings but positive sensitivity across outer-estuarine reaches. When translated into spatial priorities, Robust Priority zones occupy only 28% of the wetland area yet contribute over 73% of total enhancement potential, concentrated in Jiangmen and driven by Zhenhai Bay. These results establish that restoration priority should follow community-specific pressure response rather than wetland area or habitat suitability alone, providing a transferable basis for integrating watershed pollution control, hydrological reconnection, and coastal restoration in blue carbon governance.</p>