Assessing the long‐term carbon‐sequestration potential of the semi‐natural salt marshes in the European Wadden Sea

Salt marshes in the European Wadden Sea, despite rapid succession over the past 80–120 years, demonstrate a significant long-term carbon-sequestration potential compared to their former tidal-flat ecosystems. However, deep-core analyses reveal substantial losses of organic carbon (OC) in well-aerated marsh soils, emphasizing the need for thorough sampling to avoid overestimating sequestration rates. The study, using foraminiferal taxa and grain size distributions, found that while salt marshes effectively store more OC than tidal flats, a large portion of this preserved carbon originates from marine-derived allochthonous sources rather than atmospheric CO₂ uptake by vegetation. This insight challenges assumptions about the primary contributors to blue carbon stocks and underscores the complexity of incorporating these ecosystems into carbon-crediting programs.

Mueller, P., Ladiges, N., Jack, A., Schmiedl, G., Kutzbach, L., Jensen, K., & Nolte, S. (2019). Assessing the long‐term carbon‐sequestration potential of the semi‐natural salt marshes in the European Wadden Sea. Ecosphere, 10(1). Portico. https://doi.org/10.1002/ecs2.2556