Coastal marshes and wetlands are usually considered to be carbon sinks, meaning they trap and store carbon underwater, underground, and in vegetation, preventing it from reaching the atmosphere and contributing to climate change. However, as sea-level rise causes coastal marshes to migrate inland, the ability of coastal areas to store carbon may change. A recent article by Duke Today highlights Southeast CASC-supported research that modeled how sea-level rise could push coastal marshes in mid-Atlantic states inland, releasing carbon and reducing coastal habitat. While previous research suggested that expanding coastal marshes may capture more carbon, the authors found that low-lying forests could be overtaken by marshes and flooding. The drowned forests would leave “ghost forests” composed of dead trees that decompose, releasing more carbon dioxide into the atmosphere. 

The researchers provide maps of predicted change across seven states that managers may use to identify areas at risk of coastal marsh expansion and the key drivers that could create this change.  

This work is supported by the Southeast CASC project, “Ecosystem Services Mapping Datasets”.