By Jim Tang
Coastal wetlands, including salt marshes, mangroves, and sea grass, have a strong capacity to capture carbon dioxide from the atmosphere. By storing “blue carbon” in marine plants, organisms, and soil, coastal wetlands can offset human emissions of carbon dioxide from burning gasoline and coal.
Members of my lab, including postdoctoral scientist Faming Wang, recently installed carbon dioxide measurement systems in two coastal towns in Cape Cod, Massachusetts, in collaboration with the USGS Woods Hole Coastal and Marine Science Center. The first site is an undisturbed marsh in Barnstable while the second one is a degraded marsh in Wellfleet that is tidally restricted by invasive Phragmites grasses. The goal is to study the differences in carbon emissions and uptake rates between the undisturbed marsh and the degraded marsh. Once the degraded marsh is restored by re-introducing seawater, we will assess how much carbon storage is gained. This carbon credit can be traded at the emergent “carbon market” – a voluntary market to trade carbon between carbon emitters and carbon uptakers — to gain monetary value.
Our results will inform and support the U.S. National Park Service’s efforts to restore the Herring River wetlands, located in Wellfleet and Truro, Mass. As the wetlands are restored, progress will be assessed by monitoring carbon dioxide emissions and soil and vegetation properties.
The CO2 emissions and uptake rates are measured every half hour as part of the international AmeriFlux network. A nearby weather station monitors wind speed, wind direction, rainfall, and solar radiation. This weather data will explain the variation of carbon dioxide emissions. Soil, water, and vegetation (Spartina and Phragmites grasses) are also monitored to provide insight into the difference in carbon storage between the two sites.
Top photo caption: Carbon dioxide measurement system installed in Barnstable, Mass. Credit: Jim Tang.