Understanding carbon flows in vulnerable coastal wetlands
A new research network aims to accelerate discoveries in the science of these important natural carbon sources and sinks.
Coastal wetlands provide protection from wind and waves, support habitats and fisheries, and store large amounts of atmospheric carbon dioxide for centuries to millennia. These ecosystems can also be sources of greenhouse gas emissions to the atmosphere; wetlands that do not have the capacity to keep pace with sea-level rise, for example, can erode and release soil carbon rapidly to the atmosphere. Freshwater and brackish wetlands also emit methane, a more potent greenhouse gas over its atmospheric lifetime than carbon dioxide. High uncertainty surrounding the spatial extent and vulnerability of coastal wetland carbon stocks, as well as the dynamics of carbon storage and release, limits our ability to project future behavior of these ecosystems.
The NSF-funded Coastal Carbon Research Coordination Network (CCRCN) was established in 2017 with the goal of building a global community of scientists, policy makers, and non-governmental organizations working to reduce uncertainties and accelerates advances in carbon cycle science in tidal wetlands. CCRCN engages multiple agencies associated with USGCRP’s Carbon Cycle Interagency Working Group. A steering committee comprising Federal and non-Federal organizations—including the Smithsonian Environmental Research Center, U.S. Geological Survey, Woods Hole Marine Biological Lab, and Conservation International—supervises and directs CCRCN priorities. Current activities, guided by community input, include the development and release of two online resources related to carbon in coastal wetlands: a literature review and open workflow supporting the EPA National Greenhouse Gas Inventory, released in December 2017, and a database of 1,500 publicly-available tidal soil carbon depth profiles from the contiguous United States, released in June 2018 as a companion to a journal article[1].
1 Holmquist, J.R. et al. (2018). Accuracy and Precision of Tidal Wetlands Soil Carbon Mapping in the Conterminous United States. Scientific Reports. DOI:10.1038/s41598-018-26948-7.
Mangrove forests store large amounts of carbon, protect the coastline from erosion, and provide shelter for many species. The image shows Landsat-based mapping of change in mangrove forests in the Florida Everglades, 2000–2016. Orange indicates areas of loss and degradation in mangroves; blue indicates areas of mangrove gains and regrowth. A) highlights areas of mangrove recovery; B) highlights areas of coastal erosion and mangrove loss; and C) highlights areas of inland mangrove degradation, with areas of inland degradation and resulting collapse of carbon-rich peat soils from saltwater intrusion shown in the inset. Source: NASA/Goddard Space Flight Center.