Wetland Soil Carbon Stocks of the Conterminous United States.

Wetland soils are an important component of global carbon cycles because they represent a significant portion of terrestrial carbon storage. Additionally, these ecosystems have the potential to accumulate and/or emit carbon at higher rates relative to upland ecosystems. Utilizing data collected as part of the National Wetland Condition Assessment (NWCA), this study aims to estimate organic carbon stocks in wetland soils across the conterminous U.S. The NWCA is a nationwide survey of the ecological condition of wetlands in the U.S. conducted by the Environmental Protection Agency (EPA) and its federal, state, and tribal partners. . The NWCA sites were selected using a probability based sample design, such that the sites selected and the results reflect the full range of wetlands in the target population. Field crews sampled 1,138 wetland sites across the U.S. during the summer of 2011, collecting data on soils, vegetation, hydrology, algae, water chemistry, and the wetland buffer. The magnitude and range of soil organic carbon stocks in wetlands, and the differences among wetland types and geographic regions will be discussed.