2019 journal article

Carbon storage potential in a recently created brackish marsh in eastern North Carolina, USA


By: Y. Shiau, M. Burchell n, K. Krauss*, S. Broome n & F. Birgand n

author keywords: Carbon sequestration; Greenhouse gas emissions; Brackish marsh creation; Ecosystem services
UN Sustainable Development Goal Categories
13. Climate Action (Web of Science)
14. Life Below Water (Web of Science)
15. Life on Land (OpenAlex)
Source: Web Of Science
Added: January 28, 2019

Carbon (C) sequestration through accumulated plant biomass and storage in soils can potentially make wetland ecosystems net C sinks. Here, we collected GHG flux, plant biomass, and litter decomposition data from three distinct vegetation zones (Spartina alterniflora, Juncus roemerianus and Spartina patens) on a 7-year-old created brackish marsh in North Carolina, USA, and integrate these data into an overall C mass balance budget. The marsh fixed an average of 1.85 g C m−2 day−1 through plant photosynthesis. About 41–46% of the fixed C remained in plants, while 18.4% of the C was decomposed and released back to the atmosphere as CO2 and CH4, and 8.6–13.2% of the decomposed C was stored as soil C. In all, this created marsh sequestered 28.7–44.7 Mg CO2 year−1 across the 14 ha marsh. Because the brackish marsh emitted only small amounts of CH4 and N2O, the CO2 equivalent emission of the marsh was −0.87 to −0.56 g CO2-eq m−2 day−1, indicating the marsh has a net effect in reducing GHGs to the atmosphere and contributes to cooling. However, resultant CO2 credit (through the increment of soil C) would be worth only $30.76–$47.90 USD per hectare annually, or $431–$671 per year for the project, which, coupled with other enhanced ecosystem services, could provide landowners with some additional economic incentive for future creation projects. Nevertheless, C mass balance determinations and radiative cooling metrics showed promise in demonstrating the potential of a young created brackish marsh to act as a net carbon sink.