Determining Carbon Dioxide Emission Response in Soil Microcosms from a Shallow Mid-Atlantic Peatland: The Influence of Water Table Restoration

Johnson, A.M.; Atkinson, R.B.; Steven, J.C.; Whiting, G.; Napora, K.; Sharrett, L., and Mirda, C., 2022. Determining carbon dioxide emission response in soil microcosms from a shallow mid-Atlantic peatland: The influence of water table restoration. Journal of Coastal Research, 38(2), 261–268. Coconut Creek (Florida), ISSN 0749-0208. Determining carbon dioxide emission response in shallow microcosms from a shallow mid-Atlantic peatland: The influence of water table restoration. Peatlands provide ecosystem services such as pollution filtration, flood control, and carbon storage as these ecosystems contain 33% to 50% of the global soil carbon pool. Reestablishing soil saturation in degraded peatlands can limit microbial oxidation of organic matter; however, drainage history may alter soil saturation patterns and challenge restoration efforts. The purpose of this study was to investigate carbon emission response to water table restoration for two shallow peatlands including a Histosol and an Ultisol with divergent drainage histories. Soil cores were gathered from the top 22.5 cm of organic-rich surface horizons within Cavalier Wildlife Management Area in Chesapeake, Virginia. Cores were randomly assigned to four water level treatments that simulated restoration conditions, and carbon dioxide emissions were measured using an LI-6400XT portable open-flow photosynthesis system twice a week for 4 weeks. Despite higher organic matter content in the long-drained site, emissions (2.1 to 3.9 µmol CO2 m–2 s–1) were higher than at the historically less drained site (1.5 to 2.3 µmol CO2 m–2 s–1). Volumetric water content trends revealed that longer-drained soils retained lower water content within restoration treatments and were associated with higher carbon emissions. Restoration of long-drained peats in the mid-Atlantic region may require higher water tables than otherwise predicted to overcome a resistance to rewetting where limiting microbial soil respiration is a management objective.