Abstract
Boreal peatlands serve as long-term carbon (C) sinks and a significant source of methane (CH(4)) to the atmosphere. However, peatlands are threatened by both natural and anthropogenic disturbances, resulting in potential release of large amounts of C to the atmosphere. Linear disturbances, such as seismic lines for geologic exploration, constitute the largest area of disturbance in boreal Canada. The impact of seismic lines on peatland C cycling is not well understood, although physical changes in topography and lack of tree re-establishment are well-documented. This study used the closed chamber technique to measure growing season understory CH(4) fluxes on the footprint of the seismic line disturbance and in adjacent intact peatlands and assessed environmental controls on CH(4) dynamics across a treed fen and two treed bogs near Peace River, Alberta, Canada. Seismic lines were significantly warmer and wetter providing ideal conditions for increased CH(4) emissions at all sites. Methane emissions relative to natural areas were almost tripled in the bog sites (261-308 %) and close to double in the fen (176 %). These results will contribute to accurate greenhouse gas reporting for anthropogenic disturbances in boreal peatlands and provide a scientific foundation for practices and policies related to peatland restoration.