Lena Ström
Professor
Cutover Peat Limits Methane Production Causing Low Emission at a Restored Peatland
Författare
Summary, in English
Peatland degradation due to human activities is contributing to rising atmospheric CO2 levels. Restoring the carbon (C) sink function in degraded peatlands and preventing further stored C losses is a key climate mitigation strategy, given the global scale of peatland disturbance. Active restoration involving a combination of rewetting and vegetation reestablishment at a post-extraction peatland in Canada has been shown to successfully re-establish net CO2 uptake rates similar to undisturbed peatlands within a decade or two. However, lower than expected CH4 emissions suggest recovery of belowground C cycling processes may lag behind the recovery of the surface net flux. Using closed chamber measurements over a warm season, we determined that restored Sphagnum, which covers two thirds of the site, was a null source of CH4. Emissions from the restored site were primarily attributed to vascular plant substrate inputs, measured as acetate, and plant-mediated transport. The C isotopic fractionation factor for CH4 and CO2 in the pore water from the restored former peat field suggested reduced hydrogenotrophic CH4 production deeper in the cutover peat profile (0.8 m depth). In contrast, isotopic fractionation in the former drainage ditches showed a balance of acetoclastic and hydrogenotrophic methanogenesis deeper in the profile, indicative of some bulk peat C turnover. This study suggests that the legacy of substrate quality in the cutover peat can reduce the climate warming impact of newly restored peatlands through a reduction in CH4 production and thus emission.
Avdelning/ar
- Institutionen för naturgeografi och ekosystemvetenskap
- BECC: Biodiversity and Ecosystem services in a Changing Climate
Publiceringsår
2021-12
Språk
Engelska
Publikation/Tidskrift/Serie
Journal of Geophysical Research: Biogeosciences
Volym
126
Issue
12
Dokumenttyp
Artikel i tidskrift
Förlag
Wiley
Ämne
- Physical Geography
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 2169-8953