Methane dynamics of a restored cut‐away peatland

We measured a cut‐away peatland's CH₄ dynamics using the static chamber technique one year before and two years after restoration (rewetting). The CH₄ emissions were related to variation in vegetation and abiotic factors using multiple linear regression. A statistical model for CH₄ flux with cottongrass cover (Eriophorum vaginatum L.), soil temperature, water level, and effective temperature sum index as driving variables explained most (r² = 0.81) of the temporal and spatial variability in the fluxes. In addition to the direct increasing effect of raised water level on CH₄ emissions, rewetting also promoted an increase of cottongrass cover which consequently increased carbon flux (substrate availability) into the system. The seasonal CH₄ dynamics in tussocks followed seasonal CO₂ dynamics till mid August but in late autumn CH₄ emissions increased while CO₂ influxes decreased. The reconstructed seasonal CH₄ exchange was clearly higher following the rewetting, although it was still lower than emissions from pristine mires in the same area. However, our simulation for closed cottongrass vegetation showed that CH₄ emissions from restored peatlands may remain at a lower level for a longer period of time even after sites have become fully vegetated and colonized by mire plants.