Short-term effect of restoration on vegetation change and methane emissions from peatlands drained for forestry in southern Finland

Abstract

Methane (CH₄) fluxes from fixed sample plots in a minerotrophic fen and an ombrotrophic bog in southern Finland were measured by using a static chamber technique 1 year before and 2 years after a rewetting treatment. Methane emissions rose with rising water table after rewetting from 0.1 to 2.1 g ·m^-2 ·a^-1 at the fen site and from 0.8 to 4.6 g ·m^-2 ·a^-1 at the bog site but remained at a lower level than emissions from similar pristine site types. At the fen site the emissions were related to the short-term succession of cottongrass (Eriophorum vaginatum L.). Emissions showed high spatial and temporal variation with high emission peaks at the bog site. Temporal fluctuation of the emissions during the measurement season (from the end of May to the end of September) was correlated with peat temperature, while the seasonal fluxes were dependent on the moisture conditions in different microsites.