Differences in methane production, storage and transport among plant community types during a wet summer at Mer Bleue bog, Ottawa

This study assessed indicators of methane (CH4) production, storage and transport among plant community types to investigate the spatial and temporal variability in CH4 dynamics during a wet summer at the Mer Bleue bog. Community type was largely differentiated by sedge (Eriophorum vaginatum) presence, which increased as the average water table depth approached the surface. Stable isotope analysis identified CO2 reduction as the dominant methanogenic pathway in all plots, but with more depleted source signatures as percent Eriophorum increased, possibly due to CH4 transport via aerenchymatous tissues. Increasing peat temperature contributed to increasing CH4 concentrations at 50 cm, near the long-term average water table, and dissolved organic carbon and total dissolved nitrogen at all depths, and a seasonal increase in chamber CH4 emissions. Plant community did not relate to spatial differences in pore water characteristics, but increasing percent Eriophorum was associated with greater CH4 emissions.