Methane emissions from wetlands in the zone of discontinuous permafrost: Fort Simpson, Northwest Territories, Canada

We examined the influence of water table position, temperature, vegetation, and CH4 storage on CH4 flux at 22 wetland sites located in the zone of discontinuous permafrost, near Fort Simpson, Northwest Territories. Sites ranged from frozen peat plateaux and palsas with collapse scars to fens and bogs and ponds. Mean summer CH4 emissions ranged from −1.3 to 255 mg m−2 d−1, and the variation among sites was best explained by mean water table position (r2 = 0.62, n = 19). Large CH4 fluxes (>30 mg m−2 d−1) and high water tables occurred in ponds and graminoid sites, whereas small fluxes (