Peatland methane emissions and influencing environmental factors in the southern fringe of the discontinuous permafrost zone, Fort Simpson, Northwest Territories

• Main Author: Liblik, Laura K. (Laura Kaarin)
• Other Authors: Moore, T. R. (advisor)
• Format: Thesis
• Language: English
• Published: McGill University 1996
• Subjects: Peatlands > Northwest Territories > Fort Simpson Region; Atmospheric methane > Northwest Territories > Fort Simpson Region; Water table > Northwest Territories > Fort Simpson Region; Greenhouse gases > Environmental aspects > Northwest Territories > Fort Simpson Region; Fort Simpson; Northwest Territories; permafrost
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=24020

A static chamber technique was used to measure methane emissions in July and August, 1995 from peatland sites in the Fort Simpson area, Northwest Territories, at the southern fringe of the discontinuous permafrost zone. Sites were classified ecologically and geomorphologically, and water table and temperature regimes were monitored. Methane emissions ranged from $-$3.3 to 1144.2 mg/m$ sp2 cdot$d, from raised frozen sites to pond sites, respectively, similar to emissions recorded from other boreal regions. Water table was the strongest predictor of CH$ sb4$ emission. Although peat temperature is significantly correlated to methane flux, it did not significantly improve the flux-water table relationship. Methane storage within the saturated portion of the peat profile ranged from 0.2 to 4.2 g/m$ sp2$ over depths ranging from 30 to 76 cm, and did not play a large role in surficial emissions. The zone immediately above and below the water table appears to regulate methane diffusion to the surface. Residence times (storage/flux) ranged from 12 to 30 days in poor fens, and from 6 to 5789 days in fens. Ranges and mean fluxes of methane were determined according to landform and water table position. Based on the geomorphology of the area, overall flux determined for the Fort Simpson area, map NTS 95H, NW1/4, is estimated to be 19 mg/m$ sp2 cdot$d.