HR: 0830h
AN: B31C-0308    [PDF]
TI: Effect of {\it Eriophrum} spp. on Methane Emission and Methane Production Potential in a Melt Feature Within the Discontinuous Permafrost Region of Northern Alberta, Canada
AU: * Harrison, M D
EM: mdhh2o@aol.com
AF: Christopher Newport University, Dept. Biology 1 University Place, Newport News, VA 23606 United States
AU: Whiting, G J
EM: gwhiting@cnu.edu
AF: Christopher Newport University, Dept. Biology 1 University Place, Newport News, VA 23606 United States
AB: Increasing temperatures in northern latitudes have led to the development of collapse scars which are formed as the ice below the permafrost melts allowing the surface peat to sink, creating a wet depression. Collapse scars are {\it Sphagnum} dominated bogs, which may contain vascular wetland plant species. Some vascular plant species are associated with increased CH$_{4}$ fluxes from wetlands. This experiment was designed to determine the effect of {\it Eriophrum} spp. (cotton grass) on methane (CH$_{4}$) emission from these collapse scars. Surface CH$_{4}$ emission and CH$_{4}$ production potentials from core incubations were determined at the peak of methane flux for the growing season, August 2003. Surface fluxes were determined by using a static chamber technique, while CH$_{4}$ production potential was determined by taking 60cm cores and incubating representative slices at 10cm intervals in sealed anaerobic flasks. Headspace samples were taken every 12hr for 48 hours to determine rate of CH$_{4}$ production. Emission measurements of eight surface plots, four containing moss-only and four with moss and {\it Eriophrum}, indicated significantly higher CH$_{4}$ emitted from the {\it Eriophrum} plots (4.61 mg CH$_{4}$ m$^{-2}$h$^{-1}$ ($\pm$2.41 S.D.)) than from moss-only plots (1.16 mg CH$_{4}$ m$^{-2}$h$^{-1}$ ($\pm$0.85 S.D.)) (ANOVA, $\alpha$= 0.05). For production potential, twelve cores were taken; six in the middle of {\it Eriophrum} tussocks, and six in areas with only moss on the surface. We hypothesized that {\it Eriophrum} peat would have increased CH$_{4}$ production over the moss-only peat. Core collection and incubation showed very little difference in CH$_{4}$ production potential between the two areas. Mean CH$_{4}$ production potential was slightly greater in the top 30cm of the {\it Eriophrum} peat as compared to the moss-only sites. Below this depth, moss-only peat produced slightly more CH$_{4}$ than peat from {\it Eriophrum} sites. It is possible that {\it Eriophrum} root exudates at the 10 to 30cm depth (region of peak production) along with the ability of their vascular tissues to provide a conduit for CH$_{4}$ may contribute to the increased CH$_{4}$ production and emission observed in these melt features.
DE: 1600 GLOBAL CHANGE (New category)
DE: 1615 Biogeochemical processes (4805)
DE: 1851 Plant ecology
DE: 1890 Wetlands
SC: Biogeosciences [B]
MN: 2003 Fall Meeting