Suncor Pilot Fen Program

The Suncor Pilot Fen Program was initiated to validate the Price et al. (2007, 2009) model recommendations, and examine whether a dominant landscape feature on Suncor’s lease, the fen, can be constructed in an oil sands post-mined landscape. The project will assess success of constructed fen design through detailed examination of hydrological functioning, biogeochemical interactions and progression of the ecology at the site post‐construction. Concurrently, a series of reference fen (RF) systems are being characterized to provide background understanding of range and variability of ecohydrological characteristics of natural fens in the region and evaluate success of the constructed system. Broad‐scale objectives are to: (1) identify strengths and weaknesses in the conceptual fen design; (2) test the method for construction including materials, their placement and the sensitivity of design characteristics through modelling of water and contaminant flows; (3) develop thresholds and milestones for hydrological, water quality and carbon sequestration rates or thresholds as monitoring tools; and (4) determine the most suitable vegetation communities and reintroduction methods for fen reclamation.

Brief summary of results to date: CH4 flux greater in hollows than hummocks. Highest fluxes at poor and rich fen, lower values at treed and saline fen. Water table controls CH4 flux, particularly when near‐surface. No significant relationship between soil temperature and CH4 flux. CH4 production linked to site chemistry and water table. Evapotranspiration largely controlled by vegetation on ridges. Microclimate is the predominant control on rates of evapotranspiration at the saline fen. Brown mosses have reduced moisture retention capacity compared to Sphagnum and are reliant on lower potential evaporation to retain moisture. For brown mosses, excluding precipitation has greatest effect on reducing evaporation and CO2 sequestration. For Sphagnum mosses, free drainage has greatest effect. Survival above 90% for moss plug establishment for all species. Fabric cover improves survival for plugs. Phosphate fertilizer increased percent cover in diaspore plots. Water table in the vegetation trenches averaged between 4 cm above and 14 cm below surface, with decreased survival rates when water table lay outside this range. No trend was determined between water table, fertilizer and species percent cover. Significant water table and flow pattern variability exists within and between sites.