Carbon and water vapour fluxes for the first two years of a constructed wetland.

English Abstract:

The Sandhill Fen Watershed project is a pilot study by Syncrude Canada Ltd. involving the construction of a 50 ha mixed upland (forested) and lowland (wetland) watershed. The project is the first large scale attempt in constructing a boreal peatland and as such will help assess certification for mine closure. The physical construction was completed in 2012 with the initial re-vegetative planting occurring in the same year. In 2013 pumps were used to simulate ground water through-flow and in 2014 the pumps were disengaged to allow the system to naturally respond. Throughout this period the vegetation, both planted and colonized, developed a substantial cover over soil and peat substrates. This study contrasts the first two years of atmospheric energy, water, and carbon fluxes to the atmosphere during the wetland ecosystem’s initial development. In 2013 there was a net loss of carbon from the lowland regions, but by 2014 the carbon balance was almost neutral. Evapotranspiration from the ecosystem also increased over the same period. As the lowlands mature, energy and carbon fluxes appear to be shifting towards what is observed in naturally formed boreal peatlands. Furthermore, over the two years, and despite high concentrations of sulphur, preliminary evidence suggests that methanogenic communities appear to be establishing in the wetland.