Introduction
Boreal peatlands of Western Canada
Boreal peatland ecosystems occupy less than 3% of the earth's land surface, yet store between 250 and 455 Pg of C, which is roughly 20%–30% of the world's soil carbon (Gorham 1991; Charman 2002; Joosten & Clarke 2002; Vasander & Kettunen 2006). In continental western Canada, peatlands cover 365,157 km2 (Vitt et al. 2000) and dominate the landscape in northern Alberta, Saskatchewan, and Manitoba (Tarnocai 1984, 1998; Vitt et al. 2000; Tarnocai et al. 2005). Overall, these western Canadian peatlands have sequestered about 48 Pg of C during the past 10,000 years, with about half of this peat accumulated in the past 4000 years (Vitt et al. 2000). Peatlands provide a wide diversity of ecosystem services, not the least of which is the conversion of atmospheric CO2 into large accumulations of stored organic carbon (C) – a testament to the long-term function of these ecosystems as net C sinks since their widespread initiation after the most recent glacial retreat (Halsey et al. 2000). Bryophytes typically are dominant components of the vegetation in northern peatlands and play central roles with regard to nutrient cycling and carbon accumulation.
The initiation, development, succession, and rate of peat accumulation in boreal peatlands are dependent on regional factors such as climate, substrate chemistry, landscape position, and hydrological regime.