The evolution of permafrost in the taiga and in the forest–tundra, western Quebec–Labrador Peninsula

• Published in: Canadian Journal of Forest Research
• Main Authors: Payette, Serge, Samson, Hélène, Lagarec, Daniel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1976
• Subjects: Ecology; Forestry; Global and Planetary Change; Hudson Bay; Hudson; palsa; palsas; Peat; permafrost; taiga; Thermokarst; Tundra; James Bay
• Online Access: http://dx.doi.org/10.1139/x76-026; http://www.nrcresearchpress.com/doi/pdf/10.1139/x76-026

Major permafrost landforms of the discontinuous permafrost zone of Hudson Bay and James Bay, Quebec–Labrador Peninsula, are described and interpreted within an ecological perspective. These landforms are not fossil permafrost bodies; they are presently evolving under aggrading and degrading developmental stages. Permafrost peat complexes and permafrost mineral complexes are differentially distributed in the midtaiga, the forest–tundra, and the shrub–tundra zones of the study area. The wooded palsa complex is the most obvious permafrost complex in the midtaiga, and the palsa complex in the forest–tundra: The wooded palsa complex is related to the forest chronosequence, whereas the palsa complex, farther north, occurs where there is a suitable macroclimate for permafrost aggradation without the influence of cool forest microclimate. The wooded cryogenic mound complex in mineral landform is mainly distributed in the southern section of the forest–tundra and near the Hudson Bay shore; the cryogenic mineral mound complex is found in the northern section. The latitudinal shift of the northern complex is necessary for permafrost initiation in open sites. Degrading stages associated with thermokarst activity are similar for all these landforms and it is suggested that palsa complex is made of incipient, mature, and residual palsas whether they belong to palsa mounds or to peat plateaus. Similar conclusions are valid for cryogenic mineral mound complex.