Susceptibility of peatland permafrost in coastal Labrador to future environmental change

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Perennially frozen soil or rock (permafrost) is a critical component of northern ecosystems, altering local hydrology, vegetation and wildlife usage. Permafrost is also the only element of the terrestrial cryosphere that allows communities and infrastructure to be permanently situated on it. Thawing of ice-rich permafrost can lead to structural damage to infrastructure and degradation of current ecosystems through subsidence and hydrological changes. A recent concern is the potential release of greenhouse gases stored in permafrost in the Arctic but also in perennially frozen Subarctic peatlands. In northern Canada, it is expected that peatland permafrost will thaw in most of the southern half of the country over the next century. This could mobilize large quantities of carbon into the atmosphere and impact local ecosystems, but several recent studies showed that peatland permafrost may be less vulnerable to climate change than originally expected. Consequently, there is considerable debate as to how and where permafrost thaw may occur in Canada in the future, and ultimately how much impact this will have on a regional basis. In coastal Labrador, peatland permafrost occurs in clusters along the entirety of the >1000 km coastline. However, a lack of prior studies on permafrost in Labrador means that the abundance of these unique environments on the landscape and their vulnerability to future warming is largely unknown. This proposal aims to characterize the distribution of peatland permafrost in coastal Labrador and to assess historical and future changes to permafrost affected peatlands that could be caused by climatic and other ecosystem modifiers. This research program will combine extensive field data collection, climate monitoring, remote sensing analysis and numerical modelling to enhance our understanding of peatland permafrost susceptibility to future warming. It will also quantify carbon quantities currently stored in frozen peatlands in the region thus contributing to global carbon cycle inventorying. On a local-scale, peatland permafrost environments are found adjacent to housing and infrastructure in two communities and are expected to occur along potential road routes north proposed for the region. Peatland permafrost environments are also locally important to Indigenous and non-Indigenous Peoples in coastal Labrador because they are commonly used for hunting, trapping and berry picking. The latter includes culturally valued cloudberry (`apik' in Inuktitut) which are abundant on permafrost mounds but rarely found in wetter depressions formed post permafrost thaw. Changes to the permafrost distribution in these peatlands may thus have consequences on human foraging potential and local wildlife. Through the execution of this research program knowledge gained will contribute to local ecological integrity and environmental assessment and to national and international efforts to quantify permafrost thaw and carbon stocks.