3351, boul. des Forges
Most of the arctic land surface is underlined by permafrost that is highly sensitive to climate change. Infrastructures are dramatically affected by permafrost thawing caused by global warming. Permafrost thawing can also increase soil carbon emissions to the atmosphere, affecting climate with increasing global temperature. Predicting future permafrost state is thus important to assess possible disturbances to northern infrastructures and for ecosystem management and protection.
Assessments of climate change impacts on arctic ecosystems are typically investigated at large spatial scales. However, the permafrost response to climate change may be highly site-specific, depending on complex interactions between soils, vegetation and snow at small spatial scales (< 100 m), which can buffer large-scale climate change. For example, large vegetation changes have been detected in the Arctic, but trends are ambiguous (greening vs browning) and relate to site-specific changes in hydrology. Understanding the nature of these interactions is essential for better projecting the future state of arctic ecosystems, permafrost feedbacks on climate (carbon release), as well as the risks related to permafrost degradation.
The overall objective of this project is to assess the impacts of climate change on a high-arctic tundra environment in Bylot Island, Nunavut. The following specific objectives will be pursued:
To achieve these objectives, field data collection campaigns will take place between 2018 and 2020 at the study site on Bylot Island. The spatial heterogeneity and interactions between ground surface temperature (GST), moisture, and vegetation will be studied using a network of 100 temperature loggers installed at the soil surface as well as two vertical profiles, supplemented by manual measurements, over a two-year period. The snow cover duration will be derived from the analysis of temperature loggers while snow depth will be measured manually in the field. Field surveys will be complemented with aerial surveys of surface temperature and snow cover using an unmanned aerial vehicle (UAV). The data will be analysed to study the soil-snow-vegetation interactions at the site. Then, using the hydrological GEOTOP model (Gubler and Endrizi 2013) and the collected field data, we will investigate the response of the snow cover to future changes in air temperature and precipitation. Using the same model, we will next investigate the response of soil moisture and vegetation to the same climate scenarios.