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CMOS Virtual Luncheon Meeting – Thursday October 22, 2020
October 22, 2020 @ 12:00 - 14:00
SPEAKER: Dr. Jean Holloway, postdoctorate fellow, University of Ottawa and Chair of APECS Canada (Association of Polar Early Career Scientists)
TITLE: Impacts of wildfire on permafrost in the boreal forest of northwestern Canada
ABSTRACT: Climate change is causing increases in the frequency, severity, and extent of fires, which is expected to change how permafrost responds and recovers after disturbance. There is a pressing need to better understand how certain variables affected post-fire permafrost dynamics in a changing climate. This was addressed through in-situ measurements and analysis of permafrost conditions following fires occurring over the last half century along a 650 km latitudinal transect spanning the discontinuous zones, from isolated patches to extensive discontinuous permafrost. Overall, the findings suggested that there has been significant permafrost degradation, due to both climate warming in the region and fire, especially at sites with thin organic layers, low gravimetric moisture content, and coarse-grained soils. Degradation also occurred at high ice-content sites, where ground subsidence and thermokarst develop, particularly in severely burned areas. However, permafrost persisted at sites where black spruce canopies with organic layers generally 40 cm thick overlie fine-grained sediments. Post-fire permafrost change occurred at sites which burned in the last 10 years, but over the long-term, frozen ground appeared resilient to fire, with characteristics like active layer thickness returning to pre-fire levels. However, this may change in the future as the climate continues to warm and the fire regime shifts. This research underlines the importance of monitoring and modelling a variety of landscape types to establish post-fire permafrost impacts, and more specifically the effects of heterogeneity of drainage conditions, substrate, and organic layer thicknesses on the fate of permafrost in the boreal forest.
Jean Holloway is a Postdoctoral Fellow in the Environment, Society, and Policy group at the University of Ottawa, and her research interests are broadly focused on determining how climate change is impacting the cryosphere in the Canadian Arctic and Subarctic. She recently completed her Ph. D. at the University of Ottawa, identifying the impacts of forest fire on permafrost in the discontinuous zones of northwestern, Canada. Prior to her work at the University of Ottawa, she completed a M. Sc. at Queen’s University, where she mapped and identified permafrost thaw features, and fell in love with the North. She is the current Chair of the Canadian National Committee for the Association of Polar Early Career Scientists, and is very passionate about science communication and outreach. For her postdoc, Jean will be shifting fields and looking at the impacts of sea ice decline and subsequent increases in Arctic shipping.
Visit the CMOS website www.cmos.ca to register (free) to have the Zoom link for the forum/discussion sent to you. The proceedings will be recorded live and available to the general public on the CMOS website at a later date.