Permafrost vulnerability to climate change may be underestimated unless effects of wildfire are considered. Here we assess impacts of wildfire on soil thermal regime and rate of thermokarst bog expansion resulting from complete permafrost thaw in western Canadian permafrost peatlands. Effects of wildfire on permafrost peatlands last for 30 years and include a warmer and deeper active layer, and spatial expansion of continuously thawed soil layers (taliks). These impacts on the soil thermal regime are associated with a tripled rate of thermokarst bog expansion along permafrost edges. Our results suggest that wildfire is directly responsible for 2200 ± 1500 km2 (95% CI) of thermokarst bog development in the study region over the last 30 years, representing ~25% of all thermokarst bog expansion during this period. With increasing fire frequency under a warming climate, this study emphasizes the need to consider wildfires when projecting future circumpolar permafrost thaw.
Related Resources
Tree Regeneration on Industrial Linear Disturbances in Treed Peatlands is Hastened by Wildfire and Delayed by Loss of Microtopography
Resource Date:
July
2020
Organization
Quantification of Lichen Cover and Biomass Using Field Data, Airborne Laser Scanning and High Spatial Resolution Optical Data—A Case Study from a Canadian Boreal Pine Forest
Resource Date:
2020
Organization
Large Stocks of Peatland Carbon and Nitrogen are Vulnerable to Permafrost Thaw
Resource Date:
August
2020
Organization
Increasing Contributions of Peatlands to Boreal Evapotranspiration in a Warming Climate
Resource Date:
June
2020
Organization
Evaluation of Threshold Freezing Conditions for Winter Road Construction over Discontinuous Permafrost Peatlands, Subarctic Canada
Resource Date:
February
2020
Organization
Foestland-Peatland Hygrologic Connectivity in Water-Limited Environment: Hydraulic Gradients Often Oppose Topography
Resource Date:
February
2020
Organization
Was this helpful?
|