The recent increases in fires across Alaska sparks questions of the variable impacts of fires, particularly in areas with and without permafrost. This study examines the short- and long-term effects of forest fires on soil thermal dynamics. Researchers examine case studies from both boreal and tundra forest fires and the biggest difference between the effects can be seen in the soil when there was permafrost present. When forest fires occurred in areas with permafrost, the permafrost underlying the active layer soil mitigated the damage done by fires. Measured by the thickness of the soil organic layer and soil conductivity, researchers determined that forest fires had significantly less impact on soil temperature increases due to permafrost.
The layer of permafrost insulated the active layer soil from dehydration, leading to lower levels of drainage, moisture loss, and vegetation flammability. All of these effects are reversed when there is no permafrost layer to provide protection to the soil. Importantly, studies like these allow scientists to better predict the impact of tundra and boreal forest fires in areas with or without permafrost.
