How do forest fires change soil temperature and permafrost in taiga regions?

In the taiga (northern forest), forest fires play a significant role in regulating soil temperature and the stability of permafrost.1

Impact on Soil Temperature

Forest fires increase soil temperatures by removing the protective layers that typically insulate the ground. Specifically, fires consume the forest canopy, the insulating moss cover, and the layer of forest litter. This removal exposes the soil to greater solar radiation. Furthermore, the presence of dark ash left behind after a fire increases the absorption of solar energy at the surface for several years. In winter, the absence of an intact canopy allows for the accumulation of a deeper, more effective insulating layer of snow, which can also influence thermal conditions.1

Impact on Permafrost

By warming the soil, forest fires can lead to the degradation or thawing of permafrost. Conversely, the development of an intact forest canopy and the accumulation of moss and litter act as a cooling mechanism that promotes the development and maintenance of permafrost. Consequently, the suppression of natural fires can cause soil temperatures to decline, which may promote the expansion of permafrost.12