Fig. 5.
Effect of wildfire on permafrost thaw through development of young thermokarst bogs in western Canadian peatlands. a Current-day coverage of young thermokarst bogs in burned and unburned sections within four peatlands partially affected by wildfire 20–30 years ago. Box plots indicate median, interquartile range, and minimum and maximum young thermokarst bog coverage among classified 250 × 250 m sections, with number of classified sections indicated (n). A pairwise t-test showed a significant (p < 0.01) effect of fire on young thermokarst bog coverage. Sites are ordered left to right by likely decreasing mean annual air temperature, see text for justification. b Estimated historical development currently present young thermokarst bogs within peatlands in the study region. Young thermokarst bogs persist for 60–140 years before succession into mature thermokarst bogs17, suggesting that a significant proportion of young thermokarst bogs currently present developed prior to the more recent fires. Thermokarst bog development rates are stated with 95% CI (Methods), which are also indicated by shading