Post-ﬁre soil carbon emission rates along boreal forest ﬁre chronosequences in northwest Canada show signiﬁcantly higher emission potentials from permafrost soils compared to non-permafrost soils.
A new paper by Köster et al., 2024, compared the potential effects of forest ﬁre through post-ﬁre succession on soil carbon dioxide (CO2) emission rates and soil C turnover time in two ﬁre chronosequences, one with underlying permafrost soil and the other without permafrost.
The study demonstrates that forest ﬁres have a profound inﬂuence on soil C recovery and soil C turnover both on permafrost and non-permafrost soils. In recently burnt areas the potential soil C turnover times were two times longer than in control areas (ﬁre >100 years ago). The effect of ﬁres on soil C turnover times lasted up to 25 years after the ﬁre (in permafrost areas). Although average soil C turnover times were similar in post-ﬁre permafrost and non-permafrost soils, the soil C emissions rates in permafrost areas are approximately three times higher compared to non-permafrost areas.