Fire-Induced Carbon Loss and Tree Mortality in Siberian Larch Forests

Abstract

Climate change is intensifying the fire regime across Siberia, with the potential to alter carbon combustion and post-fire carbon re-accumulation trajectories. Few field-based estimates of fire severity (e.g., carbon combustion and tree mortality) exist in Siberian larch forests (Larix spp.), which limits our ability to project how an intensified fire regime will affect regional and global climate feedbacks. Here, we present field-based estimates of fire-induced tree mortality and carbon loss in eastern Siberian larch forests. Our results suggest that fires in this region result in high tree mortality (means of 83% and 76% at Arctic and subarctic sites, respectively). In both absolute and relative terms, aboveground carbon loss following fire is higher in Siberian larch forests than in North America, but belowground carbon loss is considerably lower. This suggests fundamental differences in wildfire behavior and carbon dynamics between dominant vegetation types across the boreal biome.