Decadal‐scale recovery of carbon stocks after wildfires throughout the boreal forests

• Main Authors: Palviainen M., Laurén, A., Pumpanen, J., Bergeron,Y., Bond-Lamberty, B., Larjavaara, M., Kashian, D. M., Köster, K., Prokushkin, A., Chen, H. Y. H., Seedre, M., Wardle, David A., Gundale, M. J., Nilsson, M. C., Wang, C., Berninger, F.
• Other Authors: Asian School of the Environment
• Format: Article
• Language: English
• Published: 2021
• Subjects: Science::Geology; Carbon Accumulation; Carbon Pools
• Online Access: https://hdl.handle.net/10356/148675
• Institution: Nanyang Technological University

Boreal forests store 30% of the world's terrestrial carbon (C). Consequently, climate change mediated alterations in the boreal forest fire regime can have a significant impact on the global C budget. Here we synthesize the effects of forest fires on the stocks and recovery rates of C in boreal forests using 368 plots from 16 long‐term (≥100 year) fire chronosequences distributed throughout the boreal zone. Forest fires led to a decrease in total C stocks (excluding mineral soil) by an average of 60% (range from <10% to >80%), which was primarily a result of C stock declines in the living trees and soil organic layer. Total C stocks increased with time since fire largely following a sigmoidal shape Gompertz function, with an average asymptote of 8.1 kg C m−2. Total C stocks accumulated at a rate of 2–60 g m−2 yr−1 during the first 100 years. Potential evapotranspiration (PET) was identified as a significant driver of C stocks and their post‐fire recovery, likely because it integrates temperature, radiation, and the length of the growing season. If the fire return interval shortens to ≤100 years in the future, our findings indicate that many boreal forests will be prevented from reaching their full C storage potential. However, our results also suggest that climate warming‐induced increases in PET may speed up the post‐fire recovery of C stocks.