Résumé - CAFD

Decadal-Scale Recovery of Carbon Stocks After Wildfires Throughout the Boreal Forests.

Marjo Palviainen, A. Laurén, J. Pumpanen, Yves Bergeron, B. Bond-Lamberty, M. Larjavaara, D.M. Kashian, K. Köster, A. Prokushkin, Han Chen, M. Seedre, David A. Wardle, M. J. Gundale, Marie-Charlotte Nilsson, C. Wang, Frank Berninger.

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.