In boreal forests, climate warming is shifting the wildfire disturbance regime to more frequent fires that burn more deeply into organic soils, releasing sequestered carbon to the atmosphere. To understand the destabilization of carbon storage, it is necessary to consider these effects in the context of long-term ecological change. In Alaskan boreal forests, we found that shifts in dominant plant species catalyzed by severe fire compensated for greater combustion of soil carbon over decadal time scales. Severe burning of organic soils shifted tree dominance from slow-growing black spruce to fast-growing deciduous broadleaf trees, resulting in a net increase in carbon storage by a factor of 5 over the disturbance cycle. Reduced fire activity in future deciduous-dominated boreal forests could increase the tenure of this carbon on the landscape, thereby mitigating the feedback to climate warming.

在北方森林中，气候变暖正在将野火干扰机制转移到更频繁的大火上，大火更深地燃烧到有机土壤中，并向大气释放了固存的碳。要了解碳储存的不稳定，有必要在长期生态变化的背景下考虑这些影响。在阿拉斯加的寒带森林中，我们发现，严重的火灾催化的优势植物物种的转移补偿了在十年时间尺度上土壤碳的更大燃烧。严重燃烧有机土壤使树木的主导地位从缓慢生长的黑云杉转移到了快速生长的落叶阔叶树上，导致整个碳循环在干扰循环中净增加了5倍。未来以落叶为主的北方森林火灾活动的减少可能会增加碳在土地上的存续期，