The Legacy Carbon Collaborative: a network to assess the impacts of wildfires on the long-term carbon storage of boreal and tundra ecosystems

Abstract:

One of the most rapid pathways through which climate warming could alter the structure and function of high northern latitude ecosystems is through intensification of wildfire disturbance. Here, we plan to investigate the impacts of intensifying wildfire regimes on the long-term carbon (C) storage of boreal and tundra ecosystems. More severe and frequent wildfires can shift northern ecosystems across a C cycle threshold: from a net accumulation of C from the atmosphere over centuries and fire cycles to a net loss. This shift can occur when organic soil C that escaped burning in previous fires or that has accumulated over centuries, termed ‘legacy carbon’, combusts. We know that more frequent wildfires can lead to legacy C loss and expect that this will vary with fire severity and soil drainage, primary factors shaping C storage in high latitude ecosystems. Here, we propose to determine the frequency of legacy C loss across a diverse array of ecosystems throughout the circumpolar region. We have developed an organic soil collection protocol and are currently collaborating with 12 distinct research groups with sites across North America, Europe, and Russia. Each research group has agreed to collect and send soil samples from 10 recently burned forest or tundra sites within their respective study regions. At Northern Arizona University, we will use radiocarbon dating to assess legacy C presence and combustion and hold a data synthesis workshop for all collaborators. We invite anyone interested in participating in the Legacy Carbon Collaborative to contact Xanthe Walker at Northern Arizona University (email: xanthe.walker@gmail.com).