Projected changes in daily fire spread across Canada over the next century

Abstract

In the face of climate change, predicting and understanding future fire regimes across Canada is a high priority for wildland fire research and management. Due in large part to the difficulties in obtaining future daily fire weather projections, one of the major challenges in predicting future fire activity is to estimate how much of the change in weather potential could translate into on-the-ground fire spread. As a result, past studies have used monthly, annual, or multi-decadal weather projections to predict future fires, thereby sacrificing information relevant to day-to-day fire spread. Using climate projections from the fifth phase of the Coupled Model Intercomparison Project (CMIP5), historical weather observations, MODIS fire detection data, and the national fire database of Canada, this study investigated potential changes in the number of active burning days of wildfires by relating 'spread days' to patterns of daily fire-conducive weather. Results suggest that climate change over the next century may have significant impacts on fire spread days in almost all parts of Canada's forested landmass; the number of fire spread days could experience a 2-to-3-fold increase under a high CO 2 forcing scenario in eastern Canada, and a greater than 50% increase in western Canada, where the fire potential is already high. The change in future fire spread is critical in understanding fire regime changes, but is also imminently relevant to fire management operations and in fire risk mitigation.

Drivers of postfire soil organic carbon accumulation in the boreal forest

“…According to our results, increasing the water supply through greater amounts of precipitation could increase mineral soil C stocks through enhanced mineral weathering and leaching, releasing metal oxides that can bind to organic matter (Doetterl et al., ; Mikutta et al., ; Porras et al., ; Rumpel & Kögel‐Knabner, ). Otherwise, the projected increase in fire frequency suggested by models (Kloster & Lasslop, ; Wang et al., ; Wotton, Flannigan, & Marshall, ) could weaken the C capture function of boreal forests (Genet et al., ; Pan et al., ). Integrating direct and indirect effects of abiotic and biotic factors on C storage processes, as presented here through mechanistic models of C dynamics in boreal forest ecosystems, could improve our ability to account for C stocks and anticipate the response of boreal forests to global change.…”

Fine‐scale spatial climate variation and drought mediate the likelihood of reburning

“…In agreement with Collins et al (2009) andParks et al (2015), our results show that extreme fire weather weakens but does not completely override the self-limiting effect of fire. Nevertheless, in the context of a warming climate, our results suggest that recently burned areas will still limit subsequent fire activity, but the strength and longevity of the effect may be reduced if the frequency of fire-conducive conditions increases as anticipated (Stocks et al 1998, Wang et al 2017. As previously discussed, we suggest these discrepancies are due to differences in methods, ecosystems evaluated, and fire regime.…”

Potential impacts of climate change on the habitat of boreal woodland caribou

“…We used mapped datasets of geology, climate, terrain, and wetland class, which were first used to build a random forest model (Breiman 2001) of present-day ecosite type (details in Stralberg et al 2018); ecosite refers to specific site moisture and nutrient availability (Beckingham and Archibald 1996). These same projections were used for monthly fire weather projections, which were then temporally downscaled to daily fire weather projections for the wildfire model (Wang et al 2017). The nested model was necessary because, while soil moisture and nutrients are critical determinants of vegetation type, high-resolution ecosite maps are not available.…”

“…Climate change in the boreal region will also lead to earlier snowmelt, moderate increases in summer precipitation, and greater drought frequency (especially in western regions; Lemke et al 2007, Price et al 2013. Wang et al (2017) have projected increases between 50% and 100% in the incidence of days with fire-conducive weather in the western boreal forest, and up to 150% elsewhere in Canada. The response of boreal forest ecosystems to climate change will be complex and likely lead to the emergence of novel ecosystems (Schneider et al 2016). Wang et al (2017) have projected increases between 50% and 100% in the incidence of days with fire-conducive weather in the western boreal forest, and up to 150% elsewhere in Canada. The response of boreal forest ecosystems to climate change will be complex and likely lead to the emergence of novel ecosystems (Schneider et al 2016).…”