Temperate and boreal forest mega-fires: characteristics and challenges

Mega-fires are often defined according to their size and intensity but are more accurately described by their socio- economic impacts. Three factors – climate change, fire exclusion, and antecedent disturbance, collectively referred to as the “mega-fire triangle” – likely contribute to today’s mega-fires. Some characteristics of mega-fires may emu- late historical fire regimes and can therefore sustain healthy fire-prone ecosystems, but other attributes decrease ecosystem resiliency. A good example of a program that seeks to mitigate mega-fires is located in Western Australia, where prescribed burning reduces wildfire intensity while conserving ecosystems. Crown-fire-adapted ecosystems are likely at higher risk of frequent mega-fires as a result of climate change, as compared with other ecosystems once subject to frequent less severe fires. Fire and forest managers should recognize that mega-fires will be a part of future wildland fire regimes and should develop strategies to reduce their undesired impacts.