Temperate and boreal forest mega‐fires: characteristics and challenges

Abstract

Mega‐fires are often defined according to their size and intensity but are more accurately described by their socioeconomic 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 emulate 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.

Climate Change Refugia, Fire Ecology and Management

“…Large, severe fire was evident in the 2013 Rim Fire, which burned over 100,000 ha, impacting a noticeable portion of our study area [60]. Refugia that historically have had physical and climatic barriers to fire may be more susceptible to high-severity mega-fires becaue they produce effects well outside of desired ranges [20].…”

“…Refugia fire occurrence will likely increase relative to historical levels due to the combination of fire suppression and climate change induced extreme fires or mega-fires [20,71]. Even as fire risk/frequency increases, refugia are likely to maintain distinct fire regimes relative to surrounding areas.…”

“…While overall temperatures are warming, the weather patterns that produce cold-air pooling at a landscape scale Fire is one example of a changing ecological process. Fire frequency and severity are changing world-wide due to land management [16][17][18][19][20] and climate change [19,[21][22][23]. Refugia populations are at a greater risk from changing fire patterns [21] due to their predisposition to local extinction because of their small, isolated nature, especially if the plants are fire avoiders [24].…”

Ectomycorrhizal fungal spore bank recovery after a severe forest fire: some like it hot

“…With evergreen vegetation maintained during an extended summer dry season, fire is inevitable (Noss et al, 2006). However, decades of fire suppression coupled to earlier spring snowmelt (Westerling et al, 2006) have changed the fire regime in some forest types from frequent, low-intensity events that cause little canopy death, to infrequent, large conflagrations termed 'mega-fires' that kill most of the trees (Stephens et al, 2014). Forest recovery in these radically altered post-fire environments may be constrained by distance to seed sources, extremes in microclimate and the absence of a mycorrhizal network (Stephens et al, 2014;Suz et al, 2015).…”

Forgetting fire: Traditional fire knowledge in two chestnut forest ecosystems of the Iberian Peninsula and its implications for European fire management policy

“…afforestations, conservation areas, recreational hunting estates, etc.) and the prohibition of traditional land use practices such as extensive animal husbandry and swidden agriculture (Fernandes et al, 2014) These changes shifted rural economies away from approaches that required the use of TFK-based practices and therefore contributed to rural abandonment (Seijo and Gray, 2012;Stephens et al, 2014). It is important, therefore, to re-evaluate the fire management potential of TFK-based practices, particularly since continent-wide European Union funded research projects such as FIRE PARADOX are calling for a reform of present fire suppression based management strategies and advocating for the promulgation of new European legislation on the matter in the form of a "Fire Framework Directive" .…”