Table 3. Drivers of flammability.

Community Agency National
Regional Science
General Vegetation, fuels, weather Vegetation, fuels, weather, topography Fuel, weather, topography (Countryman 1972)
Regional Vegetation, fuel, weather (Chapin et al. 2006, Kasischke and Turetsky 2006, Abatzoglou and Kolden 2011)
Climate Change Observed increases in landscape flammability due to warmer winters and summers and a drying landscape Climate change not addressed FLAME Act (2009): recognition only, not specific as to actions (H.R. 2996 2009) Interior Alaskan boreal forest landscapes experiencing reduction in surface water (Riordan et al. 2006)

Boreal forest browning has been detected, possibly due to drought stress and insect infestations (Verbyla 2011)

Increased area burned and large-fire seasons (Kasischke and Turetsky 2006, Kasischke et al. 2010)

Changing fire severity and burning patterns (Kolden 2010)

Time Since Wildfire Varying responses. FMP implies wildfires reduce risk of future catastrophic wildfire HFI/HFRA: Suppression increases risk of catastrophic wildfires due to fuel build up (White House 2002)
Boreal flammability driven by climate and ecosystem type, not forest age (Johnson et al. 2001, Chapin et al. 2006, Kolden 2010, Abatzoglou and Kolden 2011)