The authors found a positive feedback between the initial severity of a fire and the severity of a later reburn when the first fire burned at high severity. They suggest that high severity fires can leave behind dense stands of fire-killed trees, potentially creating heavy fuel loads and ladder fuels when a subsequent fire strikes. Alternatively, a shift to a shrub state after high severity fire can result in a subsequent reburn of high severity fire. However, they also found that stands that are within unaltered, short-interval fire regimes tend to self-regulate the burn severity of secondary fires, and burn at the same or lower severity, suggesting that the initial fire moderated the burn severity of the second fire. This mitigating effect lasted up to 22 years in some of the burned areas studied, but generally decayed as time since fire increased.

The authors found that treated sites prior to the 2011 Wallow Fire resulted in lower tree mortality, smaller patches of high severity, and significantly higher understory herbaceous cover post-fire suggesting that fuel treatments imbue resiliency to uncharacteristically severe fire in mixed conifer ecosystems.

In the Rodeo-Chediski Fire, pre-fire treatments resulted in reduced fire severity. Although fuel loads were high at both areas, pre-fire treated areas had lower levels of surface fuel loads than untreated sites with the difference between the two becoming greater over time.

The authors found that mechanical thinning with or without prescribed fire was effective at reducing wildfire hazard in pinyon-juniper woodlands and reduced stand density and canopy fuel loads. Using low severity surface fire alone did not affect overall fuels significantly, although it did reduce the tree densities of juniper trees more so than the control treatment.

The authors found that treatments that increased shrub and herbaceous understory resulted in increased fire intensity. Increases in fire intensity then reduced shrub biomass which the authors suggest is more in line with historic conditions of frequent fire.

Prescribed fire treatments reduced the potential for active crown fire compared to the control plots or pretreatment levels. Increases in drought and wind conditions input into either model produced increases in active crown fire, however, the crowning and torching index was two and three times higher, respectively, in areas that had been treated than those with no treatment.

The authors found that despite extreme and severe fire behavior over most of the fire, areas that were treated prior to the fire had lower tree mortality and reduced fire intensity when compared to untreated areas. The authors suggest that the arrangement of fuels may be more important for determining fire severity than the overall basal area or stand density, i.e. fewer larger trees have greater survivability than many smaller-diameter trees.

The prescribed fire treatments constituted the greatest treatment impact on future crown fire behavior potential by raising the canopy base height. The thin and burn treatment and prescribed fire only treatment had nearly indistinguishable effects on forest structure, suggesting that resources may be better spent on increasing prescribed fire than on minimal thinning activities.

Historically, high wind speeds were required to initiate crown fire behavior across all forest types within the project area. By the year 2000, common windspeeds of 45 km/h were projected to be sufficient to initiate crown fire at most sites due to changes in canopy bulk density. The increase in canopy fuels continuity has already and is expected to lead to broad-scale crown fire instead of a highly mixed pattern of burn severity that was common historically.

In contrast to presettlement conditions, currently there is abundant fuel able to support high?intensity fire behavior, including torching through live fuel ladders and crown fire, in hot, dry, windy weather. However, herbaceous fuel loading is probably greatly reduced in the contemporary forest.