This paper, in the July 2017 edition of the Journal of Forestry, may help us in our discussions of fuel-treatment effectiveness.
In the wrong place at the wrong time, wildfires cause damage to ecosystems and threaten homes, communities, and cultural resources. To manage the impact of future wildfire and help restore its natural role in forest ecosystems, land managers often use fuel treatments such as thinning, mowing, and prescribed burning. How well do these treatments work? Ecologist Nicole Vaillant studies fire behavior and fuel treatments, including how effective they are over time. Her work is important in helping land managers assess wildfire risk and compare different fuel treatment strategies. She recently led a study that addresses the question: Are we treating enough of the landscape to compensate for decades of fire suppression?
Vaillant and her coauthor, Elizabeth Reinhardt, evaluated the extent of fuel treatments and wildfire on all lands administered by the Forest Service from 2008 to 2012. They compared these areas with historical wildfire rates and severities; they found that each year only about 45 percent of the area that would have burned historically experienced either characteristic wildfire or fuel treatment. This indicates a “disturbance deficit.” The good news is that 73 percent of the acres burned by wildfire during this period experienced characteristic fire (wildfire at an appropriate severity level for that ecosystem). However, Vaillant’s study also found that the forest type in the highest wildfire hazard class had the lowest percentage of area treated and also the highest proportion of uncharacteristically high-severity wildfire. This suggests that locating more treatments in areas with the highest hazard could improve program effectiveness. This is the first study to intersect the actual footprint of fuel treatments and wildfire with mean fire-return interval and wildfire hazard on a national scale.