According to a recent report by the USDA Forest Service, the combination of fuel treatments (tree thinning) on the landscape and Firewise principles applied around homes in Alpine, Arizona, allowed firefighters to deliver the "knock-out punch" saving homes from the Wallow Fire that raged through 40,000 acres in just six days.
This short report includes numerous photos clearly illustrating how the fire behaved as it rapidly consumed all the available fuel in overgrown forest areas, and then slowed and dropped to the ground as it moved into the areas where trees had been thinned out to separate their crowns and where brushy fuels that serve as "ladders" for the fire had been removed. Fire in tree crowns can spread quickly along the forest, with long flame lengths and greater heat than a fire in more sparsely vegetated areas.
Besides slowing the fire and reducing the heat, fuel treatments begun as long ago as 2004 provided strategic locations for firefighters to be able to set up and fight the fire. According to one fire managment officer, "Without the fuel treatments, I never would have had a firefighter there." The potential was just too great for injury or death had the area been left untreated.
The report documents the successful "saves" of nearly every home in Alpine and the nearby community of Greer, crediting not only the fuel treatments and the defense by firefighters, but also the work of property owners themselves. The report says that, "even though they experienced ember showers and low-intensity surface fires, many of the other Alpine structures that survived the Wallow Fire did so because of these prior fuel treatments, as well as “Firewise” construction and landscaping completed by the land owners."
Photo from report "How Fuel Treatments Saved Homes from the 2011 Wallow Fire," USDA Forest Service