Effectiveness of fuel treatments in the West depends on thinning intensity

In the largest ever study of fuel treatment effectiveness, U.S. Forest Service researchers have found that intense thinning treatments that leave between 50 and 100 trees per acre are the most effective in reducing the probability of crown fires in the dry forests of the western United States. The study, the results of which are published in a recent issue of the Canadian Journal of Forest Research, provides a scientific basis for establishing quantitative guidelines for reducing stand densities and surface fuels. The total number of optimal trees per acre on any given forest will depend on species, terrain and other factors. This study proves once again that an ounce of prevention equals a pound of cure, said U.S. Forest Service Chief Tom Tidwell. Thinning dense forests reduces the impacts of the catastrophic wildfires weve already seen this year and expect to see more and more of in the future. This work helps protect communities, provides jobs and promotes overall better forest health. Decades of excluding fire in the Western states have resulted in densely packed stands and a buildup of forest-floor fuels in many dry forests, which can lead to large, continuous crown fires when wildfires do occur. Crown fires are of particular concern to managers because they are challenging to suppress and are capable of causing widespread mortality in stands. This year, Arizona and New Mexico have already experienced the worst fires in the states histories...more