USA – Some of the folks opposed to protecting lands as wilderness, national parks, national monuments and other designations often cite their fear of wildfire, suggesting that without “active management” (code for logging), these lands will create high-severity blazes.
But like a lot of mythology surrounding wildfires, the opposite is true. Active management actually increases the likelihood of wildfire.
A recent study published in Ecosphere gets at this issue. In their paper, Does increased forest protection correspond to higher fire severity in frequent-fire forests of the western United States? the researchers looked at 1,500 wildfires in ponderosa pine and mixed conifer forests across the West.
What they discovered, contrary to popular opinion, is that protected areas which presumably have higher biomass and fuels loads had lower-severity fires than forests that were actively managed.
This is not surprising if you understand why and how forests burn.
First, what burns in a forest fire are primarily the fine fuels like needles, small branches, grass and shrubs. That is why in the aftermath of a fire, there are snags. The tree boles themselves seldom burn.
Logging and thinning tend to put more fuels on the ground and promotes the growth of easily combustible fuels like grasses and shrubs.
Secondly, thinning/logging opens up the forest to drying and wind penetration. These are the primary ingredients that promote fire spread. Fuels do not drive large fires, rather extreme climate/weather conditions. When you have low humidity, high temperatures and most importantly, high winds, wildfires roar through all forest stands.
Active forest management (thinning/logging) may reduce the amount of total biomass like large logs which dont ignite and burn easily in the first place, while at the same logging increases the fine fuels and enhances the conditions for fire spread.
Plus, since most wildfires are human-caused and often occur along roads, keeping roadless lands free of logging roads, also reduces overall fire starts.
Thus, one of the additional benefits of setting aside large acreage of wilderness or national monuments is a net reduction in high severity fires and a reduction in the costs of firefighting.
George Wuerthner is an ecologist who has published 38 books, including “Wildfire: A Century of Failed Forest Policy.” Wuerthner divides his time between Livingston, Montana, and Bend, Oregon.