According to the US Forest Service and many others with a financial interest in logging and firefighting, prior to the settlement of the West, wildfires were more frequent than today. These frequent fires kept fuels low, and therefore, reduced fire severity of wildfires.
Since its inception, the Forest Service has had a policy of putting out nearly all blazes, and therefore, we now have a crisis of “too much fuel” and large “uncontrollable wildfires.”
So, the story goes, the occurrence of large wildfires in the past few decades are a direct result of this fire suppression policy.
The Forest Service justifies a lot of its logging programs to reduce fuels based on the presumption that “one hundred years” of “fire suppression” has radically altered the “historic variability” of western ecosystems.
There is, no doubt, a bit of truth to the contention that in some plant communities, a dearth of wildfires has contributed to changes in tree density, forest structure and species occurrence. But there are reasons to believe this argument does not apply to much of forest types in the West.
Fire Suppression for a Hundred Years?
First, the idea that fire suppression has been effective for 100 years can be questioned. In the early 1900s men on mules, armed with shovels, traveling through miles of wilderness lands of that era, barely made a significant different in acreage burned annually.
Only after WWII when helicopters, planes, smoke jumpers, combined with a greatly expanded logging road system provided rapid access to wildfires, did suppression begin to influence some forests.
Climate Effects Wildfires More Than Suppression
However, the fire suppression theory ignores the role of climate/weather in fire ignition and spread. If you don’t have the right weather conditions, you won’t get a large fire. All large blazes, pejoratively termed “catastrophe wildfires”, burning since 1988 have occurred during periods of extreme drought, low humidity, and most importantly high winds. Under such fire-weather conditions, even modern firefighting equipment and knowledge cannot slow wildfires.
Those favoring more logging of our forests tend to compare the past few decades with the preceding decades of the 1960 and 1970s. That comparison is invalid.
Between the late 1930s and late 1980s, the overall climate in the West was moister and cooler than at present. Moist, cool conditions reduce ignition, and any fires that start do not spread rapidly, and are easily controlled. So, to the degree that” fire suppression” had any effect, it has primarily influenced fires burning under less than ideal fire weather conditions. These tend to be small, easily controlled blazes.
If you were to compare the acreage burned during the past few decades with say the early 1900s where there were decades of drought, you would find that we have fewer acres burning today than at that time.
Why is this important?
Because all large high-severity fires are driven by climate/weather, not fuels.
Most Forest Communities Never Burned Frequently
Even more important, the idea of fire suppression is misapplied to the vast majority of forest types in the West. Most of the forest communities across the West naturally burn at long intervals of many decades to hundreds of years.
Plant communities that tend to naturally have long fire-free interval include forests dominated by lodgepole pine, spruce, various fir species, hemlock, aspen, juniper, larch, and most Douglas fir types.
Their natural growth pattern results in dense forest stands, with a lot of dead fall on the ground.
The natural fire pattern in such forests is mixed to high severity burns where a significant amount of the living trees is killed.
Therefore, it is totally inaccurate to suggest that fire suppression has contributed to denser, biomass laden forests and/or larger high severity blazes. Suggesting the occurrence of high severity wildfire is “unnatural” in such forests is ecologically flawed.
Ponderosa Pine the Exception?
In short, the only exception to this generalization of infrequent wildfire occurrence is ponderosa pine, a tree commonly found at lower, drier, elevations.
Yet even among ponderosa pine, there is growing evidence that in some areas, ponderosa stands experience decades of fire-free periods and occasionally burned at mixed to high severity. For instance, 80% of the ponderosa pine in Colorado’s Front Range historically experienced some degree of high severity stand killing wildfires.
In short, attempts to cut forest density, short-circuit natural events like wildfire, beetles, and disease, impoverishes forest ecosystem. And logging is not restoration, but forest degradation.