Prescribed burning is often seen as a way to reduce to the large climate-driven blazes now occurring across the West, however, there are many problems that proponents fail to acknowledge. Photo George Wuerthner

It seems everyone is grasping for some “solution” to big fires. And one of the common assertions is that more prescribed burning would reduce fire spread and allow firefighters to knock down a blaze.

Increasingly we also hear that tribal people kept fires from becoming large by the frequent burning of the landscape–as if this was a secret tool no one in the fire fighting agencies knew about. The evidence suggests that tribal burning likely reduced fuels in the IMMEDIATE area around villages but seldom influenced the larger landscape fire rotation. You can read more on this at  https://www.thewildlifenews.com/2020/11/23/indigenous-burning-myths-and-realities/

A prescribed burn, whether done by Indians for cultural purposes or a firefighter with a drip torch, may reduce fuels for a short period. And if a fire were to encounter the burn when fuels were reduced, it might influence fire spread. However, one of the problems with prescribed burning (as well as thinning forests) is the likelihood that any blaze will encounter a “fuel reduction” when it may be effective at influencing fire spread is exceedingly rare. So most prescribed burns (as well as thinning) have no influence whatsoever.

In addition, the very fire people are anxious to stop or control are those burning under extreme fire conditions. These conditions include high temperatures, low humidity, drought and most importantly high winds. High winds, often blow embers over and through “fuel reductions” like prescribed burns. In other words, even if such prescriptions worked under low to moderate fire weather conditions, fuel reductions including thinning and prescribed burning typically fail to alter fire spread due to wind transport of embers.

Just burning enough of the landscape to have any influence on wildfires is also problematic.  The window when burning is safe is frequently very narrow. Concerns about smoke dispersal add to the limitations.

Furthermore, there is always a chance that a prescribed burn will get away and burn far more of the landscape, including homes, prescribed burning increases the chances of fire losses. Due to the low possibility that any blaze will encounter a prescribed burn during the period when it could change fire behavior whether you would reduce the acreage charred is questionable.

A prescribed burn could get away from fire fighters and burn significant acreage as occurred with the Davis Fire near Canyon Creek, Montana and the  Cerro Grande prescribed burn that destroyed homes in Los Alamos, New Mexico.  When such planned ignitions get away from fire fighters due to changing weather conditions, the District Ranger or Park Supervisor or other responsible agency personnel get blamed for the destruction of property.

This area on the Deschutes National Forest was prescribed burn the previous season. The regrowth of grasses (fine fuels) is now denser than what existed before the burn. Photo George Wuerthner

The other problem with prescribed burning is that in many ecosystems, burning stimulates plant growth. This additional biomass results from the removal of competing vegetation and release more nutrients, water, and sunlight for the remaining plants. Consequently, within a few years of a prescribed burn, you will often get more fine fuels like grass, shrubs, and small trees than before the burn.

In addition, frequent burning was not the dominant fire regime in many ecosystems. Chaparral, sagebrush, and higher elevation conifer forests like fir, lodgepole, spruce, and others all had naturally long fire rotations and intentionally burning them harms them.

I repeatedly see around the West that agencies will perform a prescribed burn and never bother with the follow-up maintenance. While prescribed burning could be effective if strategically located by communities and repeated continuously, this seldom occurs.

The following two photos demonstrate this idea. The first photo was taken a week after the Bridger  Foothills Fire swept across forests, hayfields, and pastures in September 2020.  Note that the hayfield has very little grass after being mowed. But strong winds drove the fire across even one-inch stubble. The second photo taken in nearly the exact location shows how rapidly the grass regrew after a fire. In other words, without continuous “maintenance,” the burn would have little impact on slowing or stopping a fire.

Area burned by Bridger Foothill Fire near Bozeman in September 2020. Photo George Wuerthner

Same location (note the burnt fence post) a year later where grass (fuel) regrew. Photo George Wuerthner 

All this said I don’t oppose the strategic use of prescribed burning so long as people recognize the limitations.  Reducing fuels around communities and homes can be effective if and when a blaze threatens structures. However, the idea that somehow prescribed burning is an effective panacea that can reduce or preclude climate-driven blazes is questionable.

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About The Author

George Wuerthner

George Wuerthner is an ecologist and former hunting guide with a degree in wildlife biology

4 Responses to Why Prescribed Burning Is Seldom Effective

  1. avatar Martha S. Bibb says:

    Likely fires started by Natives peoples were escaped fires, not prescribed fires.
    Air pollution from fire smoke has been extended to almost the entire year, exposing communities to smoke both from wildfire to prescribed fire.
    Is the claim that prescribed smoke is better for humans than wildfire smoke like saying that vaping is better than cigarettes? This may be fire-industrial misinformation. Don’t know. Smoke is unhealthy from any cause. Especially during an Upper respiratory pandemic.
    Maybe we should just rake the forest floor?
    Martha

  2. avatar Jeff Reed says:

    Thank you for providing me with this useful information.

  3. avatar Beeline says:

    In my experience it has long been a dollars and cents budgetary game. BLM and USFS operations generally wanted to burn large areas that really did not need to be burned. I once surveyed about 5 sections of land (over 3000 acres) which the fire people wanted to torch and only about 350 acres of really old, decadent brush needed to be burned. No accommodation was given to slope factor or soil erosion by the fire folks either because they had to have a certain size blaze to keep their budget inflated. Never mind the soil that ran down hill and filled streams and washed out bridges etc. after the soils were laid bare.

    Agency personnel used to try and sell prescribed burning by noting that nitrogen was released after burning. It is true that inorganic nitrogen is released in the short term but it can take 50-60 years for organic forms of nitrogen (that a forest requires for its health) to re-establish.

    I think that the continued mismanagement of public lands will only contribute to further environmental stress economic difficulties.

  4. avatar Robert King says:

    We live on an oxygen-rich, fuel rich-planet. Fire is inevitable.

    I have been the burn leader for a ¾ million-acre tract, have written several controlled-burning management plans and led many scores of prescribed burns. I was trained by the U. S. Forest Service’s Fire Research Lab and by numerous prescribed fire programs in several states. During my 47 years as a wildlife biologist, my specialty was habitat management. And prescribed fire is my most desirable tool for habitat management.

    I thought (had hoped) that the great Yellowstone fires of 1988 had finally taught forest managers the futility of suppressing all fires, and proved the value of prescribed fire to reduce fuel loads.

    https://en.wikipedia.org/wiki/Yellowstone_fires_of_1988

    I agree that fire during extremely low relative-humidity and high winds is impossible to control. And that is one of the justifications for reducing fuel-loads during desirable conditions, when RH and high winds are not a threat to turn prescribed fire into wildfire.

    Although it is never discussed, no amount of chemical suppression or smoke jumping can extinguish the western wildfires during these climate changes. The professionals who “manage” these fires, know that these fires only die when they run out of fuel. Again, in extremely low RH and high winds, wild-land fires are impossible to control.

    Conversely, there is little chance that a prescribed fire will get out of control if it is planned prudently. And of course, a smoke management plan is required. For example, if there is a five-day window of desirable weather, I burn on day 3. I never burn on the last day of desirable weather conditions. Fronts often arrive early.

    You posted two pictures of the area burned in the Bridger Foothill Fire. The argument you made with these images is simply unfounded. The second image shows the area a year after the burn. But I know that just a year after a burn, any habitat is only sparsely regenerated. Plants live and plants die and it is the dead material that burns during normal conditions. A year’s time is not sufficient to build up enough dead material for the fuel continuity necessary to support any fire, even in extreme conditions. This area probably does not have sufficient continuity (of dead plant material) until three to four after the initial burn.

    I am very concerned with the future of habitats in the West. Established, native western tree species evolved over millennia and adapted to fire, because historically, fire occurred frequently. But they probably never experienced the high temperatures that they have been subjected to, since the advent of climate change.

    I believe that continued environmental conditions during climate change, will eventually result in wildfires that these tree species will not be able to survive. But I may be wrong. Perhaps, through existing mutations and Darwin’s Natural Selection, enough of them will quickly adapt to the higher temperatures and produce the seed for their species going forward. They may be begun to already!

    Apparently, this evolutionary phenomenon is happening now with African elephants that have been slaughtered for decades by poachers. Many African elephants are now not growing tusks!

    https://www.nationalgeographic.com/animals/article/wildlife-watch-news-tuskless-elephants-behavior-change

    https://www.greenmatters.com/p/african-elephants-evolving-without-tusks

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‎"At some point we must draw a line across the ground of our home and our being, drive a spear into the land and say to the bulldozers, earthmovers, government and corporations, “thus far and no further.” If we do not, we shall later feel, instead of pride, the regret of Thoreau, that good but overly-bookish man, who wrote, near the end of his life, “If I repent of anything it is likely to be my good behaviour."

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