More Hype On Fuel Breaks


Targeted grazing seeks to create vegetation free zones, which advocates suggest will assist firefighters in controlling blazes. However, the collateral damage from grazing vastly exceeds any benefits. Photo George Wuerthner 

A recent article in the Post Register described the research that the University of Idaho Range Department conducted on fuel breaks, especially those resulting from livestock grazing. The only thing the researchers said that I agreed with is that wildfires are a significant threat to the sagebrush ecosystem.

Of course, let’s start with the obvious. Range departments exist to justify livestock grazing. I know because I attended grad school in so-called “range science.” However, range science is more about an agenda to justify ranching, particularly on public lands.

The native vegetation was eliminated here (by bulldozer) and the result was invasion by highly flammable cheatgrass. Photo George Wuerthner

But beyond that bias, there are numerous problems with the idea of “targeted grazing .” First, the goal of targeted grazing is to reduce vegetation. No vegetation. No fires. But no vegetation also means no hiding cover for ground nesting birds. No food for rodents. No forage for larger mammals like pronghorns. No flowers in the spring.

Furthermore, livestock tends to select native vegetation over weedy species like cheatgrass. So heavy grazing typically leads to a loss of native grasses and other plant covers.

Heavy cheatgrass cover (as in this photo)  is a major threat to sagebrush ecosystems. Photo George Wuerthner

A recent study looked at wildfire, cheatgrass, and livestock grazing. The scientists concluded, “Increased site resistance (to cheatgrass invasion) following fire was associated with higher bunch grass cover and recovery of bunchgrasses and mosses with time since fire. Evidence of grazing was more pronounced on burned sites and was positively correlated with the cover of B. tectorum, indicating an interaction between fire and grazing that decreases site resistance.”

Biocrust covers the soil in this photo and can inhibit establishment of cheatgrass. Livestock grazing tends to destroy biocrusts. Photo George Wuerthner 

Such concentrated grazing also destroys biocrusts which hold the soil together and reduce erosion.  Loss of biocrust contributes to conversion of rip gut brome, Medusahead, and cheatgrass.

Other researchers have found that “biocrusts increase site resistance to invasion (by cheatgrass) at a landscape scale and mediate the effects of disturbance. Biocrust species richness, which is reduced by livestock grazing, also appears to promote native perennial grasses.”

Wind is the most effective agent for promoting wildfire. Under high winds, nothing stops or slow fire spread since embers can be tossed up to a mile in front of the fire front. Photo George Wuerthner

Worse for the American people, targeted grazing doesn’t work to slow wildfire under extreme conditions. That such grazing might work under low to moderate fire conditions is irrelevant because the only fires that pose a landscape-scale impact are those burning under extreme fire conditions. Under extreme fire conditions with high winds embers can be transported as much as a mile ahead of the fire front, and easily passes over any fuel break.

For instance, a much-cited research paper on targeted grazing (by a range department admitted as much in its next to the last paragraph (after ballyhooing for pages about how effective targeted grazing was) when it stated: “Targeted grazing treatment did influence fire behavior in grass/shrub communities, but its effects were limited. Although it is a promising tool for altering fire behavior, targeted grazing will be most effective in grass communities under moderate weather conditions.”

Under extreme fire weather conditions of drought, high temperatures, low humidity, and especially high winds, nothing stops a fire until the weather changes. Nothing. Not firefighters. Not airdrops. Not flame retardant. And especially not grazing the land to a golf course height.

So the very fires that pose the greatest threat to sagebrush ecosystems are those that we cannot control until the weather changes. And if you read fire reports closely, you will see that in nearly all cases, the fire is brought under control when there is rain, the wind stops, or some other variable changes to favor fire control.

Where fire jumped across fuel break in southern Idaho. Photo George Wuerthner 

A further issue with targeted grazing is getting cows to be on target. You can do this with fenced grazing plots or sometimes with range riders, but this significantly increases the cost of any operation. So, of course, the solution proposed by pro-livestock advocates is that the public should subsidize grazing because the ranchers are doing us a favor by removing grass cover, churning up biocrusts, displacing native herbivores, and so forth.

And because of these costs and infrastructure hassles, targeted grazing only works for small areas. Again under extreme fire weather, small parcels will not effectively slow or halt a fire.

However, as with all such “solutions” from thinning forests to targeted grazing, the probability that a fire will encounter such a treated area is minuscule—often less than 1% in forest thinning and even less in targeted grazing. So you get no benefits but get all the ecological damage.

Cheatgrass almost completely dominates this site (with fuel break in the background). Photo George Wuerthner 

A further problem with “fuel breaks” is that they tend to regrow with more fire-prone vegetation like cheatgrass.

In a recent critique of fuel breaks (created by targeted grazing or mechanical treatment such as bulldozing vegetation), Eight BLM scientists declared that the agency’s proposed Tri-State Fuel Break (TSFB) was flawed and will endanger sagebrush ecosystems.

The scientists contend the BLM’s proposal will likely fail to contain large fires, and the collateral damage will result in: “(1) fragment large areas of intact sagebrush ecosystems; (2) facilitate the invasion of exotics due to the disturbance created by the breaks; (3) supplant native communities with exotic dominants; and (4) destroy or degrade biological soil crusts and any native species in the sites.”

The fact is that livestock grazing, by destroying biocrusts and promoting cheatgrass across the ecosystem, is the main factor, along with warming climate, that endangers our rangelands. Therefore, the best way to reduce large fires on public lands is to terminate livestock grazing and reduce climate warming in the long term.





  1. Jeff Hoffman Avatar
    Jeff Hoffman

    Using non-native ungulates to graze areas to remove vegetation and supposedly reduce fire risk has been in vogue for a long time. Around here (SF Bay Area), they use goats to graze hillsides. Of course these people are wrong on both counts: non-native grazers do great harm, and natural wildfires need to be allowed to burn in order for the ecosystems to be healthy.

    Because humans evolved in the African savanna, perhaps forest fires create huge fear in us (the natural wildfires on the African savanna are pretty small, because there aren’t a lot of trees there, and because the fires are started by lightning during rainstorms). But we need to either get over that fear, or get the hell out of the forests. Ruining the land because we’re afraid is not OK!

    1. Maggie Frazier Avatar
      Maggie Frazier

      I remember reading that wild horses will eat cheatgrass when it first appears – from all the expansion of it in grazing allotments – cows wont?
      Sorry Jeff if this is a really dumb question but I’ve been curious.
      figured you might know.

      1. Jeff Hoffman Avatar
        Jeff Hoffman

        I don’t know. I only had horses in Illinois, and they ate whatever grass the stables planted (don’t know what it was).

        1. Maggie Frazier Avatar
          Maggie Frazier

          Same here in NY. Seems like if the horses would eat it when it was green, so would the cows! None of the ones I “knew” were picky.

          1. Jeff Hoffman Avatar
            Jeff Hoffman

            When I rode trails, my horses would eat just about anything green (I used a hack, not a bit, so eating while riding wasn’t an issue). They’d even bite leaves off trees, and I saw them doing this while grazing in a pasture bordered by a grove of trees. But of course they mostly eat grass.

    2. Ida Lupine Avatar
      Ida Lupine

      For the most cruel, destructive and dangerous creature on the planet, we certainly are big fraidy-cats when it comes to perceived threats to us.

      I truly believe we are no longer a part of nature, or at least most of us are not. We’ve fought it and tried to kill it for so long that we have succeeded in a separation from it.

      1. Jeff Hoffman Avatar
        Jeff Hoffman

        I read a book from the Rewilding Institute written by multiple authors. One I really liked said that the “humans are just part of nature” argument is an irrelevant distraction from the real issues, and I agree. Doesn’t matter whether we are or aren’t, it just matters how we feel and think about the natural world and how we act on those feelings and thoughts. I don’t think that anyone has visited all the natural areas that remain — at least the vast majority hasn’t — but we can still love the ecosystems and life there, and try to protect them from human-caused harms.

        1. Ida Lupine Avatar
          Ida Lupine

          It wouldn’t, except that the damage has been so great, and our self interests have taken so much control, that I can’t in good conscience treat it as irrelevant. It’s even rearing its ugly head in climate change, where we feel our lives are more important to save than other life. Can’t do it and won’t.

          1. Jeff Hoffman Avatar
            Jeff Hoffman

            It’s undeniable that people who see themselves as part of the natural world act much better toward it and the life there. But my point was that even we city folks can feel and act correctly in this regard. Even if your assertion is correct — that humans are no longer part of nature — that doesn’t preclude us from acting properly toward it. That’s why this argument is an irrelevant distraction.

            BTW, I agree that humans have separated themselves from the natural world and are no longer part of it. My comment, like that in the book, was a response to anti-environmentalists who claim that humans are part of nature, so that everything we do is natural.

            1. Ida Lupine Avatar
              Ida Lupine

              🙂 Thanks. I understand.

  2. Ida Lupine Avatar
    Ida Lupine

    I’ve read that too, maybe there’s an article on SFTHH? That may be where I saw it.

    I tried to find something about wild horses eating cheatgrass, I did find that cattle prefer it. (Horses do eat it too, but get blamed for spreading it too.)

    I did find this interesting article from 2021. But as we know people do not seem to like letting Mother Nature take her course, and always think they can do better, especially where predators are concerned. It is also important to people to kill predators, call it what they will. The ‘Debunking the BLM’s claims’ paragraph made me smile:

    1. Maggie Frazier Avatar
      Maggie Frazier

      On the other hand (!)doesnt seem to me to make sense that horses are blamed for spreading cheatgrass but not cows????

      1. Jeff Hoffman Avatar
        Jeff Hoffman

        I think that some people just don’t like horses. I arrived early at the national Earth First! rendezvous in Sun Valley Idaho one year. There were only a few of us before the large group arrived, and someone rode into our camp on a horse, with a dog running alongside. Dave Foreman was also there early, and after the guy rode away, Dave asked me what I thought about the animals. We agreed about dogs, but I told Dave not to say anything negative about horses, and we left it at that.

        Again, as far as grazing harms, cattle are the problem, not horses. Of course any ungulate will overpopulate if their native predators are not present, including horses. So hey, just bring back the wolves and mountain lions too!

  3. Jerry Thiessen Avatar
    Jerry Thiessen

    I could go on and on about the absurdity of using cows to manage rangelands and the spread of cheatgrass, but suffice it to say that idea is not ecologically sound and is rather a sordid joke. The referenced study is not the first nor will it be the last. Even removing livestock has little hope of fixing the fire/cheatrass/fire cycle that has dominated rangeland ecology in the semi arid west for at least 85 years. Climate change is only making conditions and outlook worse. We can all thank past unregulated livestock grazing along with past and ongoing cowboy politics for the mess with no letup in sight.

  4. Tim Freeman Avatar
    Tim Freeman

    I live in juniper shrublands of Central Oregon, and it’s so frustrating to see that local agencies still can’t fit science and management together. Since fire control and overgrazing caused the encroachment of western juniper into productive grasslands to the east of here beginning a century and a half ago, it has become commonplace recently to remove all junipers on grazing lands to increase grass cover and soil moisture, and many people around here now seem to believe that juniper is always an invasive species and a fire threat, not understanding that junipers have thrived in the sandy soils between lava ridges locally for eons. As population here and the fear of wildfire has skyrocketed, many “firebreaks” have been created recently around expanding developments, namely Eagle Crest Resort and Crooked River Ranch subdivision. These firebreaks involve removing most juniper and bulldozing a wide belt clear of most all other vegetation. The result has been breaking down of the biologic crusts, a drastic increase in fire-prone annual invasives, a break in the protective cover of the woodland, and an ugly swath of human destruction 100-300 yards wide. I’ve routinely counted over 800 growth rings on many of the fresh stumps, and I don’t see many with less than 200. After a century and a half of logging for firewood and timber, and clearing for agriculture, it’s a shame to see any of the last of the world’s largest old growth juniper woodland reduced to cheat and tumble mustard. Besides increasing the actual fire risk, these belts completely disregard the natural fire breaks (rimrock, lava ridges, canyons, and intact native vegetation with biologic crust) that exist here that have allowed these ancient junipers to develop in the first place. People apparently don’t understand that a policy that makes sense on a ranch covered in grass doesn’t necessarily work in a juniper woodland with completely different soils, ecology, and fire cycle. The extent to which policy is created and controlled by grazing interests, today in Oregon, in a place that’s supposedly proud of and economically reliant on its natural heritage, blows my mind.

  5. rastadoggie Avatar

    The highly flammable cheatgrass invasion post grazing, logging and prescribed fire is beyond belief and unsolvable. Also conveniently ignored by the cutters/grazers and their ilk.


George Wuerthner is an ecologist and writer who has published 38 books on various topics related to environmental and natural history. He has visited over 400 designated wilderness areas and over 200 national park units.

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George Wuerthner