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.