When I worked for the Bureau of Land Management, us “ologists” (hydrologist, ecologists, biologists, archaeologists, geologists and botanists) used to refer to range conservationists as range “cons” because they conned the public into believing many myths about livestock grazing.

George Wuerthner

George Wuerthner

It is essential to keep in mind that range cons have a financial conflict of interest. If there are no cows, there is no reason to have a range conservationist on the payroll.

One of the “cons” heard continuously from range conservationists and repeated by ranchers that grazing can help preclude large “mega” fires by “reducing” fuels. This is one of those many assertions that have a grain of truth but is nevertheless misleading.

Whenever you read such pronouncements, be skeptical. Almost all the “evidence” for the value of grazing to reduce wildfires comes from government apologists with connections to the livestock industry.

Many of the studies purporting to demonstrate the influence of livestock grazing on fire spread were done on small experimental plots of land. The transfer of these findings to the larger landscape scale is questionable.

In a widely cited Arizona study, the researchers had several small plots (several acres in size). They grazed some of the plots and kept others ungrazed as controls. They concluded (with modeling) that light utilization in treated sites, reduced fire rate of spread by more than 60% in grass communities and by more than 50% in grass/shrub communities.

A real-life problem that their study ignores is that keeping cattle on the desired target area is exceedingly difficult. Typically, this is done by transporting cattle by truck to the target site, then herding or using moveable fences to keep cattle grazing focused.

All of this adds immensely to the cost of any livestock grazing operation. Most ranchers are simply not interested in spending that kind of money to get a bit of cheap forage.

But the real problem with this and many other studies that presume to show a livestock-grazing induced reduction in fire spread is that they do not work under extreme fire weather.

The researchers in the Arizona study admit as much in their next to the last paragraph: “Although it is a promising tool for altering fire behavior, targeted grazing will be most effective in grass communities under moderate weather conditions.”

The weather factors are significant because nearly all massive wildfires burn under “extreme fire weather conditions.” Under such conditions, targeted grazing, prescribed burning, thinning of forests, and fuel breaks, fail to contain or stop fires. In attempting to reduce fuels, such prescriptions often lead to more fire-prone species like cheatgrass.

In an overview of various fuel reductions, fire ecologists at the Missoula Fire Lab concluded that: “Extreme environmental conditions ... overwhelmed most fuel treatment effects. ... This included almost all treatment methods including prescribed burning and thinning. ... Suppression efforts had little benefit from fuel modifications.”

Although they primarily examined forest management options, the same necessary conclusions apply to reducing fuels on rangelands.

Other evidence supporting grazing as a fire reduction strategy is simply anecdotal. Cattle graze a strip of cheatgrass. A fire arrives, and the fire slows or is easily suppressed by firefighters.

Without knowing the circumstances at the time of the fire, such as topography, vegetation, or weather conditions, one can’t assume that grazing had anything to do with the fire’s behavior.

Did the wind shift directions or simply stop? Was the fire even burning under “extreme conditions,” which are the only times you have large fires-the very fires that cattle grazing advocates are suggesting grazing is effective in halting or slowing?

Typically, under extreme weather conditions which always includes high winds, any wind-blown fire spews embers up to a mile or more beyond the burning front. Such a blaze will easily skip over a strip of grazed land, making such fuel breaks or targeted grazing ineffective.

Furthermore, the process of getting cattle to remove such a high percentage of cheatgrass or other vegetation results in collateral damage.

This includes soil compaction, which reduces water infiltration. Social displacement of native herbivores like elk and deer that avoid areas of active cattle grazing. Water pollution of streams. Destruction of riparian areas (the green line of vegetation influenced by water). Reduction in grass stubble needed as hiding cover by wildlife like sage grouse.

Finally, since one cannot predict where a fire would occur, so most of these treatments only provide the livestock impacts to our public lands, without any potential “benefit” of halting a blaze.

George Wuerthner is an ecologist who has published many books on environmental and natural history topics.