In a recent news story, the Sacramento Bee speculated that cattle grazing might be a “secret weapon” to fight fire. The story presents the dangerously simplistic claim that cattle grazing reduces fire risk, based on an unpublished study funded by the California Cattle Council, the results of which have yet to be subjected to the rigors of scientific review.
The reality is a lot more complicated. Sure, when cattle (or native wildlife, for that matter) eat grasses, those grasses are removed. There have already been studies showing that cattle grazing can provide short-term reductions in flame length, but that’s a far cry from showing that cattle make fire conditions better rather than worse. Indeed, the heavy levels of livestock grazing required to make a meaningful dent in fine fuels actually increase the combustible nature of the landscape by encouraging fire-prone annual weeds to take over.
The bunchgrasses native to California are perennials, adapted to stay alive even during droughts. As a result, they have a greater moisture content in late-summer fire season than annual invasive weeds like cheatgrass, red brome, and ripgut brome, which die soon after spring green-up and become tinder-dry. By converting moist native plant communities to drier and more flammable annual weeds, livestock radically accelerate the fire-return interval, a change that lasts for decades. Just as importantly, livestock also replace long-lived, deep-rooted native plants that sequester tons of carbon per acre with weedy shallow-rooted plants that die and give up their carbon every year.
Livestock have made the West much, much more fire-prone over the past century and a half, and have simultaneously bankrupted the land’s ability to store carbon underground. That combination makes livestock a major culprit in the very climate disruption that is the root cause of the major conflagrations we are currently seeing throughout the West.
This is not the first time the industry has tried to claim that livestock reduce fire risk, and cows aren’t exactly a ‘secret’ weapon. In court proceedings last year, the interim head of the Department of Agriculture, Veterinary & Rangeland Sciences from the University of Nevada-Reno tried to make very similar claims that cattle grazing was necessary to reduce fire risk near Malheur National Wildlife Refuge in Oregon. Other scientists argued that cattle grazing actually increased the risk of fire, citing the known link between cattle and cheatgrass invasions and pointing out the absence of fire from the public lands in question during their previous 5-year reprieve from livestock grazing. When the judge weighed the merit of the competing narratives, he ruled that “Grazing to reduce fire intensity requires a reduction in exotic and invasive grasses, but that would require that first the native bunchgrasses and forbs be overgrazed, which is harmful,” and “sagebrush steppe in the absence of grazing is more fire resistant.”
The California Cattle Council study, which has not yet passed the peer-review process, is a simplistic look at how many pounds of vegetation cattle remove during heavy grazing. It’s pretty straightforward to estimate how many pounds of grass a cow eats. But the study runs afoul of scientific methodology by speculating that “[c]attle grazing plays an important role in reducing fine fuels” even while these conclusions “still need to be experimentally validated in California.”
The reality is that most of California’s current fires are burning in woody chaparral, coniferous forest, and oak woodlands, none of which are candidates for livestock grazing to make a difference.
When a lobbying group like the California Cattle Council starts funding scientific studies that – lo and behold! – advance its members’ own profit motives, red flags start popping up. This ‘study’ belongs in the same place as timber industry claims that we should ignore climate change because fires are the result of too little logging (even as the flames race across heavily-clearcut forests). Which is to say, filed in the recycling bin.