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 The story presents the dangerously simplistic claim that cattle grazing reduces fire risk, based on an unpublished study funded by the California Cattle Council, the results of which have yet to be subjected to the rigors of scientific review.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.
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Erik Molvar is a wildlife biologist published on the herbivore optimization hypothesis of plant-herbivore interactions, and is executive director of Western Watersheds Project, a nonprofit conservation group.
Comments
I tweeted this. Hope the author doesn’t mind.
I did a little research a few years ago regarding cheat grass (which, incidentally, lives up to that name).
Cheat grass is an ‘anticipator’ – it sprouts very early in the season, sucking up moisture and nutrients well before its competitors have even germinated. Then it grows tall, shading its competitors from the sun.
Clever, that.
Early in its growth, it’s green and somewhat tasty, and some grazers will eat it. But as it dries out, its nutritional value is nil; an anecdote from Nevada Department of Wildlife recalls a necropsy done on an adult buck illustrated the animal had died of starvation with a belly full of dried cheatgrass – spiked seed heads and all. So, expecting cattle to target this weed is a little outside of the realm of reality.
As cattle tend to stick to favorite grazing spots, they would have to increase dramatically the number of animals on the range – and those would have to be driven to have no other food source to accomplish what that ‘study’ postulates.
I live in southeast Idaho, elevation 4600 feet. The cheatgrass is just beginning to sprout. It will probably be a beautiful green carpet in a month, ready grow again in early March. It will start developing those sharp seed heads by early April. The cheatgrass will be fully mature and ready to burn by early May.
I have experimented by mowing it in March. After three mowings (simulating heavy grazing) it still produced seed heads on spindly 2-inch high blades.
And as I understand it, those seeds can survive pretty much anything – fire, boiling water (from putting out the fire) – and remain viable for a few years.
And yet – the propaganda continues on!
At this point, I wonder how long it would take to repair these lands IF – IF there ever is a return to common sense & knowledge. Which sure wont happen under the watchful (!) eye of the current Sec. of Int.
All over the Nevada desert are these little ‘exclosures’ – fenced off parcels where no one any bigger than a rabbit can enter to gnaw on the plant life. These were a study undertaken by the University of Nevada Reno in (if I recall correctly) the late 40s-early 50s.
Somewhere between 2006 and 2008, a paper was published. After more than 60 years of non-disturbance, many of the plants in those exclosures had shown little appreciable recovery.
I’m a Nevada girl originally, so these studies are important to me. All the plants that have evolved in those deserts owe their success to growing slowly. You won’t find a stand of sage brush much over 5 1/2 feet tall, but you will find they are at least a century old. (They chain them out of the ground at a frightening and unsustainable rate). Winterfat is a short, long-lived shrub highly prized by wildlife for its high calorie and oil content; it’s also prized by stockmen for late-season fattening of their cattle. Some specimens have been found to be 130 years old; once they’re gone, they will not recover in a human lifetime.
A friend sent me a few Google Books pages from the diary of a USGS ranger, who was surveying the Great Basin – in the late 1800’s. He wrote about native grasses so thick and high, they ‘brushed the belly of my gelding, and at times made distance viewing impossible’.
We have to imagine that, because those days are GONE.
(Hang on; my sermon is almost at an end.)
I have watched deer, prong horn and wild horses nibble at native plants and move on. They don’t decimate their food source. Their methodology actually seems to preserve these plants. They leave seed heads behind. They leave the roots intact. They understand instinctively that they need a variety of grasses and forbs for nutritional and medicinal purposes. Perhaps at one time cattle and sheep had these skills but I think that’s been bred out.
These areas vulnerable to wildfire would have to be planted massively with a food cattle or sheep would willingly eat down to the ground.
What a wonderful post. Thank you!
I wish that the politicians had even the intelligence of ants.