In the past several decades, fire has become the biggest threat to natural resources in Western states, destroying wildlife habitat, timber resources, livestock forage and private property. One major factor leading to increased incidence of fire on rangelands has been excessive “fuel” from ungrazed forage.
Unless animals remove the fuel, nature takes it out with lightning-caused fires. With excess fuel, a fire burns hot enough to destroy both annual and perennial plants; the former grass-shrub plant community is replaced by invasive annual grasses like cheatgrass and medusahead. Fire-return intervals are shortened, fire burns more readily the next time, and the range condition and fire danger keep getting worse in a downward negative spiral.
“These fires correlate with range adjudication — when the BLM [Bureau of Land Management] started reducing cattle grazing on public land, thinking it would improve rangeland health,” says Robert (Bob) Alverts, owner of Science and Management Consulting and a part-time faculty member at the University of Nevada, Reno, referring to a map showing sites of large fires occurring since 1970. The map was prepared by the National Interagency Fire Center in Boise, Idaho.
“Forgotten was the fact that ungrazed forage becomes fuel. A small fire going through a grass-shrub landscape that doesn’t have excessive fine fuels doesn’t burn as hot or spread as far. It generally doesn’t damage plants and soil as much, or burn up all the seeds in the soil,” he says. Small, quick fires are renewal events that remove some of the old, dead grass — in contrast to catastrophic fires that leave the ecosystem in worse shape.
“Fire in nature is meant to be a renewal event. Given appropriate plant community and plant density, fire goes through quickly and lightly, and takes out some of the plants competing for space, and provides nutrients so the remaining plants can thrive better,” explains Alverts. Managing vegetation by grazing extends fire-return intervals, and fire is not very damaging.
“We don’t see as much fire damage on a properly grazed range or well-managed forestlands. It’s all about plant density and fuel loads. For nearly three decades, between 5 and 10 million acres of forests and rangelands have burned each year [10,125,149 acres in 2015], most of them in federal ownership,” he says.
“These areas, primarily in Western states, are plagued with excessive fuel loads of beetle-killed timber or non-native annual grasses, leading to extreme fires that cost taxpayers millions of dollars in suppression costs alone, without counting post-burn rehabilitation and restoration costs,” says Alverts.
“Federal agency suppression costs are more than double their budgets for fuel reduction treatments. Reducing fire risk through management practices such as late-season grazing, timber harvest and other prevention tools is much less costly and can generate revenue important to rural communities — providing livelihoods to ranchers, improved environmental conditions and essential food and fiber for Americans.” But instead of benefiting from these resources we’re just burning them up, he says.
Several projects have demonstrated the value of late-season grazing to remove fuel on cheatgrass-dominated rangelands. Alverts has been involved with a cooperative project among the University of Nevada, the Burns District BLM, Oregon Cattlemen’s Association, Oregon Beef Council, Harney County Court, and Bill and Pat Wilber’s Drewsey Valley Ranch in Oregon.
“This 14,000-acre allotment has a permit for 330 to 400 cows. Given the large area, limited grazing period and number of cows, it will take several years to fully change the plant community and effectively reduce cheatgrass dominance. But each year, we are making progress, improving the land with this tool,” Alverts says.
“The good news is that BLM authorizes late-season grazing on this allotment. Most BLM allotments don’t have provisions for fall grazing in their AMP [Allotment Management Plan].” Without those provisions, ranchers cannot graze in the fall, and millions of acres that could be treated for cheatgrass reduction are not being helped.
“Late-season grazing doesn’t hurt the land or grass. Forage is dormant at that period of use. This allows us to really hammer annual plants like cheatgrass. At that time of year, the cows prefer the annuals over rank, mature bunch grasses.” That’s because mature annuals like cheatgrass are softer and more palatable.
By that time of year, the sharp seeds have dropped off, and after fall rain, cheatgrass softens up. “When we distribute protein supplement around the pasture to attract cattle to certain areas, it works well. They crave the supplement, which enables them to digest the fiber [meaning they can eat a lot more of it] and makes them also crave the fiber. We keep moving the supplement around the pasture, and between the supplement and the water sources, we can influence how cows graze cheatgrass,” says Alverts. Over time, the reduction in cheatgrass enables perennial grasses to come back and dominate those plant communities.
“I have another project on the Roaring Springs Ranch, with Stacy Davies. It’s only a 1,400-acre pasture, but it’s on private land [meaning they can manage it the way they choose], and they put 1,500 cows in there the first year to eat all the cheatgrass. The first year, there were 2,000 pounds of cheatgrass per acre. The cows were in that pasture for 60 days and grazed it off to a fuel load less than 100 pounds per acre. When we get below 200 pounds per acre, fire risk is significantly reduced. Likelihood of catastrophic fire disappears when fuel loads are under 100 pounds per acre,” he says.
“Now, with all that competition gone, shrubs and perennial grasses are coming back — plant communities that are not as prone to catastrophic fire. We have changed the plant community in a positive way,” Alverts says.
“By using late-season grazing in the fall, ranchers can save about $50 per head per month, because they don’t have to feed high-priced hay, and don’t have to be out there every day feeding cows,” he says. The rancher has to provide and move the supplement tubs, moving the cows around, but it’s not as intensive or expensive.
“When we take that covering of cheatgrass off, it reduces next year’s production. Cheatgrass has lots of seeds that remain viable for several years, but when the next crop grows up in the spring, without that cover from the former years’ thatch to protect it from full sunlight, it doesn’t grow as vigorously. It needs the litter and protection from old, dead grass to shade new seedlings. If cattle keep grazing it off every year, this reduces cheatgrass’ competitive edge on the perennials,” explains Alverts.
“If we keep grazing cheatgrass in the fall to clean up the old grass, soon the perennials outcompete, and we’ll have a plant community of perennials that are more robust. Then the fire risk is significantly lowered, and ranchers can go back to traditional grazing. It’s a win-win situation if we can keep at it,” he says.