Cattle grazing on a nearly half mile wide targeted strip of cheatgrass near Beowawe, Nevada, created a firebreak that recently helped limit a range fire to just 54 acres compared to rangeland fires that more commonly race across thousands of acres of the
This same grazed fuel break held the Boulder Creek Fire to just 1,029 acres in July 2018 and kept the fire out of sage-grouse habitat located downwind.
These “targeted grazing” firebreaks and eight others are part of an evaluation project being managed by the Agricultural Research Service. The agency is partnering with the Natural Resources Conservation Service and Department of the Interior agencies as well as state and local authorities and local cattle ranchers in Idaho, Nevada and Oregon. The demonstration sites are being coordinated into a multi-regional experiment so the targeted grazing concept’s efficacy and environmental impacts can be uniformly evaluated and compared. DOI Bureau of Land Management is funding much of the program.
“The basic idea is to use cattle grazing in the early spring to mow extensive strips of highly-flammable cheatgrass down to 2- to 3-inch stubble in strategic places to remove the fuel that can turn small rangeland fires into megafires in a matter of hours. These fuel breaks are intended to slow fire spread, make it less intense, and provide places from which firefighters can more safely attack and contain the fire,” explained ARS rangeland scientist Pat Clark with the Northwest Watershed Research Center in Boise, Idaho, who directs the targeted grazing evaluation project.
Clark is tracking how much fuel is reduced by targeted grazing, whether these fuel reductions can be maintained up to the start of the wildfire season and what effects targeted grazing might have on environmental health such as changes in plant composition.
“The most challenging part of the project is getting the targeted grazing treatment applied within the narrow and dynamic window when cheatgrass is palatable and sought out by grazing cattle,” Clark said.
“The duration and timing of that palatability window changes every year, depending on temperatures and soil moisture. Consequently, the logistics of getting cattle to the right place at the right time and keeping them there is challenging for all involved, ranchers, BLM managers and ARS researchers,” Clark added.
Cheatgrass (Bromus tectorum) is an invasive cool weather annual grass that came to this country in the late 1800s, probably in shipments of European wheat. Today, it dominates more than 100 million acres of the Great Basin in the western U.S.
Germinating each winter, cheatgrass grows furiously in spring and dies in early summer, leaving the range carpeted in golden dry tinder, easily sparked into flames. The Great Basin now has the nation’s highest wildfire risk and rangeland fires are outpacing forest fires when it comes to acreage destroyed.
Participating ranchers are trying a variety of approaches to keep cattle focused in the strategic firebreak locations, with efficiency and economy in mind since cows do not willingly stay on cheatgrass once it browns.
One obstacle is that some targeted grazing locations may need to have cattle grazing on public land at times not specified under traditional BLM grazing permits so additional planning and permissions are required for ranchers to get cattle to the cheatgrass before it dries out.
So part of the evaluation project is to look at the impact of targeted cattle grazing on environmental health as well as the effectiveness of the firebreak to see if such permissions should be routine.
