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RESOURCEUWPACTSOFCHEATGRASS
AND WILDFIRES ON PUBLIC LANDS
AND LIVESTOCK GRAZING
.Thomas C. Roberts, Jr.
ABSTRACT
acres that have been dominated by cheatgrass in Tooele
or Box Elder Counties. We also had some acreage burned
under prescription and noncheatgrass wildfires.
In the past decade, nearly 500,000 acres of rangeland
have burned in the Salt Lake (Utah) District of the Bureau
of Land Management. Most of the acreage consumed has
been dominated by cheatgrass (Bromus tectorum). This
paper addresses the resource impacts on lands dominated
by cheatgrass and burned areas where cheatgrass was not
dominant. Included are discussions of impacts on vegetation, forage, wildlife, and budgets.
NONCHEATGRASSFURES
These comparatively few acres will be addressed first.
In the early and mid-1980's, we had some wildfires go
through Rich County. I will review a couple of them. At
the south end of the county, a lightning strike the evening
of July 24, 1981, caused a fire that consumed approximately 1,100 acres of sagebrush interspersed withjuniper
stands. The hot and dry conditions prior to fire contributed to the hot fire that in combination with high winds
resulted in a very clean burn. The fire moved so fast
through the country that cattle on the South Woodruff Allotment were nearly stranded and killed. Postfire evaluations resulted in rehabilitation efforts on the site. We
used a mix of grasses and forbs in a rangeland drill, and
we were also able to use a Dixon Land Imprinter. We
found the Imprinter to be effective on this site, but because of a narrower swath and poorer control of seed dispersal, it was probably more expensive than the drill to
use. Two years later some clipping studies showed that
the net results of the fire were positive. An unburned plot
yielded a clipped weight equivalency of 880 pounds to the
acre while a burned plot nearby yielded the equivalency of
nearly 1,500 pounds to the acre, an increase of 69 percent.
The notes taken at the time indicate that those areas not
reseeded had also greatly improved.
Clearly the net impact on range productivity was positive. Nonetheless, this fire did require two growing seasons of nonuse on the allotment and an additional workload on the part of the permittees, BLM resource area
staff, Soil Conservation Service district staff, and the expenditure of funds by all concerned. The fire took place
in what was then considered a critical deer winter range,
and they were affected also, shifting their use elsewhere.
The blowing and drifting soil that resulted from the fire
and reseeding operations may have indicated some soil
loss.
On August 25, 1983, a dry lightning strike caused a fire
that burned through the Rabbit Creek area of northern
Rich County. This fire involved parts of two allotments,
the Duck Creek Allotment and the Rabbit Creek Allotment, both summer cattle allotments. The Rabbit Creek
fire was apparently a fast-moving, cool fire in rangelands
that were in pretty good shape with a diversity of grasses
and shrubs, in the sagebrush-grass community type. The
permittees had grazed it conservatively for years and the
INTRODUCTION
The previous days' sessions have included some ideas
on revegetation, the ecology of cheatgrass, and fire ecology
and management. This morning I will address some of
the resource impacts of cheatgrass and wildfires on public
lands and their management.
I will address some of the concerns that we have in the
Salt Lake District of the Bureau of Land Management
(BLM). Our District comprises over 3 million acres of
public land in Box Elder, Rich, and Tooele Counties in
the northern third of Utah. Elevations range from about
4,200 feet at the surface of the Great Salt Lake to over
12,000 feet at the top of the Deep Creek Mountains.
Some of the vegetation comniunity types include: a limited acreage in the spruce-fir type; the aspen community
type; the mountainbrush type; the pinyon-juniper type;
the juniper type; the sagebrush-grass type; the salt desert
shrub type; and the cheatgrass type.
In our District, most of the cheatgrass (Bromus tectorum) type is located in what was or is the salt-desert
shrub community type. Unfortunately, in some parts of
the Pony Express Resource Area, cheatgrass population
is becoming more dense in the sagebrush-grass community type and the juniper community type. Consequently,
its presence is becoming a factor in any vegetation management decision process.
However, my task today is to discuss the resource impacts of cheatgrass and wildfires on the public lands and
livestock grazing in our District. In the last 10 or so years
nearly 500,000 acres have burned in our District. Most of
this acreage has been in cheatgrass wildfires. These are
Paper presented at the Symposium on Ecology, Management, and Restoration of Intermountain Annual Rangelands, Boise, ID, May 16-22, 1992.
Thomas C. Roberts, Jr. is a Range Conservationist for the Pony Express
Resource Area, Salt Lake District Office, Bureau of Land Management,
Salt Lake City, UT 84119.
167
crews of both the Forest Service and BLM were involved.
The rehabilitation work took the commitment of two BLM
Districts and the State Office.
The District has also had a couple of other fires in the
edge of the juniper type that further extended into that
community. One of them, believed to have been started
by a motorcycle, was a fire that burned over 1,100 acres
in August, 1986. This fire was assisted by the slope of the
west side of the Onaqui Mountains. Due to the slope and
community type involved, little suppression action was
taken. However, a few years after the fire, the area is doing well with a str ong population ofbluebunch wheatgrass and Indian ricegrass. Because of the distance from
water, the area was grazed very little by domestic livestock, and consequently there was little impact upon any
human use of the area. The area now receives use by deer
and wild horses.
fuel load and diversity reflected it. When the fire occurred we were able to determine that the area would
need only rest to return to better than prefire productivity. This assessment was confirmed in the clipping studies that showed there to be an increase in productivity of
257 percent, from an equivalent of740 pounds to the acre
to 2,640 pounds to the acre in one allotment and an increase from 680 pounds to the acre to 770 pounds to the
acre in the other allotment. Because of the good condition
on this piece of rangeland, the only loss was some nonuse
for a couple of seasons. The gentle topography and good
rootmasses probably held any soil losses to a minimum.
These two fires may also illustrate the difference in postfire measures needed for sites that are in different conditions; the Rabbit Creek site needed no rehabiltitation
work, while the burn in the South Woodruff area did need
some work.
As described by A. C. Hull (1965), the fire frequency is
less in a community type with a low frequency of cheatgrass, and our experience in Rich County, with less cheatgrass than the rest of the District, confirms his statement.
The major amount of the rest of the acreage that has
been burned in the District over the past decade has been
in the sagebrush-grass community type (with a sizable
cheatgrass component) or in what had historically been
the salt-desert shrub type gone to cheatgrass. A notable
exception would be a fire that included a crested wheatgrass seeding while burning through the sagebrush-grass
and salt-desert shrub types near the Tooele-Juab County
line. This fire happened in July with high temperatures,
high winds, and low relative humidities. In total, about
7,000 acres burned in the Richfield and Salt Lake Districts. Much of the acreage was reseeded with a mix of
grasses, a few forbs, and a small amount of fourwing saltbush. The seeding took place in January and February
and, except for fourwing saltbush, was fairly successful.
This fire was beneficial to us in that it cleaned up a 20year-old chaining of trees and shrubs that were reinvading. It also illustrated that contrary to what some people
may believe, a crested wheatgrass seeding can burn. The
livestock forage impact of this fire was some displaced
livestock grazing use. We were fortunate in our District
that the amount of acreage was only about 1,500 acres,
and the grazing use was transferred elsewhere in one allotment, while in the other allotment there were 2 years
nonuse. This burn also illustrates that the more conservatively stocked and better condition an area is in prior
to a fire, the better it will be after the fire. The fire encompassed two allotments, one that had been conservatively stocked under a cooperative Allotment Management
Plan with the Forest Service, U.S. Department of Agriculture, and one operator, the other allotment with 10 operators, all with their own management goals. The area was
in the transitional range for mule deer from the Sheeprock
Mountains and probably rejuvenated some of the grass
plants that had been getting rank. Some of the sagebrush
plants are returning to the scene. For both native and domestic ungulates, the net result of the fire 6 years ago appears to be positive. However, this had been an expensive
fire, both while it was happening and during the rehabilitation stage. While it was burning for 3 days the fire
CHEATGRASS FIRES
The greatest impact of fire in our District has been
in the cheatgrass type, or in what was probably the saltdesert shrub community type. The problem is best illustrated by the following fire statistics. The Initial Attack
Analysis Model, a part of the National Fire Management
Planning Analysis System, is a system to track statistics
on wildfires. District fires for the last 10 years (1981-90)
have been broken into four classes, defined by fuel type,
in our case analagous to the following vegetation types;
cheatgrass, sagebrush-grass, pinyon-juniper, and fires
along the National Forest boundary, generally at higher
elevations. These models show the average number of
fires per year to be 26 in the cheatgrass type, 15 in the
sagebrush-grass type, 16 in the pinyon-juniper type, and
only eight at the higher elevation Forest boundary.
The statistics can also be broken down by acreage per
year. In 1981, there were 144 fires in the District burning
nearly 34,000 acres. In 1982 there were 44 fires burning
nearly 37,000 acres, and in 1983, 45 fires burned almost
275,000 acres. It would be an understatement to say that
fire and fire rehabilitation took on a life of their own in
1983. The BLM acreage in that amount ofland burned
required the reseeding of over 46,000 acres with nearly
500,000 pounds of seed. The additional District funds for
this total project were over $800,000, requiring the efforts
of a joint team consisting of personnel from the BLM
State Office, the District and Area Offices, and the Soil
Conservation Service. If the problems pertinent to cheatgrass had not been clear before, they were hammered
home that year. The lack of dependability as a source of
forage afforded by cheatgrass had always been a concern,
but this was a solid demonstration. Using an estimated
annual average productivity of 20 acres per animal unit
month (AUM), the fires of that year caused the displacement of nearly 14,000 AUM's, affecting numerous ranching operations for two growing seasons. Another problem
that we attempted to limit was the soil loss. Efforts included gulley plugs and bank stabilization work for an additional cost of $48,000. The soil losses were evident with
estimates of up to 6 feet of gulley erosion and 6 inches of
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sheet erosion taking place that fall. The problems affiliated with rehabilitation projects of this size include: the
disruption of daily routines; the hiring of temporary help,
who may or may not be familiar with the needs of the
land and project; and the high secondary costs, like extra
vehicles, related to the startup and maintenance of projects of this size and immediate nature. Also consider
that this was during a period when we may have been a
little less sophisticated in our demands and skills in rehabilitation efforts.
I think that we have learned a lot since then, and hopefully not all that experience went for naught. That 1983
had a wet spring after a number of wet years and probably set us up for a bad fire year is now a moot point.
That year, if nothing else, taught us that cheatgrass fires
are expensive. If we use the average cost for fire suppression of $5.00 per acre and a minimal rehabilitation cost
of$30.00 per acre for a total cost of$35.00 per acre, we
can see that cost of these fires to the taxpayer is also significant. Unfortunately, not all of our rehabilitation efforts were successful, and even where they were, we are
left with a vegetation type conversion that many people
(and birds or animals) find less than optimal. I also believe that because of the aggressive nature of cheatgrass
as a cool-season annual that it exacerbated any condition
that may have been peripheral to causing the shrub dieoff that we had in the District a few years ago.
Consequently, we have found the cheatgrass type or
its invasion to be frustrating and challenging. Cheatgrass
is an undependable forage source and is a fuel source for
rangeland fires. These fires cause a loss of forage to the
ranching community and wildlife most of us enjoy. Concomitant with that is the ultimate loss of diversity in the
plant and animal communities that we administer. Add
to this the risk of soil loss in an uncontrolled and unplanned fire situation in the precipitation belt where
rehabilitation is difficult, and we have a much less than
desirable condition. According to any common definition,
the loss of diversity and soil would probably fit the term
"desertification."
Is there a ray of light at the end of the tunnel? Yes,
I think that there is. We are gaining knowledge in our
skirmishes with cheatgrass. Although, as we have heard
this week and as we have seen in our District, it is moving
out into other community types, I think that we are becoming more skilled in planning and implementing rehabilitation projects. We are also more cognizant of the potential problems that an aggressive annual plant can
cause, and we are more willing to try new ideas. And we
are seeing the natural revegetation by salt-desert shrubs
(shadscale, Gardner saltbush, and winterfat) in some
areas where we thought they had been eliminated. Examples are along the Pony Express Trail in the Resource
Area and a railroad section that had burned clean in 1984
that have shadscale returning on them. We are also more
willing to attempt to use a diversity of plant materials,
native and exotic, in rehabilitating these burned-over
areas. Although the use of exotics like forage kochia is
debated in some circles, it should be maintained in the
arsenal of plant material to be used in some conditions.
I also feel encouraged with the emphasis that the cheatgrass and native rangeland restoration problem is receiving in the research arena, including the research effort
that the BLM is making.
CONCLUSIONS
We have found that, in general, noncheatgrass burn
areas are less likely to need rehabilitation and, depending
on the prefire management and condition, may not need
any rehabilitation. Consequently these fires are cheaper
and often beneficial from a resource viewpoint. Whereas
fires are expensive to suppress and rehabilitate, cheatgrass burn areas often have a lower rate of success in
rehabilitation. In general, a 2-year, sometimes longer,
period is required after a fire to allow the area to come
back, eliminating the use of the area by domestic livestock. Cheatgrass fires tend to be self perpetuating, decreasing the period between fires. Cheatgrass fires also
decrease flora and fauna diversity in a time when we as
a populace are becoming more concerned with biological
diversity. However, to reiterate, the future is not all that
bleak; we are seeing an increased emphasis on the research and restoration of our native rangelands, and in
some cases a natural revegetation with native salt-desert
shrubs. There is also an increased awareness of the importance of our native rangelands from an overall resource viewpoint, not just their grazing capacity. In
conclusion, I see a future that is interesting, challenging,
and has the potential for great successes.
REFERENCE
Hull, A. C. 1965. Cheatgrass-a persistent homesteader.
In: Proceedings, symposium on the management of
cheatgrass on rangelands; 1965 July 27-30; Vale, OR.
Portland, OR: U.S. Department of the Interior, Bureau
of Land Management: 20-26.
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