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Desert Experimental Range
The Desert Experimental Range is in Pine Valley approximately
70 km (43 miles) west of Milford, Utah. It is geographically a
nd floristically representative of approximately 200,000 square kilometers
(77,220 square miles) of the Great Basin,
an arid region of the Western United States comprising a
series of north- and south-aligned ranges and closed basins.
It was established in 1933 when President Herbert Hoover
withdrew 225 sqare kilometers (87 square mile sections) from
the public domain "as an agricultural range experiment station."
Construction of an office, living quarters, support buildings, well, tennis court, major roads, and over 190 km (118 miles) of fence were completed before 1935 by a large camp of the Civilian Conservation Corps.
These facilities have allowed the Desert Experimental Range to serve not only as a year-round research center at a remote location, but also as a range ecology educational facility of international significance. Appropriately, in 1976 the Desert Experimental Range was designated a Biosphere Reserve by the United Nations Educational, Scientific, and Culture Organization (UNESCO) under the Man and the Bioshpere (MAB) program. Currently, it participates as one of a handful of Biosphere Reserves representative of cold-desert biomes worldwide and is unique in this respect in the Western Hemisphere.
Sheep grazing studies began in the winter of 1934-35 to
study the economic and ecological impacts of grazing at
different intensities, seasons, and frequencies. The core of
those grazing treatments has been maintained to date.
Several permanent exclosures ranging in size from 0.4 to
740 ha are scattered throughout the Desert Range on
most plant community types. This allows direct
examination of the effects of grazing and non-use.
Climate
The climate is that of a cold desert, with cold winters and
warm summers. Mean January temperature is -3.5 °C,
and 23.3 °C for July. Mean daily range in temperature is
18 °C, though daily swings of 28 °C are not unusual in
the summer. The average frost-free period is from about
mid-May to late-September (125 days). Elevation ranges
from 1,547 to 2,565 m. Mean annual precipitation at
valley sites is 157 mm, about half of which falls from
May to September. Generally, monsoonal precipitation
(July-August) does not reach the effective root zone
(deeper than 8 cm) of most species, providing little value
for plant growth. Winter and spring precipitation
typically reaches soil depths of 15 to 70 cm, and is
available to plants during the growing season.
Precipitation on surrounding hills can be as much as 50
percent higher than that in valley locations.
Soils
The mountain ranges surrounding the Desert Range are
composed primarily of sedimentary rock of Paleozoic
origin. Dolomite, limestone, and quartzite are the
primary parent materials of soil formation. Some early
Tertiary igneous extrusions are present. Soils are Aridisols
(Calciorthids and Camborthids) and Entisols
(Torrifluvents and Torripsamments). They are mostly
gravelly loams, sandy loams, and loamy sands with low
clay content, except for the mostly barren hardpan, or
playa, in the valley bottom. Soil pH averages around 8.0
and salt concentrations are low (upper 30 to 40 cm).
Carbonate content is relatively high in most series.
Soil disturbance is important on local and landscape
scales. For example, burrowing mammals occupy and
continually disturb patches 3 to 12 m in diameter. This
retards soil horizon development and thus alters
vegetative composition. These patches create a distinctly
spotted appearance when viewed from above and occur
on 10 to 15 percent of the landscape. On a larger scale, a
small Pleistocene lake filled the lower regions of Pine
Valley and left still recognizable shorelines and a playa.
Infrequent but intense summer storms scour ephemeral
washes, moving sediments down the long alluvial fans
that skirt the rocky peaks.
Vegetation
Native vegetation for the alluvial slopes and valley
bottom that make up about 75 percent of the Desert
Range comprises relatively few perennial shrubs, grasses,
and forbs, commonly referred to as the salt-desert shrub
vegetative community. Dominant shrub species are short,
approximately 25 cm, and include shadscale saltbush,
winterfat, budsage, and low rabbitbrush. Larger shrubs
that become important on upper alluvial fan sites and in
washes include Nevada ephedra, rubber rabbitbrush, and
desert almond. Primary grasses include Indian ricegrass,
bottlebrush squirreltail, galleta grass, sand dropseed,
purple three-awn, and blue grama. Gooseberryleaf
globemallow is the most widespread perennial forb.
Important annuals include cheatgrass, halogeton, and
Russian thistle, all nonnatives. Numerous distinct
combinations of two to eight dominant species and near
monocultures are common.
Black sagebrush, Utah juniper, singleleaf piñon pine, and
littleleaf mountain mahogany often dominate the shallow
soils of foothills and mountain slopes. Numerous species
of shrubs, grasses, and forbs result in communities with
considerably greater floristic and structural diversity than
those in valley locations.
Long-Term Data Bases
Daily precipitation and daily temperatures (minimum
and maximum) are available from 1934 to 1981.
Collection of hourly data on precipitation, air and soil
temperatures, soil moisture, solar radiation, and
windspeed and direction began in 1993. Field-drawn
vegetation maps were completed in 1934 and 1974.
Community composition data on paired grazed and
ungrazed exclosures were collected periodically from
1934 to 1994. Biomass production data are also
available. Maps reveal grazing treatments, roads,
vegetative communities, and fences. Aerial photographs
were taken in 1953 (1:60,000), 1970 (1:30,000), and
1973 (color 1:15,000). A soils map is available.
Research, Past and Present
Research on the Desert Range has focused on the
following topics: disturbance and successional processes
in North American cold-desert plant communities;
desertification; winter sheep management on the cold
desert; rodent ecology; pronghorn antelope biology and
management; cryptobiotic soil-crust ecology; and avian
and mammalian population dynamics.
Facilities
Three dwellings with running water, electricity,
telephone, and oil furnaces are maintained at the DER.
Support structures include power house, garages, shops,
horse barn, and well house. Potable water is available.
There are no laboratory facilities. An automated weather
station is maintained at the headquarters. Use of the
facilities must be scheduled in advance.
Location
The Desert Experimental Range is located in Pine Valley
about 70 km west of Milford, Utah, on State Road 21.
The headquarters complex is about 4 km north of
Highway 21 on an improved gravel road accessible by
ordinary vehicles year round. Travel to the Desert Range
is about 4 hours from Provo, and 2 hours from Cedar
City, Utah.
Lat. 38°40' N, long. 113°45' W
Contact Information
Desert Experimental Range
US Forest Service
Rocky Mountain Research Station
Shrub Sciences Laboratory
735 North 500 East
Provo, UT 84606
Tel: (801) 356-5100
Forest website
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