Mojave Desert stretches from the wedge-shaped Antelope Valley
eastward across the Colorado River. Bordering the Sonoran Colorado
Desert and running north to the majestic Sierra Nevada mountain
range, the land in between is anything but what we first imagine a
desert to be, flat and featureless
The Mojave Desert
is the driest desert in North America
Mojave Desert is found at elevations of 2,000 to 5,000 feet, and is
considered a "high desert". Temperatures have been as low
as 8°F in January and as high as 119°F in August. The night
temperatures in July and August can at times be in the low to mid
90s. In late winter and early spring the wind is a prominent
feature, with dry winds blowing in the afternoon and evening. Winds
in excess of 25 mph, with gusts of 75 mph or more are not uncommon.
Although it is windy during all months, November, December and
January are the calmest. The humidity is below 40% most of the year.
During most winter nights, and during and after summer rains the
humidity can get above 50%.
Mojave's desert climate is characterized by extreme variation in
daily temperature and an average annual precipitation of less than 5
inches. Almost all the precipitation arrives in winter. Freezing
temperatures occur in winter, while summers are hot, dry and windy.
Most of the rain falls between November and April. There is,
however, a summer thunderstorm season from July to September with
violent and heavy rainstorms possible. In 1986 only 1.5 inches of
rain fell on the Eastern Mojave Desert, while in 1983 6.5 inches
came down. May and June are usually the driest months. The Mojave
Desert experienced very heavy rains in the 1950s, when surface
runoff resulted in severe erosion of gullies and washes and heavy
silt deposits. A long dry period followed, ending with the present
& Land Description
processes including accumulation and vertical redistribution of clay
minerals and calcium carbonate in different soil horizons lead to
increasing soil profile development over time. The degree of soil
development has a deep impact on soil water balance. The Mojave
Dessert consists of a landscape of sand dunes, Joshua tree forests,
and mile-high mountains in the heart of the desert. Wind action
plays a major role in shaping the landforms in the Mojave Desert.
Because vegetation is sparse in arid regions such as the Mojave,
wind can move sand and fine gravel in suspension. Sand is carried
much higher than gravel and for longer distances, sometimes for
thousands of feet into the air while it makes its long journeys.
Uses/ Problems/ Solutions
Mojave has been selected for study because it represents a wide
variety of land uses within a relatively homogeneous natural
landscape. Much of the Mojave Desert is designated wilderness that
is owned and managed by the federal government, particularly the
Bureau of Land Management (BLM Wilderness Areas, 1995), but a large
proportion of the desert belongs to Army and Navy training
facilities. Recently the National Park Service has gained land
ownership surrounding Death Valley National Park and Joshua Tree
National Park after enactment of the California Desert Protection
Act of 1992. Private lands are held primarily by ranchers, and some
mining interests yet exist throughout the desert. Overall, the
diversity of land use and the factors that force change within the
Mojave Desert make this region a natural choice to study the effects
of anthropogenic disturbance on flora and fauna in a desert
Weather Events Commonly Experienced
Mojave Dessert regularly has a summer thunderstorm season; from July
to September, during which the Soda Springs area has experiences
violent and heavy rainfall, up to 2 inches in 2 hours.
Mojave Desert is dominated by low, widely spaced shrubs, including
the creosote bush (Larrea tridentata) and Mojave sage (Salvia
mohavensis). The Mojave flora includes few trees other than the
signature Joshua tree (Yucca brevifolia), but features a number of
cacti, several parasitic plants, and a vast variety of wildflowers.
Groundwater and the Mojave and Colorado Rivers are the primary water
sources for the Mojave Desert's plants and animals, and for the
booming populations of desert cities.
Plants and other producers
- Creosote bush
- Joshua tree
- Saguaro Cactus
- Mojave aster
- Barrel cactus
- Red tailed
- Red Racer
- Horned lizard
- Giant desert
- Desert iguana
- Fire Ants
Much of the less
spectacular desert land in the southern USA and northern Mexico has
been converted to agricultural use, supported by irrigation canals
that draw water from the major rivers such as the Colorado River.
The crop yields can be very high because of the warm growing
conditions in these regions. The high-value market crops grown in
these conditions include onions, peppers, tomatoes, alfalfa, citrus
crops, grapes and nuts such as pecans and walnuts. Some examples are
shown in the images below.
However, the ecological impacts of
this are raising concerns, for at least two reasons.
Many of these intensively farmed crops rely on the use
of insecticides and herbicides, which can seriously affect the
populations of native pollinator species (moths and bees). The
insecticides can kill these organisms, and the herbicides destroy
the native "weed" plants that provide pollen and nectar
The widespread conversion to agricultural use causes
fragmentation of the desert habitat, which can seriously disrupt the
migration of pollinators and other migratory species (e.g.
hummingbirds, bats, hawkmoths, monarch butterflies). These animals
need "corridors" of wild vegetation on which they can feed
during their annual migrations.