Death Valley also contains these minerals colemanite and ulexite. The largest mine in near the town of Boron. Gypsum, used in Plaster of Paris is an evaporite composed of calcium sulfate. Talc is also mined in the desert mountains. Rare-earth minerals are also found in the desert, used in glassmaking, petroleum and metallurgy, the important mineral is bastnaesite mined in area where the Clark Mountains and Interstate 15 cross. Joshua Tree habitat is well-drained loose gravel and sand, on the upper part of gentle slopes.
Joshua Trees Yucca brevifolia , the symbol of the Mojave Desert, are pollinated by yucca moths and produce white flowers when temperature and precipitation are favorable. The germination of the tree's seeds occurs with the winter rain, but rarely survive the predation of rodents. Survival is increased for those trees located under nurse plants. Joshua Trees are host to many insects. The Yucca Weevil larvae kill stem tips, thereby creating branching. This action makes the Yucca Tree the largest flowering plant in the Mojave Desert.
Approximately 25 different species of birds have been identified in the Joshua Tree habitat. The most obvious are the woodpeckers, which thrive in the environment due to the soft wood of the Yuccas and the abundance of termites. Lizards also benefit from the supply of termites. Snakes such as the Night Snakes live under the fallen boughs and feed on the lizards and a variety of insects.
Antelope Valley, in the western portion of the Mojave Desert, was the fastest growing area in the state in the s. Ordinances were created to protect the Joshua Trees and other sensitive species. Overgrazing in the already deficient ecosystem causes erosion and arroyos, the increase of weeds and unpalatable species. The food production is so poor that it takes 10 acres to support 1 steer or 5 sheep without any other herbivorous animals.
Desert grazing can destroy the microbiotic crust of the soil, which functions as an absorbent for water and prevents erosion from water and wind.
The problem of overgrazing is increased by feral "domesticated" animals horses and burros. Those animals have been hunted in the past until Congress passed laws in It is believed that there are approximately 2, feral horses in California. The issue of how to control the feral horse population continues to be a matter of debate among ranchers, BLM, and animal rights activists.
Likewise, Burros pose a threat to native plants and animals competing for food and water. The Burros who take over the few water holes that exist have particularly threatened the Bighorn Sheep. BLM has created "adopt-a-burro", a program to relocate the Burros. California's Deserts by Jane Wright, The Chickadees The state has 3 main desert geomorphic earth form provinces, which are caused by rain shadow effect.
A desert is an area that receives less than 10 inches of precipitation per year. Some of the deserts in California receive even less. Our deserts also have wide variation in when they obtain their precipitation.
Using water from several lakes to irrigate the land, the Modoc Plateau is being used as agriculture and pasture land. Located further north the Great Basin is cooler than the other California deserts therefore; its growing season is in the spring vice the winter.
Like the Great Basin the drainage is internal does not flow to the sea flowing into a salt lake. The most common plant in this desert is the Great Basin Sagebrush. Other plants include the Blackbrush, Shadscale, and some Pinyon Pine. These plants all grow in their own niches. The Mojave is a very hot desert with its precipitation falling mostly in the winter in the form of rain and snow.
The dominant vegetation is the Joshua Tree. Other plants are pinyon pines and Blackbrush, Creosote Bush, Shadscale, and cactus. Located in some washes you can find Desert Willows, or Honey Mesquite. The precipitation in the desert falls mainly in the winter, but it does experience some summer rain as well. The dominant plant is the Creosote Bush. In seeps and oases the California Fan Palm grows. Desert Chaparral and pinyon pine grow at the western edge of the desert. Due to the climate in the deserts you can find ancient landscapes that have survived the test of time.
The Mojave Desert has metamorphic rocks older that a billion years old. Shales, sandstones, and limestones are left over from the Paleozoic Era when the deserts were cover with seawater.
Since 65 million years ago the deserts areas built up freshwater sediments and fossils of land mammals indicating that the areas were now above sea level. From 25 millions year ago to today the major faulting transpired. The west coast began moving northward along the San Andreas Fault this caused the deserts to spread. The Garlock fault affected the Basin-Range Province. The faulting caused the mountains to uplift and the valleys to sink.
It also caused rivers to be blocked or redirected leaving freshwater lakes without runoff and to eventually dry up. Volcanism was another important aspect in the creation of the deserts changing the landscape, leaving lava deposits, disturbing the soils, and leaving sediments. Volcanism deposited many useable minerals and ores making mining a significant economic pursuit in our deserts. Mineral and ores found are gold, silver, lead, zinc, tungsten, iron, salts, potash, potassium, borates colemanite, ulexite, and kernite , gypsum, talc, and rare earths.
Joshua Trees are usually grown in areas that have well-drained loose gravel and sanded soils. They also prefer gentle sloping terrain. These trees form the overstory for some very important understory plants. Without some of these plants, particularly the "nurse plants" the Joshua Trees might all be destroyed by rodents.
Many animals and insects are associated with the Joshua Trees including Yucca moths, Yucca weevil, termites, and 25 species of birds most conspicuous - Northern Flickers and Ladder-backed Woodpeckers.
Overgrazing of herd animals has dramatically affected California Deserts. Herd animals grazing changes and destroys the natural vegetation and increases the distribution of weeds. They also compact the soil, which increases run off, and erosion. The bottom line is that the deserts cannot support the magnitude of the herd animals that are allowed to graze. Due to the low productivity in the desert, it is estimated that at least 10 acres are required to support a single cow or five sheep.
Feral horses, burros, and donkeys are a growing problem for the desert ecology. Overgrazing has also destroyed or does not provided sustenance for the natural desert animals such as the Desert Bighorn Sheep. Mojave Desert. Creosote Brush dominates over most of the area with saltbushes occurring where soil becomes alkaline. Entire desert valleys sit uncomfortably in what's called a "transition zone" between the Mojave and Colorado deserts -- or at least they would be uncomfortable if they paid attention to the mapmakers, which they do not.
Mojave Desert plants and animals grow right next to Sonoran Desert plants and animals in the desert valleys north of Interstate 10 in California. On the other side of the Colorado River, even the indicator species stop cooperating with the mapmakers. There are places in Arizona where saguaros -- the signature tree of the Sonoran Desert -- grow interspersed with Joshua trees, the signature tree of the Mojave. Fuzzy boundaries like this are pretty much the only kind that exist in nature. The easier it is to draw a precise line surrounding a thing, the less likely that thing is to be real.
That's not to say the fuzzy boundary doesn't exist. The Mojave Desert does have real boundaries. Barstow, Lancaster and Baker are inside those boundaries. Wrightwood, Tehachapi, and Needles? It depends who you ask. I write here in the Back Forty about the California Desert, and I suspect most readers understand that it's a term of convenience.
But it's useful every so often to remind oneself that while the various deserts that make up the eastern part of the state are real, physical things with fuzzy boundaries, the state of California is more a shared social assumption than a physical thing, and that the desert doesn't end on the other side of that "Welcome" sign with the coastal California poppies on it.
People do forget that. Clark Mountain in the Mojave National Preserve tops out at 7, feet; a couple dozen miles north is Mount Charleston, almost 4, feet taller. But Mount Charleston is in Nevada, and Clark Mountain is just inside California, and so Californians often refer to Clark Mountain as the "tallest mountain in the Mojave Desert," even if they really ought to know better.
Even the "Colorado Desert," which is a California Desert pretty much by definition, includes quite a number of square miles of desert in adjacent Baja California, Arizona and Sonora. California hosts portions of three of North America's four great deserts -- the Sonoran, the Mojave, and the cold Great Basin desert to the north -- but shares each of them with other states, and in the case of the Sonoran, a number of those states are in Mexico.
As for the Mojave, a majority of it is indeed in California, and it's the Mojave that most non-Californians picture when they think of the California desert. But the Mojave Desert also occupies the southern third of the state of Nevada, a corner of Washington County in Utah, and a broad swath of northwestern Arizona.
The rounded granite boulders of Joshua Tree National Park and the eroding Miocene cliffs of Red Rock Canyon State Park are defining places in the Mojave Desert, but so is the edge of the Mojave near Kingman, where the Mojave slowly fades out in the face of the Mogollon Rim, and the slopes around Beaver Dam Wash in Utah, where Joshua trees and blackbrush grow out of Colorado Plateau red rock, and the Tikaboo Valley in Central Nevada, tucked into a corner of Area 51, the one place on earth where the two subspecies of Joshua trees grow together.
There are places in the Mojave where good dirt roads wind around mountains astride a state line, or two, and you can park with your front wheels in a state governed by Mormons and your rear wheels in a state governed by Mammon, and everyone who cares about that imaginary mapmaker's line is in a state capitol far outside the Mojave's real but fuzzy boundaries.
In years California, Nevada, Arizona and Utah may be dimly remembered trivia, but the Mojave will still be the Mojave.
Chris Clarke is an environmental writer of two decades standing. Read his recent posts here. Tending Nature. The Mallorca Files. A large amount of rain that the Mojave gets is in the winter season from October to March. Animals of the Mojave have light colored feathers and fur to reflect the light of the sun.
Desert tortoises have a good adaptation for the desert. They can store up to one quart of water in their bladder. They feed on plants in the spring so that they have enough water to last them the rest of the year.
Plants have adaptations also, such as shallow root systems, spines, and thorns. Shallow root systems can easily absorb rain because they are so close to the surface.
Spines store water by expanding like an accordion. In addition, thorns protect the plants from danger. The Mojave Desert is jeopardized by large cities, such as Los Angeles, which are spreading rapidly through the desert. Military bases are moving in, and farms are developing along the Colorado River. Off-road vehicles are ruining the desert by churning up sand and destroying the shallow root systems.
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