Images © by the Norton-Brown Herbarium, University of Maryland, unless otherwise credited.

Creosote bush flat and sand dunes, Death Valley, California

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XIIIb. Mojave Desert:

• A. Location: Southeastern California across southern Nevada to extreme southwestern Utah and into northwestern Arizona; smallest of the North American deserts.
  B. Features:
  • 1. Low, mostly treeless mountain ranges and broad, open valley bottoms.
    2. Extremes in elevation (-282 ft below sea level; near by Panamint Peak is 11,049 ft or -86 m to 3270 m) and temperatures (Death Valley recorded the hottest temperature in the United States at over 126° F).
    3. Precipitation mostly Dec through Mar; 2-5 in (5-12.5 cm) annually; results in winter annuals - plants that flower and fruit in about 8 weeks (see right).
    4. Summer convection storms mean local flash flooding and summer annuals.
    5. Great diversity of annual species resulting in numerous endemics.

  
  

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  Desert floor in flower, Panamint Valley, California

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  C. Vegetation:

  • 1. Dominant shrub is creosote bush (Larrea divaricata), often with bur sage (Ambrosia dumosa) a co-dominant. More arborescent plants include Joshua tree (Y. brevifolia see right), ocotillo (Fouquieria splendens) and mesquite (Prosopis glandulosa var. torreyana).
    2. Moist areas include saltbush, greasewood and pickleweed, with the Old World desert tree or large shrub tamarisk (Tamarix) common along the edges of springs.
    3. Pinyon-juniper are the co-dominant conifers on the mountain slopes; other species of pine occur at higher elevations.
    4. Cacti (members of the cactus family, Cactaceae) are fairly common; more obvious here than in the cold desert, less so than either Sonoran or Chihuahuan.
    5. Many annuals only flower when conditions are ideal. Golden carpet (Gilmania lutea), a Death Valley endemic, will carpet the edges of the valley when it flowers, which is not often, each of the millions of plants producing several thousand seeds which enter into the seed bank.

  D. Animals:

  • 1. Some deer, wild sheep (at higher elevations in isolated mountains), coyotes, jackrabbits, and a multitude of mice (including the packrat), lizard (including the large chuckwalla and horned lizards or "horny toads"), and snakes (e.g., sidewinder, a rattlesnake that moves with only a small portion of its body actually touching the ground).
    2. Numerous birds, many ground-dwellers (quail and the roadrunner); large raptors; resident song birds.
    3. Several endemic species (even genera) of fish and reptiles in isolated, small ponds.

  E. History:

  • 1. Mojave Desert largely occupied by cold desert through much of the Pleistocene, forming over the last 12,000 years.
    2. Many endemics recently evolved; some desert pupfish form new species at a rate of one new species every 4000 years.

  
  

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  Ash Meadows, Nevada
  On 14,000 acres, home of 24 species found no where else in the world

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  F. Exploitation:

  • 1. Mining and grazing are serious problems in places with some recovery programs established; now often caused by feral horses and donkeys ("wild horses").
    2. ORV activities are destroying considerable desert; recently established protection of some Bureau of Land Management (BLM) lands and expansion of some national monuments reducing wide spread damage.
    3. Military activities (including atomic testing) on the desert have greatly altered the environment; some efforts are now being made to study the impact.
    4. Numerous endangered and threatened recovery programs for plants and animals (see one for the desert tortoise sponsored by the U.S. Army).

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Limestone desert ranges with Joshua trees, Nevada

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Desert main page Sonoran Desert
Main Terrestrial Biomes page

Last revised: 17 Oct 1997 - Reveal