Transcript PowerPoint Presentation - mrjs

THE MOJAVE DESERT:
A UNIQUE ECOSYSTEM
Geography
 Approximately 25,000 square miles
 Parts in California, Utah, Arizona, and Nevada
 Mountain ranges, salt pans, seasonal saline lakes
 Las Vegas is the largest city in the Mojave
 Elevation mostly 2000 to 5000 feet
 Colorado river and Mojave river (intermittent river)
 Smallest North American desert
Water and Precipitation
 Usually gets around 5 inches of rain a year
 In the rain shadow of the California Coast Ranges
 May and June are the driest months, October to March is wet season
 Seasonal lakes created based on rainfall
 There is a year round supply of ground water
 Wells and agriculture are causing water tables to drop to low levels
Climate
 Temperature can go anywhere from 8°F to 119°F depending on season and time of day
 25 mph winds have been recorded, and are common
 July to September is thunderstorm season
 Humidity is almost always below 40%, with the exception of some winter nights and after
rain
Urban Areas
 27 cities
 Most populated area is Las Vegas (~1.9 mil.)
 Mojave is attached to Los Angeles
 Lancaster is the largest California city
 Many other smaller towns
 Major roads are Interstates 15 and 40 and Highways 58, 395, and 95
 Death Valley National Park, Joshua Tree National Park, and Mojave National Park
 Hoover Dam
 Many shallow root systems are being destroyed by off-road vehicles churning up sand
Death Valley
 Located in Eastern California
 Lowest elevation in North American (282 ft below sea level) in Badwater Basin
 Highest recorded temperature in the world (134°F)
 Mean annual temperature of 77.2
 1.9 inches annual average rainfall
 Mostly Flat
 Rocks have been found that are at least 1.7 billion years old
 Salt pans are rich in Sodium and Borax
 Because of the abundance of salt and lack of precipitation, the Valley is mostly devoid
of plant life.
Ghost Towns
 Many ghost towns in the Mojave, mostly mining towns
 Oatmon, Arizona used to be a gold mining hotspot
 Calico, California was a silver-mining town
 Towns along Route 66 became abandoned when Route 66 was abandoned
Calico, CA
Animal Life
Desert Bighorn Sheep
Mule Deer
Bobcat
Coyote
Mojave Green Rattle Snake
Horned Lizard
Desert Tortoise
Turkey Vulture
Adaptions of Animals
 Animals such as owls are nocturnal
 Owls keep their mouths gaped open to evaporate water from the mouth cavity to keep cool
 Many animals have light colored fur to reflect sunlight
 Large ears of jackrabbits keep them cool
 Desert tortoises have the capacity to hold one quart of water in their bladder
 Desert tortoises spend 95% of their lives in burrows to escape the extreme temperatures
 Only a few out of every hundred tortoises make it to adulthood as they are prey to
animals such as coyotes, roadrunners, and gila monsters
 Kangaroo rats have specialized organs that function to recoup water from their urine
Plant Life
Joshua Tree
Spiny Limbs
Yellow and Green Flowers
Average life span 150 years
Grow in elevations from 3,000 – 7,000 feet
Creosote Bush
Waxy green leaves with yellow flowers
Releases a distinct odor when it rains
Average life span 100 years
Cholla
The only cactus with sheaths over their spines
Most of them have orange or yellow flowers
There are many varieties of cholla
Adaptations of Plants
 Some plants, such as the Joshua tree, are Xerophytes
 Xerophytes have few leaves in order to cut down on transpiration (loss of water vapor)
 The creosote bush contains a deep tap root system and tastes bitter to discourage
animals from eating it
 The cholla cactus has the ability to store water and has thick spines to protect it
from potential predators
 Plants such as the octillo are dormant during dry periods but perform photosynthesis
after rainfall
Unique Traits of Mojave Desert Life
 The Joshua tree is native to the Mojave Desert and does not naturally grow anywhere else
 The Mojave Rattlesnake’s venom is ten times more toxic than that of most rattlesnakes
 The Mojave Rattlesnake gives live birth to its young, rather than laying eggs
 Fungus is found in the desert in the form of desert varnish, which turns rocks different
colors
 The Timbisha Shoshone tribe of Native Americans, which have inhabited the Death Valley
region of the Mojave desert for the last 1,000 years, has been forced to adapt to a modern
way of life as people have moved into their native land over the past 150 years
 Approximately 50-60 people from the Timbisha tribe reside in Death Valley today
Works Cited
http://mojavedesert.net/overview/a02.html
http://www.nps.gov/moja/naturescience/plants.htm
http://www.blm.gov/pgdata/etc/medialib/blm/ca/pdf/pdfs/needles_
pdfs/brochures.Par.29114.File.dat/Wildlife.pdf
http://www.blueplanetbiomes.org/mojave_desert.htm