 Deserts cover about one fifth of the Earth’s surface and occur where rainfall is less than 50 cm/year. Although most deserts, such as the Sahara of North Africa and the deserts of the southwestern U.S., Mexico, and Australia, occur at low latitudes, another kind of desert, cold deserts, occur in the basin and range area of Utah and Nevada and in parts of western Asia. Most deserts have a considerable amount of specialized vegetation, as well as specialized vertebrate and invertebrate animals. Soils often have abundant nutrients because they need only water to become very productive and have little or no organic matter. Disturbances are common in the form of occasional fires or cold weather, and sudden, infrequent, but intense rains that cause flooding.

 Soil  Sand  Rocks  Rain  Sunlight

DOMINANT PLANTS  Ocotillo  Saguaro Cactus  Desert Sage

DOMINANT WILDLIFE  Armadillo Lizard  Desert Tortoise  Water-holding Frog  Camel  Desert Kangaroo Rat  Thorny Devil  Sonoran Desert Toad  Coyote

GRAPH

GEOGRAPHIC DISTRIBUTION  A desert's landforms change almost daily, dpeending on the winds and how strong they are.Desert winds tend to be hot and long. If a desert wind last long enough it may stir a sandstom, which can last for hours.During sandstorms sand is carried over long distances which may cover or bury things previosly there in sand.After the sand storm, sand dunes are usually formed over whatever may have been burried. In most cases however, sand dues are randomly formed and because the sand is so tightly packed its like walking on solid land.  Deserts are located in the hot,dry reigons of the world.Most of them near the eqator because most of the sun's energy lies in that reigon. One of the most famous deserts is the Sahra desert located in nothern Africa. Another large deseert is located in the middle of Austraila. While not near the eqator, it is still a hot and dry region, sometimes reffered to as the outback. The United states holds a desert as well located near the Rocky mountain range.

INTERESTING FACTS  The world’s largest desert is Antarctica. That’s right, an area doesn’t have to be hot to qualify—it just needs to lose more moisture than it gains.  If you get lost in the desert, you don’t have to urinate on your shirt and wear it on your head like Bear Grylls to avoid dying of thirst. You can suck water from the branches of some palms, such as buri and rattan.  The world record for crossing the Sahara by bicycle was set in 2011 by Reza Pakravan, 36, a market security analyst in London, who made the 1,084-mile journey in 13 days, 5 hours, 50 minutes, and 14 seconds. He started in Algeria, cycled south, then turned east through Niger and Chad to reach Sudan.  In northeastern China, a Green Great Wall of shrubs and trees now being planted may win back the edges of the Gobi Desert. The wall will eventually stretch 2,800 miles from outer Beijing through Inner Mongolia.  German particle physicist Gerhard Knies calculated that in six hours, the world’s deserts receive more energy from the sun than humans consume in a year. An 8,100-square-mile stretch of Saharan desert—an area the size of Wales—could power all of Europe.

QUESTIONS?  How can I tell cacti from other spiny desert plants?  How old do desert plants get?  What is trichomoniasis?

RESOURCES    know-about-deserts know-about-deserts   plants.html plants.html 