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Hot and Cold Deserts
We usually think of deserts
as hot, dry places. However scientists define deserts as
areas of land where less than ten inches of rain falls per year
and few plants grow. In both arctic and Antarctic regions
there is very little rainfall. The precipitation that does
fall is almost always frozen in the form of snow or ice.
Therefore plants cannot grow. These regions are considered
deserts and called "cold deserts" to describe the
temperatures, which range from 10 to 50 degrees Fahrenheit in
summer and from -50 to 10 degrees Fahrenheit in winter.
Hot deserts have high
temperatures. They are usually over 75 degrees Fahrenheit in
the shade. Hot deserts may be cold at night or in the
winter. Very little water is available for plant growth, but
hot deserts are not lifeless. These deserts are home to a
variety of plants and animals that have learned to adapt to the
hot temperatures and lack of water. The acacia tree, for
example sends its roots down over one hundred feet to reach
groundwater. Many desert animals drink no water at
all! They get all the water they need from the foods they
eat.
Deserts can be flat and
covered with shifting sand dunes caused by winds. They can
also have steep, rocky mountains.
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