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These deserts occur in moderately cool to warm areas such as the Nearctic and Neotropical realm. A good example is the Atacama of Chile. The cool winters of coastal deserts are followed by moderately long, warm summers. The average summer temperature ranges from 13-24° C; winter temperatures are 5° C or below. The maximum annual temperature is about 35° C and the minimum is about -4° C. In Chile, the temperature ranges from -2 to 5° C in July and 21-25° C in January. The average rainfall measures 8-13 cm in many areas. The maximum annual precipitation over a long period of years has been 37 cm with a minimum of 5 cm. The soil is fine-textured with a moderate salt content. It is fairly porous with good drainage. Some plants have extensive root systems close to the surface where they can take advantage of any rain showers. All of the plants with thick and fleshy leaves or stems can take in large quantities of water when it is available and store it for future use. In some plants, the surfaces are corrugated with longitudinal ridges and grooves. When water is available, the stem swells so that the grooves are shallow and the ridges far apart. As the water is used, the stem shrinks so that the grooves are deep and ridges close together. The plants living in this type of desert include the salt bush, buckwheat bush, black bush, rice grass, little leaf horsebrush, black sage, and chrysothamnus. Some animals have specialized adaptations for dealing with the
desert heat and lack of water. Some toads seal themselves in burrows
with gelatinous secretions and remain inactive for eight or nine
months until a heavy rain occurs. Amphibians that pass through larval
stages have accelerated life cycles, which improves their chances
of reaching maturity before the waters evaporate. Some insects lay
eggs that remain dormant until the environmental conditions are
suitable for hatching. The fairy shrimps also lay dormant eggs.
Other animals include: insects, mammals (coyote and badger),
amphibians (toads), birds (great horned owl, golden eagle and the
bald eagle), and reptiles (lizards and snakes).
The Atacama Desert of Chile is a sparsely populated
virtually rainless plateau, running from the Pacific Ocean to the
Andes Mountains. The average width is less than 100 miles but it
extends 600 miles south from the Peruvian border. The mountains
nearest the ocean are the Pacific coastal range, with an average
elevation of 2500 feet. The Cordillera Domeyko, a range of foothills
of the Andes Mountains, lies east. The Atacama is made up of salt
basins (salars) sand and lava flows. The landscape is so desolate
it is sometimes described as "moon like". In fact the
Atacama has been chosen as a good site to test the prototype of
a future lunar rover.
Coyote
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Use the navigational bar to above to move through each specific ecosystem, resources and adaptations.
Click on the snake to view a QuickTime
Virtual Reality clip of the Saguauro National
Park Visitor Center. You need to have Apple QuickTime to view the image.
Black Sage
Bunch Sage
Llama
Great Horned Owl |
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