What Is a Temperate Desert?
- The Great Basin of North America covers a good portion of the inter-mountain West. It is so named because precipitation that falls in the region has no natural path to the sea. The only means of escape is by evaporation or filtration into underground aquifers. Desert conditions exist over most of this land, because it lies in the shadow of the Sierra Nevada mountains. Most of the region's precipitation comes during the winter in the form of snow. Isolated pockets like the Wasatch Mountains of Utah support dense conifer forests because of a large winter accumulation. Elsewhere in the region three types of desert exist: the hot semiarid desert, the cool temperate desert and the salt flats.
- In South America along the coast of Chile, there exists a most unusual place called the coastal desert. Better known as the Atacama, this area sits at the base of the Andes mountains, wedged against the Pacific Ocean. This desert region is extremely dry, with some places not having received any rainfall in more than 400 years. Since the Atacama borders the Pacific Ocean, it may seem puzzling why it remains so dry. The answer lies in the trade winds that blow in from the east, leaving this coastal region on the dry side of the Andes. Summertime temperatures are also quite cool, seldom exceeding 75 degrees.
- Besides America's Great Basin and Chile's Atacama, temperate deserts can be found in Eurasia, the Himalayas, Afghanistan and China. Most of these areas are characterized by being in the shadow of very high mountains and supporting a type of vegetation that differs somewhat from hotter subtropical deserts. Missing are the succulent cacti, aloe, agave and yucca plants. In their place is a predominance of clumps of grasses, low-lying shrubs and dwarf trees. For example, the Great Basin region of Nevada, Utah and Oregon is dominated by sagebrush, greasewood, blackbrush, snakewood and sometimes the prickly pear, a spreading cactus that is able to survive the cooler climate.
- Not only are there temperate deserts, but there are also polar deserts. By definition, the entire Antarctic ice shield is a desert, because average annual precipitation does not exceed 10 inches. Moreover, in some places the total amount of moisture, which falls solely as snow, is closer to 2 inches. This is even less moisture than that received by the Sahara Desert. Because the temperatures are so cold, this frozen precipitation scarcely melts during the course of a year. Much of the same can be said about the Arctic region, as well.
