Desert Biome: the Driest of All Terrestrial Biomes (original) (raw)

The Habitat Encyclopedia: Desert Biome

The driest of all terrestrial biomes

Photo © Alan Majchrowicz / Getty Images.

Updated on January 02, 2018

The desert biome is a dry, terrestrial biome. It consists of habitats that receive very little rainfall each year, generally less than 50 centimeters. The desert biome covers about one-fifth of the Earth's surface and includes regions at a variety of latitudes and elevations. The desert biome is divided into four basic types of deserts—arid deserts, semi-arid deserts, coastal deserts, and cold deserts. Each of these types of deserts is characterized by different physical characteristics such as aridity, climate, location, and temperature.

Daily Temperature Fluctuations

Although deserts are highly varied, there are some general characteristics that can be described. The fluctuation in the temperature throughout a day in a desert is far more extreme than the daily temperature fluctuations in more humid climates. The reason for this is that in damper climates, humidity in the air buffers the daytime and nighttime temperatures. But in deserts, the dry air heats up considerably during the day and cools off quickly at night. The low atmospheric humidity in deserts also means there is often a lack of cloud cover to hold the warmth.

How Rainfall in the Desert Is Different

Rainfall in deserts is also unique. When it does rain in arid regions, precipitation often comes in short bursts that are separated by long periods of drought. The rain that falls evaporates quickly—in some hot arid deserts, rain sometimes evaporates before it hits the ground. The soils in deserts are often coarse in texture. They are also rocky and dry with good drainage. Desert soils experience little weathering.

The plants that grow in deserts are shaped by the arid conditions in which they live. Most desert-dwelling plants are low-growing in stature and have tough leaves that are well-suited to conserve water. Desert plants include vegetation such as yuccas, agaves, brittlebushes, lack sage, prickly pear cacti, and saguaro cactus.

Key Characteristics

The following are the key characteristics of the desert biome:

• little rainfall (less than 50 centimeters per year)
• temperatures vary greatly between day and night
• high evaporation rates
• coarse-textured soils
• drought-resistant vegetation

Classification

The desert biome is classified within the following habitat hierarchy:

Biomes of the World > Desert Biome

The desert biome is divided into the following habitats:

• Arid deserts - Arid deserts are hot, dry deserts that occur at low latitudes around the world. Temperatures remain warm year-round, although they are hottest during the summer months. There is little rainfall in arid deserts and what rain does fall is often exceeded by evaporation. Arid deserts occur in North America, Central America, South America, Africa, southern Asia, and Australia. Some examples of arid deserts include the Sonoran Desert, Mojave Desert, Sahara Desert, and the Kalahari Desert.
• Semi-arid deserts - Semi-arid deserts are generally not as hot and dry as arid deserts. Semi-arid deserts experience long, dry summers and cool winters with some precipitation. Semi-arid deserts occur in North America, Newfoundland, Greenland, Europe, and Asia.
• Coastal deserts - Coastal deserts generally occur on the western edges of continents at approximately 23°N and 23°S latitude (also known as the Tropic of Cancer and the Tropic of Capricorn). In these locations, cold ocean currents run parallel to the coast and produce heavy fogs that drift over the deserts. Although the humidity of coastal deserts may be high, rainfall remains rare. Examples of coastal deserts include the Atacama Desert of Chile and the Namib Desert of Namibia.
• Cold deserts - Cold deserts are deserts that have low temperatures and long winters. Cold deserts occur in the Arctic, Antarctic, and above the treelines of mountain ranges. Many areas of the tundra biome can also be considered cold deserts. Cold deserts often have more precipitation than other types of deserts. An example of a cold desert is the Gobi Desert in China and Mongolia.

Animals of the Desert Biome

Some of the animals that inhabit the desert biome include:

• Desert kangaroo rat (Dipodomys deserti) - The desert kangaroo rat is a species of kangaroo rat that inhabits the deserts of southwestern North America including the Sonoran Desert, Mojave Desert, and the Great Basin Desert. Desert kangaroo rats survive on a diet that consists primarily of seeds.
• Coyote (Canis latrans) - The coyote is a canid that inhabits a wide range throughout North America, Central America, and Mexico. Coyotes inhabit deserts, grasslands, and scrublands throughout their range. They are carnivores that feed on a variety of small animal prey such as rabbits, rodents, lizards, deer, elk, birds, and snakes.
• Greater Roadrunner (Geococcyx californianus) - The greater roadrunner is a year-round resident of the southwestern United States and Mexico. Greater roadrunners are fast on their feet, they can outpace a human and use that speed and their sturdy bill to catch their prey which includes lizards, small mammals, and birds. The species inhabits deserts and scrublands as well as open grasslands.
• Sonoran Desert Toad (Incilius alvarius) - The Sonoran desert toad that inhabits semi-deserts, scrublands, and grasslands in southern Arizona at elevations below 5,800 feet. The Sonoran desert toad is one of the largest toads native to North America, growing to lengths of 7 inches or more. The species is nocturnal and is most active during the monsoonal season. In drier periods of the year, Sonoran desert toads remain underground in rodent burrows and other holes.
• Meerkat
• Pronghorn
• Rattlesnake
• Banded Gila Monster
• Cactus wren
• Javelina
• Thorny devil