The desert has the driest climate among all biomes, receiving less than 20 inches of rainfall each year. Deserts cover a fifth of the planet’s surface and are mostly located between 20 degrees and 30 degrees north and south latitude, where equatorial air falling toward the Earth’s surface causes a significant reduction in rainfall. Deserts come in four main types — hot and dry, semiarid, coastal and cold — depending on their general location and proximity to mountain ranges as well as on the overall atmospheric pressure.
Advantage: Habitat for Specialized Flora and Fauna
The desert plays home to a diverse group of plants and animals, all especially adapted for survival in the desert through their efficient use of water. Specialised plant features include thick, waxy leaves and large root or water storage systems, which contribute to their high resistance to drought. Examples of thriving desert plants include various cactus species, prickly pears, yuccas and agaves. A combination of unique evolutionary traits — both physical and behavioural — makes the survival of desert animals possible. Examples include the jackrabbit’s large ears for heat regulation, the spadefoot toad’s hibernation during the driest months, and accelerated breeding among various desert insects and amphibians. Several species are nocturnal, allowing them the best use of the desert’s coolest hours.
Advantage: Abundance of Soil Nutrients
Because most deserts receive little to no rainfall and contain no subsurface water, soils have fairly low salt concentrations — a feature highly favourable for desert plant growth. Depending on the type of desert, soil types range from fine-textured sands to gravel and loose rock. Desert soil holds an abundance of nutrients because of the minute amounts of rainfall and surface runoff, and therefore lends itself easily to agricultural use, provided that an efficient irrigation system is developed.
Disadvantage: Lack of Water
Lack of water, the most evident disadvantage to deserts in general, results from the combined effects of insufficient rainfall and rapid water evaporation by nearby land masses. The rate of rainfall rarely exceeds the rate of evaporation, and it is not uncommon for rain to vaporise even before hitting the ground. The Atacama Desert in Chile, known as the driest place on Earth, receives less than 1 inch of rain per year — on some years virtually none at all — because of moisture blockage and draw-off by the Andes and the Chilean Coast mountain ranges. Though fairly seasonal, desert rainfall is unpredictable and very localised.
Disadvantage: Extreme Weather Conditions
Compared with more humid regions, deserts lack the temperature-buffering effects of water vapour, exposing them to more than twice the amount of solar radiation during daylight hours and to the loss of nearly twice as much heat come nighttime. Daily temperature extremes in arid deserts reach up to 54.4 degrees Celsius at the sun's peak and plummet below freezing in some locations. Other less frequent weather disturbances include sudden wildfires and intense, flood-causing rains.