Deserts: Ecosystems, Characteristics, and Adaptations

Deserts: Arid Ecosystems

A desert is an ecosystem that receives little precipitation. While often reputed to have little life, this depends on the type of desert. Many deserts support abundant life, with vegetation adapted to low humidity. Fauna typically hide during the day to preserve moisture. A desert ecosystem is arid, and this characteristic even enables the establishment of sustainable social groups.

Deserts are the most extensive land area on the planet, covering a total area of 50 million square kilometers, approximately one-third of the land surface. This constitutes 30% of the land surface (16% hot deserts and 14% cold deserts).

Dunes of the Namib Desert

Common Desert Characteristics

Deserts share several characteristics. The desert soil is often composed of sand, and dunes are common. Rocky terrain is typical (a desert where the soil is rock or pebbles is called a hamada), reflecting the low degree of soil development and lack of vegetation. Lowlands can be salt flats. Eolian processes are important factors in shaping the landscape.

Deserts may contain valuable mineral deposits formed in the arid environment or exposed by erosion. Due to the dry conditions, deserts are ideal places for the preservation of human artifacts and fossils.

Desert Classifications

• Semi-arid areas: These areas have an average rainfall of 200 to 500 mm annually. They are usually located at the edges of deserts and cover about 15% of Earth's land surface.
• Arid zones: These zones receive annual rainfall of 25 to 200 mm, comprising 16% of the Earth's land surface.
• Hyper-arid areas: These areas are so dry that sometimes it does not rain for years. They constitute 4% of the land area. Temperatures can range between 30 and 40 degrees Celsius during the day and -10 to 0 degrees Celsius overnight.

Desert Fauna and Flora

Only a few animals survive in the desert, including camels (which can lose three-quarters of their weight in water), lizards, snakes, spiders, owls, scorpions, squirrels, vultures, and coyotes.

Similarly, only a few plants survive. They are protected from animals by spines and thick skin. Examples include cacti, palms, and other plants found in oases.