Desert Biome: Animals and Plants

Deserts occur in areas where rainfall is less than 50 cm a year. There are deserts like the Sahara of North America and the deserts of southwestern U.S Mexico and Australia that occur at low altitudes and then there are the cold deserts that occur in the basin and range area of Utah and Nevada and in parts of western Asia. Some deserts have an isolated area of vegetation in a desert, which surrounds a similar water source or spring, this feature is called a desert oasis.

Most of the deserts have a considerable amount of specialized vegetation and vertebrate and invertebrate animals as well. There are few large mammals in the deserts because they are not capable of storing sufficient water and withstanding the heat.

The desert biomes can be separated according to several features.
Deserts are of four kinds.

• Cold
• Hot and Dry
• Semiarid
• Coastal

What are the characteristics of Cold deserts?

The deserts that occur in Greenland, Antarctic and the Nearctic realm are called cold deserts. These deserts are characterized by cold winters with snowfall and high overall temperatures throughout the winter and sometimes the summer too. The mean winter temperatures in cold deserts is between –2 to 4°C and the mean temperature is between 21-26°C.

The mean annual precipitation in cold deserts range from 15-26 cm. The soil in this area is salty, silty and heavy. The plants in cold deserts are widely scattered and vary between 15 cm to 122 cm in height. The main plants in this area are deciduous, most of them having spiny leaves.

The animals found in the cold deserts are the jackrabbits, kangaroo rats, grasshoppers and pocket mice and antelope ground squirrel. Deer are found too but only in winter.

What are the characteristics of Hot and Dry deserts?

The temperatures in the hot and dry deserts exhibit extremes as the atmosphere contains little humidity to block the rays of the sun. The mean annual temperature in the hot and dry deserts range from 20 to 25°C. The rainfall in this area is very low and concentrated in short bursts between long periods of no rain. The evaporation rates in this area are greater than the rainfall that results in rain falling and evaporating before it reaches the ground.

The soils in the hot and dry deserts are coarse-textured, shallow, rocky and gravely with good drainage and have no subsurface water, the reason of the coarse texture is the chemical weathering. Plants here are mostly ground-hugging and short woody trees. The leaves of the plants have been made with water conserving characteristics. Some of the plants in this area open their stomata only at night when evaporation rates are lowest. Yuccas, ocotillo, turpentine bush, prickly pears, false mesquite, agaves and brittlebush are some of plants found in this area.

Small nocturnal carnivores make up the animal life here. Animals like the burrowers and kangaroo rats make up the dominant animals.

What are the characteristics of Semiarid deserts?

The sagebrush of Utah, Montana and Great Basin along with the Nearctic realm make up the semiarid deserts. Here the summers are moderately long and dry with the winters normally bringing low concentrations of rainfall. Plants and animals are benefited by the cool nights that reduce moisture loss from transpiration, sweating and breathing.

The soil in the semiarid deserts range from sandy and fine-textured to loose rock fragments, gravel or sand. Near the mountain slopes the soil is shallow, rocky, gravely, well drained and with good drainage whereas in the bottom land the soil is sandy and fine-textured.

Plants protect themselves in the semiarid deserts with the help of spines. These also help to shade the surface enough to reduce transpiration to a large extent. Some of them also have silvery or glossy leaves that allow them to reflect more radiant energy. Creosote bush, bur sage, white thorn, cat claw, mesquite, brittle bush and jujube are some of the names of some of the plants found in the semiarid desert.

Mammals such as rabbits, kangaroo rats and skunks along with grasshoppers, ants, snakes and lizards inhabit this desert.

What are the characteristics of Coastal deserts?

The Nearctic and the Neotropical realm is the home of the coastal desert. The average temperature in this area ranges from 13 to 24°C with the winter temperatures dropping to 5°C and below. The average rainfall measures in the coastal desert measures 8-13 cm.

The soil in the coastal desert is fine-textured with moderate soil content, and is fairly porous with good drainage. The plants have thick and fleshy leaves or stems that can take large quantities of water when it is available and store it for future use, some plants also have corrugated surfaces with longitudinal grooves and ridges. The salt bush, buck wheat bush, black bush, rice grass, little leaf horse brush and black sage are some of the plants living in the coastal desert.

Like all animals found in the desert, the ones here are also specialized adaptations. Some of them like toads seal themselves in burrows with gelatinous secretions and remain inactive for eight or nine months until a heavy rain occurs while some insects that lay eggs remain dormant until the environmental conditions are suitable for hatching.

Particulars of a Few Desert Animals

Armadillo Lizard

The armadillo lizard is a prey animal that preys on bigger and stronger predators like humans etc. Its body length is 15-17 inches, the tail is 14-16 inches long and it weighs 8-17 lbs. The back legs of an armadillo lizard are a little shorter than the front. It is able to wriggle easily because of the head, body and the club like tail that are all flattened. Predators are unable to harm the armadillo lizard because of the armour on its body.

Desert Tortoise

The front legs of a desert tortoise are muscular and flattened with long claws, which are adapted for digging deep burrows. Desert tortoises make popping, hissing and poinking sounds out of distress and fear. These tortoises live in burrows to escape the cold and the heat. Desert tortoises catch the infrequent rain that falls in basins. Most of the water intake comes from moisture found in the widflowers and grasses that they eat in the spring. The desert tortoise is blessed with the ability to store about a quart of water in its bladder to be used when necessary. The desert tortoise is considered a threatened species, thus it is unlawful to touch, harass, harm or collect a desert tortoise.

Camel

The camel is the largest animal of the desert. This animal has the ability to store large amounts of water for a long time because of that it is able to survive in the dry and harsh desert. Camels are the desert dwellers main mode of transportation. These animals are blessed with a transparent eyelid which enable them to keep sand out of their eyes.

Desert Rat

Kangaroo or desert rats live in large dens with wide openings. It is a very cute critter that resembles a mini kangaroo but is only as large as mouse. It has hair that is yellow buff in color above and white below. The tail of the desert rat has a white turf at the end. This animal has adapted its body by getting its water from the food it consumes. It also has a cheek pouch in which it is able to store food for weeks while looking for shelter. Thankfully, the desert or kangaroo rat is not an endangered species.

Particulars of a Few Desert Plants

Mojave Aster

This is a shrubby plant that is able to grow up to 30 inches high. It has stems that are gray-green and long with silverfish-green, narrow, hairy leaves. This desert plant has narrow purple flowers to lavender rays surrounding a yellow disk, which grows up to 2 inches in diameter. Unfortunately this desert plant dies after flowering.

Cactus

This desert plant is also known by a host of other names like the hedgehog cactus, Claret cup cactus, King’s cup cactus and the Mound cactus. The stems of this plant are cylindrical in shape and are up to 1 foot long and 1 to ½ inches thick. It has about 9 to 10 ribs on the stem. The flowers of this beautiful plant are deep red with many petals that form the shape of a cup. It has fruit too that are red and edible. The cactus uses the cool night temperature to exchange oxygen and carbon dioxide.

Soaptree Yucca

This desert plant is a 10-18 foot plant with palm treelike leaves, with the leaves at the base of the plant. The soaptree yucca is so called because of the presence of a soap like material inside the roots and the trunk of the plant. This plant is also used for decoration in many American gardens.