Definition of desert biome
The desert biome is a an extremely hot and dry ecosystem form as a result of low rainfall it receives yearly; this desert covers about 1/5 of the planet earth and it is further categorized into four groups which are- hot, dry, semi-arid or steppe, coastal and cold desert biomes. The desert usually receives low rainfall each year and for this reason, many plants and animals have developed some unique feature to adapt to the weather condition of the deserts. The temperature of the desert biomes is extremely hot during day, but gets cold in the night, however the desert animals are nocturnal in nature (sleeping during the day and coming out at night when the temperatures are more tolerable).
Desert biomes location
The desert biomes are located at the lower latitudes, between the Tropic of Cancer and the Tropic of Capricorn, since they are subdivided into 4 major types it will be wise to know their location based on the type.
- Hot deserts are located at the Sahara, Arabian, Australian, Australia, Arabian, Peninsula, Mexico/ S.W. USA, S.W. Africa, S.W USA. Others include Argentina, South America, North Africa, Indian, Pakistan and Kalahari deserts.
- Coastal deserts are found at Peru and Chile
- Cold deserts are located at china, Mongolia, Iran, Afghanistan, S.W Africa, W. China, Argentina, South America, Middle East, Antarctica and USA.
- Semi-arid deserts/ Steppes or moderately dry lands are located at USA, Canada, Ukraine and China.
Desert biomes Climate (temperature)
Deserts are characterized by low moisture levels and precipitation, which is both infrequent and unpredictable from year to year, with little moisture to absorb and store heat. Daily seasonal temperatures can fluctuate widely. Deserts that have less than 2.5cm (inches) of measurable precipitation support almost no vegetation, however, deserts with 2.5- 5cm (1-2 inches) annual precipitation have sparse vegetation (less than10 per cent of the ground is covered), and plants ( mostly xerophytes) in this harsh climate needs a variety of specializations to conserve water and protect tissues. The plants have fleshly stems and swollen leaves, they absorbs large amounts of water during the infrequent period of rain, thereby swelling up the stems only to contract later as moisture is slowly lost through transpiration. Transpiration takes place through the stems, but it is reduced by the stomata closing during the day and then opening nocturnally. The stems also have a thick and waxy cuticle.
Warm, dry, descending air creates broad desert bands in continental interiors at about 300 North in American southwest, North and South Africa, China and Australia. These descending air currents also help create desert striped along the west coast of South America and Africa that are among the driest regions in the world. Although we think of deserts as hot, barren and filled with sand dunes, those at high altitudes or high elevations are often cool or even cold and sand dunes are actually rather far away from coastal areas. Most deserts around the world are gravelly or rocky scrublands where 5 to 10cm (2 to 4 inches) of annual precipitation supports a sparse, but often rich community dominated with shrubs or small trees. In rare years when winter rains are adequate, a breath-taking profusion of spring ephemerals (plants with very short life cycle: normally two or three weeks) can carpet the desert with flowers.
Desert biomes plants
Dry deserts vegetation is made up of dwarf trees, Shrubs, Camel thorn tree, Saguaro ,prickly pear and various types of cactus (these are drought resistance plants). In some deserts, plants of such are gravelly and sandy virtually no plants exist. Extremely high temperatures, low humidity, high pressure and very little rainfall characterize the climate of the deserts. The rainfall type is convectional, but sporadic. In dry climates, wind is a powerful agent of erosion and deposition. Limited vegetation in dry areas leave exposed particles of sand, clay and silt subject to movement by wind, thus, many of the sculptured features found in dry areas result from mechanical weathering; that is from the abrasive action of sand and dust particles as they are blown against rock surfaces. Sand and dust storms occurring in a drought-stricken farm area may make it unsuitable for agriculture. Types of landforms produced by wind driven sands are dunes e.g. barchans (crescent shaped), loess (pale yellow or buff coloured and silty in texture).
Desert biome animals
Animals of the desert have both structural and behavioural adaptation to meet their three most critical needs: food, water and heat survival. Many desert animals escape the main onslaught of daytime heat by hiding in burrows or rocky shelters from which they emerge only at night. Pocket mice and kangaroo rats (and their old world counterparts, gerbils) get most of the moisture they need from the seeds and grains they eat. Reptiles are the dominant desert animals; they have many adaptations to conserve water such as producing highly concentrated urine and nearly dry faeces that allow them to eliminate body waste without losing precious moisture. Since the desert vegetation are very short and few due to limited amounts rainfall, the desert biomes only accommodate few animals with unique characteristics to survive the harsh Sun by hiding under small scrubs or hiding in burrows.
Example of animals found in various desert biomes of the world are Quokka, rabbit-eared bandicoot, bilberry, dingo, kangaroo, dromedary, dung beetle. Others include-Arabian horse, hyena, ibex, Jackal, Jerboa, lizard, locusts, Oryx, peregrine falcon, porcupine, sand cobra, scorpion, veil chameleon, monitor lizards,gazelle, fan- tailed raven, mouse, sand fox., mouse, black widow spider, red tailed hawks, addax antelope, carmels, wild burros and lots of other animals.
Deserts may seem formidable, but they are more vulnerable than you might imagine desert soils are unproductive mainly because of lack of moisture and humus, but potentially, they are not particularly infertile for plant growth. Areas under irrigation are capable of producing high quality crops. Deserts soils are constantly disturbed by human activities and are slow to recover because the harsh desert climate severally reduces the ability of the desert community to recover from damages. Mainly domestic livestock have overgrazed many dry areas of the desert, while other areas have been converted into agricultural land despite the uncertain future availability of water to sustain crops. Often times, after humans have degraded and abandoned desert areas, they remain wastelands for a very long time, unsuitable for native vegetation or wildlife.
- Examples of deserts are Sahara, Gobi, and Western US , Kalahari, great Victoria basin, Chihuahua, Mojave, Monte, Namib, Antarctic, great basins, Iranian deserts.