A desert is a barren area of landscape or region that receives very little precipitation occur and most harmful condition for living plants and animals. But some Plants and animals have adaptation survive in the harsh environment. About 1/3 part of Earth is covered with is a desert which have many surface area on earth. The 4 types of deserts are found on the earth i.e. polar deserts, subtropical deserts, cold winter deserts, and cool coastal deserts. The two largest deserts on Earth are found in the polar areas of earth.
1 – Antarctica
Antarctica is the largest desert on the earth located at South Pole of the Antarctic Circle surrounded by the Southern Ocean. Antarctica is named as Greek word meaning “opposite to the North or Arctic”. It is the 5th largest continent about 1.3 times large as Europe. Antarctica is twice in the size of Australia. Approximately 98% of Antarctica is covered by ice that averages 1.9 kilometers. It is the coldest, driest, and windiest continent of the earth, with annual precipitation of only 200 mm. About 14,000,000 square kilometers land area is covered by Antarctica with no permanent residents but about 5000 temporary residents throughout the year resides for research stations. The Antarctica’s temperature has reached −89 °C, But many living organisms have cold adaptation surviving, like some type fungi, algae, bacteria, plants, protista, and certain animals, like mites, nematodes, penguins, seals and other organisms.
2 – Sahara
Sahara is the largest subtropical hot desert and 2nd largest desert after Antarctica and the Arctic. Sahara is derived from Arabic word meaning “The Great Desert” having About 9,400,000 square kilometers surface area is extended on North Africa with Algeria, Egypt, Libya, Western Sahara, Morocco, Tunisia and Sudan. It is divided into Western Sahara Ahaggar Mountains, Tibesti Mountains and Air Mountains. It covers 1⁄4 part of the African continent Emi Koussi is the highest peak in Sahara with height 3415 metres in Tibesti Mountains of North Chad. The Sahara Desert is the driest and extremely windy deserts in the world, with low annual average precipitation. The climate of Sahara is quite uniform during summer season with average high temperatures 38 °C and average low temperatures is 21 °C. Some living organism i.e. Flora and fauna are found on Sahara like 2800 species of vascular plants, many species of fox, Saharan cheetah, monitor lizards, hyrax, sand vipers and African wild dog etc.
3 – Arabian Desert
Arabian Desert is the 3rd largest desert in the world located in Western Asia, Occupies most of the Arabian Peninsula, Having area 2,330,000 square kilometers with length 2,100 km. The center of Arabian Desert is the Rub’al-Khali is one of the largest continuous bodies of sand in the world. The climate is mostly dry (with 100 mm of rain per year) and Averages high temperatures are about 40 °C and Averages low temperatures is over 20 °C. Deserts and xeric shrublands biomeand the Palearctic ecozone is the part of Arabian Desert. There are only 37 species in Arabian Desert like plants Calligonum crinitum, Cornulaca arabica (saltbush) and Cyperus conglomeratus. Other species are a woody perennial Calligonum comosum and annual herbs such as Danthonia forskallii.
4 – Gobi Desert
Gobi Desert is the largest desert region in Asia covers the parts of northern and northwestern China, and of southern Mongolia. It is bounded by the Altai Mountains, grasslands and steppes Mongolia on the north. The Gobi Desert is most notable in history as part of great Mongol Empire having 1,000,000 square kilometers surface area with 1,500 km length. It is widest in the west and 4th largest desert in the world extend the joining line of Lake Bosten and the Lop Nor, Located at plateau roughly 910 to 1,520 metres above sea levels. Gobi desert is not sandy but has exposed bare rock and climate is very extreme with rapid changes. The temperature ranging in winter is –40 °C and +50 °C in summer. It is the source of many important source of fossils, like the first dinosaur eggs. Despite the harsh conditions, many animals like Mongolian wild ass, marbled polecats, bactrian camels and black tailed gazelles are survived.
5 – Kalahari Desert
Kalahari Desert is a large semi-arid sandy land desert in southern Africa covering the part of Argentina and Chile extending Botswana, Namibia and South Africa. Kalahari meaning, waterless place and have vast areas covered by red sand without any permanent surface water. It is 5th largest Subtropical desert in the world having 900,000 square kilometers surface area with 4,000 km length. . The 8,550 ft high peak point at Brandberg Mountain in Kalahari Desert. A semi-desert due to good rains supports to survive more animals and plants than others. It is the home of many migratory birds and animals like elephants, giraffes, lions and cheetahs. The Kiwano fruit like Horned melon, melano and jelly melon, or hedged gourd were found in Kalahari Desert. The climate of Kalahari Desert is sub-humid rather than semi-arid with average temperature 44.8°C at Twee Rivieren in 2012. The San people have lived in the Kalahari for 20,000 years for hunting.
