Our planet heats up unevenly, so on its surface there are many different climatic zones that form natural zones. One of them is the desert. It has a sparse flora or is generally characterized by its absence. There are several types of deserts:
- sandy;
- salt marshes;
- rocky;
- clayey.
The Arctic desert, that is, the territories of the Arctic and Antarctica, is singled out in a separate category. The lands of these zones may or may not have snow cover.
Dry McMurdo Valley
This is a snow-white dry desert of Antarctica. These are Antarctic oases on Victoria Land. The total occupied area is 8 thousand square kilometers, on which there is no ice. This is the driest place on the planet where rain and snow have not fallen for more than 2 million years. It is believed that this place maximally reflects the natural conditions of the planet Mars. In the desert, frequent katabatic winds, that is, reaching 320 kilometers per hour, which cause the evaporation of moisture. In winter, the air temperature drops to –50 ° C.
Despite these harsh conditions, endolithic plants were found in this area. But there are no animals in the desert. Researchers found only endolytic bacteria that live on the so-called Bloody Waterfall. Relatively moist rocks protect them from dry air. With the onset of summer heat, bacteria get out, because of this place they called it Red Waterfall. And their color is associated with a diet based solely on sulfur and iron.
Arctic
The Arctic desert zone stretches from North America to Asia. The climate here is quite severe - in some places the atmospheric temperature can reach –50 ° C with a small amount of precipitation. The vegetation is sparse. We will call animals of the Arctic deserts:
- Pink gull A fairly large bird, in weight it can reach 250 grams, with a body length of 35 centimeters. It tolerates harsh winters.
- Narwhal. It belongs to the genus of cetaceans, has a horn that sticks out of the mouth, although in essence it is an ordinary tooth. This tooth can grow up to 3 meters in length.
- Seal. It is in the Arctic that one can meet several species of this ancient and amazing animal: Greenland, sea hare and harbor seal.
- Walrus. The closest relative of seals. It has gigantic dimensions - up to 3 meters in height, with a weight of about 1 ton. It is a predator.
- Polar bear. One of the largest land predators on the entire planet. In height it can reach 2.5 meters, with a weight of 500 kg. It attacks almost everyone, even large animals, seals and walruses.
Sahara
The most famous and largest sand desert on the whole planet. The total occupied area is about 9 million m². On this territory, the hottest thing on the planet. Sometimes the air temperature reaches +57 ° C. At the same time, heavy rains constantly occur here, but there are often sandstorms, in which sand can rise 1000 m in height.
The animal world of the Sahara desert is very diverse, despite the harsh living conditions. Therefore, these representatives of the fauna can be called the most interesting on the planet, and they are very rarely found in other parts of the globe:
- Horned viper. The venom of this reptile is so dangerous that it causes irreparable damage to the blood cells of the victim. As a rule, a meeting with her ends in death, although this desert animal is classified as an endangered species.
- Dromedary, or one-humped camel. To date, it is present exclusively in households. A very hardy and strong animal, capable of a long time without water.
- Gazelle dorkas. Very fast (running reaches 80 km / h) and a light animal (average body weight - 25 kg). It has a sandy color, which allows artiodactyls to hide among the dunes.
- Dung beetle, or scarab. It was once considered sacred. It feeds on manure of artiodactyl animals of the desert. Finding a litter, rolls it into the underground voids with its hind legs, where it eats.
- Yellow scorpion. Insect venom rarely causes health problems in adults, but it can be fatal for old people and children. This is a very small animal with very toxic neurotoxins.
Semi desert
Such territories are also called desert steppe. This is something between savannahs and deserts, which are located in the temperate geographical zone. In such a desert, animals and plants are more diverse. There are no forests yet, but there is a specific ground cover. The average temperature here is from +20 ° С to +25 ° С, and in the tropical parts of the Earth it reaches +30 ° С. The semi-deserts on the planet have many similarities, but also differences depending on the belt.
Temperate zone
This is a strip of 500 kilometers from the Caspian lowland to South America. Territories in Eurasia differ from the terrain in North and South America by atmospheric temperature. In Eurasia in the winter, it can drop to -20 ° C. The soil can be characterized as saline, brown and light chestnut. Closer to the south there are more signs of a real desert.
For the wildlife of Russia, the semi-deserts of Russia are characterized by gazelles of gazelles, viskachs, and bustards-beauties. In South and North America, there are lizards, turtles, saigas and snakes.
Subtropics
Such a natural zone is located on the slopes of plateaus, uplands and plateaus. These are the Armenian Highlands, the Anatolian Plateau, the Valley of the Rocky Mountains, Karru and Fliders, etc.
The fauna of the desert in the subtropics is different from the temperate zones. Porcupine, cheetah, striped hyena and Mediterranean viper live here. It is in the subtropical deserts that you can see cobra, sandy efu and kulans. A huge role in the ecosystem is played by termites.
