Among the most arid ecosystems and poor in biodiversity on the planet we have deserts. There are numerous types of deserts and many times they are talked about lightly. However, many people do not know what is a desert and what are the unique characteristics of these ecosystems.
For this reason, we are going to dedicate this article to telling you what a desert is, its characteristics and types.
what is a desert
A desert is a bioclimatic landscape (or biome), hot or cold, characterized by low precipitation rates, dry climates, extreme temperatures, and dry soils. In the desert, few plants and animals (and humans) are able to adapt to these harsh living conditions.
Deserts cover about a quarter of the Earth's surface, 53% of which correspond to hot deserts (such as the Sahara) and the rest to icy deserts (such as Antarctica). Deserts are found on all five continents, the icy plains of North Africa, northern Mexico, the Russian tundra, Antarctica, Greenland, and Alaska, as well as northern and southern Chile.
In hot deserts, wind erosion and solar radiation are very intense, temperatures are high, and soils are often sandy, stony, or rocky. On the other hand, in the polar deserts, the temperature is usually below 0°C, the climate is dry and there is little flora and fauna.
desert features
Some of the main characteristics of deserts are:
- Little rainfall and dry weather. Deserts are areas that receive very little rain because they are areas where clouds do not form. For an area to be a desert, it must receive less than 250 mm of rainfall per year, and a lack of rainfall can lead to soil drought and biological scarcity. The rainfall that deserts can receive is usually sporadic and abundant, which causes erosion of the land due to the lack of vegetation that absorbs water.
- Dry ground. The lack of precipitation produces dry and parched soils. These soils are poor in nutrients and generally consist of sand or stones. In the case of polar deserts, the ground is covered by a large layer of ice.
- Extreme temperatures. In the desert, temperatures are extreme, hot and cold (as the case may be). In polar deserts, the temperature is usually below 0°C, while in hot deserts, the temperature is usually above 40°C and solar radiation is very strong. In most deserts, there is a large temperature difference between day and night.
- The number of plants and animals is low. The lack of precipitation and nutrients in the soil are some of the reasons that hinder the growth and development of organisms in deserts. Most desert-dwelling species use mechanisms to store water or escape extreme temperatures.
- Erosion and low nutrient soils. Winds in desert areas are often strong and persistent, causing soil erosion due to lack of vegetation. In addition, erosion, coupled with low rainfall, can lead to depletion of soil nutrients, preventing continued or impaired growth of plant organisms.
types of deserts
The main types of deserts are:
- tropical desert: They are deserts located near the equator or the tropics. They are characterized by high temperatures, large thermal amplitudes during the day and night, and low precipitation and humidity. An example of such a desert is the Sahara desert in North Africa.
- polar desert: They are those deserts with very intense low temperatures, very dry, low solar radiation and little annual precipitation. Due to its harsh climate, there are few species of organisms that inhabit this biome. The Arctic Circle and Antarctica are regions of the planet's polar deserts.
- coastal desert. They are those deserts located near the coast and the Tropic of Cancer and Capricorn. Despite being close to the water, they are arid areas with very little rainfall, since due to the wind, the rain falls into the sea and the humidity does not reach the coast. An example of such a desert is the Atacama Desert in Chile.
- Semi-arid desert. They are those deserts with very little humidity, but more precipitation than tropical deserts. They are characterized by hot, dry summers and cold winters with little rainfall. An example of such a desert is the forest desert in Russia.
Desert climate
Temperatures in deserts are often extreme, with large temperature differences between day and night. In the hot desert temperatures exceed 40°C during the day and drop below freezing at night.
For its part, in the polar deserts, temperatures are always very low (about -40°C) and can exceed 0°C in summer. There are three types of desert climates based on mean annual precipitation:
- Semi-arid climate (steppe). They receive an average of 250 to 500 mm of rain per year, covering 15% of the earth's surface. They are usually found on the outer edge of the desert.
- Dry weather. Its annual precipitation ranges between 25 and 250 mm (maximum), covering 16% of the earth's surface.
- Super arid climate. They have very low rainfall rates, often rainless years in these areas. This climate exists in the heart of the polar deserts and hot deserts.
Flora and fauna
The desert flora is very specific and often scarce, due to low humidity, and many plants are unable to carry out photosynthesis. The flora of the deserts varies according to the type of climate.
In hot deserts, life has adapted to unfavorable conditions, which is why there is usually xerophytic vegetation: thorny, succulent, resistant plants with a great capacity for storing water. Some examples of desert heat flora are: cacti, agave, acacia, roses of Jericho, cacti and succulents.
In hot deserts, there are areas with water (called oases) and humid conditions that encourage plants to bloom. An oasis is home to palm trees and taller shrubs, including fruit trees such as dates or coconut palms.
In the polar deserts, on the other hand, there is very little vegetation due to the lack of precipitation and the cold and permafrost. The flora of the arctic deserts is more abundant than that of Antarctica (only Antarctic grasses, Antarctic carnations and moss), inhabited by plants such as mosses, herbs, meadows and shrubs.
Living animals that are adapted to their desert environment and have mechanisms to keep their bodies hydrated. Some people hide in burrows to avoid the sun during the day, and some have water reserves in their bodies or physical characteristics that can help them cope with extreme temperatures and dehydration.
The frozen deserts, on the other hand, they do not have so many living beings, and the life of algae and bacteria stand out. However, the polar deserts of the Arctic have more animal species than Antarctica, and in the outermost areas of the desert it is possible to find bears, reindeer, foxes, hares and other mammals, which have insulating fur and store a lot of fat. Seals, killer whales, whales, fish, and plankton live in coastal areas and oceans.
In Antarctica, birds such as penguins, seagulls, albatrosses, terns and Antarctic petrels stand out, although most live near the coast (seals and marine animals can also be seen).
I hope that with this information you can learn more about what a desert is and its characteristics.