Desert ecosystem: characteristics, flora and fauna

The desert is one of the driest biomes on our planet, due to high temperatures and low rainfall. These climatological characteristics, added to the aridity of its soil , which is mainly covered by desert sand, give rise to bare and solitary landscapes, in which hardly any species inhabit.

Thus, both the fauna and the flora of these biomes are scarce and, in fact, the few species that we can find show great traits of adaptation in order to be able to survive in one of the most hostile biomes on Earth.

Hot desert climate

Deserts are distributed in zones:

• Steppe or semi-arid areas: average rainfall of 250 to 500 mm per year. They are usually located on the limits of these biomes.
• Arid areas: their annual rainfall is between 25 and 250 mm.
• Hyper-arid areas: they are so dry or arid that it can go years without rain. The temperatures in these areas can vary widely, in fact they can vary by more than 20 degrees Celsius.

Cold desert climate

The temperatures mentioned above are the most frequent in the warm ones, but in the cold ones, where there really are areas where there is no rainfall, they are also very extreme.

For example, Antarctica, the largest desert in the world, has an average temperature of about -20ºC.

Hydrography

As we have indicated before, rainfall in the desert biome is irregular and very scarce . The main reason this is so is that there are constant tropical anticyclones . The desert areas that suffer the least from this water shortage are the semi-arid or steppe areas because they are on the edges or limits of the biome, already close to other types with less presence of tropical anticyclones. Thus, in one of these areas it can rain an average amount between 150 mm and 170 mm per year. Even so, the months with the highest drought are usually more than half a year. In the rest of the inland areas, rainfall does not reach 150 mm per year and the whole year is dry or arid, with a more extreme climate than that of the edges.

There are areas in the deserts in which rivers circulate sometimes a year and are called wadis , but they only carry water just after the scarce rainfall, which usually falls in a short time in the form of a downpour, and immediately dries up again, leaving the road of the river marked in the sand and remaining dry the rest of the year. In fact, wadis rarely reach the seas because their water is absorbed, evaporated or stagnant very quickly.

Although at first it may seem that this is not the case, there are different types of deserts :

• Deserts in trade wind or tropical regions.
• Mid-latitude deserts.
• Deserts due to barriers to humid air.
• Monsoon deserts.
• Coastal deserts.
• Cold deserts or cold desert areas.
• Indlandsis, polar desert or polar desert areas.

As we have mentioned previously, the vegetation and flora of the desert is scarce. This is due to low rainfall and low humidity, since water is a vital and essential element for the growth of species and their development and without it, many plants are unable to photosynthesize.

Therefore, the plant species that we can find show adaptations to make up for the lack of this resource, such as physiological structures that make perspiration difficult, thus presenting a short stature and very homogeneous forms. In addition, its walls are usually fleshy, succulent and succulent in order to be able to store water as a supply and thus use it in conditions of scarcity.

Another adaptation of desert plants is found in their leaves, these being, in many cases, small and hard, that is, spikes and thorns , in order to avoid the loss of water that occurs due to evaporation. On the contrary, its roots are large and elongated , covering as much of the surface as possible to obtain the water and nutrients it needs.

Can you think of species that have these characteristics? We present you some listings with some of them and images.

Although, at first glance, as in the case of the vegetation, the desert fauna is quite poor, in reality there are several species of animals that have developed their habitat in this biome, being able to adapt and get used to its peculiar characteristics. .

Reptiles , for example, are some of the easiest animals to find, since they are cold-blooded animals, which allows them to combat the extreme temperatures of the desert, although it is common to find them buried in burrows or under the sand, to protect themselves from the sun’s rays. We can also find numerous insects , beetles, ants, scorpions and spiders that use the same techniques.

On the other hand, we can find small mammals such as foxes or rodents, which have light coats, to camouflage themselves in the desert sand and nocturnal habits, so that they sleep during the hottest hours and take advantage of the lesser hours of the day. temperature to search for food. In contrast to these, we can find large mammals , such as dromedaries and camels, capable of storing a large amount of water in the body to survive high temperatures. This is something they can achieve thanks to the humps and other parts of the body, although it is not water that camels and dromedaries store most in their humps., but mostly contain fat, as a reserve for survival in an extreme ecosystem.

Finally, we can find some birds , both small such as owlets and turtle doves, even larger, such as vultures. The latter feed both on carrion (dead animals) and small mammals and have one of the most surprising characteristics in terms of adaptation to the desert, which is the absence of sweat glands.

To finish, we offer a list of the world’s deserts , mentioning some of the best known:

• Antarctica
• Arctic
• Sahara
• Gobi
• Sonora
• Kalahari
• Namib
• Great Sandy Desert
• Great Victoria Desert
• Atacama
• Karakum
• Negev
• Taklamakan
• Arabian desert
• Rub al-khali
• Syrian desert
• Judean Desert
• Desert and xerophilous mount of Arabia and Sinai