The desert differs from other places in its very dry and hot climate. Plants have developed many adaptations for growing and living in such dry places. An example is various types of thorns, with the help of which you can not only gain a foothold, but also accumulate a certain amount of moisture in reserve. The well-known camel thorn has almost no leaves.
The roots of desert plants have unprecedented power; they go deep into the soil, thereby providing access to groundwater. For example, sandy sedge penetrates with its roots to a depth of 70 cm. You can often find plants with rather fleshy or even trunks. This is another way to store water in reserve.
In the desert there are shrubs and even trees, but their distinctive feature is their small height. The trunk can be perfectly straight and elongated, like that of an acacia, or curved and literally adjacent to it, like that of saxaul. The plants are located quite scattered from each other, their crowns never touch.
What plants grow in the desert
When people talk about desert plants, the name that immediately comes to mind is cactus. There are a large number of cacti growing in the desert; they have different shapes, sizes, and some even bloom. They grow singly or in entire colonies. Cacti have a fleshy body and a special fibrous tissue that retains moisture. Some desert cacti are real long-livers, their age reaches 150 years.An unusual and majestic plant can be called baobab. It has a simply huge trunk, which can reach 9 meters in diameter. During the driest periods of the year, the tree simply sheds its leaves to reduce the amount of moisture consumed. And the baobab blossoms, then fleshy and quite tasty fruits appear. The tree is very tenacious and resistant to lack of moisture; it can sink its roots quite deeply into the soil in search of water.
The most stunning sight is the blooming desert. This is just an incredible picture to see. After the desert gets rained on, it literally blooms. Flowers are mainly represented by bulbous ones, which are also capable of storing moisture for a long time. However, you can also find verbena and primrose, which bloom in all their glory after the rainy period.
The flora of the desert is beautiful and unusual. In conditions of drought and the absence of normal fertile soil, plants not only manage to bloom, but also become established in the sand for many years.
Desert. Having heard this word, everyone probably imagines a vast territory where vegetation is rather a luxury. In fact, these are not only endless sands and rocky mountains, where the temperature at night drops far below minus, and during the day - high above plus, but also the homeland various types family of cacti. These amazing plants have been adapting to the climatic conditions of the capricious desert for thousands of years in order to survive.
Rare cacti
Stenocereus tubera
This cactus loves warmth and does not react well to cold, so it grows exclusively on sunny mountain slopes. In appearance, Stenocereus resembles an old church organ, since it does not have a central trunk, and its numerous shoots (from 5 to 25) grow vertically upward and reach 7-8 m. When the plant reaches maturity, flower buds begin to bloom at the ends of the stem, the size of which about 8 cm. What is noteworthy is that the flower blooms only at dusk, and with sunrise it curls up into a tube. Flowering continues for several weeks, as the buds open in turn on different days.The cactus feeds on days when it rains, stocking up on water in advance. After all, the stems of this plant are designed to absorb water and store moisture to survive the dry seasons.
Interestingly, the Stenocereus cactus is protected by US law, as it is a rare endangered plant species.
Pachycereus Pringle
The southern part of the Sonoran Desert is considered the homeland of this cactus. The second name of the plant is cardon. It does not tolerate severe frosts and favorable conditions its age can reach 200 years, and its height can be 20 meters. Cardon has a main trunk from which many branches grow, which at a “young age” are covered with needles.With the arrival of spring, beautiful white buds open at the ends of each branch. Each flower blooms for only 24 hours, but thanks to the huge number of buds, flowering continues for several weeks. Also, after the flowering process, red fruits with large spikes appear.
Interestingly, cardone fruits have been used by the local population since ancient times, as they contain substances. Just like the Stenocereus tubera cactus, cardone is protected by the state.
What are the spines for?
The thorns are, of course, protection from animals that will not be able to feast on the plant. But the main and main function is to protect the cactus from overheating and strong winds. By reflecting the sun's rays, the spines reduce the level of evaporation and retain moisture. And after rain or morning dew, they retain drops of water that flow to the base, giving additional nutrition to the plant. Thus, thorns are simply an indispensable assistant for plants in special desert conditions.
So, the cactus can be called one of the most daring, original plants. After all, he is one of the oldest inhabitants of the planet who was able to adapt to the extreme conditions of a hot climate.
Deserts may seem empty and lifeless only at first glance, but in fact this natural area can be very different. In addition to sandy deserts, in nature there are clayey, gravelly, saline and even ice deserts of the Arctic and Antarctica. They occupy vast territories and significantly influence the Earth's climate.
Climate Features
The desert and semi-desert zone is located south of the steppe. Summer here lasts five months, and during this time the weather is very hot. In a cloudless sky, the sun burns simply mercilessly, and there are often cases when not a drop of precipitation falls during the entire summer.
In summer, the merciless rays of the sun can heat the surface so much that its temperature rises to 80 degrees Celsius. This is enough to easily bake a raw egg in hot sand.
Rice. 1. Hot desert sands.
Despite the fact that at midday the air temperature fluctuates between 30-50 degrees, with the onset of night it noticeably decreases, and temperature changes can be 15-20 degrees.
Winter in the desert lasts 2-3 months and, compared to summer, it is quite severe. The average temperature is -10-15 degrees below zero, but can be much lower. The snow cover in winter is not too heavy, and its height rarely exceeds 10 cm.
Because deserts are located far from the oceans and very close to the equator, they receive very little rainfall. Distinctive features of desert climates include:
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- abundance of light;
- dryness;
- heat.
In the desert, dry winds are not uncommon - hot winds, which are harbingers of prolonged drought and drying out of small bodies of water.
Desert types
The surface of deserts can be very different, and depending on its type, the following types of deserts are distinguished:
- Sand and sand-crushed stone . The appearance of such deserts can be very different, from endless sand dunes without the slightest vegetation, to large areas completely covered with grass and small shrubs. It is very difficult to move on such a surface, despite the fact that sands occupy a smaller part of the deserts.
- Rubble, gypsum, rocky . These types of deserts have one common feature - a hard and very rough surface. These deserts are more common than others on our planet.
- Salt marshes . These are the saltiest deserts in the world. They are covered with a dry salt crust or a dangerous quagmire that can completely engulf even a large animal.
Rice. 2. Salt marsh deserts.
- Clayey . Impressive areas of such deserts are covered with a smooth clay layer.
Desert Plants
The flora of deserts is not diverse, because not every plant is able to survive in such an arid region.
Desert plants were able to adapt to the hot and dry climate using the following "tricks":
- the leaves are very small, narrow and hard, often spines grow instead of leaves;
- roots penetrate deep into the ground;
- plants grow singly, occasionally forming small groups.
The most common desert plant is camel thorn. In order to extract valuable moisture from the depths of the earth, its root penetrates to a depth of 20 m. Thanks to this, the leaves remain fresh for a long time and fall off only after the fruits ripen. Camel thorn is an important part of the desert food chain.
Rice. 3. Camel thorn.
Also in deserts you can find such unpretentious plants like dzhuzgun, grate, saxaul, tumbleweed.
Desert Animals
Representatives of the desert fauna also have features that allow them to live in the harsh conditions of the desert zone:
- small sizes;
- body coloring the color of sand;
- nocturnal lifestyle;
- unpretentiousness in food;
- high speed of movement or the ability to hibernate in order to feed less often.
The desert is home to several species of lizards, scorpions, scarabs, long-eared hedgehogs, Corsac foxes, gerbils, jerboas, saigas, and camels. It is difficult to find birds in the desert because they do not tolerate heat very well.
Unbearable heat during the day, very cold at night. There is only dried earth, sand or cracked stones around. Not a single green tree nearby. Instead of trees there are dry trunks or “swaying” bushes. How and what does the desert live on? More precisely, how do plants and animals survive in these harsh desert conditions?
There are areas in nature where there is little or no vegetation and very few animals. Such natural areas are called deserts. They are found on all continents of the globe and occupy about 11% of the land surface (about 16.5 million sq. km).
A prerequisite for the formation of a desert on the surface of the earth is the uneven distribution of heat and moisture. Deserts form where there is little rainfall and dry winds prevail. Many are located nearby or are already surrounded by mountains, which prevent precipitation.
The desert is characterized by:
- - Aridity. The amount of precipitation per year is approximately 100-200 mm, and in some places it does not happen for decades. Often, even these small precipitations, evaporating, do not have time to reach the surface of the earth. And those precious drops that fall into the soil will replenish groundwater reserves;
- - Winds arising from excessive heating and associated air flows that reach 15 - 20 m/s or more;
- - Temperature, which depends on where the desert is located.
Desert climate
The climate in Putin is influenced by geographical location. There can be either a warm or dry climate. When the air is dry, it practically does not protect the surface from solar radiation. During the day the air warms up to + 50 °C, and at night it quickly cools down. During the day, the sun's rays, without lingering in the air, quickly reach the surface and heat it. Due to the lack of water, there is no heat transfer, which is why it is so hot during the day. And at night it’s cold for the same reason - lack of moisture. There is no water in the soil, therefore there are no clouds to retain heat. If daily temperature fluctuations in the desert of the tropical zone are 30-40 ° C, then in the temperate zone it is 20 ° C. The latter are characterized by hot summers and cold winters (up to - 50 ° C with a light cover of snow).
Desert flora and fauna
Few plants and animals can survive in such difficult climatic conditions. They are characterized by:
- - Long roots to extract moisture in deep layers of soil;
- - Small, hard leaves, and in some they are replaced by needles. Everything for less moisture evaporation.
Desert inhabitants vary depending on the location of the desert. Wormwood, saxaul, solyanka, koslosnyak, dzhuzgun are characteristic of the desert of the temperate zone, in subtropical and tropical deserts Africa and Arabia, succulents (cacti) are added. Lots of light, poor soil, lack of a lot of water - that's all cacti need. Cacti have adapted perfectly: the spines do not allow unnecessary waste of moisture, the developed root system collects morning dew and night soil moisture.
The deserts of North America and Australia are much richer and more diverse (low-growing acacia, eucalyptus, quinoa, twig, etc.). In oases and large river valleys in the temperate zone of Asia, trees grow: jida, willow, elm, turango poplar; in subtropical and tropical - evergreen palm, oleander. And this small list is very valuable in the desert. The plants serve as food for camels and for warmth on cold nights.
The fauna is not picky about food and water, and the color is close to the color of the earth's surface. Many people are nocturnal and sleep during the day.
The most famous and widespread is the camel, the only one that can eat camel thorn and survive for a long time without water. All thanks to its hump, which contains a supply of nutrients.
Reptiles also live: lizards, agamas, and monitor lizards. The length of the latter can reach one and a half meters. A variety of insects, arachnids, and mammals (jerboas, gerbils) make up the desert fauna.
What is the secret of scorpion survival in deserts?
Scorpions are representatives of the arachnid species. And this is surprising, since they are not at all like spiders. Scorpions prefer dry, hot deserts, but even some species have adapted to tropical rainforests. These arachnids also live in Russia. For example, the yellow scorpion can be found in the forests of Dagestan and Chechnya. In the Lower Volga region, the motley scorpion lives in wastelands and dried desert areas, and the Italian and Crimean scorpion is found on the Black Sea coasts.
Because respiratory system These arachnids are poorly adapted to dry and hot climates; this feature forces the insect to take refuge from the heat in various gorges, cracks, under stones, and bury itself in sand or soil. There they find at least some moisture. That is why scorpions are nocturnal animals: during the day they sleep, waiting out the heat, and at night they are good-natured. Desert scorpions can do practically without water, feeding on various insects, and large individuals can eat a lizard or a small rodent. Cases have been recorded where a scorpion survives after starvation for 0.5 to 1.5 years. In the desert, scorpions mainly obtain moisture from food, but sometimes suck it from wet sand.
For any animal and plant in the desert, the main difficulty is the lack of moisture, the lack of water. It is this feature that gives the world such bizarre forms of life. Some people have adapted not to drink, but to limit themselves to moisture obtained from food. Some people often change their location in search of water. Some people move closer to the water during the dry season. Some people produce metabolic water during their metabolism. Somehow, desert animals have found a way to survive in the harsh desert climate.
In addition, watch the BBC documentary from the Forces of Nature series, the film explains in detail the features of desert branding
Although the flora in different areas of the desert is different, it is still united common feature- strong sparseness. Of course, only plants that are resistant to lack of moisture can live in the desert.
Shrubs and trees have adapted well to drought. Usually they are not tall, but even an old two-meter tree among the sands seems huge, a real giant. Tree trunks are either strongly curved (like saxaul) or perfectly flexible and straight (like sand acacia). But what powerful and long roots they have! Covered with thick bark, durable, they can penetrate the ground to a depth of 15 meters, and a camel thorn can reach moisture to a depth of 30 meters! Now it’s clear why even in extreme heat, when all living things suffer from drought, they flaunt a bright green leaf, as if the scorching sun does not touch them.
Herbs in the desert are not particularly important, except, of course, ephemeral plants that live when there is enough moisture in the desert. Most ephemerals are small plants, their stems reach only 8-10 cm. In spring, ephemerals form a colorful carpet. The basis of this coating is sand sedge (ilaka), a perennial with long rhizomes that penetrate the soil to depths of 50-70 cm. The roots of sand sedge, together with other ephemera, are closely intertwined and make the sand motionless.
It is here that you can understand the transience of life and learn to enjoy every new day.
Saxaul forests grow on motionless, fixed sands. But they have nothing in common with shady forests. The saxaul bushes are located at such a distance from each other that their crowns never close. From a distance, the saxaul bush resembles a weeping willow or a fruit tree, but in fact, this tree does not have a single leaf, so it is impossible to hide in the shade from the scorching sun.
Echinocactus Gruzoni is the only cactus whose juice can quench your thirst. The plant reaches a height of up to one and a half meters and produces about a liter of juice.
Stapelia is a plant with a very unusual appearance: Its leaves are like thorns and its star-shaped flowers are covered with thick hairs. The smell that these flowers emit is very similar to the smell of rotting meat.
In the South African Namaqualand desert you can find a very amazing plant - Lithops fenestraria. Only a few leaves of this plant are visible on the surface, but its root system is a real mini-laboratory in which complex photosynthesis processes take place, thanks to which Lithops fenestraria can bloom... underground.
In Russia and the CIS it is distributed from the lower Volga to Lake Balkhash, occupying the plains of Kazakhstan and Central Asia.
Depending on soil conditions, there are sandy, clayey, rocky And saline deserts.
Desert climate
The main feature of the desert climate is low rainfall and very intense summer heat. Evaporation here is many times higher than precipitation, and plants almost constantly lack moisture. In addition, the desert is characterized by strong temperature fluctuations during the day and different seasons of the year: sultry summers give way to rather harsh winters.
Desert soils are highly saline, contain harmful, easily soluble salts and little organic matter.
Features of desert plants
The vegetation cover of deserts varies in different areas, but almost everywhere it is very sparse. Desert plants have adapted to cope with lack of moisture in different ways. Some have devices that reduce evaporation: small leaves or their complete absence, dense pubescence, a thick layer of cuticle or a waxy coating. Other plants shed their leaves and some young shoots with the onset of heat. Many desert plants store water in their stems or leaves, which make them juicy and fleshy ( succulents).
Plants that cannot tolerate drought also grow in deserts; they develop in the spring, when it is still quite humid and not hot ( ephemera And ephemeroids). The nature of vegetation is strongly influenced by soil conditions. This dependence is especially great in the desert zone, since water supply conditions depend on the composition of the soil.
Finally, in deserts there are many species of plants that have root systems that penetrate deep into the soil and reach the level groundwater. These plants are always provided with sufficient water.
Plants of clay deserts
The vegetation of clay deserts varies in different areas, which is due to the frequency of precipitation. Distinguish northern clay deserts, where precipitation occurs throughout the year, and southern clay deserts- Precipitation here occurs mainly in the spring.
Northern clay deserts
Northern clay deserts are dominated by wormwood and solyanka. Their largest areas are located in Southern Kazakhstan. Typical plants of these deserts are subshrubs: wormwood (Artemisiaterrae-albae), salt marsh anabasis, or biyurgun (Anabasissalsa),(Fig. 164): leafless anabasis (A.aphylla). The underground organs of these plants are much larger in development and weight than the aboveground ones. Grows from trees in the northern desert black saxaul (Haloxylonaphyllum)(Fig. 165): its trunk is low (3-5 m), winding, there are no leaves, their function is performed by thin long branches hanging from the branches. The flowers of saxaul are small and inconspicuous, and the fruits, equipped with filmy wings, look like flowers from a distance. It is very hardy, its wood is very hard and heavy.
Southern clay deserts
The vegetation of the southern clay deserts is completely different than in the north. There are almost no subshrubs here, but they are dominated by herbaceous plants. Most of them are ephemera and ephemeroids. The appearance of the southern desert changes greatly throughout the growing season. In the spring, when it rains, the soil is covered with a continuous green carpet, and in the summer, with the onset of drought, the vegetation completely burns out, the soil surface becomes completely dry and hard as stone. Typical plants of southern clay deserts are bulbous bluegrass (Poabulboa), desert sedge (Carexpachystylus), spring grain (Erophilaverna), desert alyssum (Alyssumdesertorum), some milkweed (Euphorbia), astragalus (Astragalus) and etc.
Sand Desert Plants
Sandy deserts occupy large areas in Central Asia: Karakum, Kyzylkum, Muyunkum, etc. Unlike other deserts, sandy deserts have a relatively favorable water regime: the weak capillarity of the sand makes evaporation difficult, and moisture is better retained. In addition, sand in desert conditions has the ability to condense water vapor that is in the atmosphere.
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| Rice. 167. Juzgun (Calligonum) |
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| Rice. 168. Tamarisk (Tamarix) |
The sandy desert has a rich and varied flora. Not only herbs grow here, but also trees and shrubs: white saxaul or sandy (Haloxylonpersicum)(Fig. 166), sand acacia (Ammodendronconnolly), juzgun (Calligonum)(Fig. 167), tamarisk (Tamarix)(Fig. 168), etc. In addition to trees and shrubs, the sandy desert also contains a variety of herbaceous plants, including many ephemerals and ephemeroids. When the vegetation cover is destroyed, sand, not held together by plant roots, begins to move under the influence of the wind, causing sandstorms. The danger of being buried always haunts sandy desert plants. However, they have a variety of adaptations that allow them to survive in these conditions. One of them is the ability to quickly form new roots on stems partially covered with sand.
Trees and shrubs covered with sand produce root shoots from horizontal roots extending far to the sides from the mother plant. Material from the site
Plants of salt marsh deserts
Saline deserts develop in low areas of the relief, on the river terraces of the Syrdarya, Amu Darya, and Murghab. Here the vegetation cover is dominated by succulents - succulent, fleshy plants with very thick stems or leaves: saltwort (Salicorniaeuropaea)(Fig. 169), sarsazan (Halocnemumstrobilaceum), solyanka (Salsolasoda),(Fig. 170), S.brachiata and etc.), sweda (Suaedaconfusa,S.prostrata).
The flora of these deserts is poor. Often no more than 10 species can be found over large areas. Plants of saline deserts never dry out; they always remain fresh and juicy. The vegetation cover is very thick, its colors are quite attractive and change throughout the year from bright -- green spring to pink and bloody - red autumn.
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