The tundra zone is a unique part of Russian territory in its own way. Its existence is due climate change, observed when moving from any point on the globe to the north or south. Landscapes and the composition of flora and fauna take on a different appearance: closer to the north there are fewer trees and more lichens, and arctic foxes, reindeer and other animals not found in other regions live there.
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The concept of a natural geographical zone
Natural (otherwise, physical-geographical) zone This is an area in the geographic envelope of the Earth that is characterized by a complex of climatic, geological and geochemical conditions unique to it. In addition, the characteristics and composition of the soil, relief, and what types of plants and animals are characteristic of a particular area are taken into account. But still, the greatest importance is when highlighting and describing the location natural area have climatic conditions.
Zonal changes in climate and landscape can practically be observed every degree along the meridian or every 120-140 kilometers. If you move from the equator to one of the Earth’s poles, you can arrange the physiographic belts in this way:
Each natural zone corresponds to a specific climate zone. For example, mixed forests are located in temperate zone, and constantly wet ones - in the equatorial region.
The presence of this natural area typical for the Northern Hemisphere, on the map it stretches across two continents, North America and Eurasia, occupying a significant part of the area of Russia. The location of the tundra is determined by its neighboring location with arctic deserts and taiga.
The wealth of natural resources of the tundra entails a serious interest in its features already from school. Common topics are “Flora World” or “Birds of the Tundra” for reports in the 4th grade, various tables are compiled, schoolchildren prepare reports about the local population or even write interesting stories based on information received from lessons according to a specific plan.
The tundra is located in the subarctic (or subantarctic) belt between temperate and arctic. This determines the rather harsh living conditions in this area. There is a very long winter here, the duration of which reaches seven months, and in the short summer period snow often falls and frosts occur. The upper temperature limit is 10 degrees above zero. Due to low temperatures, not much evaporates from the surface of the earth. a large number of water, so the soils in the tundra are very wet. For the same reason, there are practically no relatively heavy rains.
Another important characteristic in describing the climate of the tundra is a very strong wind. It prevents deep snow from forming and the ground often remains open. Therefore, the entire living world of the tundra is forced to survive in permafrost conditions: closer to the north, the ground freezes to a depth of 500 meters. The short summer period does not contribute to thawing of the soil: on average, about 40 centimeters of land are freed from the ice shell. The absorption of moisture in such conditions is difficult, so a significant part of the territory becomes swampy.
Animals and plants of the tundra are very peculiar, since the local nature is determined by harsh climatic conditions, the polar night, which lasts throughout the winter, and the short summer day.
Vegetable world
The main feature of tundra vegetation is that trees cannot grow here: frozen soils do not allow the root system to develop, and strong winds simply blow away tall plants. Therefore, low-growing species are especially common here: various shrubs and shrubs, grasses, mosses and lichens. Closer to the south, where the tundra turns into forest-tundra, some trees may grow, but this is not observed in the rest of the natural zone. This fact influenced the name of this area: translated from Finnish, tunturia means “land without forest.”
Mosses and lichens
Perhaps the most important in the tundra ecosystem are numerous species of mosses and lichens: cuckoo flax, moss or reindeer moss, pleurocium and many others. They are an important part of the diet of herbivores and survive in such harsh conditions due to the following factors:
The largest of the tundra lichens: moss. Its height ranges from 9 to 15 cm. This is a real tree in miniature. In the largest specimens, one can notice a striking resemblance to the branches and leaves of a real tree.
Shrubs and herbs
In addition to mosses and lichens, there is a variety of shrubs and shrubs. These are dwarf willows and birches, wild rosemary, blueberries, and crowberries. Perennial grasses are widespread: alpine meadow, fescue, Arctic bluegrass, sedge, Rhodiola rosea and cloudberry. Shrubs do not exceed one meter in height. Their branches do not point upward, but, on the contrary, spread along the ground. Small size leaves allows you to reduce the amount of evaporated moisture, and the back side of the leaf is pubescent.
In the summer, the leaves of the trees and grass are bright green, and closer to autumn, crimson shades appear in their color more and more. Many species are flowering, so yellow, white and reddish flowers on a bright green background make these places especially beautiful in the summer, allowing you to fully enjoy what the tundra looks like.
Fauna of the tundra
Tundra fauna are distinguished by significant diversity, despite the harsh conditions for survival in this natural area. Only lizards and other reptiles cannot be found here: the lack of a long warm season does not allow cold-blooded species to live here.
Terrestrial mammals
Animals in the harsh subarctic climate are forced to adapt to the conditions: they have thick and dense fur, and birds acquire lush feathers. Among herbivores the most famous reindeer. Their wide and powerful hooves make long journeys through the snow easier (the length of deer’s migration routes is up to 500 km), and special depressions allow them to rake the snow and find moss or other plants that they feed on.
Powerful antlers allow the deer to successfully defend itself from predators. But in particularly harsh and hungry years, they weaken and often become victims of tundra wolves. They live in large flocks with a pronounced hunting specialization: there are beaters and attackers. This is a very hardy animal, capable of going without food for a week. But if you manage to catch someone, then a feast begins: wolves sometimes eat the victim with skin and bones.
To others dangerous predator tundra is wolverine. Outwardly, she resembles a bear and seems very clumsy. But that's not true. The wolverine's body is very flexible, strong legs allow it to develop high speed. At the same time, the wolverine is distinguished by its endurance: if the victim cannot be caught, then the predator starves it out, chasing it until it collapses from fatigue.
A frequent victim of wolverines, and sometimes wolves, are lemmings: small and fertile rodents. They do not hibernate and are constantly in search of food. Food may include deer antlers, bark, and buds of bushes. Since lemmings reproduce quickly, their usual habitats become overpopulated, and the animals are forced to migrate. Following them, predators also migrate: owls, arctic foxes and others.
The Arctic fox is known for its fur: it is fluffy and long (up to 30 cm). They usually hunt lemmings and migrate after them, but sometimes they do not disdain carrion. Arctic fox burrows dug in the hills are used by several generations of predators: making new holes in permafrost conditions is a difficult task. They live in small flocks, helping each other, including caring for cubs whose parents have died.
Bird species
Along with mammals, it lives in the tundra significant number of bird species. This is determined by two interrelated factors:
- an abundance of wetlands, rivers and lakes;
- availability in these areas significant amount insects, especially in summer.
Many birds adapt to seasonality and do not migrate, for example, the ptarmigan. In winter, its color allows it to camouflage itself in the snow from large predators, and in summer its feathers become variegated. At the same time, the partridge relatively rarely rises into the air and lives in burrows that it digs in the snow.
Lives near the swamps white crane or Siberian crane. This is an endemic species and is on the verge of extinction, therefore it is listed in the Red Book. The Siberian Crane is a fairly large bird; its body height reaches half a meter. Living conditions determined the body structure of the white crane: it has the longest beak in comparison with other representatives of the genus, and long legs allow movement on a viscous surface. The Siberian Crane is omnivorous: it can eat eggs of other birds and fish, as well as various berries and certain parts of plants.
The white, or polar, owl is a serious danger to small mammals and other birds. She has excellent eyesight, so from a small height (most often she inspects the area from high hummocks or stones) she detects a possible victim. After a successful hunt, it does not eat the whole prey, leaving everything that is not consumed for food to various scavengers. At the same time, an owl can go without food for a long time, but this significantly affects the appearance of offspring.
The abundance of rivers and direct access to the seas and oceans are the reason that the tundra is home to many waterfowl. Among them, a special place occupies tundra swan- another rare animal that is in danger of extinction. Tundra swans feed on algae, plants growing near water, and also catch fish. The short duration of the summer period forces animals to raise young animals in a short time: on average, this happens in 40 days.
Another representative of waterfowl - loon. On land it is a clumsy bird, an easy prey for predators, but on water it is almost impossible to catch it: thanks to its streamlined body shape and sharp beak, the loon is an excellent diver. This skill allows you not only to catch fish for food, but also to avoid many dangers.
Water mammals
Many mammals also live in water. They are protected from low temperatures by a thick layer of subcutaneous fat. Some also have thick fur, for example, the sea lion. This protection allows it to dive to depths of up to 400 meters. During the warm season, sea lions often come ashore to bask in the sun. In this case, they move on four limbs.
Seals have become a kind of symbol of the tundra. They live in coastal areas, which is due to their mode of life. They get food in the water and reproduce on land. The seal's nose and ears are built so that they close tightly when diving. An interesting fact is that this animal is able to hold its breath for up to one hour, and this allows it to escape from terrestrial predators.
Another characteristic of tundra regions animal - walrus. Its weight ranges from one ton to one and a half, and its body dimensions reach up to five meters. Walruses are known for their large and powerful tusks. Their direct purpose may seem surprising: walruses use their tusks to dig up the bottom in search of shellfish, which make up the bulk of their diet. But if his life is in danger, the walrus uses its tusks as a formidable weapon. In addition, it is a matter of status: the longer the tusk, the more authority the walrus enjoys in its group.
What is the tundra in people's minds? The imagination begins to picture a snowy, deserted desert, or rather a steppe, only the northern one. Permafrost, or, as they now say, permafrost, does not bring the desire to visit these places. But people live here too, some lead a sedentary life, some lead a nomadic life. And our story is about tundra plants.
Geographical location and climatic conditions of the tundra
It should be noted that the tundra is not monotonous, it can be of different types:
- Arctic.
- Typical.
- Forest-tundra.
- Mountain.
The Arctic tundra is located in North America. It is characterized by strong hurricane winds, air temperatures up to -60 o C. Summer is short, only a few weeks with temperatures up to +5 o C. Permafrost does not allow melted moisture to go deep into the ground, and the tundra takes the form of a swamp with plants in the form of mosses and lichens .
The typical tundra is located south of the Arctic not only in America, but also in Russia; the climate here is somewhat milder. Winter temperatures are down to -50 o C. The warm period lasts from May to October, the average temperature is +5-10 o C. Temperatures up to +25 o C can remain for several days. The earth warms up deeper, but even here there is swampiness, the presence of small streams and lakes. Shrubs appear among mosses and lichens.
Forest-tundra, accordingly, is located south of the typical tundra and is represented by a vast territory on two continents. Characterized by the appearance of small trees. Temperatures range from -40 o C to +15 o C. There are many lakes here.
Climatic conditions depend not only on how many degrees north of the equator a given territory is located, they also change depending on the altitude above sea level. In other words, in mountain systems. The higher the mountains, the closer the climate is to the arctic (strong winds, low precipitation, low temperatures, except that there are not so many swamps and lakes).
What plant grows in the tundra?
Plants here are forced to adapt to harsh conditions, and they do this very successfully. The tundra flora has a number of distinctive characteristics:
So what plant grows in the tundra? One that meets the features listed above, ensuring its survival in unfavorable climatic conditions.
Plant names
What plants are found in the tundra? The main representatives of the plant world are mosses and lichens. According to official data, about 200 species of lichens have been identified in Yamal. Mosses and lichens are closely intertwined with each other, making up “carpets”, usually of the same type. The most common include: green and peat mosses, moss (reindeer moss), Cladonia lichen, Arctic red bearberry. The tundra plants pictured above look like a colorful carpet.
Plant species such as cloudberry, blueberry, lingonberry, black crowberry, late Lloydia, onion, princess, cotton grass, sword-leaved sedge, dwarf birch, wedge-leaved willow and others are also widespread.
Why are plants in the tundra short?
The reason is corrosion. The word is similar to “corrosion” not only visually, but also in its essence - the desire to destroy. Strong hurricane winds in winter move blocks of ice, rock fragments, various boulders, and sand. This mass moves across the tundra with at different speeds, grinding and polishing all hard objects in its path. What plants in the tundra can resist it? There is no such! Anything above the dense cover of snow is cut off and carried away.
Another argument in favor of dwarf plant species is the fact that the surface of the earth thaws no deeper than 50 cm, and then permafrost extends for 500 m. To combat wind and frost, a strong branched root system is needed, and 50 cm does not allow this.
Moss or reindeer moss
Resin moss is one of the most useful lichens in the tundra (and not only). It is a symbiosis of marsupial fungi, green algae and bacteria. It is a very strong natural antibiotic. Not picky about climate and soil. It does not tolerate pollution, so it does not grow near large cities. This perennial plant develops slowly and can be up to 500 years old. Reindeer love moss, but people often use it as a medicinal plant. If reindeer pastures have been in the same place for several years, then it may take up to 15 years to grow a new reindeer moss.
Cloudberry
Even if you are unfamiliar with many tundra plants, cloudberries are likely an exception. It is a perennial herb with a bony fruit that looks like an orange raspberry. It is considered a valuable commercial plant. Both its leaves and flowers and fruits can be harvested. Like many tundra plants, cloudberries are a striking example of northern flora: they ripen in a short period, and the fruits are simply a storehouse of vitamins and minerals. It contains cobalt, potassium, iron, chromium, phosphorus, sodium, copper. The vitamin A content is higher than in the recognized leader - carrots, and vitamin C is higher than in an orange.
Cowberry
A small shrub plant up to 30 cm high. The berries are tart and bitter, so they are frozen and soaked, then they become sweet. Lingonberry is used as a medicinal plant. Many people are familiar with the diuretic properties of the leaves; in addition, lingonberries have anti-inflammatory, tonic, wound-healing, antipyretic, antiscorbutic, and anthelmintic properties. And that's not all. Therefore, it is harvested from May until October.
Blueberry
It is a low shrub. Blueberries are another spectacular representative of northern berries. It is a close relative of blueberries and lingonberries. It would take a very long time to describe its beneficial properties. Blueberries are most often used for eye, cardiovascular, gastric and intestinal diseases, as well as diabetes. It may be easier to tell what this plant does not contain, and what diseases it does not treat.
By the way, blueberries are very popular among gardeners living in warmer climates for their taste and medicinal qualities.
Black crowberry
Crowberry, a small creeping shrub, got its name because of the color of the berries: black, crow. Another name is crowberry, as its berries are watery and sour. The branches look like fir trees due to the frequent elongated leaves. The leaves and berries are used as a medicine against headaches and scurvy.
Lloydia late
Perennial plant up to 15 cm high, moisture-loving. Another name is Lloydia alpine. It blooms in June, tolerates frosts well down to -30 o C. Decorates the tundra with its flowers.
Bow of speed
A bulbous perennial herb that grows in the tundra on swampy and moist, poor soils. Onion feathers are used in food as a seasoning, including meat dishes. Contains vitamin C, carotene, essential oil, organic acids.
Prince
There are other names for this tundra plant. For example, raspberry, polyanina, mamura, drupe, khokhlushka, midday. In all these cases we are talking about the prince. It is a herbaceous perennial shrub with multi-bone fruits. Tasty and aromatic berries are consumed fresh, as well as in confectionery products. They contain glucose, fructose, citric and malic acids, and vitamin C. Therefore, the berries are used for the prevention and treatment of scurvy and vitamin deficiency.
Cotton grass
A perennial herb that grows in the tundra in swamps and along the edges of reservoirs. Participates in the formation of peat. Blooms in early spring. Decoctions are used for treatment gastrointestinal diseases, pain due to rheumatism, and also as an anticonvulsant and sedative.
Dwarf birch
It is also called dwarf. The dwarf birch bears little resemblance to its relative, the common birch. This is no longer a tree, but a bush with several branches. The plant is found in the tundra in the form of overgrown islands. The leaves are similar to the leaves of ordinary birch, but smaller. By winter, the branches fall to the ground. The birch tree reproduces vegetatively, taking root in the area freed from moss. As a rule, these are places plucked by birds or broken by deer hooves. She also has earrings, but, ripening by August, they remain on the branches to “hit the road” in the spring.
Willow cuneifolia
Cluneifolia willow is not the only one in the harsh terrain. There are also such willows: Arctic, creeping, Nakamura willow. All of them are small shrubs (60-100 cm) with creeping branches.
Red Book of Tundra
Like all places on the planet, there is a Red Book of the tundra. Plants included in it are represented by Arctic sunflower, Lapland poppy, purple heartwood, Senyavin wormwood, and Beringian primrose. What unites them? That they are rare, but not endangered. Brought to the north by some unusual event (for example, during times of natural disasters), they took root here and became hardened.
Thus, the center of distribution of the Arctic sunflower is the Mediterranean Sea, Crimea. It is assumed that it came to the north during interglacial warming. It grows on the Cape Turi peninsula, on the seashore 4 km long.
Lapland poppy - found on the Kola Peninsula and Norway, endemic. What plant in the tundra can compare in beauty with the Lapland poppy? Therefore, its numbers are rapidly declining due to people picking the flower for bouquets.
Purple core - lives on the St. Lawrence and Nunivak Islands in the Bering Strait, as well as in Alaska. May reduce its numbers due to human disturbances natural conditions a habitat.
Senyavinskaya wormwood is a representative of Chukotka, endemic, considered an ancient immigrant from the American side.
The Beringian primrose, another Chukchi representative, may be declining in numbers due to human presence.
Why does human intervention negatively affect representatives of the Red Book? Among other things, the lack of roads requires the use of all-terrain vehicles, whose tracks disrupt habitats for a long time and are visible even after several years.
Tundra soil
A story about tundra plants would be incomplete without a story about soil. It is represented by widespread gley soils consisting of clay, loam and sand. Peaty, swampy soils are often found on the plains. The humus layer is small, only a few centimeters, since due to the short summer, the processes of decomposition of organic substances are slow. Mosses and lichens often grow on rocky rocks and their weathering products. There is practically no humus in such soils. The tundra soil is very poor and oversaturated with moisture, characterized by an indefinite soil horizon due to swelling and outpouring of the soil.
As a result of climatic and soil characteristics, tundra plants have developed high viability. Some of them acquired the ability to give birth viviparously, receiving bulbs or small nodules instead of flowers, ready for further germination. There are predator plants that hunt insects. All tricks are used to complete the entire life cycle in full and in a short time, and then stick as close to the ground as possible, cover yourself with a blanket of snow and fall asleep until next summer.
Since there is little warm and sunny time, the flowering time of most plants falls on the same period. At this time, the tundra is incredibly transformed, becoming like a bright canvas with green, brown, yellow and red spots. At this time, the tundra no longer seems cold and unfriendly. And it’s hard to understand how you can not love her for such beauty!
The tundra zone is quite extensive, located from the Kola Peninsula to Chukotka - that is, it covers almost the entire north of Russia. The boundaries of the tundra almost coincide with the Arctic Circle in the south and west, and in the east it extends quite far, to the coast of the Sea of Okhotsk.
Tundra is a natural zone that is located in the northern part of the continents. These are limitless expanses of permafrost. The local soil never thaws to a depth of more than a meter. Therefore, all the vegetation of the tundra, as well as all its inhabitants, are adapted to life in such a way as to be the least demanding of external conditions.
The tundra zone is characterized by very harsh living conditions:
So, short cold summer, harsh long winters, permafrost, special lighting - these are the conditions in which the flora of the tundra grows.
Tundra vegetation differs in small sizes: strong gusts of wind blow away the fallen snow, consisting of hard ice crystals, moving it at high speed. This phenomenon is called snow corrosion; it not only damages plants, but also causes even stone to be sanded.
In summer, plants grow in absolutely amazing conditions: the sun is low and heats weakly, but it shines 24 hours a day, this phenomenon is called “polar day”. Therefore, herbs and shrubs adapt well so much long day, which does not interfere with their development.
However, representatives of short-day flora will not be able to survive here. Let's consider which plants and animals of the tundra have adapted to these harsh conditions.
Features of the flora and fauna of the tundra
The most common species found here are lichens and mosses, low-growing shrubs, shrubs and herbs. Trees for the most part cannot live in such harsh conditions.
Summer is too short, so young shoots simply do not have time to build up the protective layer necessary for overwintering. Only in the southern regions are rare trees sometimes found, however, these zones it would be more correct to call it forest-tundra.
Lichens and mosses. These are very important representatives of the flora of the tundra, of which a huge number of species grow here. Mosses often form a continuous carpet and serve as food for local fauna. Why do they manage to survive in harsh conditions:
- They are short-growing, so even a small layer of snow reliably covers them.
- These plants do not obtain nutrients and moisture from the soil, taking them from the atmosphere. Therefore, poor soil does not interfere with their normal development.
- Lack of true roots - mosses and lichens are attached to the soil by small thread-like shoots.
The main varieties of mosses and lichens of the tundra are as follows:
- cuckoo flax;
- chylocomium;
- pleurocium;
- reindeer moss (moss).
Average height of moss reaches 15 cm. This is one of the largest lichens. Each light gray plant resembles an amazing tree in appearance, which has a “trunk” and thinner “branches”.
Wet moss lush and soft, a dry plant becomes hard, but very fragile, crumbling from the slightest mechanical impact. It has a very slow growth rate - only a few millimeters per year, which is why reindeer cannot be grazed on the same reindeer pasture for several years in a row.
Plants, grasses and shrubs of the tundra
Among flowering plants, perennial herbs, shrubs and shrubs are primarily represented. The shrubs and shrubs are very low and in winter they are completely covered with snow. The most common types include the following:
Some are evergreen, others - deciduous. Tundra grasses are mostly perennial, the most common are grasses and sedges, and there are several types of legumes. What kind of grasses can be seen in the tundra zone:
- alpine meadow grass;
- alpine foxtail;
- squat fescue;
- arctic bluegrass;
- hard sedge;
- obscure penny;
- umbrella astragalus;
- the hollyweed is rather dirty;
- viviparous knotweed;
- European and Asian swimsuit;
- Rhodiola rosea.
Many representatives of the flora have large flowers of various colors: crimson, white, yellow, orange. Therefore, the summer blooming tundra looks very picturesque. Tundra vegetation well adapted to harsh conditions: the leaves of shrubs and shrubs are small - this reduces the evaporation of moisture from their surface, and the lower part of the leaf blade is densely pubescent, which also helps to avoid excessive evaporation.
The most common inhabitant of the tundra is dwarf birch, also called yornik. The height of such a plant is less than a meter, it grows not as a tree, but as a shrub, so it bears little resemblance to the birch we are used to, although these plants belong to related species.
The branches of the plant do not rise horizontally, but are spread out on the ground, the leaves are small, round and wide. IN summer season They have a rich green color, becoming crimson-red by autumn. The plant's catkins are also small, usually oval in shape.
Blueberry is a low deciduous shrub, whose length rarely reaches more than half a meter. The leaves are bluish in color, the flowers are small, white, sometimes with a pinkish tint. The fruits are round berries, similar to blueberries, but larger.
Cloudberry is a perennial herbaceous plant.. It has a thin rhizome, from which in the spring a stem grows with several rounded leaves and a single flower. By winter, the above-ground parts of the plant die off and appear again in the spring. The fruit is a complex drupe.
Fauna of the tundra
The fauna world in the tundra is unique. There is little food here, the climate is very harsh, so the animals have to adapt with all their might. That is why the fur of the local inhabitants is thick, and the birds have lush plumage.
The following animals can most often be found in the tundra:
- Reindeer.
- Polar Wolf.
- White Arctic partridge.
- Arctic fox.
- Polar owl.
- Lemming.
Arctic foxes feed on lemmings, so in winter predators migrate after their victims. In hungry years, animals often have to eat plant foods or even carrion.
By wintering they well adapted: the fur becomes thick and warm in the fall, helping animals survive even freezing temperatures. Interestingly, arctic foxes have small ears that are completely hidden in their fur - this way they are protected from frostbite.
Reindeer They love to eat reindeer moss: with their powerful hooves they pull out the lichen from under the snow. In summer, an abundance of birds flock here to nest: waders, ducks, geese, swans. They feed on a large number of insects: mosquitoes, gadflies and midges.
The flora and fauna of the tundra is an example of how in nature all the inhabitants learned to adapt to difficult conditions and survive in the harshest climate.
The tundra zone extends in the north of our country in a continuous strip from the Kola Peninsula to Chukotka. It occupies about 14% of Russia's territory. The southern border of the tundra zone in the European part of the country (except for the Kola Peninsula) and in Western Siberia almost coincides with the Arctic Circle. In Eastern Siberia it is sharply pushed to the north, and in the extreme east of the country, on the contrary, it descends far to the south, reaching the coast of the Sea of Okhotsk.
The living conditions of plants in the tundra are quite harsh. Winter lasts 7 - 8 months, and summer is short and cool. average temperature the warmest summer month (July) usually does not exceed + 10 °C. The life span of plants is very short - only 3-4 months. Even at the height of summer, in July, there are frosts and snow on some days. Sudden returns of frost catch plants at a time when they are in a state of active growth and full flowering.
There is little precipitation in the tundra, usually no more than 250 mm per year. However, in cold climates this relatively small amount is more than enough. Much more water comes from the atmosphere than can evaporate from the earth's surface. Tundra soils are provided with abundant water. The bulk of precipitation occurs in the summer; in winter there is very little precipitation (about 10% of the annual amount). There are no heavy downpours; it usually just drizzles. There are especially many rainy days in autumn.
The snow cover in the tundra is very shallow - on level ground it is usually no more than 15-30 cm. It barely covers low-growing bushes and shrubs. Strong winds completely blow away the snow from hillocks and elevations, exposing the soil. The surface of the snow is constantly in motion under the influence of the wind. The mass of tiny ice crystals that make up the snow moves at high speed in the horizontal direction, exerting a strong mechanical effect on everything located above the snow cover. This powerful stream of solid ice particles can not only destroy or damage plant shoots protruding above the snow - it even grinds rocks. The mechanical effect of snow driven by strong winds, the so-called snow corrosion, does not allow tundra plants to grow any tall. The flow of ice crystals seems to trim them. Only in deep depressions, which in winter are filled to the brim with snow, can relatively tall shrubs be found (they can be as tall as a person).
Wind speed in the tundra can reach 40 m/sec. This wind is so strong that it knocks a person off his feet. IN winter time wind affects plants mainly mechanically (through corrosion). But in summer it has a predominantly physiological effect, increasing evaporation from the aboveground organs of plants.
Permafrost is widespread throughout almost the entire territory of the tundra zone. The soil thaws in summer to a shallow depth - no more than 1.5-2 m, and often much less. Below is a permanently frozen pound. Permafrost has a huge impact on tundra vegetation. This influence is mostly negative. The close proximity of cold, ice-bound soil limits the deep growth of plant roots and forces them to be located only in a thin surface layer of soil. Permafrost serves as an aquifer, preventing moisture from seeping down and causing waterlogging in the area. Tundra soils usually have well-defined signs of swampiness: a peaty layer on the surface, underneath a bluish gley horizon. The soil temperature in the tundra in the summer drops rapidly with depth, and this also adversely affects plant life. The surface of the vegetation cover, even well north of the Arctic Circle, can heat up in summer to + 30 °C or more, while the soil already at a depth of 10 cm is quite cold - no more than +10 °C. Thawing of tundra soils at the beginning of summer is slow, because the upper horizons are usually penetrated by layers of ice that absorb a lot of heat. Therefore, tundra plants develop in the summer under conditions of a very special light regime. The sun does not rise high, but for many days it shines around the clock. Thanks to round-the-clock lighting, plants manage to receive quite a lot of light even during a short growing season - not much less than in mid-latitudes. The light intensity in the Far North is relatively high due to the high transparency of the atmosphere. Tundra plants are well adapted to long days; they develop well under this unique light regime. Short-day plants cannot develop normally in tundra conditions.
Thus, in the tundra, among many factors unfavorable for plant life, one of the most important is lack of heat. Summer here is too short and cold, the soil thaws to a shallow depth and does not warm up well. The air in summer is also often quite cold, and only on the surface of the soil, when the sun is shining, is it relatively warm. Consequently, in the tundra only the most favorable conditions for plant life are upper layer soil and the lowest layer of air adjacent to the earth's surface. Both layers measure only a few centimeters. It is not surprising, therefore, that many tundra plants are very short, they are spread out on the ground, and their root systems grow mainly in the horizontal direction and almost do not go deep. In the tundra there are many plants with leaves collected in a basal rosette, creeping shrubs and shrubs. All these plants, due to their short stature, make the best use of the heat of the ground layer of air and protect themselves from excessive evaporation caused by strong winds.
Let's get acquainted in more detail with the flora of our tundras.
A typical tundra is a treeless space with low and not always continuous vegetation cover. It is based on mosses and lichens, against which low-growing plants develop. flowering plants- shrubs, shrubs, herbs. There are no trees in the real tundra - the living conditions here are too harsh for them. During the short and cold summer, the protective layer of integumentary tissue necessary for normal overwintering does not have time to fully form on young shoots (without such a layer, young branches die in winter from loss of water). Conditions for overwintering trees in the tundra are extremely unfavorable: strong drying winds, snow corrosion, which systematically “cuts” young trees and does not allow them to rise above the snow.
Another important circumstance is also important - low temperature tundra soil in summer, which does not allow the roots to replenish large water losses from the above-ground part of the tree during evaporation (the so-called physiological dryness of tundra soils).
Only in the very south of the tundra zone, in more favorable climatic conditions, can individual trees be found. They grow against the background of a characteristic tundra vegetation and stand quite far from each other, forming the so-called forest-tundra.
Mosses and lichens play a very important role in the vegetation cover of the tundra.
There are many types of them here, and they often form a continuous carpet over vast areas. Most mosses and lichens found in the tundra are not associated in their distribution exclusively with the tundra zone. They can also be found in forests. These are, for example, many green mosses (pleurocium, chylocomium, cuckoo flax) (lichens of the genus Cladonia (this includes deer moss and other related and similar species). However, there are also specific tundra species of mosses and lichens.
Both mosses and lichens tolerate the harsh conditions of the tundra. These low-growing, unpretentious plants can overwinter under the protection of even a thin snow cover, and sometimes without it at all. The soil layer as a source of water and nutrients is almost not needed for mosses and lichens - they get everything they need mainly from the atmosphere. They do not have real roots, and only thin thread-like processes develop, the main purpose of which is to attach plants to the soil.Finally, mosses and lichens, due to their short stature, make the best use of the ground in summer, the most warm layer air.
The bulk of flowering plants in the tundra are shrubs, dwarf shrubs and perennial herbs. Shrubs differ from shrubs only in their smaller size - they are almost the same in height as small herbs. But nevertheless, their branches become lignified, covered on the outside with a thin layer of protective cork tissue and bear wintering buds. It is enough to draw a clear line between shrubs and shrubs difficult.
On flat areas of the tundra, where the snow cover is shallow, both shrubs and shrubs are low and do not rise above the snow. Among these plants we find some dwarf species of willows (for example, grass willow), wild rosemary, blueberry, crowberry, and dwarf birch. It often happens that shrubs and shrubs are located in the thickness of a thick moss-lichen cover, almost without rising above it. These plants seem to seek protection from mosses and lichens (in the forest the situation is completely different). Some of the shrubs and shrubs are evergreen (crowberry, lingonberry, wild rosemary), others shed their leaves for the winter (various willows, dwarf birch, blueberry, arcticus, etc.).
Almost all herbaceous plants of the tundra are perennial.
Perennial herbaceous plants of the tundra are characterized by short stature. Among them there are some grasses (squat fescue, alpine meadow grass, arctic bluegrass, alpine foxtail, etc.) and sedges (for example, hard sedge). There are also a few legumes (astragalus umbelliferum, common pennyweed, and common oleaginus). However, most species belong to the so-called forbs - representatives of various families of dicotyledonous plants. From this group of plants we can name the viviparous knotweed, the Eder's grass, the European and Asian swimworts, rosea rhodiola, alpine cornflower, woodland and white-flowered geraniums. A characteristic feature of tundra herbs is large, brightly colored flowers. Their colors are very diverse - white, yellow, crimson, orange, blue, etc. When the tundra blooms, it looks like a motley colorful carpet. The tundra usually blooms immediately, suddenly - after the first warm days arrive. And many plants bloom at the same time.
Many representatives of the tundra flora have adaptations aimed at reducing evaporation in the summer. The leaves of tundra plants are often small, and therefore the evaporating surface is small. The underside of leaves, where the stomata are located, is often covered with dense pubescence, which prevents too much air movement near the stomata and, therefore, reduces water loss.
Let's take a closer look at some of the most important tundra plants.
Dwarf birch, or dwarf birch (Vegina papa). The dwarf birch bears little resemblance to our ordinary, familiar birch, although both of these plants are close relatives (different species of the same genus). The height of a dwarf birch is small - rarely more than half a person's height. And it grows not as a tree, but as a branchy bush. Its branches rise slightly upward, and often even spread across the surface of the ground. In short, the birch tree is truly dwarf. Sometimes it is so small that its creeping shoots are almost entirely hidden in the thickness of the moss-lichen carpet, and only leaves are visible on the surface. It must be said that the leaves of a dwarf birch are not at all the same as those of an ordinary birch. Their shape is round, and the width is often greater than the length. And they are relatively small in size - like small copper coins. Along the edge of the leaf there are small semicircular projections one after another (botanists call this edge of the leaf crenate). The leaves are dark green, glossy above, and paler, light green below. In autumn, the leaves become beautifully colored - they turn bright red. Thickets of dwarf birch are unusually colorful at this time of year; they always surprise with their bright crimson color.
Seeing a dwarf birch branch with leaves for the first time, few of us would say that it is a birch. Even if we notice earrings on a branch, it will also be difficult to determine that in front of us is a birch tree. Like the plant itself, these earrings are dwarf, very short - their length is no more than a fingernail. And their shape is not at all the same as that of an ordinary birch - oval or elongated-ovoid. When ripe, the earrings crumble into separate parts - small three-lobed scales and tiny, nut-like fruits, equipped with a narrow membranous edge. In this respect, the dwarf birch differs little from the ordinary birch.
Dwarf birch is one of the most common tundra plants. It can be found in almost the entire tundra zone. It is especially abundant in the southern part of the tundra, where it often forms thickets. In summer, deer feed on its leaves. And the local population collects larger specimens of the plant for fuel.
In the North, dwarf birch is often called dwarf birch. This name comes from the Nenets word “era”, which means “shrub”.
Blueberry, or gonobobel (Uasstsht iN§tosht). This is the name of one of the low tundra shrubs (its height rarely exceeds 0.5 m). Distinctive feature This plant has a bluish tint to the foliage. The shape and size of the leaves are almost the same as those of lingonberries, but relatively thin and delicate. They appear in the spring and fall off by autumn. Blueberries, unlike lingonberries, are deciduous shrubs.
Blueberry flowers are inconspicuous, dim, whitish, sometimes with a pink tint. They are no larger than a pea, their corolla is almost spherical, shaped like a very wide jug.” The flowers are located on the branches so that the corolla opening is directed downwards. There are 4-5 small teeth along the edge of the hole. The denticles represent the ends of the petals (along the rest of the length the petals are fused into one whole).
Blueberry fruits are bluish, round berries with a bluish bloom. They resemble blueberries, but are larger. The pulp of the fruit is not watery, as a result of which this plant is sometimes called crowberry.
Cloudberry (Kubus cataetoris) is the closest relative of raspberry (another species of the same genus). However, this is not a shrub, but a perennial herbaceous plant. Every spring, a short, erect stem with several leaves and only one flower grows from a thin rhizome in the soil. By winter, the entire above-ground part of the plant dies, and in the spring another shoot grows again. Cloudberries are different from raspberries in many ways. Its stems are devoid of thorns, the leaves are rounded-angular (shallowly 5-lobed). The flowers are much larger than raspberries, with five white petals pointing towards different sides. Cloudberries are unlike raspberries in one more respect: they are dioecious plants. Some of its specimens always bear only male, sterile flowers, others - only female ones, from which fruits are subsequently formed. I wonder what male flowers larger than female ones, they can be up to 3 cm in diameter.
Cloudberry fruits are similar in structure to raspberry fruits: each of them consists of several small juicy fruits fused together into one whole. An individual fruit is somewhat similar to a tiny cherry: there is pulp on the outside and a pit on the inside. Botanists call such a simple fruit a drupe, and the entire complex cloudberry fruit is a complex drupe. Raspberries have exactly the same type of fruit.
However, in appearance, the cloudberry fruit bears little resemblance to the raspberry fruit. Its individual particles are much larger than those of raspberries, and the color of the fruit is completely different. At the beginning of ripening, the fruits are red; when fully ripe, they are orange, like wax. Ripe cloudberry fruits have a pleasant taste and are highly valued by local residents, who collect them in large quantities in the tundra. The fruits contain from 3 to 6% sugar, citric and malic acids. They are eaten mainly steamed and soaked; they are also used to make jam.
Lichen moss, or reindeer moss (C1ac1osha gangireppa). This is one of our largest lichens, its height reaches 10-15 cm. An individual moss plant resembles some kind of fancy tree in miniature - it has a thicker “trunk” rising from the ground, and thinner winding “branches”. Both the trunk and branches gradually become thinner and thinner towards the ends. Their ends almost completely disappear - they are no thicker than a hair. If you put several of these plants next to each other on black paper, you get a beautiful white lace.
Resin moss has a whitish color. It is due to the fact that the bulk of the lichen consists of the thinnest colorless tubes - fungal hyphae. But if we look at a cross-section of the main “stem” of moss under a microscope, we will see not only fungal hyphae. Near the surface of the “stem” there is a thin layer of tiny emerald green balls - microscopic cells, algae. Resin moss, like other lichens, consists of fungal hyphae and algae cells.
When wet, moss is soft and elastic. But after drying, it hardens and becomes very brittle and crumbles easily. The slightest touch is enough for pieces to break off from the lichen. These tiny fragments are easily transported by the wind and can give rise to new plants. It is with the help of such random fragments that moss mainly reproduces.
Resin moss, like other lichens, grows slowly. It grows in height only a few millimeters per year, although its size is quite large. Due to the slow growth of moss, the same tundra pasture cannot be used for several years in a row; it is necessary to constantly move to new areas. If deer in the tundra eat moss, it takes quite a long time (10-15 years) to restore the lichen cover.
Resin moss is of great economic importance. It is known to serve as one of the most important food plants for deer in the tundra. Interestingly, deer unmistakably find it by smell even in winter under a layer of snow.
Fauna of the tundra
The fauna in the tundra is very unique and differs in some features from the animals of the Far North. They are not picky about food. Animals have thick fur, and birds have fluffy plumage. Animals change color: in summer they are light brown to match the color of the vegetation, and in winter they are white or light gray to match the color of snow.
Typical animals of the tundra are the arctic fox, lemming, reindeer, ptarmigan, polar wolf and snowy owl.
The Arctic fox hunts pieds and polar partridges. He has very valuable fur. Reindeer are not afraid of frosts and snowstorms. Wide hooves allow him to run through the snow without falling through and rake the snow in search of food.
In summer, countless mosquitoes, midges, and gadflies appear in the tundra. There are so many of them that you can’t work in the tundra without mosquito nets; they bite and get into your eyes, nose, and mouth.
At this time, many birds fly here to nest: geese, swans, ducks, waders. Many of them feed on insects.
The flora of the tundra natural zone is not rich. First of all, this is due to harsh climatic conditions. Tundra landscapes can be swampy, peaty and rocky. There is no fertile soil ideal for plant development here. They grow in swampy areas different kinds moss. Among the mosses there are entire fields of lingonberries, cloudberries and blueberries. By autumn, many fruits ripen in these berry fields. Plants similar to moss grow on the peat and rocky soils of the tundra. One of these is moss. This plant covers vast areas of the tundra. There is so much reindeer moss that all year round Whole herds of wild deer feed on it.
Not only mosses and reindeer moss are found in the tundra. Here, in places well protected from strong winds, in the valleys of rivers or lakes, you can find large meadows where a variety of grasses reach a height of half a meter.
The tundra is also characterized complete absence forest areas. The only trees found are polar willow and dwarf birch. These trees are more similar to shrubs. The dwarf birch is so small that its thin, curved trunk practically lies and hides in moss or reindeer moss. Only small branches with miniature leaves are raised upward. The polar willow is even smaller than the birch. During snowfalls, all its branches are covered with snow.
Animals of the tundra
The most numerous inhabitants of the tundra belong to the class of birds. Especially in summer, a large number of geese, ducks and. In lakes and rivers they look for food, mainly insects, plants and small fish. There are so many birds in the tundra that some of its reservoirs are either white with geese or black with ducks. The screams and cackling of birds can be heard everywhere.
In summer, the tundra is infested with midges and mosquitoes. They rush through the air like clouds, attack animals and people, and give them no rest either night or day. To get rid of annoying insects, people light fires or dress in special suits.
During severe winters, most birds fly to the southern regions. It is not uncommon for numerous herds of reindeer to pass through here. With the help of their hooves, they dig moss out of the ground. Sometimes you can see arctic foxes, musk oxen, lemmings and stoats here. Occasionally a polar owl is seen in the tundra. Her white, and therefore the partridges and pieds that she hunts simply do not notice her against the background of the snow.
Most of the animals of the tundra are covered with thick plumage or fur. Their winter color, as a rule, turns white, which helps them hide from enemies or sneak closer to their prey.