Arctic air, radiation balance for the year less than 400 MJ / m 2, the average temperature of July 4-2 ° C over the year here. Relative air humidity is very large - 85%. The precipitation drops 400-200 mm, and almost all of them fall in solid form, which contributes to the occurrence of glacial shields and glaciers. However, in some places, the supply of moisture in the air is small and therefore, with a rise in temperature and strong wind, a great drawback is formed and strong evaporation of snow occurs.
The soil formation process in the Arctic occurs in a low-power engineering layer and is at the initial stage of development. In the valleys of rivers and streams and sea terraces, two types of soils are formed - typical polar-deserted on polygonal drainage plains and polar-desert solonchard at saline seaside sites. They are characterized by a small content of humus (up to 1.5%), weakly pronounced genetic horizons and very low power. There are almost no swamps in the Arctic deserts, little lakes, salt spots are formed on the surface of the soil in dry weather with severe winds.
The vegetation cover is extremely resolved and later, it is characterized by the poverty of species composition and extremely low productivity. Low-organized plants dominate: lichens, mosses, algae. The annual increase of moss and lichens does not exceed 1-2 mm. Plants are exclusively selective in its distribution. More or less closed plants groupings exist only in places sheltered from cold winds, on fine-seed, where more power of the active layer.
The main background of the arctic deserts form boothy lichens. Major hypinate mosses, sphagnum moss appear only in the south of the zone in very limited quantities. From higher plants are characterized by a stone, polar poppy, alarm, star, arctic puffy, mint and some others. The cereals are magnificent growing, forming semi-shaped pillows with a diameter of up to 10 cm on a fertilized substrate at the nesting gulls and Nor Levelings. Snow spots grow an icy buttercup and polar will, reaching only 3-5 cm of height. Fauna as a flora, poor views; There are lemming, sands, reindeer, a polar bear, and white partridge and polar owl are common from the birds. On the rocky shores, the birds are numerous bazaars - mass nests of sea birds (Cayra, hollows, white seagulls, stash, gaga, etc.). The southern shores of the Land of Franz Joseph, the Western shores of the new land are a solid bird market.
Natural zone - Territory with close temperatures and humidification conditions that define uniform soils, vegetation and animal peace. On the plains of the zone extend in the latitudinal direction, we naturally replacing each other from the poles to the equator. Often, significant distortions in the drawing of the zone make the relief and the ratio of sushi and the sea.
Arctic and Antarctic Desert . These are cold deserts with very low air temperatures in Arctic and Antarctica. In this zone, snow and ice remains almost all year round. In the very warm month - August - in the Arctic, the air temperature is close to 0 ° C. Free free of ice spaces are abandoned by eternal Merzlot. Very intense frosty weathering. Precipitation drops a little - from 100 to 400 mm per year in the form of snow. In this zone, up to 150 days a polar night lasts. Summer short and cold. Only 20 days, rarely 50 days a year air temperature exceeds 0 ° C. Soils are low, underdeveloped, stonysty, distributed raspecks of a roughly broken material. Less than half of the Arctic and Antarctic deserts are covered with scanty vegetation. It is devoid of trees and shrubs. Lichens, mosses, various algae, only some flowering plants are common here. Animal world is richer than floral. These are white bears, sands, polar owls, deer, seals, walruses. From birds there are penguins, gagags and many other birds, nesting on rocky shores and summer forming "bird markets". In the zone of the icy desert, fishery of marine animals is carried out, among the birds, Gaga is of particular interest, in the down of which nests are smelted. The collection of gagachy fluff is produced from abandoned nests for the production of clothing, which is worn by polar sailors and pilots. In the Ice Desert Antarctica there are Antarctic Oasis. These are free from the ice cover of the mainland coastal strip, an area of \u200b\u200bseveral tens to hundreds of square meters. kilometers. The organic world of oasis is very poor, there are lakes.
Tundra. This space lying within the parts of the Arctic and subarctic belts in the northern hemisphere, in the southern hemisphere of Tundra is common only on some islands. It is a territory with a predominance of moss-lichen vegetation, as well as low-spirited perennial herbs, shrubs and low shrubs. Shrub trunks and herbs roots are hidden in Mokhovaya and lichen turf.
The climate of the tundra is severe, the average temperature of July only in the south of the natural zone does not exceed + 11 ° C, the snow cover holds 7-9 months. The precipitation falls out 200-400 mm, and in some places up to 750 mm. The main reason for the champs of the tundra is low air temperatures in combination with high relative humidity, strong winds, a widespread multi-year permafrost. In the tundra there are also unfavorable conditions for the germination of seeds of wood plants on the Mokhovo-Lichetic Pockery. Plants in the tundra are pressed against the surface of the soil, forming densely intertwing shoots in the form of a pillow. In July, Tundra is covered with a carpet of flowering plants. In the tundra due to excessive moisturizing and many years of milling many swamps. On the warmed banks of rivers and lakes, you can meet poppies, dandelions, polar forget-me-not, pink flowers of the mint. According to prevailing vegetation in the tundra, 3 zones are distinguished: arctic tundra characterized by scanty vegetation due to the severity of the climate (in July + 6 ° C); mokhovo-lichen Tundra characterized by richer vegetation (except for mosses and lichens here are found here, Mattik, whining IVA), and shrub tundra Located in the south of the tundra zone and characterized by richer vegetation, which consists of overgrown Shrubs Willow, alder, which in places rise into human growth. In the areas of this subzone, the shrub is an important source of fuel. The soil of the tundra zone is predominantly tundrovo-gley, characterized by flunk (see "Soil"). She is not good. Frustrate soils with a low-power active layer are widespread. The animal world of the tundra is represented by the reindeer, lemming, sand, white partridge, and in the summer - many migratory birds. Shrub tundra is gradually moving into a timber tundra.
Lesotundra . This is a transition area between the tundra and the zone of the moderate belt. It is common in the northern hemisphere in North America and Eurasia. The climate is less severe than in the tundra: the average temperature of July here is + 10-14 ° C. Annual precipitation is 300-400 mm. The precipitation in the Festundra falls more than evaporates, therefore the forestandra is characterized by excessive moisture, it is one of the most wetrated natural zones. Snow covers holds more than six months. The flood on the rivers Forestandra usually happens in summer, since the rivers of this zone feed on her waters, and the snow becomes in the forest in the summer. Wood vegetation, which appears in this zone, is growing according to the valleys of rivers, as rivers have a spelling effect on the climate of this zone. Forest islands consist of birch, spruce, larch. Trees of low-spirits, seats naught to the ground. The area of \u200b\u200bforests increases in Festundra when moving along it to the south. In the interflies there are forests and rarefied forests. Thus, the Latstundra is an alternation of flavored shrub sites and a steady. Soil tundra (peat-bollard) or forest animal world of Fondra looks like an animal world of tundra. Here, also inhabit the sands, white partridges, polar owl and a wide variety of migratory waterfowl. Foreturdra has the main winter pastures of reindeer and hunting grounds.
Forest of moderate belt . This natural zone is located a temperate climatic belt and includes subzones. taiga, mixed and large forests, monsoon forests Moderate belt. Differences in climatic features contribute to the formation of vegetation characteristic of each subzone.
Taiga (Turk.). This zone of coniferous forests is located in the north of North America and in the north of Eurasia. The climate of the subzone from the marine to a sharp continental with a relatively warm summer (from 10 ° C to 20 ° C), and the temperature of the winter is lower than the more continental climate (from -10 ° C in the north of Europe to -50 ° C in northeastern Siberia). Many areas of Siberia are widespread a long-term permafrost. It is characteristic of subband excess moisturizing and, as a result, the wetlands of interfluve spaces. Distinguish two types of taiga: svetochvoy and topnoahvoy. Svetochkoy Taiga - This is the least demanding of soil-climatic conditions. Pine and larch forests, the Nehbid Croon of which passes the sun rays to the ground. Pines, possessing a branched root system, acquired the ability to use nutrients from lowland soils, which is used to secure soils. Such a feature allows these plants to grow in areas with many years of milling. The shrub tier of the Svetochvoy Taiga consists of Olchovenik, dwarf birches, polar berez, polar IV, berry shrubs. This type of taiga is distributed in Eastern Siberia. Darkness taiga - These are coniferous, consisting of numerous species of firing, fir, cedar. This taiga, in contrast to Svetochvoy, does not have an undergrowth, since its trees are tightly closed, and in these forests is quite afraid. The lower tier makes shrubs (lingonberry, blueberries, blueberries) and a thick fern. This type of taiga is distributed in the European part of Russia and in Western Siberia.
The soil of the taiga zone is podzolic. They contain little humus, but when applying fertilizers can provide a high harvest. In the Taiga of the Far East - acidic soils.
The animal world of the taiga zone is rich. There are numerous predators, which are valuable fishing animals: otter, cunning, sable, mink, caress. From large - wolves, bears, lynks, wolverines. In North America, in the taiga zone earlier there were bison and wapiti deer. Now they live only in reserves. Rich Taiga and Rodents, of which are the most typical beavers, ondatres, proteins, hares, chipmunks. The world of birds is distinguished by a large variety.
Mixed Moderate Belt Forests . These are forests with different rocks of trees: coniferous-wide, finely pine. This area is located in the north of North America (on the border of the United States and Canada), and in Eurasia, forms a narrow strip between the taiga and the zone of deciduous forests. The zone of mixed forests is also found in Kamchatka and in the Far East. In the southern hemisphere, this forest area takes small territories in the south of South America and New Zealand.
The climate of the zone of mixed forests is marine or transient to the continental (towards the center of the mainland), the summer is warm, winter is moderately cold (in the marine climate with positive temperatures, and in a more continental climate to -10 ° C). Moisturizing here is sufficient. The annual amplitude of temperature fluctuations, as well as the annual precipitation vary from oceanic areas to the center of the mainland.
The variety of vegetation zone of mixed forests of the European part of Russia and the Far East is explained by differences in the climate. For example, in the Russian plain, where the sediments fall all year round due to the Western winds coming from the Atlantic, European spruce, oak, elm, fir, beech - coniferous-deciduous forests are distributed.
Soils in the zone of mixed forests are gray forest and turf-podzolic, and in the Far East brown forests.
The animal world is similar to the animal world of the taiga and the zone of large forests. It lives here, sable, bear.
Mixed forests have long been subjected to strong cutting and losses. They are best preserved in North America and in the Far East, and in Europe they cut down under agricultural land - field and pasture lands.
Wildlightened Forests of Moderate Climate . They occupy East of North America, Central Europe, and also form a high-rise zone in the Carpathians, Crimea and the Caucasus. In addition, individual decorators are found in the Far East of Russia, Chile, in New Zealand and in the center of Japan.
The climate is favorable for growing deciduous trees with a wide sheet plate. Here, moderately continental air masses bring precipitation from the oceans (from 400 to 600 mm) mainly in the warm season. The average temperature of January -8 ° -0 ° C, and July + 20-24 ° C.
Women, Grab, Elm, Maple, Lipa, ash grow in the forests. In the zone of broad forest forests of North America, there are species that are missing on other continents. These are American oaks. Trees with a powerful spreading crown prevail here, often accused by curly plants: grapes or ivy. Magnolias are south. For European wide forests, the most typical oak and beech.
The animal world of this natural zone is close to Taiga, but there are such animals such as black bears, wolves, minks, raccoons that are not characteristic of taiga. Many animals of broad forest Eurasia are protected, since the number of individuals is sharply reduced. These include animals such as bison, Ussuri tiger.
Soil under the broad forest forests are gray forest or brown forests. This zone is greatly mastered by man, forests on large areas are reduced, and the lands of rapida. In the true form of the zone of large forests, it was preserved only in uncomfortable areas for earthland and in reserves.
Forest-steppe . This natural zone is located within a moderate climatic belt and is a transition from the forest to the steppe, with alternating forest and steppe landscapes. It is common in the northern hemisphere: in Eurasia from the donutany lowland to Altai, then in Mongolia and the Far East; In North America, this zone is located in the north of the great plains and in the west of central plains.
The forest-steppe is naturally common inside the mainland between the forest areas, which are chosen here the most moistened sections, and the steppes zone.
The forest-steppe climate is moderately continental: winter snow, cold (from -5 ° C to -20 ° C), summer warm (+ 18 ° C to + 25 ° C). In different long-term zones, the forest-steppe varies in atmospheric precipitation (from 400 mm to 1000 mm). Moisturizing is somewhat lower enough, very large evaporation.
In forestry arrays, which are mixed with steppe, are more commonly encouraged (oak) and fine breeds of trees (birch), less often - coniferous. The soil of forest-steppe mainly gray forests, which alternate with chernozem. The nature of the forest-steppe zone is very much changed by the economic activity of man. In Europe and North America, the piping of the zone reaches 80%. Since in this zone are fertile soils, then wheat, corn, sunflower, sugar beet and other cultures are grown here. The animal world of the forest-steppe zone accommodates species characteristic of the forest and steppe zone.
Wosted West Siberian forest-steppe with numerous birch groves-oscillates (food). Sometimes they have an admixture of aspen. The area of \u200b\u200bindividual rings reaches 20-30 hectares. Numerous rods, alternating with the plots of steppes, create a characteristic landscape of southwestern Siberia.
Steppe . This is a landscape with a herbaceous type of vegetation, located in moderate and partially in the subtropical belt. In Eurasia, the steppe zone is extended in the latitudinal direction from the Black Sea to Transbaikalia; In North America, Cordillera so distributes air flows that the zone of insufficient moistening and together with it the steppe zone is located from the north to south along the eastern outskirts of this mountainous country. In the southern hemisphere, the steppe zone is located within the subtropical climate, in Australia and Argentina. Atmospheric precipitates (from 250 mm to 450 mm per year) are irregularly and insufficient to grow trees. Winter is cold, the average temperature is below 0 ° C, in some places to -30 °, a minor. Summer is moderately roast - + 20 ° C, + 24 ° C, frequent drought. Inner waters in the steppe are well developed, the river flow is small, often the river dry.
The impudent vegetation of the steppe is a thick herbal cover, but the undisturbed steppes around the world remained only in the reserves: all the steppes are rapping. Depending on the nature of vegetation, three subzones distinguish between steppes. They differ from each other with predominant vegetation. it meadow steppes (Mattik, Bonfire, Timofeevka), zlakovy And southern foln-cereal .
The soils of the steppes zone are chernozems - have a significant humorous horizon, thanks to which they are very fertile. This is one of the reasons for the strong deposit of the zone.
The animal world of steppes is rich and diverse, but he has changed a lot under the influence of man. Back in the XIX century, wild horses, tours, bison, roofing disappeared. Deer are pushed out in the forest, saigas - in the cereal steppes and semi-deserts. Now the main representatives of the animal world steppes are rodents. These are gopters, tushkans, hamsters, voles. Occasionally, drifts, streptags, larks and others are occasionally.
Steppes and partly forest-steppered and subtropical belts of North America are called prairiy . Currently, they are almost entirely unpaved. Some of the American prairies is a dry steppe and semi-desert.
The subtropical steppe on the plains of South America, located mainly in Argentina and Uruguay, is called pampo . In the eastern regions, where precipitates, brought from the Atlantic Ocean, fall sufficient, and to the West, aridness increases. Most of the pampane dice territory, but in the West, a dry steppes with spiny shrubs used as pastures for livestock are still preserved.
Semi-desert and desert temperate belt . In the south, the steppes go in the semi-desert, and then in the desert. Semi-deserts and deserts are formed in dry climate conditions, where there is a long and hot warm period (+ 20-25 ° C, sometimes up to 50 ° C), strong evaporation, which is 5-7 times the amount of annual precipitation (up to 300 mm in year). Weak surface drain, poor development of inland waters, a lot of drying beds, vegetation is not closed, sandy soils are increasing in the afternoon, but quickly cool down cool at night, which contributes to physical weathering. Here the wind is very draining here. The deserts of the moderate belt differ from the deserts of other geographic belts with a colder winter (-7 ° C-15 ° C). The deserts and semi-deserts of a moderate belt in Eurasia from the Caspian lowland are spread to the northern radiation of Juanhe, and in North America - in the foothills and the Cordiller. In the southern hemisphere of the desert and the semi-deserts of a moderate belt only in Argentina, where they are found by torn areas in the inner parts and foothills. From the plants there are steppe picked, Ticacher, wormwood and the Solyanka, Camel Kolya, Agava, Scarlet. From animals - saigas, turtles, many reptiles. Soil here is light brown and brown desert, often saline. Under conditions of sharp fluctuations in temperature during the day with a small moisture on the surface of the desert, dark crust is formed - desert tan. It is sometimes called protective, as it protects rocks from rapid weathering and destruction.
The main use of semi-desert - pasture animal husbandry (camels, fine-sized sheep). Agriculture of drought-resistant crops is possible only in oases. The oasis (from the Greek name of several settlements in the Libyan desert) is the place of growing wood, shrub, and grassy vegetation in deserts and semi-deserts, in conditions of more abundant surface and soil moistening compared to neighboring areas and plots. The sizes of oasis are different: from ten to tens of thousands of kilometers. Oasis - Centers for concentration of the population, areas of intensive farming on irrigated lands (Nile Valley, Fergana Valley in Central Asia).
Desert and semi-desert subtropical and tropical belts . These are natural zones located in both hemispheres, on all continents along the tropical zones of high atmospheric pressure. Most often, the semi-desert subtropical belt is located in the transitional part of the desert to the mountain steppes in the form of a high-rise belt in the intramaterial parts of Cordiller and Anda America, in Western Asia, Australia and especially wide in Africa. The climate of the desert and the semi-desert of these climatic belts is hot: the average temperature in the summer rises to + 35 ° C, and in the coldest months it does not fall below + 10 ° C. Precipitation drops 50-200 mm, in semi-deserts up to 300 mm. Sometimes precipitates fall out in the form of short rainstones, and in some areas of precipitation may not fall out for several years in a row. With a lack of moisture, the edge of the weathering is very low.
Groundwater linked very deeply and can be partially salinated. In such conditions, only plants can dwell capable of carrying overheating and dehydration. They have a deep branched root system, small leaves or spines, which reduce evaporation from the surface of the sheet. In some plants, the leaves are published or covered with a wax chain, which protects them from sunlight. In semi-deserts of the subtropical belt, cereals are common, cacti appear. The number of cacti increases in the tropical belt, agaves, sand acacia grow, various lichens are spreading on the stones. A characteristic plant for the desert of Namib, located in the tropical belt of South Africa, is an amazing plant Velvigia, which has a short trunk, from the top of which two leaf sheets are departed. The age of Velvigia can reach 150 years. Soil - serous gravelly, gray-brown, they are very fertile, as thin layer of humus. Animal world deserts and semi-desert rich in reptiles, spiders, scorpions. There are camels, antelope, rodents are quite widespread. Agriculture in semi-deserts and deserts of subtropical and tropical belts is also possible only in oases.
Tighted forests . This natural zone is located within the subtropical belt of the Mediterranean type. These are mainly growing in the south of Europe, in the north of Africa, in the south-west and southeast of Australia. Separate fragments of these forests are found in California, in Chile (south of the Atakam desert). Tighted forests are growing under conditions of soft temperate warm climate with hot (+ 25 ° C) and dry summer and with cool and rainy winter. The average amount of precipitation is 400-600 mm per year with rare and short-lived snow cover. Rivers have mainly rain nutrition, and the flood falls on the winter months. In a rainy winter, herbs rarely grow rapidly.
The animal world is very exterminated, but characterized by herbivores and lodging forms, many birds of prey and reptiles. In the forests of Australia, you can meet the Bear Koala, who lives in the trees and leads a night-living lifestyle.
The territory of severe forests is well mastered and is largely changed by the economic activity of man. Large areas of forests are cut here, and their place was taken by plantations of oilseeds, gardens and pastures. Many tree species have solid wood, which is used as a building material, and oils, paints, medications (eucalyptus) are made of leaves. Large yields of olives, citrus fruits, grapes are removed from plantations of this zone.
Monsoon forest subtropical belt . This natural zone is located in the eastern parts of the mainland (China, Southeast of the United States, East of Australia, South Brazil). It is located in the conditions of the most wet, compared to other zones of the subtropical belt. The climate is characterized by the presence of a dry winter period and a wet summer. Annual precipitation is more evaporation. The maximum amount of precipitation falls in summer due to the influence of monsoons bringing moisture from the ocean. In the territory of monsoon forests, the inner waters are rich enough, there are shallow winds of fresh groundwater.
Here, high-seat mixed forests grow in red-vendible mixed forests, among which there are evergreens and leaf falls, dropping the foliage for dry season. The species composition of plants may vary depending on soil-ground conditions. Subtropical species of pines, magnolia, camphor laurel, camellia grow in the forests. On flooded coasts of Florida in the United States and on Missisypan lowland, forests of marsh cypress are common.
The zone of monsoon forests of the subtropical belt has already been mastered by a person. At the place of the forests of the forests are located field and pasture lands, rice, tea, citrus, wheat, corn and technical crops are grown here.
Forests of tropical and subequatorial belts . They are located along the East of Central America, on the Islands of the Caribbean, on the island of Madagascar, in the south-east of Asia, and in the northeast of Australia. Two seasons are clearly expressed here: Dry and wet. The existence of forests in a dry and hot tropical belt is possible only through precipitation, which bring monsions in summer from the oceans. In the subequatorial zone, sediments come in summer when equatorial air masses are dominated here. Depending on the degree of moisturizing among forests of tropical and subequatorial belts distinguish constantly wet and seasonal-wet (or variable-wet) forests. For seasonal wet forests, a relatively poor species composition of woody breeds is characterized, especially in Australia, where these forests consist of eucalyptus, ficuses, laurels. Often in seasonal wet forests are found areas where Tick, Sal grow. Very little in the forests of this group of palm trees. In its species diversity of the vegetable and animal world, constant wet forests are close to equatorial. There are many palm trees, evergreen oaks, tree fern. Many lian and epiphytes from orchid and fern. Soils located under the forests are mostly lard. During dry period (in winter), most deciduous trees do not dump the whole foliage, but some species remain completely naked.
Savannah . This natural zone is located mainly within the subsystem climate, although it is also within the limits of tropical and subtropical belts. In the climate of this zone, the change of the wet and dry season of the year is clearly expressed at consistently high temperatures (from + 15 ° C to + 32 ° C). As it removes from the equator, the period of the wet season from 8-9 months decreases to 2-3, and the precipitation is from 2000 to 250 mm per year.
For Savannan, the predominance of herbaceous cover is characterized, among which the high (up to 5 m) cereals are dominated. Among them, shrubs and single trees rarely grow. Herbal covers near borders with an equatorial belt are very thick and high, and borders with semi-deserts - rarefied. Such regularity is traced in the trees: the frequency increases towards the equator. Among the trees of Savannan, you can meet a variety of palm trees, umbrella acacias, tree cacti, eucalyptus, baobabs, stocking water.
Soil Savannon depend on the duration of the rainy season. Closer to equatorial forests, where the rainy season lasts up to 9 months, red ferrality soils are located. Closer to the border of the savannah and semi-desert are red-brown soils, and even closer to the border, where the rains fall out for 2-3 months, low-product soils are formed with a thin layer of humus.
Very rich and diverse the animal world of Savannan, since the high herbal cover provides animals feed. Elephants, giraffes, hippos, zebras, who attract Lviv, Gien and other predators in turn. The world of birds of this zone is rich. Naks dwell here, ostriches are the largest birds on Earth, a secretary bird that hunts in small animals and reptiles. Many in savanna and termites.
Savannes are widespread in Africa, which occupy 40% of the mainland territory, in South America, Australia and India.
Highly harvested savannahs in South America, on the left bank of the Orinoco River, with dense, mainly cereal herbal cover, with separate specimens or groups of trees, are called Lianos (from Use. Of the numbers "plains"). Savannas of the Brazilian plateau, where the area of \u200b\u200bintensive animal husbandry is located, are called camposa .
Today, savannas play a very large role in man's economic life. Significant areas of this zone are placed, grain, cotton, peanuts, jute, sugar cane are grown here. In more dry places a developed animal husbandry. The rocks of many trees are used in the economy, since their wood does not rot in water. Human activity often leads to the desertification of Savann.
Wet equatorial forests . This natural zone is located in the conditions of the equatorial climate and partly subequatorial. These forests are common in Amazon's pools, Congo, on the Malacca Peninsula and the Stern Islands, as well as on other, smaller islands.
The climate is hot here and wet. All year round temperature + 24-28 ° C. Seasons are not expressed here. Wet equatorial forests are located within the low pressure area, where rising air flows are formed as a result of intensive heating and many precipitation falls (up to 1500 mm per year) throughout the year.
On the coasts, where the impact of the wind from the ocean, the precipitation falls even more (up to 10,000 mm). The preciputes fall uniform throughout the year. Such climatic conditions contribute to the development of the magnificent evergreen vegetation, although, strictly speaking, the trees have a change of leaves: some of them are reset every six months, others - after a completely arbitrary term, the third replacement of the leaves goes in parts. Periods of flowering are also vary, and even more randomly. The most frequent cycles of ten and fourteen months. Other plants can bloom once every ten years. But at the same time, plants of one species bloom at the same time so that they managed to pollinate each other. Plants of this zone are little branched.
The trees of wet equatorial forests have disc-shaped roots, large leathery leaves, the brilliant surface of which saves them from excessive evaporation and scorching rays of the Sun, from the blows of rain jets with strong rains. Many leaves end with elegant spike. This is a tiny drainage. In plants of the lower tier leaves, on the contrary, thin and gentle. The upper tier of equatorial forests form ficuses, palm trees. In South America in the upper tier, the saba grows, reaching the height of 80 m. Bananas, tree ferns grow in the lower tiers. Large plants are liaison. On the trees of equatorial forests, many orchids are epiphytes, sometimes the flowers are formed directly on the trunks. For example, cocoa wood flowers. The equatorial belt in the forest is so hot and humid that favorable conditions are created for the development of moss and algae, which fill the crown and hang from the branches. They are epiphyts. Flowers of trees in Crown can not be polled by the wind, because the air is almost immobile there. Consequently, they are pollinated by insects and small birds, which are embarrassed by a brightly painted by a wedge or sweet smell. The fruits of plants are also brightly painted. This allows them to solve the problem of transportation of seeds. Ripe fruits of many trees eaten birds, animals, seeds are not digested and together with the litter are far from the parent plant.
In the equatorial forests, many planting plants. This is primarily a liana. Life they begin on the ground in the form of a small bustle, and then, tightly shuffling the stem-giant, clogged up. The roots are in the soil, so the plant nutrition does not occur at the expense of the tree-giant, but sometimes the use of these trees to support these trees can lead the latter to oppression and death. "Robber" are some ficuses. Their seeds germinate on the crust of any tree, the roots are tightly wrapped with the trunk and bunches of this host tree, which begins to die. The trunk rotates, but the roots of the ficus became thick and dense and already able to keep themselves.
Equatorial forests are the birthplace of many valuable plants, such as oilseed palm, from the fruits of which palm oil is obtained. The wood of many trees is on the manufacture of furniture and exported in large quantities. This group includes an ebony tree, whose wood has black or dark green. Many plants of equatorial forests give valuable fruits, seeds, juice, boron, which are used in technique and medicine.
Equatorial forests of South America called selva . Selva is located on the periodically flooded territory of the Amazon River basin. Sometimes, describing wet equatorial forests, apply the name giley. , sometimes these forests are called jungle Although, strictly speaking, the jungle call the forest thickets of South and Southeast Asia, located within the sub-screen and tropical climate.
What is a natural zone, knows every student, and those who have subscribed this concept can familiarize themselves with it by reading this article.
Natural zones: Definition and types
The earth's ball consists of all sorts of natural complexes localized on different climatic belts. Despite the variety of landscapes, plants and animals, the individual territories of the Earth are similar to each other. They are combined into a separate group of natural zones. This is the largest gradation of the entire natural complex on the planet.
Natural zones and their features
Natural zones are located in accordance with adapted to certain parameters of temperature and humidity. Basically, they occupy certain latitudes, but the specific area depends on the distance to the ocean and the surrounding relief. The exceptions make up the mountainous areas, on the characteristics of which affect the height of localization. Closer to the top temperature becomes lower, so zonality is located in the direction from the equator to the poles. Below is a natural complex similar to that on the plain. The higher the mountain range, the tops are localized more northern landscapes.
What is a natural zone located not on land? In the ocean, there is also a natural complex that is characterized by a climatic location and depth of the occurrence. His boundaries are vague, compared to land.
Natural zones of tropics and subtropics, desert
For forests of equator and tropics located on the territory of Africa, South America and Asia, characterized by high humidity and temperature. What is a natural zone in these areas of the globe? This is a complex of evergreen trees with severe multi-party (from small shrubs to giant trees). The accelerated circulation of substances leads to the formation of a super-flowed soil layer, which is rapidly spent. In the tropics and subtropics allocate the zone of dry forests, where the trees drop their foliage in the hot period.
The description of the natural zone includes savanna - transition zone from the forests of the tropics to the northern landscapes with a clearly pronounced parel, constantly high temperatures and infrequently falling precipitation. For this complex, a dry period is characterized, as a result, it occurs to reservoirs.
The evergreen forests of the Mediterranean climate mainly consist of plants with rigid leaves. There are many coniferous trees, characteristic of soft winter. Most of the species of animals of this natural zone on the verge of extinction.
Tundra and Fierotoundra occupy the territory of subogenous and polar zones. The vegetation is low with a surface root system due to soil poverty, many moss and lichen, mainly migratory birds, most of the territory is covered with permafrost.
Animals in the Arctic desert are predominantly inhabiting in water, in a warm period, which lasts a few months, birds arrive. That's what is the natural zone of the northern hemisphere.
Often lowered up to -50 ° C, there are strong winds, many days with a purgy and; 85% of the area of \u200b\u200bthe zone is covered. Developed floral cover consists of moss, lichen, algae and rare flowering plants. Polar-desert soils are very low. Usually, they have a peat layer (1-3 cm). Significant evaporation for a long polar day (about 150 days) and dry air lead to the formation of salt marsh varieties of polar-desert soils.
The animal world in the Arctic zone is poor, since the productivity of the plant mass is very small. On the islands inhabit the sands and polar bear. Especially many polar bears. On the rocky banks of the islands there are "bird bazaars" - colonies of seabirds. On coastal rocks and thousands of gagars, chumbs, cumbers, Kair, Moevok, deadlocks and other birds nest.
The tundra zone takes about 8-10% of the country. In a short and cool summer with the middle temperature of July from + 4 ° C in the north to + 11 ° C in the south. Winter is long, harsh with strong and. The winds are cold throughout the year. In the summer, they blow from the northern ice ocean, in winter - from the cooled mainland. The precipitation falls very little - 200-300 mm per year. Despite this, the soils in the tundra are universally converged, which is facilitated by the waterproof perennial permafrost and weak evaporation under conditions of low temperatures. Tundra typical and apodoline soils have a small power, low humus content, relatively high acidity and usually wetched.
The vegetation cover is formed by mkhami, lichens, shrubs and shrubs. All plants have characteristic forms and properties that reflect their fitness to the harsh climate. There are planning and pillow-shaped forms of plants that help to use surface heat and hide from strong winds. Due to the fact that summer is very short and the vegetative season is limited, most plants are represented by perennials and even evergreen. These include lingonberry and cranberries. All of them begin to immediately vegetate, as soon as the snow melts. In the north of the zone there are arctic tundras with the domination of moss-lichen groupings and. Among herbaceous - Source, Pushiza, Polar Mac. In the middle of the zone - a typical tundra with moss, lichen and shrub groups. In the eastern part of the country, Occo-Pushitzia Kochkarny Tundras dominate. For deer feed, a bushy lickey is used - a yagel ("deer moss"). The yagel grows very slowly, at a speed of 3-5 mm per year. Therefore, the recovery of pastures occurs for a very long time - for 15-20 years. For this reason, only nomadic animal husbandry is possible in the tundra, in which numerous herds of deer move all the time in search of feed. Among plants a lot of berry: cloudberry, lingonberry, blueberries, blueberries. There are thickets of bush willow. In the south of the zone, where more heat and weaker winds are dominated by shrub tundra. Among shrubs are the most common dwarf birch birch, different types of IV. In the shelters, the tundra from the south comes the thickets of alder kustyat. There are a lot of berry plants - blueberries, blueberries, lingonberries, growing driek shrubs, mushrooms.
The animal world of the tundra is very poor in species, but is overhaul by the number of individuals. Throughout the year, northern deer (wild and home), lemming, sands and wolves, tundra partridge and white owl are inhabited in the tundra. In the summer, many birds arrive. The abundance of food in the form of midges and mosquitoes attracts a huge number of geese, ducks, swans, Kulikov and Gahar to the tundra to remove chicks.
Agriculture in the tundra is impossible due to the low soil temperature and their poverty with nutrients. But in the tundra there are numerous flocks of deer, mining the fur, collect the Gagachi Pooh.
Forestandra is a transition zone between tundra and forest. In Festour Tundra is significantly warmer than in the tundra. In some places about 20 days a year, the average daily temperature is above + 15 ° C, and the average temperature of July to + 14 ° C. The annual precipitation amount reaches 400 mm, which far exceeds evaporation. As a result, the Forestandra has excessive moisturizing.
Forestandra exists near forest and tundra vegetable groups. Forests consist of curved low-spirited birch, fir trees and larchs. The trees in the forests are far away from each other, since their root system is located in the upper layers of soil over the long-term Marzlot. There are the most productive deer pastures in Festundra, as the yagel grows here much faster than in the tundra. In addition, deer can be hidden in forests from strong winds and forest vegetation as feed and forest vegetation. Animals of both tundra and forests - elk, brown bear, squirrel, hare-beaches, depth and row-pots. Hunting gives a lot of fur, of which the most valuable sand skins.
The forest zone takes more than half of Russia. But the lounged area is only 45% of the country's area. Most of the winter zone is severe and cold. The temperature of January is even in the south below 0 ° C. But summer is warm, and sometimes roast. The average temperature of July in the north of the zone + 15 ° C, and in the south - + 20 ° C.
In the taiga subzone, summer is cool. The average temperature of July is not higher + 18 ° C. The amount of precipitation (300-900 mm) slightly exceeds evaporation. Snow cover is stable and keeps all winter. The ratio of heat and moisture is that it everywhere favors the growth of trees.
In the forest-steppe zone, summer becomes hot. The average temperature of July rises to + 19 ... + 21 ° C. In the north of the zone, the amount of precipitation (560 mm per year) is approximately equal to evaporation. In the south, evaporation slightly exceeds the amount of precipitation. Here are common drought. The climate of the zone is unstable - wet years alternate with arid. In general, the forest-steppe has a warm and relatively dry climate.
Throughout the zone, small forest arrays alternate with the swollen steppes. On the Eastern European Plain in the forest-steppes prevail the oaks with admixtures of maple, ash, limes and elm. In the West Siberian Plain in the forests, birch and aspen are dominated. In Eastern Siberia, pine-larch forests with admixtures of birch and aspen. Under deciduous forests, the same soil-forming processes proceed as in the subzone of broad forest. Therefore, gray forest soils are common here. Under the sections of the varnish steppes were formed with black earth soils.
In the forests of the zone inhabit the usual forest types of animals and birds. And on open steppe spaces there are gophers and hares - Rusaki (often), surs, hamsters, drofs (rarely). Both in the forests and in the steppe areas of the zone are common wolves and foxes.
Favorable climatic conditions, high soil fertility led to the forest-steppe intensively mastered and settled. Up to 80% of the land of this zone is unpaved. It is grown wheat, corn, sugar beets, sunflower. In extensive gardens, a rich harvest of apples, pears, apricots and drains are removed.
The steppe zone is extended in the south of the European part of Russia from the Black and Seas, the premiems. In the east, it stretches to a solid strip before. For the steppe areas are found only in the interguric basins of the south of Siberia.
In the steppes dwells a lot - Susliki, Surki, hamsters, voles. Fox and wolf meet. From the birds are the most common larks and steppe partridges. Some types of animals adapted to the plowed territory, and their number not only did not decrease, but even increased. These include gophers who cause great damage to sow grain.
The semi-desert zone is in the Caspiani. It has a dry sharp continental climate. In the summer, the average temperatures of July rise to + 23 ... + 25 ° C, and in January lowered to -10 ... -15 ° C. The annual precipitation amount does not exceed 250 mm per year. Winter is extremely unstable - often there are strong winds and temperatures may drop to -40 ° C. Frosts can suddenly change the thaws accompanied by ice or (with further decrease in temperature). At the same time, a lot of sheep dies, as they can not get grass from under an ice crust.
In semi-deserts dominate the midst and cereal communities. But spotted vegetation cover and rarely. There are areas of bare soil between the cloths of plants. Kickl, Typsum, Tyrshal, Tyrshal. Many types of semi-staples - white wormwood, prucunion, biurgun and others. Wheld-cereal vegetation is used as pastures. Many semi-desert plants are extremely rich in nutrients and their horses, horses and camels eagerly eaten. Agriculture is carried out only with irrigation.
Zonal in semi-desert are brown soils. Compared to, they are much poorer humus, have less power and are often solentage. All the zones meet Solonins and less often Solonchaki. In semi-desert animals of steppes and deserts live. Major animals - Rodents: Suslik, Tushkanchiki, voles, mice. Typical animal semi-desert - antilopa saigak. Wolf, steppe hoorfish, fox-korsak are found. From birds - steppe eagle, drof, larks.
The desert zone is in the Caspian lowland. This is the most arid territory of Russia. Summer is long and very roast. The average temperature of July + 25 ... + 29 ° C. But very often the temperature in the summer reaches + 50 ° C. Winter short, with negative temperatures. The average temperature of January -4 ... -8 ° C. Snow cover is low and unstable. The annual precipitation amount is 150 - 200 mm. Evaporability of 10 - 12 times more precipitation.
The vegetation cover of the desert is closely associated with the character of the soil. In the sands are common plants having powerful rhizomes and apparent roots, which strengthen the plant in the rash soil and help find moisture. Solonkov, Sarsazan, Sarsazan are timed to the salt marsh. In the northern part of the desert, wormwood and solicky predominate. Sand soils are common in the north and are often gray-brown. They are carbonate, brainsevants and contain little humus. Takers are common. These are clay soils in lowering - with impassive mud in springtime and solid cracking crust - in dry. Tactics are practically deprived of vegetation.
In the life of saigas, a barish cat. A large number of rodents - tubes and gerbils, many lizards. A varied numerous insects - scorpions, tarantulas, mosquitoes, locusts.
The abundance of sunlight and heat, the long vegetation period allows you to grow high yields of the most valuable crops - grapes, Bakhchyev. For irrigation, numerous channels are built, and. Thanks to irrigation in the scorched desert, agricultural farms and new oases occurred. Extensive pastures desert are used for grazing sheep and camels.
The subtropical zone takes small areas covered from the north the mountains. The Caucasus coast in Novorossiysk is located dry subtropics with hot dry summer, with a medium-sized temperature + 24 ° C. Winter is relatively warm and wet. The average temperatures of the coldest month - February are close to + 4 ° C. Frosty periods are rare and short. The annual precipitation amount reaches 600-700 mm with a maximum in winter. The best time of the year is autumn when warm sunny days are standing during September and October.
In the past, dry subtropics were covered with fluffy oak forests, a tree juniper, and Pitsund Pine, groves of strawberry and sandalwood. Sustained shrub thickets of the shiblyak and McWis. Shiblyak - low-speed thickets of fluffy oak leafy plants, spiny shrubs holding a tree, suma, rosehip. McWis - Thickets of evergreen shrubs and low trees: Mirt, Wild Oblina, Strawberry Tree, Tree Heather, Rosemary, Stone Oak. Soils dry subtropics are represented by brown forest and brown.
Currently, natural floral cover is almost negligible. Most of the territory are engaged in vineyards, gardens, parks of numerous sanatoriums and rest houses.
- Remember what a natural zone is.
- What are the patterns in the placement of the natural zones of the Earth?
- What natural zones are located in Eurasia?
- With which sources of geographic information, you can make a characteristic of the natural zone?
Natural zonality - One of the main geographical laws.
The largest German naturalist Alexander Humboldt analyzed climate change and vegetation and found that there is a very close connection between them, that climatic zones are simultaneously and vegetation zones. In the future, it became clear that the climate change causes the zonal placement of not only communities of plants, but also of animal communities, as well as soils, characteristic features of the surface and soil drain, water regime, exogenous relief education processes, etc.
At the end of the XIX century, the great Russian scientist Vasily Vasilyevich Dokuchaev proved that the zonality is the universal law of nature. It manifests itself to a greater or lesser extent in all natural components and on the plains and in the mountains. Since all the components of nature are in close cooperation with each other, the consequence of the area of \u200b\u200bzonality is the existence of large zonal natural and territorial complexes (PTC), or natural (natural historical - in V. V. V. Dokuchaev) zones (Fig. 67).
Fig. 67. Natural areas of the world
Each of them is characterized by a certain ratio of heat and moisture, playing a leading role in the formation of soil-vegetation cover.
Natural zones of our Motherland. On the territory of Russia there is a shift from the north to the south of the following natural zones: arctic deserts, tundras, timres, taiga, mixed and deciduous forests, forest-steppes, steppes, semi-desert.
Almost all the zones of our country stretch thousands of kilometers from the west to the East, and nevertheless, they still retain significant common features due to the dominant climatic conditions, the degree of moistening, soil types, the nature of the vegetation cover. Similarities are also traced in surface waters and modern relief processes.
Figure 67, determine how natural zones are located in our country. Why not all zones extend from Western to Eastern Out of Countries? What zones are located only in the European part of the country? How can this be explained?
Academician Lev Semenovich Berg was introduced to the study of the natural zones of our country. He gave the characteristics of all natural zones of Russia and showed that each zopa consists of a natural combination of landscapes. Natural zones are also called landscaped or geographical. Natural zones are natural laboratories in which scientists study the characteristics of the nature of this territory, investigate the possibilities for the development of each zone, predict the possible consequences of the influence of human activity. Therefore, biosphere reserves and protected areas have been created in each natural zone.
Fig. 68. Potential productivity of natural zones (shown by dotted line)
In a number of natural zones of our country, for example, in steppe and forest-steppe, initial virgin vegetation has not been preserved due to agricultural activities of people. But in nature everything is interconnected, so the soils and the relief, and the water regime, and, of course, the animal world have become strongly changed together with vegetation.
Less, such modern natural zones such as tundra and forestry were injured. But it is about the territories of these natural zones that are still not mastered by a person. And these are primarily part of the Siberian Taiga and the Siberian Tundra.
Arctic desert zone Located on the islands of the Arctic Ocean and the Last North of the Taimyr Peninsula. A significant part of the surface here is covered with glaciers; Winter is long and harsh, summer is short and cold. The average temperature of the warmest month is close to zero (less -1-4 ° C). In such conditions in summer, snow does not have time to melt everywhere. Glaciers are formed. Large areas are occupied by stone browsing. The soil is almost not developed.
Fig. 69. The relationship of nature components within the natural zone
The vegetation free of snow and ice surface does not forms closed cover. These are cold deserts. Among the plants are moss and lichens. Flower plants are represented by a small number of species and are rare. Among the animals are those who feed the sea: birds and white bears. On the rocky shores in the summer there are noisy bird bazaars.
Zone TundR. It takes the coast of the seas of the Northern Arctic Ocean from the western border of the country to Bering Strait. Tundras places reach the northern polar circle. The greatest length from the north to the south zone reaches in the West and Medium Siberia. This zone takes almost 1/6 of Russia.
Fig. 70. The relationship of nature components in the TundR zone
Compared to the Arctic deserts in the summer in the tundra warmer, but winter is long and cold. The average temperature of July in the tundra zone is +5 ... + 10 ° C. The southern border of the zone almost coincides with the heater of July + 10 ° C. The precipitation falls a little, only 200-300 mm per year. But with a lack of heat, evaporation is small, therefore moisturizing is excessive (the humidification coefficient exceeds 1.5).
There are almost universally common in the tundra a long-term Merzlot, which pulls out only a few dozen centimeters in the summer. In places of deeper thickening of the marzlota there were shallow basins filled with water. Without leaking into a frozen soil, the moisture remains on the surface. Tundra is literally littered with shallow and small lakes. Great and river stock. Rivers in the summer time.
Fig. 71. Typical Inhabitant of Arctic Desert - Polar Bear
Soils zone low-power, tundrov-gley. There is a tundra vegetation from moss, lichens and shrubs.
In Nezlesia, the tundra is obeyless not only the cold and eternal Merzlota, but also strong winds. Purga, filling with legs and man and deer, in some places there is a drift, and in others it blows up with the soil of the already small snow cover, burns with ice crystals of the kidneys and grinding trunks, dehydrates vegetable fabrics. Dwarf trees and shrubs therefore got up here "on his knees", crawled on the ground, pressed to her, hiding under the snow raincoat.
"Forest" knee-deep, even by ankle. "Trees" a little more fungus ... age of one juniper staber, the trunk of which had only 8 cm in diameter, turned out to be 544 years old. He grew up before the opening of America Columbus!
The total stock of the plant mass in the tundra is much larger than in the Arctic deserts. Richer here and animal world.
There are plants in the tundra wintering in green. How do you explain this fact? Name the famous representatives of the plant and animal world tundra. Think how they adapt to harsh climatic conditions.
Tundra is heterogeneous in all its space. Three subzones are distinguished from the north to the south: the Arctic tundra is replaced by typical (moss-lichen), and then shrub of the dwarf birch and polar IV.
It entered the custom to consider the nature of this zone scarce. But the connoisseurs of the tundra do not exaggerate when they are enthusiastic about its beauty and wealth and decisively do not agree to consider the tundra "backyards" of the Earth. In addition, the tundra is just as generous as in more southern latitudes.
In the short months of the summer, Tundra is a bright colors, pigeons from blueberry berries, brusca beads, cranberries, orange - bridgeberry berries. There are in the tundra and edible mushrooms. The huge herds of the reindeer graze in the tundra. In the summer, they eaten not only lichens, but also the foliage of the tundra shrubs. In winter, they produce their favorite "deer moss" from under thin snow cover - Lichen Yagel.
Fig. 72. Typical inhabitants of the tundra
The zone of tundra with poor heat reserves, the spread of many years of marbles, moss-lichen and shrub communities is the areas of reindeer herding. They grow here in some way and vegetables, but only in the greenhouses.
Fox mined here. In the tundra lakes a lot of fish.
Determine the same map, what major mineral deposits of our country are located in the tundra area.
Zone Lesotandr The lane stretched along the southern border of the tundra zone.
The average temperature of July is +10 ... + 14 ° C, the annual precipitation is 300-400 mm. The precipitation falls much more than it can evaporate, therefore Ferotundra is one of the most wetrated natural zones. In the nutrition of rivers, talar snow waters prevail. The flood on the rivers is at the beginning of summer, when snow is melted.
Forestandra is a transition zone from tundra to a taiga. It is characterized by a combination of tundra and forest communities of plants and animals, as well as soils. According to the valleys of rivers, stripes of a rather high-herbal forest stretch. In the interflunes there are small islands of the edge - low-rolled straws with lichen cover. They alternate with shrub tundra.
In the forest Tundra in winter, the northern deer is conjugated on its winter pastures. Potatoes, cabbage, turnip, radishes, salad, green onions are grown in open ground. Together with the North and Middle Taiga, Festourdra enters the zone of focal agriculture.
Questions and tasks
- What components of Nature form a natural zone?
- What does the change of natural zones depend on?
- On the example of our country, justify the pattern of changing natural zones.
- Think how the vegetable and animal world of the Arctic deserts towards the habitat is adapted.
- Specify the features of the tundra zone of our country and explain them.
- Think what cause is the strong vulnerability of the nature of the TundR zone.
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