§ 55. Geographic zones and natural areas
Geographic zones and natural areas. Geographic Zones - A natural complexes, a wide zone extending in the latitudinal direction and change each other from the equator to the poles. Geographical area differ amount of heat, prevailing air masses and prevailing winds. Geographical area called for appropriate climatic zones. On Earth balls emit 13 geographical zones: equatorial, two subekvatorialnyh, two tropical and two sub-tropical, two moderate, two subpolar (subarctic and subantarktychnyy) and two polar (Arctic and Antarctic).
Miscellaneous ratio of heat and moisture within the same geographical area determines its division of natural areas.
Natural areas. Here for dominate, the cold arctic air masses. The long polar night. Temperatures low air: in winter to -30 0C in summer 5 0S. Snow cover is held 300 days a year. Little rainfall - 300 mm per year. On is shallow permafrost. It cools the soil, prevent seepage of surface water and promotes waterlogging. Vegetation and fauna is very poor.
Arctic desert zone includes islands Arctic Ocean. Among the common plants, lichens, mosses, polar Mack, kuripkova grass. Here, live reindeer, polar bear, polar fox, lemming. Summer nesting gulls, chornodzobi goose.
Fig. Arctic desert
Tundra Zone wide strip reaches the Arctic Ocean in Asia and in North America. The winter is too severe, but a little warmer in summer. Temperature in July equals 12 0S. tundra-wetland soils. Rainfall increased to 400 mm. In tundra richer vegetation: along with mosses and lichens growing sedge, cereals, cranberries, dwarf birch, alder bushes. Plants stunted, stelyutsya land slope of strong winds. Among the common animals reindeer, polar fox, lemming, white partridge, white owl. Many Waterfowl birds: geese, ducks, swans, loons.
У Zone lisotundry summer longer and warmer than the tundra. Among mosses grow birch, pine, spruce. Taiga is inhabited by representatives: elk, brown bear, wolverine, rabbit-Bilyak, protein from birds - grouse, hazel hen. In winter, residents here wandering the tundra - reindeer and polar fox.
Area of coniferous forest (taiga) occupies the northern part of the zone. There's a long cold winters and warm summers. January temperature -24? -30 0C, July 1919 0C. The annual rainfall - 600 mm. Snow cover 200 days a year. Waterlogged area. Soils - podzol and peat-swamp. Growing coniferous forests of spruce, pine, birch and is aspen. A more diverse than in tundra fauna: elk, hare-Bilyak, squirrel, wolf, fox, brown bear, lynx, wild weasel, ferret, please.
Zone of mixed forests located south of the zone taiga. Soils there sod-podzol. In forests combined coniferous and deciduous tree species: spruce, pine, birch, aspen, oak, ash, linden, beech. They live moose, brown bear, roe deer, wolf, fox, hare-Bilyak, hare. Many birds: woodpeckers, titmouse, siskin, black grouse, hazel hen.
Wide-area forest is south of the zone of mixed forests. There's a cool summer (temperatures in July 1916 0C) but warm winter (temperature of January 7 0C). Persistent snow cover is formed. Rainfall is 800 mm per year. Soils brown wood. Grow broadleaf forests of oak, beech, linden, maple, elm, ash and hornbeam. Usual many animals: deer, wild boar, roe deer, badger, forest marten, hare, protein. Birds common woodpecker, blue titmouse, finch.
The forest-steppe zone occupies a narrow strip and spread south of the zone of mixed forests. It is, and forest and prairie vegetation. Winter cold January temperature reaches -20 0C. Summer is warm with the July temperatures 22 0C. Annual precipitation is 400 mm per year. Fertile soils - forest gray, black. Therefore, the zone much plowed. Vegetable cover - meadows and steppes, combined with the wide-forests. In the plains grow tall grass - feather grass, typchak, tonkonih, timothy, buttercup. Animals: moose, marten, wild cat, squirrel, gopher, and other large jerboa.
Steppe zone occupies the central part of the moderate zone. The temperature in July is 24 0S, Jan. - -5? -12 0S. Winter is very cold and long. Because of strong winds light snow. The rainfall is 400 mm. Among the plants is dominated by feather grass, typchak, zhytnyak, tonkonih, astragalus, sage. Soils - black and chestnut. Animals - mostly rodents: ferret, earth hare, jerboa, hamster. There steppe ferret, badgers and foxes. Many steppe birds: bustard, partridge, skylark, steppe eagle. Common prairie adder snake.
Zone semi-deserts temperate formed in moderate sharply continental climate. There are hot summers (35 0C) and cold winters with annual rainfall less than 200 mm. Because plant cover is poor, very tenuous. Significant areas occupied by sand. There are growing tonkonih, wormwood, soup, tamarisk bush, haloxylon. There are found antelope (Saiga, dzeren), wild ass - Kulan, dvohorbyy Manhattan. Among rodents common ferret, gerbil, jerboa. There are predators: foxes, Sand Cat, Sand badger. Many lizards and snakes: udavchyk sandy, steppe viper, ETF and hyurza cobra. Usually there is a tarantula spider, karakurt, scorpion.
Zone tverdolystyhevergreen forests and shrubs lies in the subtropical zone and has subtropical climate with hot and dry summers and warm wet winters. Summer dominated continental tropical air is set dry, hot weather. The temperature in July is 27 0C, January temperature - 10 0S. Precipitation falls of 500 mm per year. Soils brown, brown wood. Vegetation dominated evergreen forest and Trees, consisting of an evergreen oak, pine and cedar, strawberry tree oil, juniper. But the prevailing shrubs.
Zone variable-wet monsoon forests occupies the eastern mainland and stretching across several geographic zones. Climate has significant seasonal differences. Winter is dry and cool (temperature January 8 0C) summers are warm and humid. Frequent showers. The rainfall, as temperature, increases from north to south from 500 mm to 1500 mm per year. Soils - zhovtozemy and chervonozemy. Platyphyllous growing evergreen and deciduous forests (Oak, beech, maple, ash, linden, walnut, pine, spruce, fir). In subtropical species grow cypress, tulip tree, camphoric tree. However, the subtropical Forests in this zone largely destroyed and the land under cultivation. It grows rice, cotton, tea bush, tobacco, mulberry, citrus. In remnants are found monkeys, lemurs, bamboo panda bear, black bear, Himalayan, raccoon dog, wild boar. Many birds - pheasants, parrots, hen, partridge. On the banks of lakes and rivers are inhabited herons, pelicans, ducks, geese and cranes.
У area and semi- deserts, lying in the tropical zone, within a year rule dry tropical continental air. The result is a high temperature and a handful of precipitation. This led to widespread desertification. Wilderness has exceptional drought. The rainfall there exceeds 200 mm per year. Summer is hot (temperature in July is 33 0 C). Winter heat (temperature January 1916 0 С). Soils - sirozemy. Huge expanses of quicksand or covered with gravel. In plants, as them very little to grow up wormwood sand, camel thorn, perekoty-field. Grows in the oases of date palms, coffee tree, acacia. Animals deserts - gazelle, antelope, jackal, striped hyena, fox Fenech, jerboa. Sometimes occurs almost destroyed ostrich. Many snakes (cobra, adder hyurza) and lizards.
"Fire wind "simoom
Unfavorable phenomenon in the tropical belt is a hot dry wind hurricane - sandstorm that accompanied by a sandy storm. Arabs call him the "breath of death." When he blowing, the air temperature rises to 50 0C and relative sometimes humidity decreases to 0%. Under these conditions, increases sharply evaporation from the body. Then begins severe headache and may come death. Disaster ago traveler whose simoom overrun on the road.
For subekvatorialnyh zones typical seasonal changes of air masses. Summer displacement due to pressure zones in latitude subekvatorialni come Wet and a hot equatorial air mass in winter - hot and dry tropical air masses. So hot in summer and wet, as the equatorial belt, and hot and dry in winter as in tropical zone. Such a climate is called continuously variable hot and humid.
Zone shroud - a plain covered with grass, with individual groups of trees and forests in river valleys. Where rains lasts 9 months and the annual rainfall reaches 1000 mm, cereals (elephant grass and bearded) rising to 3-5 m height. Soils - red. Where humid reduced to 3 months and annual rainfall is 800 mm, the grass becomes lower - up to 1m. Under such conditions, baobab and acacia grow. Where humid lasts no more than 2 months, and the annual rainfall is 300 mm, vegetation form a prickly bushes and acacia. There are also date palm and palm songs. Wildlife rich savannas, especially in Africa: antelopes, giraffes, zebras, buffalo, elephants, hippos, rhinos. Among the predators common lions, leopards, cheetahs, hyenas. Many monkeys. The largest bird - African ostrich. Since termites and insects common tsetse fly.
Equatorial geographic zone stretches narrow strip on both sides of the equator. The climate there is always hot and always humid. The temperature during the year is 25 0S. rainfall to 2000 mm.
Equatorial humid forest zone impressive species richness and density vegetation. The forests alone trees comprising 3000 species. Trees four to five tiers, Fighting a light. Soils - red and yellow. Animals living mainly in trees and river banks. This - monkeys, pygmy hippo, Okapi. The largest predator is the leopard. Very common snakes, most of which are poisonous. In equatorial forests of many valuable species of trees - black or ebony, mahogany, bamboo, rubber plant.
Fig. Humid equatorial forest
Vysotna explain. The mountains also natural areas is a change with changes in temperature and rainfall, but not in a horizontal direction and vertically. For example, in Alps distinguish seven high zones. In the first Low zone to a height of 800 m grow oak forests on brown forest soil. Moderate mountain zone to a height of 1200 m are beech forests mountain brown forest soils. In top middle mountain zone to 1800 m altitude coniferous forests growing on spruce, larch, pine mountain podzolic soils. Subalpine zone to a height of 2000 m are crookedand mountain pine, rhododendron and vysokotrav'ya. To altitude 2800 m common Alpine vysokotravni bows. High - dominates zone rocks and stony placers, which has little vegetation. In the top waist - mountain glaciers.
Questions and Tasks
1. What geographical area is called?
2. What are the natural features distinguish geographical area?
3. What geographical area were formed on Earth world?
4. What natural zone are distinguished in the Arctic and subarctic zones?
5. Why temperate zone features a variety of natural areas?
6. Describe the natural area of tropical zone.
7. Explain why the equatorial belt rule lush vegetation and abundant animal life?