Among the natural zones there are those confined to a specific zone. For example, the zone of Arctic and Antarctic ice deserts and the tundra zone are located in the Arctic and Antarctic belts; the forest-tundra zone corresponds to the subarctic and subantarctic zones, and the taiga, mixed and deciduous forests correspond to the temperate zone. And such natural zones as prairies, forest-steppes and steppes and semi-deserts are common in both temperate, tropical and subtropical zones, having, of course, their own characteristics.
Natural areas, their climatic features, soils, vegetation and animal world Each continent is described in Chapter 10 and in the table "Continents (reference information)". Here we will only focus on common features ah natural zones as the largest natural-territorial complexes.
___________________________
Arctic and Antarctic desert zone
Air temperatures are constantly very low and there is little precipitation. On rare ice-free areas of land - rocky deserts (in Antarctica they are called oases), sparse vegetation is represented by lichens and mosses, flowering plants rare (only two species were found in Antarctica), soils are practically absent.
Tundra zone
The tundra zone is widespread in the Arctic and subarctic zones, forms a strip 300-500 km wide, stretching along northern coasts Eurasia and North America and the North Islands Arctic Ocean. IN Southern Hemisphere areas of tundra vegetation are found on some islands near Antarctica.
The climate is harsh with strong winds, snow cover lasts up to 7-9 months, the long polar night gives way to a short and humid summer (summer temperatures do not exceed 10 °C). Precipitation falls a little - 200-400 mm, mostly in solid form, but it does not have time to evaporate, and the tundra is characterized by excessive moisture, an abundance of lakes and swamps, which is facilitated by widespread permafrost. home distinctive feature tundra - treeless, predominant sparse moss-lichen, sometimes grass, cover; V southern parts with shrubs and shrubs of dwarf and creeping forms. The soils are tundra-gley.
Forest-tundra and woodland zone
Zone of forest-tundra and woodlands. This transition zone which is characterized by alternating treeless tundra areas and forests (open woodlands), combines the characteristics of the zones bordering it. Tundra natural complexes are characteristic of watershed spaces; open forests climb north along river valleys. To the south, the areas occupied by forests increase.
In the Southern Hemisphere (subantarctic belt), the forest-tundra on islands (for example, South Georgia) is replaced by oceanic meadows.
Forest zone
The forest zone in the Northern Hemisphere includes the subzones of taiga, mixed and deciduous forests and the subzone temperate forests, in the Southern Hemisphere only the subzone of mixed and deciduous forests is represented. Some scientists consider these subzones to be independent zones.
In the taiga subzone Northern Hemisphere The climate varies from maritime to sharply continental. Summers are warm (10-20 °C, the severity of winter increases with distance from the ocean (at Eastern Siberia to -50 °c), and the amount of precipitation decreases (from 600 to 200 mm). Precipitation exceeds evaporation, and watersheds are often swampy and rivers are high in water. Poor people predominate species composition dark coniferous (from spruce and fir) and light coniferous (from larch in Siberia, where permafrost soils are widespread) forests with an admixture of small-leaved species (birch, aspen) and pine, in the east of Eurasia - cedar. The soils are podzolic and permafrost-taiga.
The subzone of mixed and deciduous forests (sometimes two independent subzones are distinguished) is distributed mainly in the oceanic and transitional belts continents. In the Southern Hemisphere it occupies small areas, winters here are much warmer and snow cover does not form everywhere. Coniferous-deciduous forests on soddy-podzolic soils are replaced during internal parts continents with coniferous-small-leaved and small-leaved forests, and to the south (in North America) or to the west (in Europe) broad-leaved oak, maple, linden, ash, beech and hornbeam on gray forest soils.
Forest-steppe
Forest-steppe is a transitional natural zone of the Northern Hemisphere, with alternating forest and steppe natural complexes. Based on the nature of natural vegetation, forest-steppes with broad-leaved and coniferous-small-leaved forests and prairies are distinguished.
Prairies
Prairies - a subzone of forest-steppe (sometimes considered as a subzone of steppe) with abundant moisture, stretching along the eastern coasts Rocky Mountains in the USA and Canada with tall grass on chernozem-like soils. Almost no natural vegetation has been preserved here. Similar landscapes are characteristic of the subtropics of the eastern regions South America and East Asia.
Steppe
This natural zone is distributed in the northern temperate or both subtropical geographical zones and is a treeless area with herbaceous vegetation. Unlike the tundra, the growth of woody vegetation here is hampered not by low temperatures, but by a lack of moisture. Trees can grow only along river valleys (so-called gallery forests), in large erosive forms, such as ravines, collecting water from the surrounding interfluve spaces. Now most of the zone is plowed, in subtropical zone Irrigated agriculture and pasture cattle breeding are developing. Soil erosion is highly developed on arable lands. Natural vegetation is represented by drought- and frost-resistant herbaceous plants with the dominance of turf grasses (feather grass, fescue, tonkonogo). The soils are fertile - chernozems, dark chestnut and chestnut in temperate zone; brown, gray-brown, in places saline in the subtropical).
The subtropical steppe in South America (Argentina, Uruguay) is called pampa (i.e. plain, steppe in the language of the Quechua Indians).
Deserts and semi-deserts
These natural zones are distributed in six geographical zones - temperate, subtropical and tropical on both sides of the equator, where precipitation falls so little (10-30 times less evaporation) that the existence of living organisms is extremely difficult. Therefore, the grass cover is sparse and the soils are poorly developed. In such conditions, they become very important rocks, composing the territory, and depending on them, clay deserts (takyrs in Asia), rocky deserts (hamads of the Sahara, middle Asia, Australia), sandy (Thar Desert in India and Pakistan, North American deserts). In the temperate zone, deserts form in areas with a sharply continental climate, subtropical and tropical desert They owe their existence to constant pressure maxima at 20-30° latitudes. Rare fate of increased moisture ( high level groundwater, spring outlets, irrigation from nearby rivers, lakes, wells, etc.) - centers of population concentration, growth of woody, shrub and herbaceous vegetation are called oases. Sometimes such oases occupy vast areas (for example, the Nile Valley stretches over tens of thousands of hectares).
Savannah
Savanna is a natural zone, distributed mainly in subequatorial zones, but also found in tropical and even subtropical zones. main feature The climate of the savannas is a clear change of dry and rainy periods. The duration of the rainy period decreases when moving from equatorial regions (here it can last 8-9 months) to tropical deserts (here rainy season- 2-3 months). Savannas are characterized by dense and tall grass cover, trees standing alone or in small groups (acacia, baobab, eucalyptus) and so-called gallery forests along rivers. Soils typical tropical savannas- red soils. In deserted savannas, the grass cover is sparse and the soils are red-brown. Tall grass savannas in South America, on the left bank of the river. Orinoco is called llanos (from Spanish “plain”).
Forest subtropics
Forest subtropics. The monsoon subtropical subzone is characteristic of the eastern margins of the continents, where seasonally changing circulation of air masses is formed at the contact between the ocean and the continent and there is a dry winter period and a wet summer with abundant monsoon rains, often with typhoons. Evergreen and deciduous (losing leaves in winter due to lack of moisture) with great variety tree species They grow here on red earth and yellow earth soils.
The Mediterranean subzone is characteristic of the western regions of the continents (Mediterranean, California, Chile, southern Australia and Africa). Precipitation occurs mainly in winter; summer is dry. Evergreen and broad-leaved forests on brown and brown soils and hard-leaved shrubs are well adapted to summer drought, the plants of which have adapted to hot and dry conditions: they have a waxy coating or pubescence on the leaves, thick or dense leathery bark, and secrete fragrant essential oils.
The article contains information that allows you to better understand the features and distinctive features mainland. Supplements data from the 7th grade geography course. Explains the difficulties that prevent the start of mining in Antarctica.
Nature of Antarctica
The nature of Antarctica is fascinating and at the same time mysterious. This is the least explored continent on the planet. This is explained by the unique climatic conditions. The territory is almost completely covered with ice.
Difficult climatic conditions also affect the possibility of using natural resources mainland.
The ice of Antarctica contains 80% fresh water planets. The main continental territory is located beyond the Arctic Circle, so here you can observe the phenomenon of polar day and polar night.
Interesting: At the pole, the duration of this phenomenon reaches 6 months. Only once a year does the sun rise and set in this area.
TOP 3 articleswho are reading along with this
Extremely tough natural conditions and the climate has caused most of the continent to lack flora and fauna. This phenomenon is referred to in the scientific community as the Antarctic ice desert.
The basis species diversity Antarctica is composed of:
- bacteria,
- lichens,
- mushrooms,
- seaweed,
- several species of angiosperms.
Rice. 1. Antarctic mushrooms.
The species range of the coast is richer. South ocean contains enough fish in its waters, and therefore a lot of birds nest on its shores: penguins, skuas, petrels, cormorants.
Rice. 2. Petrel bird.
IN sea waters There are blue whales, sperm whales, and pinnipeds.
Many representatives of the animal world are protected by wildlife conservationists.
Natural areas of Antarctica
Much of the continent is dominated by the icy Antarctic desert.
Representatives of the local fauna are mostly inhabitants of the ocean depths.
Rice. 3. Glacial relief.
The continent is conventionally divided into two natural areas. The western tip of the continent is represented by subglacial mountain-like and glacial relief. East Antarctica conquered a large area of the mainland.
More than one and a half dozen states (16), and Russia is no exception, have established scientific bases here on which research activities regarding the nature of the continent. In 1959, at the proposal of the USSR, the International Treaty on Antarctica was ratified, which categorically prohibits testing of any types of weapons here.
The prospects that will make it possible in the future to mine what is still hidden in the ice are tempting for most countries. Natural resources Antarctica.
Some states have taken initiative in the development of mineral deposits. Since 1991, a proposal has been made to ban such activities. The reason is that human intrusion into the fragile ecosystem of the mainland can become a factor that will lead to irreversible consequences.
Geological exploration is still being carried out in order to find out the exact amount of reserves that may be located in the bowels of the continent. Total ratings received: 178.
The southern continents include Africa, South America, Australia and Antarctica. Connects their location in the Southern Hemisphere of the Earth, as well as for the most part hot climate, with the exception of Antarctica. Natural areas southern continents have many common features, but the characteristics of vegetation and animal life determine the geographical zones in which they are located.
Antarctica
It is the southernmost continent, but its entire surface is covered with blocks of ice and snow. Even in summer, the temperature here rarely exceeds 0-5 degrees Celsius. Soils are constrained permafrost, which does not allow vegetation to develop. In the natural zone of the Antarctic deserts one can find only a sparse growth of mosses and lichens. The local fauna is also very poor. Polar bears live here, seals and walruses can be found on the coast, and in summer bird colonies form on the rocks.
Rice. 1. Antarctica is the southernmost continent on the planet.
Africa
Africa is rightfully considered the hottest continent on Earth. Its distinctive feature is its symmetrical location relative to the equator. This means that the equatorial line divides the continent into two equal parts. As a result, Africa is characterized by the presence of several natural zones, including moist equatorial and variable-humid forests, savannas, tropical deserts, and hard-leaved forests.
On African continent is the most big desert in the world - Sahara. Despite the apparent lifelessness, here you can still find sparse vegetation and representatives of the animal world that have adapted to life in the difficult desert conditions.
Australia
Australia is considered the driest continent, so it is not surprising that you will not find lush and varied vegetation here. There are practically no forests in Australia, but there are many deserts.
Due to the flat topography of the continent, the most pronounced latitudinal zonation. Since the main part of the continent is located in tropical latitudes, tropical deserts and semi-deserts predominate here. A much smaller area is occupied by savannas, tropical and subtropical forests.
TOP 4 articleswho are reading along with this
Rice. 2. Nature of Australia.
For a long time Australia was in great isolation. This is precisely what explains the antiquity and originality of the local flora and fauna, the majority of which are endemic - species that live exclusively on this continent.
South America
This unique continent, on which more than half of all tropical and equatorial forests planets. The climate on the mainland is moderately humid and warm, the temperature difference between seasons is insignificant.
Rice. 3. Equatorial forests South America.
Natural zones are distributed unevenly due to the strong differences between the western and eastern parts of the continent, and are represented by several species:
- selva- equatorial rain forests;
- Llanos- zone of savannas and woodlands;
- pump- subtropical steppes;
- Patagonia- deserts and semi-deserts;
- temperate forests.
The flora and fauna are mostly represented by endemic species.
The territory of Antarctica is located in the Antarctic and subantarctic climatic zones. The border between them lies in the ocean and only the northwestern tip of the Antarctic Peninsula belongs to the subantarctic belt. The Antarctic polar climate is determined by the Antarctic anticyclone over Antarctica and the Antarctic air masses. The snow line is everywhere near the coast near sea level.
In winter, there is polar night for several months. During the long polar day, the continent receives a lot solar radiation, but up to 90% of it is reflected by the ice surface. The continental coast is influenced by stable areas of high and low pressure Antarctica, defining unsustainable weather. The territory of the Antarctic ice sheet by complex natural features and processes are divided into four concentric zones: central, katabatic winds, Antarctic coast and oceanic.
Low temperatures prevail throughout the year in Antarctica. Average winter July temperatures range from -60°C inland to -32°C on the coast. The lowest temperature on Earth was recorded in Antarctica - 91.2 °C. The previous record, recorded at the Vostok station, was two degrees higher. Summer January temperatures are much higher, but they are also negative and range from –32 °C to –16 °C. On the coast of the mainland, the air temperature rarely drops below –40 °C in winter, and rises to 0 °C in summer.
Over the continent, due to strong constant cooling of the air, a huge area of high atmospheric pressure, which, together with the World Ocean, has a great impact on the general circulation of the Earth’s atmosphere. Cold air masses flow from high central regions and ice domes to the outskirts of the continent, forming strong katabatic winds (up to 30-50 m/s or more). Maximum speed wind in Antarctica was recorded by the Belarusian polar explorer A. Gaidashov - 88 m/s. Winds are very powerful and tear off and move loose loads over long distances. The dry snow they carry can saw through thick ropes. At low temperatures, due to hypothermia, the metal loses its properties and breaks into pieces, like glass.
At high blood pressure and low temperatures in the central part of the continent there is little rainfall atmospheric precipitation(50-100 mm). Much more precipitation falls on the Antarctic islands located in the subantarctic belt. The climatic conditions here are less severe: winter temperatures are slightly below 0 °C, summer temperatures rarely exceed +10 °C. But even here hurricane winds blow (up to 75 m/s), which are caused by strong sea storms. The Antarctic coastal zone and the oceanic zone are characterized by the most intense snow accumulation and ice cover consumption.
Flora and fauna of Antarctica
Antarctica is almost universally cold Antarctic desert- glacier surface with harsh conditions for the development of life (lack of soil, low temperatures, strong winds). Life on the mainland exists only in coastal zone, on subantarctic islands and in oceanic waters. The vegetation of the mainland is represented by mosses, lichens, algae and microscopic fungi.
In the zone of Antarctic deserts, three subzones are distinguished: the northern - northwestern part of the Antarctic coast and adjacent islands, the middle - coastal oases, islands and mountain ranges, and the southern - land within the continent. Lichens are found in Antarctic oases - in areas free of ice. They differ in color in Antarctica - from black to bright orange. This is how lichens adapt to local conditions and strive to get as much solar heat. Algae appear in lakes that form in summer. And only in the north of the Antarctic Peninsula and on the islands are stunted higher plants with small flowers.
Despite the harsh natural conditions, Antarctica exhibits altitudinal zone: lower coastal belt with maximum diversity of nature (oases, ice shelves), middle belt (icy deserts with snowy relief forms) and a belt of eternal frost without signs of life.
The fauna of Antarctica is poor. Crustaceans, wingless insects, and some bird species live here. Penguins are the most interesting representatives birds. Penguins move slowly on land, but are good swimmers. In total, four of the 18 species of penguins found on Earth live in Antarctica. IN coastal waters About 10 species of penguins are known on the islands.
The most common species is the Adelie penguin. Its height is up to 30 cm, weight - several kilograms. The biggest - emperor penguin. Its height reaches more than a meter, and its weight reaches 50 kg. These penguins breed their offspring in the harsh winter. Females lay eggs, and males, holding them on their paws and pressing them to the down of their warm belly, “raise” the chicks.
The richest flora and fauna of coastal waters. Here are the most large mammals- cetaceans, including blue whale, or vomit (up to 33 m in length, weighing up to 150 tons), fin whales, sperm whales, killer whales (predators from the dolphin family), as well as pinnipeds - seals, elephant seals, sea lions. Antarctic waters are home to several species of seals that differ from their northern relatives. This indicates their adaptation to the harsh Antarctic waters. Petrels, gray gulls, and skuas nest along the shores of Antarctica. Birds feed on fish or small sea animals.
Gray gulls are the most predatory birds of Antarctica; they feed on the eggs of penguins, petrels, and also attack small chicks.
There is an abundance of fish in Antarctic waters. In the vast expanses of the sea, microscopic algae form “ocean pastures.” There is a lot of krill - the smallest crustaceans.
Scientists believe that the annual catch of krill in the amount of 70-80 million tons (at the level of the world fish catch) without damaging the Antarctic ecosystem can provide half of the world's population with 20 g of animal protein per day. Sales of food products from 10 million tons of krill are equivalent to 3 million tons of beef in slaughter weight. Scientists have calculated that the annual production of this species in the oceanic zone of Antarctica is 1.7-1.8 billion tons, and the total biomass is up to 6 billion tons. And if no other products are grown on the planet, then the biological resources of Antarctica can feed everything humanity for 7 years.
The harsh climate of Antarctica is formed due to the characteristics geographical location, the presence of ice cover and is the cause of extremely poor organic world. The continent is almost universally a cold Antarctic (biological) desert. Antarctica plays a key role in the general circulation of the planet's atmosphere and climate.
The warmth of the sun fresh air and water are the main criteria for life on Earth. Numerous climatic zones led to the division of the territory of all continents and waters into certain natural zones. Some of them, even separated by huge distances, are very similar, others are unique.
Natural areas of the world: what are they?
This definition should be understood as very large natural complexes (in other words, parts geographical zone Earths) that have similar, homogeneous climatic conditions. The main characteristic of natural areas is the flora and fauna that inhabit the given territory. They are formed as a result uneven distribution moisture and heat on the planet.
Table “Natural areas of the world”
Natural area | Climate zone | Average temperature (winter/summer) |
Antarctic and Arctic deserts | Antarctic, Arctic | 24-70°C /0-32°C |
Tundra and forest-tundra | Subarctic and subantarctic | 8-40°С/+8+16°С |
Moderate | 8-48°С /+8+24°С |
|
Moderate | 16-8°С /+16+24°С |
|
Moderate | 8+8°С /+16+24°С |
|
Steppes and forest-steppes | Subtropical and temperate | 16+8 °С /+16+24°С |
Temperate deserts and semi-deserts | Moderate | 8-24 °С /+20+24 °С |
Hardleaf forests | Subtropical | 8+16 °С/ +20+24 °С |
Tropical deserts and semi-deserts | Tropical | 8+16 °С/ +20+32 °С |
Savannas and woodlands | 20+24°С and above |
|
Subequatorial, tropical | 20+24°С and above |
|
Permanently wet forests | Equatorial | above +24°С |
This characteristic of the natural zones of the world is only for informational purposes, because you can talk about each of them for a very long time, and all the information will not fit into the framework of one table.
Natural zones of the temperate climate zone
1. Taiga. It surpasses all other natural zones of the world in terms of land area (27% of the territory of all forests on the planet). It is characterized by very low winter temperatures. Deciduous trees they cannot be maintained, so the taiga is dense coniferous forests (mainly pine, spruce, fir, larch). Very large areas Taigas in Canada and Russia are occupied by permafrost.
2. Mixed forests. Characteristic to a greater extent for the Northern Hemisphere of the Earth. It is a kind of border between the taiga and deciduous forest. They are more resistant to cold and long winters. Tree species: oak, maple, poplar, linden, as well as rowan, alder, birch, pine, spruce. As the table "Natural zones of the world" shows, soils in the zone mixed forests gray, not very fertile, but still suitable for growing plants.
3. Broad-leaved forests. They are not adapted to harsh winters, are deciduous. Occupy most Western Europe, south Far East, northern China and Japan. Suitable for them is maritime climate or temperate continental with hot summers and quite warm winter. As the table “Natural zones of the world” shows, the temperature in them does not fall below -8°C even in the cold season. The soil is fertile, rich in humus. Characteristic the following types trees: ash, chestnut, oak, hornbeam, beech, maple, elm. The forests are very rich in mammals (ungulates, rodents, predators), birds, including game birds.
4. Temperate deserts and semi-deserts. Their main distinguishing feature is the almost complete absence of vegetation and sparse fauna. There are quite a lot of natural areas of this nature; they are located mainly in the tropics. There are temperate deserts in Eurasia, and they are characterized by sharp changes in temperature across the seasons. Animals are represented mainly by reptiles.
Arctic deserts and semi-deserts
They are huge areas of land covered with snow and ice. A map of the natural zones of the world clearly shows that they are located in North America, Antarctica, Greenland and the northern tip of the Eurasian continent. In fact, these are lifeless places, and only along the coast are polar bears, walruses and seals, arctic foxes and lemmings, and penguins (in Antarctica). Where the ground is free of ice, lichens and mosses can be seen.
Equatorial rainforests
Their second name is rain forests. They are located mainly in South America, as well as in Africa, Australia and the Greater Sunda Islands. The main condition for their formation is constant and very high humidity(more than 2000 mm of precipitation per year) and a hot climate (20°C and above). They are very rich in vegetation, the forest consists of several tiers and is an impenetrable, dense jungle, which has become home to more than 2/3 of all types of creatures now living on our planet. These rain forests are superior to all other natural areas in the world. The trees remain evergreen, changing foliage gradually and partially. Surprisingly, the soils of humid forests contain little humus.
Natural zones of the equatorial and subtropical climate zone
1. Variably humid forests, they differ from rain forests in that precipitation falls there only during the rainy season, and during the period of drought that follows, the trees are forced to shed their leaves. The flora and fauna are also very diverse and rich in species.
2. Savannas and woodlands. They appear where moisture, as a rule, is no longer enough for growth variable-humid forests. Their development occurs in the interior of the continent, where tropical and equatorial air masses dominate, and the rainy season lasts less than six months. They occupy a significant part of the territory subequatorial Africa, the interior of South America, parts of Hindustan and Australia. More detailed information about the location is reflected in the map of natural areas of the world (photo).
Hardleaf forests
This climate zone is considered the most suitable for human habitation. Hard-leaved and evergreen forests are located along sea and ocean coasts. Precipitation is not so abundant, but the leaves retain moisture due to their dense leathery shell (oaks, eucalyptus), which prevents them from falling. In some trees and plants they are modernized into spines.
Steppes and forest-steppes
They are characterized by an almost complete absence of woody vegetation, due to the poor level of precipitation. But the soils are the most fertile (chernozems), and therefore are actively used by humans for farming. The steppes occupy large areas in North America and Eurasia. The predominant number of inhabitants are reptiles, rodents and birds. Plants have adapted to the lack of moisture and most often manage to complete their life cycle during the short spring period, when the steppe is covered with a thick carpet of greenery.
Tundra and forest-tundra
In this zone the breath of the Arctic and Antarctic begins to be felt, the climate becomes more severe, and even conifers trees cannot withstand it. There is an abundance of moisture, but there is no heat, which leads to swamping of very large areas. There are no trees at all in the tundra; the flora is mainly represented by mosses and lichens. It is considered to be the most unstable and fragile ecosystem. Due to the active development of gas and oil fields it is on the verge of an environmental disaster.
All natural areas of the world are very interesting, be it the seemingly absolutely lifeless desert, the endless arctic ice or thousand-year-old rain forests with boiling life inside.
Loading...
