Major land biomes. The main biomes of the globe Which biomes

Scientists have been trying to classify ecosystems on the planet for a long time. But due to lack of rank and huge amount natural ecosystems, it is not possible to classify each puddle and sand dune with its own ecosystem. Ecologists decided to classify multiple combinations of ecosystems - biomes.

Biome - what is it?

We hear a lot about different biomes, but few of us realize how precisely this word is characterized. AT general meaning, a biome is a large biological system with its own climate. This system is characterized by the dominant plant species or landscape in it. There is such a definition as terraria biomes. This means what minerals, wood, animals are mined on its territory. For example, the deciduous forest biome is dominated by deciduous trees. Or a mushroom biome - an area with a humid climate suitable for life different types fungi and their spores. If you move from the north to the equator, you can see all the major biomes.

How many main biomes?

Which biomes predominate and how many are there? Ecologists have identified nine major biomes on land. The first biome - the second - taiga. Further, the deciduous forest biome in the temperate climate zone, the steppe biome, chaparol (Mediterranean flora), savannahs, thorny (tropical) woodlands, and the ninth biome is tropical forests. Each of them is unique in terms of climate, flora and fauna. As a separate, tenth point, one can single out eternal ice- winter biome.

Tundra and taiga

The tundra is a biome with perennial plants. She takes most northern Eurasia and part of North America. Located between southern forests and polar ice. The farther the tundra moves away from the ice, the more extensive the area of ​​treelessness becomes. Conditions for life in the tundra are harsh, but despite this, great things and plants live here. The tundra is especially beautiful in the summer season. It is covered with a thick layer of greenery and becomes a haven for migrating animals and birds. The basis of the plant world is lichen, moss. Undersized are a rarity. The main inhabitant of the tundra - there are many polar foxes, hares and voles. Another resident is the lemming. This little animal causes great harm to the tundra. These animals eat a huge amount of not rich vegetation of the tundra, which is not able to recover quickly. Due to the lack of food, the entire animal world of the biome suffers.

Taiga is a biome of coniferous (northern) forests. Located in the Northern Hemisphere, it occupies approximately eleven percent of all land. Almost half of this territory is occupied by larch, the rest of the trees are pines, spruces, and firs. There are also some deciduous ones - birch and alder. The main animals are moose and deer (from herbivores), there are more predators: wolves, lynxes, martens, mink, sable and wolverine. A huge number and variety of rodents - from voles to moles. Amphibians live here, viviparous, this is due to short summer, for which there is no way to warm up the masonry. The partridge also belongs to the main inhabitants of the taiga.

Deciduous forests and steppes

Deciduous forests are located in a comfortable zone with temperate climate. This is mainly the east of the United States, Central Europe and part of East Asia. There is a sufficient amount of moisture, harsh Cold winter and long warm summer. The main trees of this biome are broad-leaved: ash, oak, beech, linden and maple. There are also conifers - spruce, sequoia and pine. The flora and fauna are well developed here. A variety of predators are represented by wild cats, wolves, foxes. Large population of bears and deer, badgers, rodents and birds.

Steppes. The basis of this biome are the prairies of North America and the steppes of Asia. There is not enough rainfall here, which would be enough for the growth of trees, but enough to prevent the formation of deserts. In the steppes of North America, a great variety herbaceous plants and herbs. There are undersized (up to half a meter), mixed grass (up to one and a half meters) and tall grass (plant height reaches three meters). Altai mountains divided the Asian steppes into eastern and western. These lands are rich in humus, constantly sown with cereals, and places with tall grass are adapted for pastures. All artiodactyl mammals have long been domesticated. And the wild inhabitants of the steppes - coyotes, jackals and hyenas have adapted to live peacefully in the neighborhood of people.

Chaparol and the desert

Mediterranean vegetation occupied the area around mediterranean sea. It has very hot dry summers and cool winters with high humidity. The main plants here are bushes with thorns, herbs with a bright aroma, plants with thick glossy leaves. Trees cannot grow normally due to climatic conditions. Chaporol is famous for the number of snakes and lizards that live here. There are wolves, roe deer, lynxes, cougars, hares and, of course, kangaroos (in Australia). Frequent fires prevent the invasion of the desert, favorably influencing the soil (return to the ground useful material), which has a good effect on the growth of grasses and bushes.

The desert stretched its possessions over one third of the entire land mass. It occupies arid territories of the earth, where precipitation falls less than two hundred and fifty millimeters per year. There are hot deserts (Sahara, Atacama, Aswan, etc.), and there are also deserts where the air temperature drops to minus twenty degrees in winter. This is the Gobi Desert. Sands, bare stones, rocks are typical for the desert. Vegetation is sparse seasonal, mainly spurges and cacti. Animal world consists of small creatures that can hide under rocks from the sun. From large species only a camel lives here.

tropical biomes

Savannahs are vast expanses of thick grass and occasional lone trees. The soil here is rather poor, tall grass and spurge predominate, trees - baobab and acacia. Large herds of artiodactyls live in the savannas: zebras, wildebeest and gazelles. Such a number of herbivores is not found anywhere else. The abundance of herbivores also served as an abundance of predators. Cheetahs, lions, hyenas, leopards live here.

Spiny woodland is found in South and Southwest Africa. There are rare deciduous trees, bizarrely shaped prickly bushes.

Tropical forests are found in South America, West Africa, Madagascar. Constant high humidity promotes the growth of dense and huge plants. These forests reach seventy-five meters in height. Rafflesia arnoldi grows here - this is the most large flower in the world. Soil in the tropics is poor nutrients concentrated in already existing plants. Annual felling of a huge number of these tropics in fifty years can provoke the largest biological catastrophe.

Lentic (stagnant) waters. Puddles, oxbow lakes, natural and artificial ponds, lakes and reservoirs. Living conditions are determined primarily by the depth (and illumination) and the amount of nutrients. The exchange of nutrients and gases between surface and depth is often difficult.

Lotic (flowing) waters. Streams, streams and rivers. The conditions are very dependent on the speed of the current. Capable of moving significant amounts of water and other inorganic and organic matter, are closely related to the surrounding ground systems.

swamps. Reservoirs with a large amount of organic matter, the destruction of which is slowed down due to a lack of oxygen in the water; mainly characteristic of temperate and moderately cold climates.

Marine biomes

Pelagial. open ocean and sea ​​depths away from the coast. Producers (first of all, phytoplankton) are concentrated in a relatively thin near-surface layer of water, where light penetrates. Characteristic is the continuous lowering of biogens from the surface to the depth.

continental shelf. Coastal zone of the seas and oceans, reaching to a depth of approximately 200 m. Rich in species and diverse marine communities. The most diverse aquatic ecosystems are characteristic of coral reefs, also belonging to the continental shelf. "Hot spots" of biodiversity are also characteristic of great depths - for example, for places where volcanic gases enter the sea water ("black smokers" and other phenomena).

Upwelling zones. Relatively small areas of the ocean where rise to the surface occurs deep waters enriched with nutrients. They have an exceptional impact on the productivity of the entire ocean as a whole. ecosystem organism sediment biocenosis

Estuaries. Mixing zones of river and sea ​​waters, formed in the seas opposite the mouths big rivers. They are characterized by a significant amount of organic matter that is carried into the sea by rivers, and constant fluctuations in salinity.

Biomes are large regions of the planet, which are divided according to characteristics such as geographical position, climate, soils, precipitation, flora and fauna. Biomes are sometimes called or ecological regions.

The climate is perhaps the most an important factor, which determines the nature of any biome, but there are other factors that determine the belonging of biomes - topography, geography, humidity, precipitation, etc.

Scientists disagree on the exact number of biomes that exist on Earth. Many different classification schemes have been developed to describe the planet's biomes. For example, on our site we have taken five main biomes: aquatic biome, desert biome, forest biome, grassland biome and tundra biome. In each kind of biome, we also describe a set of various types habitats.

They include water-dominated habitats around the world, from tropical reefs, mangroves to arctic lakes. Aquatic biomes are divided into two main groups: marine and freshwater habitats.

Freshwater habitats include bodies of water with low salt concentrations (below one percent). Freshwater bodies include lakes, rivers, streams, ponds, wetlands, lagoons, and swamps.

Marine habitats are bodies of water with a high concentration of salts (more than one percent). Marine habitats include seas, coral reefs and oceans. There are also habitats where fresh and salt waters mix. In these places, you will find salty and muddy marshes.

The various aquatic habitats of the world support a wide range of wildlife, including almost all groups of animals: fish, amphibians, mammals, reptiles, invertebrates and birds.

Includes terrestrial habitats that receive very little precipitation throughout the year. The desert biome covers about one-fifth of the Earth's surface. Depending on aridity, climate and location, it is divided into four groups: arid deserts, semi-arid deserts, coastal deserts and cold deserts.

Arid deserts are hot, dry deserts that are located at low latitudes around the world. Temperatures are high throughout the year and rainfall is very low. Arid deserts are found in North America, Central America, South America, Africa, South Asia, and Australia.

Semi-arid deserts are generally not as hot and dry as arid ones. They have long dry summers and relatively cool winters with little rainfall. Semi-arid deserts are found in North America, Newfoundland, Greenland, Europe and Asia.

Coastal deserts are usually located on western regions continents approximately 23° north and south of the equator. They are also known as the Tropic of Cancer (the parallel north of the equator) and the Tropic of Capricorn (the parallel south of the equator). In these places, cold ocean currents form heavy fogs that drift over the deserts. Although the humidity of coastal deserts can be high, rainfall is low. Examples of coastal deserts include the Atacama Desert in Chile and the Namib Desert in Namibia.

Cold deserts - regions earth's surface who have low temperatures and long winters. Cold deserts are found in the Arctic and Antarctic. Many areas of the tundra biome can also be classified as cold deserts. Cold deserts generally receive more precipitation than other types of desert.

Includes extensive habitats dominated by trees. Forests cover an area equal to about one-third of the Earth's land mass and are found in many regions around the world. There are three main types of forests: temperate, tropical and taiga (boreal). Each forest type has its own climatic characteristics, species composition and features of wildlife.

They are found in temperate latitudes of the world, including North America, Asia and Europe. Temperate forests experience four well-defined seasons of the year. The growing season in the forests temperate zone lasts about 140-200 days. Precipitation is regular and falls throughout the year, and the soils are rich in nutrients.

Grows in equatorial regions between 23.5° northern latitude and 23.5° south latitude. AT tropical forests There are two seasons: rainy season and dry season. The length of the day practically does not change throughout the year. Soils rainforest more acidic and less nutrient dense.

Also known as boreal forests, they are the largest terrestrial habitat. Taiga is a strip of coniferous forests that surround Earth in high northern latitudes from about 50° to 70° north latitude. The taiga forests form a circumpolar habitat that runs through Canada and extends from northern Europe all the way to eastern Russia. The taiga forests border the tundra biome to the north and temperate forests on South.

Includes habitats where grasses are the dominant vegetation type, and trees and shrubs are present in small numbers. There are three main grassland types: temperate grasslands, tropical grasslands (also known as savannas), and steppe grasslands. Meadows are characterized by dry and rainy seasons. During the dry season, grasslands are prone to fires.

In temperate grasslands, grasses predominate, and trees and large shrubs are absent. The soil of temperate grasslands has a nutrient-rich topsoil. Seasonal droughts are often accompanied by fires that prevent the growth of trees and shrubs.

Tropical grasslands are grasslands located near the equator. They are warmer and humid climate than the meadows of temperate latitudes. Tropical grasslands are dominated by grasses, but trees are also found in places. Tropical grassland soils are very porous and dry out quickly. Tropical grasslands are found in Africa, India, Australia, Nepal and South America.

Steppe grasslands are dry grasslands that border semi-arid deserts. Grasses growing in steppe meadows are much shorter than those of temperate and tropical grasslands. Trees are found here only along the banks of lakes, rivers and streams.

Cold habitat characterized by: permafrost soils, low air temperatures, long winters, low vegetation and a short growing season.

The Arctic tundra is near North Pole and extends south to the border, where coniferous forests grow.

The Antarctic tundra is located in the Earth's Southern Hemisphere on remote islands off the coast of Antarctica such as the South Shetland and South Orkney Islands, as well as on the Antarctic Peninsula.

The Arctic and Antarctic tundra supports about 1,700 plant species, including mosses, lichens, sedges, shrubs, and grasses.

Alpine tundras are found in mountains all over the world at altitudes that are above the tree line. Alpine tundra soils are different from soils in the polar regions, where they tend to be well-drained. Vegetable world mountain tundra is represented mainly by grasses, small shrubs and dwarf trees.

Question 1. How can we explain the differences between the flora and fauna of different continents?
Differences in the flora and fauna of the continents are explained by:
1) geological history continents;
2) difference in climatic conditions;
3) isolation of continents from each other.

Question 2. What are the reasons for the allocation of individual biogeographic regions on Earth?
Biome- a large biosystem consisting of several ecosystems (biogeocenoses) of one natural and climatic zone and is characterized by some dominant type of vegetation or other landscape feature.
The following biomes exist on Earth: temperate forests (deciduous forests), steppes, deserts, coniferous forests (taiga), tundra, savannahs, tropical rainforests.
The main factor determining the type of biome is the climate, since the nature of the environment is created mainly by temperature, precipitation, as well as the direction and strength of the winds. Taking into account the relationship of species inhabiting certain territories, the following biogeographic regions are currently distinguished:
1. Holarctic ( North America with Greenland, Eurasia without India, Iceland, Korea, Japan and North Africa).
2. Paleotropical (Africa south of the Sahara, Madagascar, India and Indochina).
3. Australian (Australia, New Guinea, New Zealand, Oceania).
4. Neotropical (South and Central America).
5. Antarctic (Antarctic).

Question 3. Describe the main land biomes of various biogeographic regions.
Tundra of the Nearctic and Palearctic regions: undersized vegetation - mosses, lichens, sedges, stunted shrubs. Main animals - deer, musk ox, lemming, polar hare, arctic fox, wolf, white polar bear, White Owl.
coniferous forests Nearctic region: mostly dense forests of spruce, fir and other coniferous trees. The main animals are elk, deer, porcupine, vole, shrew, wolverine, lynx, woodpecker, American hazel grouse. Coniferous forests of the Palearctic region: tree species composing these forests - pine, fir, spruce. They belong to the same genera as the corresponding Nearctic trees, but are distinct species. The same applies to animals - elk, wolverine, lynx.
Deciduous forests of the Nearctic and Palearctic: broadleaf forests consist of trees with a dense crown - oak, beech, maple; lots of flowers. The main animals are mole, ground squirrel, black squirrel, raccoon, opossum, chipmunk, red American fox, black bear, songbirds.
Hard-leaved forests of the Nearctic: thickets of juniper and shrubs with leathery leaves. representatives of the fauna come from neighboring biomes. Palearctic Hardwood Forests: The Mediterranean region is very similar to the corresponding Nearctic biome, with animals from various neighboring communities.
Nearctic steppes: various combinations of herbaceous and shrubby vegetation. The main animals are bison, antelope, wild rabbit, american badger, fox, coy<5т, степной тетерев, большое количество гремучих змей. Палеарктические степи: травы примерно такие же, как в Неарктике. Типичные животные - сайгак и антилопа; дикие ослы, лошадь и верблюд, а также суслик, хомяк, тушканчик, куница, шакал.
Neotropical steppes (pampa): the vegetation cover is a mixture of various grasses. Fauna - nandu, pampas deer, guinea pig, tuco-tuco, pampas cat, South American fox, skunk, swallow, steam owl.
Tropical forest of the eastern region: an abundance of hundreds of species of plants forming impenetrable thickets; typical plants are creepers, bamboo, manila hemp, teak, banyan and ebony. Animals: primates are widely represented - gibbons, orangutans, small relatives of monkeys; also characteristic are the Indian elephant, the tapir, two genera of rhinos, the tiger, the sloth bear and the bamboo bear, the deer and the antelope. Lots of pheasants, poisonous snakes and lizards.
The rainforest of the neotropical region is unusually rich in lichens, orchids, and bromeliads. Cabbage palm, tropical almond, bamboo, creepers are characteristic. Among animals there are chain-tailed monkeys, tenacious-tailed bear, nosoha, sloth, pygmy deer, opossum mouse, parrots, hummingbirds.
The rainforest of the Ethiopian region is poorer than the rest of the tropical forests. Plants - mahogany, a lot of heavy, ferns, orchids and other epiphytes. Of the animals, the pygmy antelope, pygmy hippopotamus, gorilla, chimpanzee, and green monkey are noteworthy.
The rainforest of Australia is either a typical continuous canopy rainforest or a rare eucalyptus forest. Tree kangaroo, koala, opossum, marsupial wolf, Tasmanian devil, platypus, flying dog, lyrebird live in the forests.
The Ethiopian savannah is mainly covered with grasses and shrubs, there are acacias, baobabs, euphorbia and palm trees. The fauna is represented by herbivores - zebra, eland, oryx, wildebeest, etc. Giraffe, elephant, lion, white and black two-horned rhinoceros, warthog, cheetah, hyena dog, gopher, golden mole are also typical.
Australian savanna: mostly steppes and thickets of various shrubs, eucalyptus. Animals - giant red kangaroo, emu, bandicoot, marsupial rabbit, wombat, parrots.
Palearctic deserts: scattered bushes of wormwood, palmate grass, thickets of camel's thorn and tamarisk. The animal world is represented by several species of herbivores, as well as hedgehogs, jerboas, pouched rats and hamsters; birds: eagles, falcons, owls.
Neotropical deserts: rare grasses, low shrubs, cacti, yucca. Of the animals - nandu, armadillo, vulture, fox, tuko-tuko.
Ethiopian deserts: vegetation consists mainly of grasses and rare shrubs, date palms grow in oases. Euphorbia and plants with tuberous roots are found in the south. Of the animals, the gazelle, porcupine, jerboa, eagle, and lizards are common.
Australian deserts: vegetation - local forms of quinoa, acacias and various eucalyptus trees. Of the animals - marsupial mole, kangaroo mouse, jerboa marsupial rat, parakeets.

Question 4. Find on the geographical map the territories mentioned in the paragraph; note their climatic conditions.
1. The Nearctic region includes the territory of the whole of North America, Newfoundland, Greenland. In the north, snow and ice are replaced by tundra. Further south is an array of coniferous and temperate forests in the east, prairies in the central part, and a mixture of mountains, deserts and coniferous forests in the west.
2. The Palearctic region includes all of Eurasia. In the north, a strip of eternal ice, tundra and coniferous forests. In the temperate zone, broad-leaved forests are richest in the Asian part. The central regions of Asia are arid and treeless.
3. The eastern region includes India and Indochina, as well as the islands of Ceylon, Java, Sumatra, Taiwan, Borneo. The islands are completely covered with tropical forests, most of the mainland is mountains with a diverse vegetation cover, in the west of India there are dry steppes.
4. The neotropical region includes South and Central America, the tropical part of Mexico, the islands of the Caribbean archipelago. Since this area has been isolated for a long time, its flora and fauna differ sharply from the flora and fauna of other areas.
5. Ethiopian region. It includes almost all of Africa, about. Madagascar and the southern part of the Arabian Peninsula. In the central part of Africa there are savannahs and steppes; Western Africa and the mountainous part of eastern Africa are covered with tropical forests.
6. The Australian area includes Australia, New Zealand, New Guinea and the Pacific Islands. The central part of Australia is represented by a desert bordered by steppes, savannahs with a rare patch of tropical forest. The biomes of the islands are different - from tropical New Guinea to relatively cold New Zealand.