Fauna of the variable rainforests of South America. Types of flora_geobotany. Zone of variable-moist and humid evergreen equatorial forests of Africa

Africa is an amazing continent, where a large number of geographical zones are combined. Nowhere else are these distinctions so visible.

The natural areas of Africa are very clearly visible on the map. They are distributed symmetrically about the equator and depend on uneven precipitation.

Characteristics of the natural zones of Africa

Africa is the second largest continent on Earth. It is surrounded by two seas and two oceans. But the most important feature is its symmetry in position with respect to the equator, which divides Africa into two parts along the horizon.

Hard-leaved evergreen moist forests and shrubs are located in the north and south of the mainland. Next come deserts and semi-deserts, then savannahs.

In the very center of the continent there are zones of variable-moist and permanent-moist forests. Each zone is characterized by its climate, flora and fauna.

Zone of variable-moist and humid evergreen equatorial forests of Africa

The zone of evergreen forests is located in the Congo Basin and runs along the Gulf of Guinea. Over 1000 plants can be found here. In these zones, predominantly red-yellow soils. Many types of palm trees grow here, including oilseeds, tree ferns, bananas, and creepers.

Animals are placed in tiers. In these places, the animal world is very diverse. A huge number of shrews, lizards and snakes live in the soil.

A huge number of monkeys live in the zone of humid forests. In addition to monkeys, gorillas and chimpanzees, more than 10 species of individuals can be found here.

Dog-headed baboons cause a lot of anxiety to local residents. They are destroying the plantations. This species is distinguished by ingenuity. They can only be frightened by weapons, they are not afraid of a person with a stick.

African gorillas in these places grow up to two meters and weigh up to 250 kilograms. Elephants, leopards, small ungulates, forest pigs live in the forests.

Good to know: The tsetse fly lives in the eucalyptus regions of Africa. It is very dangerous for humans. Its bite infects with deadly sleeping sickness. A person begins to be disturbed by severe pain and fever.

savannah zone

About 40% of the entire territory of Africa is occupied by savannahs. The vegetation is represented by tall grasses and umbrella trees towering above them. The main one is the baobab.

This is the tree of life, which is of great importance to the people of Africa. , leaves, seeds - everything is eaten. The ash from the burnt fruit is used to make soap.

In dry savannahs, aloes grow with fleshy and prickly leaves. In the rainy season, the savannah is very abundant vegetation, but in the dry season it turns yellow, fires often occur.

The red soils of the savannah are much more fertile than those in the rainforest zone. This is due to the active accumulation of humus during the dry period.

Large herbivores live on the territory of the African savannah. Giraffes, elephants, rhinos, buffaloes live here. The savannah area is the habitat of predators, cheetahs, lions, leopards.

Tropical and semi-desert zones

Savannahs are replaced by zones of tropical deserts and semi-deserts. Precipitation in these places is very irregular. In certain areas, it may not rain for several years.

The climatic features of the zone are characterized by excessive dryness. Often there are sandstorms, during the day there are strong temperature differences.

The relief of the deserts is a placer of stones and salt marshes in those places where once there were seas. There are practically no plants here. There are rare spines. There are species of vegetation with a short lifespan. They grow only after the rains.

Zones of evergreen hard-leaved forests and shrubs

The most extreme zone of the continent is the territory of evergreen hard-leaved leaves and shrubs. These areas are characterized by wet winters and hot dry summers.

Such a climate favorably affects the condition of the soil. In these places it is very fertile. Lebanese cedar, beech, oak grow here.

In this zone, the highest points of the mainland are located. On the peaks of Kenya and Kilimanjaro, even in the hottest period, there is always snow.

Table of Natural Areas of Africa

The presentation and description of all the natural zones of Africa can be visualized in the table.

Name of the natural area	Geographic location	Climate	Vegetable world	Animal world	The soil
Savannah	Neighboring zones from equatorial forests to the north, south and east	subequatorial	Herbs, cereals, palms, acacias	Elephants, hippos, lions, leopards, hyenas, jackals	Ferrolitic red
Tropical semi-deserts and deserts	Southwest and north of the mainland	Tropical	Acacias, succulents	Turtles, beetles, snakes, scorpions	Sandy, rocky
Variable-humid and humid forests	north of the equator	Equatorial and subequatorial	Bananas, palm trees. coffee trees	Gorillas, chimpanzees, leopards, parrots	brown yellow
Hardwood evergreen forests	Far north and far south	Subtropical	Arbutus, oak, beech	Zebras, leopards	brown, fertile

The position of the climatic zones of the mainland is delimited very clearly. This applies not only to the territory itself, but also to the definition of fauna, flora and climate types.

The tundra occupies such territories as the coastal outskirts of Greenland, the western and northern outskirts of Alaska, the coast of Hudson Bay, some areas of the Newfoundland and Labrador peninsulas. On Labrador, due to the severity of the climate, the tundra reaches 55 ° N. sh., and in Newfoundland it drops even further south. The tundra is part of the circumpolar Arctic subregion of the Holarctic. The North American tundra is characterized by the spread of permafrost, strong soil acidity and rocky soils. The northernmost part of it is almost completely barren, or covered only with mosses and lichens. Large areas are occupied by swamps. In the southern part of the tundra, a rich herbaceous cover of grasses and sedges appears. Some dwarf tree forms are characteristic, such as creeping heather, dwarf birch (Betula glandulosa), willow and alder.

Next comes the forest tundra. It is to the west of the Hudson Bay takes its maximum size. Woody forms of vegetation are already beginning to appear. This strip forms the northern border of forests in North America, dominated by species such as larch (Larix laricina), black and white spruce (Picea mariana and Picea canadensis).

On the slopes of the mountains of Alaska, the plain tundra, as well as on the Scandinavian Peninsula, is replaced by mountain tundra and bald vegetation.

In terms of species, the vegetation of the tundra of North America is almost no different from the European-Asian tundra. There are only some floristic differences between them.

Temperate coniferous forests cover most of North America. These forests form the second after the tundra and the last vegetation zone, which stretches across the entire mainland from west to east and is a latitudinal zone. Further south, latitudinal zonality is retained only in the eastern part of the mainland.

On the coast of the Pacific Ocean, taiga is distributed from 61 to 42 ° N. sh., then it crosses the lower slopes of the Cordillera and then spreads to the plain to the east. In this territory, the southern border of the coniferous forest zone rises north to a latitude of 54-55 ° N, but then it descends back to the south to the territories of the Great Lakes and the St. Lawrence River, but only its lower reaches.<

Coniferous forests along the line from the eastern slopes of the mountains of Alaska to the coast of Labrador are characterized by a significant uniformity in the species composition of the rocks.

A distinctive feature of the coniferous forests of the Pacific coast from the forest zone of the east is their appearance and composition of the rocks. So the forest zone of the Pacific coast is very similar to the eastern regions of the Asian taiga, where endemic coniferous species and genera grow. But the eastern part of the mainland is similar to the European taiga.

The “Hudson”, eastern taiga is characterized by the predominance of fairly developed coniferous trees with a high and powerful crown. This species composition includes such endemic species as white or Canadian spruce (Picea canadensis), Banks pine (Pinus banksiana), American larch, balsam fir (Abies balsamea). From the latter, a resinous substance is extracted, which finds a direction in technology - Canadian balsam. Although conifers predominate in this zone, there are still many deciduous trees and shrubs in the Canadian taiga. And in the burnt places, which are very numerous in the Canadian taiga region, even deciduous ones predominate.

Deciduous tree species of this coniferous zone include: aspen (Populus tremuloides), balsam poplar (Populus balsamifera), paper birch (Betula papyrifera). This birch has a white and smooth bark, with which the Indians built their canoes. A very diverse and rich undergrowth of berry bushes is characteristic: blueberries, raspberries, blackberries, black and red currants. Podzolic soils are characteristic of this zone. In the north, they turn into soils of permafrost-taiga composition, and in the south, these are soddy-podzolic soils.

The soil and vegetation cover of the Appalachian zone is very rich and diverse. Here, on the slopes of the Appalachians, rich broad-leaved forests grow in species diversity. Such forests are also called Appalachian forests. These forests are very similar to the genera of East Asian and European forests, in which the dominant role is dominated by endemic species of noble chestnut (Castanea dentata), May beech (Fagus grandifolia), American oak (Quercus macrocarpa), red plane tree (Platanus occidentalis). A characteristic feature of all these trees is that they are very powerful and tall trees. These trees are often entwined with ivy and wild grapes.

Geographical location, natural conditions

In the subequatorial zone, due to seasonal precipitation and uneven distribution of precipitation over the territory, as well as contrasts in the annual course of temperatures, landscapes of subequatorial variable humid forests develop on the plains of Hindustan, Indochina and in the northern half of the Philippine Islands.

Variably humid forests occupy the wettest areas of the lower reaches of the Ganges-Brahmaputra, coastal regions of Indochina and the Philippine archipelago, are especially well developed in Thailand, Burma, the Malay Peninsula, where at least 1500 millimeters of precipitation falls. On drier plains and plateaus, where the amount of precipitation does not exceed 1000-800 millimeters, seasonally moist monsoon forests grow, which once covered large areas of the Hindustan peninsula and southern Indochina (Korat Plateau). With a decrease in precipitation to 800-600 millimeters and a reduction in the rainfall period from 200 to 150-100 days a year, forests are replaced by savannas, woodlands and shrubs.

The soils here are ferralitic, but predominantly red. With a decrease in the amount of rain, the concentration of humus in them increases. They are formed as a result of ferralitic weathering (the process is accompanied by the decay of most of the primary minerals, with the exception of quartz, and the accumulation of secondary ones - kaolinite, goethite, gibbsite, etc.) and humus accumulation under the forest vegetation of the humid tropics. They are characterized by low content of silica, high content of aluminum and iron, low cation exchange and high anion absorption capacity, predominantly red and variegated yellow-red color of the soil profile, very acid reaction. Humus contains mainly fulvic acids. Humus contain 8-10%.

The hydrothermal regime of seasonally humid tropical communities is characterized by constantly high temperatures and a sharp change in the wet and dry seasons, which determines the specific features of the structure and dynamics of their fauna and animal population, which noticeably distinguish them from communities of tropical rainforests. First of all, the presence of a dry season lasting from two to five months determines the seasonal rhythm of life processes in almost all animal species. This rhythm is expressed in the confinement of the breeding period mainly to the wet season, in the complete or partial cessation of activity during the drought, in the migratory movements of animals both within the biome under consideration and outside it during the unfavorable dry season. Falling into full or partial anabiosis is typical for many terrestrial and soil invertebrates, for amphibians, and migration is typical for some insects capable of flight (for example, locusts), for birds, bats and large ungulates.

Vegetable world

Variably humid forests (Figure 1) are similar in structure to hylaea, differing at the same time in a smaller number of species. In general, the same set of life forms, variety of vines and epiphytes is preserved. Differences are manifested precisely in the seasonal rhythm, primarily at the level of the upper tier of the forest stand (up to 30% of the trees of the upper tier are deciduous species). At the same time, the lower tiers include a large number of evergreen species. The grass cover is represented mainly by ferns and dicots. In general, these are transitional types of communities, in places largely reduced by man and replaced by savannahs and plantations.

Figure 1 - Variably humid forest

The vertical structure of humid subequatorial forests is complex. Usually there are five tiers in this forest. The upper tree layer A is formed by the tallest trees, isolated or forming groups, the so-called emergents, raising their “heads and shoulders” above the main canopy - a continuous layer B. The lower tree layer C often penetrates into layer B. Tier D is commonly called shrub. It is formed mainly by woody plants, of which only a few can hardly be called shrubs in the exact sense of the word, or rather, these are “dwarf trees”. Finally, the lower tier E is formed by grasses and tree seedlings. The boundaries between adjacent tiers may be better or worse. Sometimes one tree layer imperceptibly passes into another. Tree layers are better expressed in monodominant communities than in polydominant ones.

The most common teak forest, which is characterized by a teak tree. Trees of this species can be considered an essential component of the summer green forests of India, Burma, Thailand and the relatively dry regions of eastern Java. In India, where very small patches of these natural zonal forests are still preserved, ebony and marada or Indian laurel grow together with teak mainly; all these species provide valuable timber. But teak wood, which has a number of valuable properties, is especially in great demand: it is hard, resistant to fungi and termites, and also reacts poorly to changes in humidity and temperature. Therefore, teak growers specially grow teak (in Africa and South America). The monsoon forests are best explored in Burma and Thailand. In them, along with teak wood, there are Pentacme suavis, Dalbergia paniculata, Tectona hamiltoniana, whose wood is stronger and heavier than teak wood, then giving bast fibers Bauhinia racemosa, Callesium grande, Ziziphus jujuba, Holarrhenia dysenteriaca with white soft wood used for turning and woodcarving. One of the bamboo species, Dendrocalamus strictus, grows in the shrub layer. The layer of grasses consists mainly of grasses, among which the bearded vulture predominates. Along the shores of estuaries and in other areas of the sea coast protected from storms, the muddy tidal strip (littoral) is occupied by mangroves (Figure 2). The trees of this phytocenosis are characterized by thick stilted roots, like thin piles extending from the trunks and lower branches, as well as respiratory roots sticking out of the silt in vertical columns.

Figure 2 - Mangroves

Extensive swamps stretch along the rivers in the tropical rainforest zone: heavy rains lead to regular high floods, and floodplain areas are constantly flooded. The marshy forests are often dominated by palm trees, and the species diversity is less here than in drier places.

Animal world

The fauna of the seasonally humid subtropical communities is not as rich as the fauna of the moist equatorial forests due to the dry period, which is unfavorable for animals. Although the species composition of various groups of animals in them is specific, at the level of genera and families, a great similarity with the gilea fauna is noticeable. Only in the driest variants of these communities, in light forests and thorny bushes, do species related to typical representatives of the fauna of arid communities begin to noticeably predominate.

Forced adaptations to drought contributed to the formation of a number of special animal species characteristic of this particular biome. In addition, some species of phytophagous animals are here more diverse in species composition than in Hylaea, due to the greater development of the herbaceous layer and, accordingly, the greater diversity and richness of herbaceous food.

The layering of the animal population in seasonally humid communities is noticeably simpler than in humid tropical forests. The simplification of layering is especially pronounced in light forests and shrub communities. However, this mainly concerns the tree layer, since the stand itself is less dense, diverse and does not reach such a height as in the hylaea. On the other hand, the herbaceous layer is much more pronounced, since it is not shaded so strongly by woody vegetation. The population of the litter layer is also much richer here, since the deciduousness of many trees and the drying of grasses during the dry period ensure the formation of a rather thick litter layer.

The presence of a layer of litter formed by leaf and grass decay ensures the existence of a trophic group of saprophages with a diverse composition. The soil-litter layer is inhabited by nematode roundworms, megacolocidal annelids, small and large nodule worms, oribatid mites, springtails, springtails, cockroaches, and termites. All of them are involved in the processing of dead plant mass, but the leading role is played by termites already familiar to us from the giley fauna.

Consumers of green mass of plants in seasonal communities are very diverse. This is determined primarily by the presence of a well-developed herbaceous layer in combination with a more or less closed tree layer. Thus, chlorophytophages specialize either in eating the leaves of trees or in using herbaceous plants, many feed on plant sap, bark, wood and roots.

Plant roots are eaten by larvae of cicadas and various beetles - beetles, gold beetles, dark beetles. The juices of living plants are sucked by adult cicadas, bugs, aphids, worms and scale insects. Green plant mass is consumed by caterpillars of butterflies, stick insects, herbivorous beetles - beetles, leaf beetles, weevils. Seeds of herbaceous plants are used as food by reaper ants. The green mass of herbaceous plants is eaten mainly by various locusts.

Numerous and diverse consumers of green vegetation and among vertebrates. These are terrestrial turtles from the genus Testudo, granivorous and frugivorous birds, rodents and ungulates.

The monsoon forests of South Asia are home to the wild chicken (Callus gallus) and the common peacock (Pavochstatus). In the crowns of trees, Asian necklace parrots (Psittacula) get their food.

Figure 3 - Asian ratuf squirrel

Among herbivorous mammals, rodents are the most diverse. They can be found in all tiers of seasonal tropical forests and light forests. The tree layer is inhabited mainly by various representatives of the squirrel family - palm squirrels and a large ratuf squirrel (Figure 3). In the terrestrial layer, rodents from the mouse family are common. In South Asia, large porcupine (Hystrix leucura) can be found under the forest canopy, Rattus rats and Indian bandicots (Bandicota indica) are common everywhere.

Various predatory invertebrates live in the forest floor - large centipedes, spiders, scorpions, predatory beetles. Many spiders that build trapping nets, such as large nephilous spiders, also inhabit the tree layer of the forest. Praying mantises, dragonflies, ktyr flies, predatory bugs prey on small insects on the branches of trees and shrubs.

Small predatory animals prey on rodents, lizards and birds. The most characteristic are various viverrids - civet, mongoose.

Of the large carnivores in the seasonal forests, the leopard is relatively common, penetrating here from the hylae, as well as tigers.

Variably humid forests, unlike permanently humid forests, grow in areas of the planet where precipitation does not occur all year round, but only during the rainy season. At the same time, with the drought season, they have to shed their leaves in order to protect themselves from excessive evaporation in conditions of moisture deficiency. Variably humid forests grow mainly on the territory of the subequatorial climatic zone. They occupy the northern tip of South America, the countries of the American isthmus, large areas of Brazil, where they are called caatinga, in Africa - south and north of the equator, the central part of Madagascar, northeast Hindustan, the east coast of Indochina and northern Australia. They are also often referred to as deciduous variable rain forests or monsoon forests, as they often grow in areas with monsoonal climates. The biodiversity here is also very high, however, much less than in the humid equatorial forests. Animals and plants here have to adapt to strongly changing weather conditions throughout the year. Precipitation falls here during the summer, reaching an average of 1000 to 2000 mm per year, but at the end of the rainy season, drought sets in sharply, and there is practically no rain during the winter. Variably humid forests are home to significantly more mammals, deer, many rodents, monkeys and felines live here. There are many birds in the trees. The soils here are also ferralitic, but predominantly red. With a decrease in the amount of rain, the concentration of humus in them increases. Alternately humid forests, as well as equatorial forests, are threatened by man. The restoration of these forests is possible, however, it will take a long time, so it is necessary to think about their rational use.

Variably humid forests, unlike permanently humid forests, grow in areas of the planet where precipitation does not occur all year round, but only during the rainy season. At the same time, with the drought season, they have to shed their leaves in order to protect themselves from excessive evaporation in conditions of moisture deficiency. Variably humid forests grow mainly on the territory of the subequatorial climatic zone.

They occupy the northern tip of South America, the countries of the American isthmus, large areas of Brazil, where they are called caatinga, in Africa - south and north of the equator, the central part of Madagascar, northeast Hindustan, the east coast of Indochina and northern Australia. They are also often referred to as deciduous variable rain forests or monsoon forests, as they often grow in areas with monsoonal climates.

The biodiversity here is also very high, however, much less than in the humid equatorial forests.

Animals and plants here have to adapt to strongly changing weather conditions throughout the year.

Precipitation falls here during the summer, reaching an average of 1000 to 2000 mm per year, but at the end of the rainy season, drought sets in sharply, and there is practically no rain during the winter. Variably humid forests are home to significantly more mammals, deer, many rodents, monkeys and felines live here. There are many birds in the trees. The soils here are also ferralitic, but predominantly red. With a decrease in the amount of rain, the concentration of humus in them increases.

Alternately humid forests, as well as equatorial forests, are threatened by man. The restoration of these forests is possible, however, it will take a long time, so it is necessary to think about their rational use.

Variably moist forests wikipedia
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Permanently humid equatorial forests. There are 3 arrays along the equator:

Forests of the Amazon (South America), the northern coast of the Gulf of Guinea and about. Madagascar (Africa), Southeast Asia, New Guinea, Malay Peninsula, southern Philippines.

Also, permanently humid forests can be found in the subtropical and tropical zones, due to the fact that there are high temperatures throughout the year and the territory is constantly under the influence of the trade winds.

These territories are: Northern coast of Australia, Eastern coast of Brazil, Western part of India.

Climate characteristic:

Rainfall - 1500-2000

Evaporation - 700-1200

High-Ivanov coefficient 1.5-3 (excessive moisture - more precipitation than evaporation)

Vegetation:

Phytomass – 650T/ha, Productivity – 40T/ha per year

There are 50-100 plant species per 1 ha.

Forests differ in tiers, are polydominant - several species of plants dominate on each tier. The upper tier - trees 50-60m (characterized by diversity), the middle - 20-30m (well developed and closed), the lower one is rather poorly expressed due to low radiation. Under the canopy of the forest, there is significant shading.

Soils: Greyolitic (yellow) soils are formed on powerful weathering slopes (20 m or more), have excessive moisture and leaching regime throughout the year.

Soils are poor in bases and humus (5.7cm), because there is a rapid decomposition of plant residues, but are rich in oxides of iron and aluminum.

Variably humid equatorial forests. They are located between the zone of permanently humid forests and the savannah. This is the wettest part of the subequatorial climate. Summer rains and a dry period are characteristic. The zone in Africa is presented from the north and south of the equator, the forests of the South.

America on the periphery of the Amazonian permanently humid forests, For the forests of Central America, in the east of about. Java, Bali, Also in the region of Hindustan (Bombay).

Climate characteristic:

Rainfall - 1200-1600

Evaporation - 1200-1400

Coefficient of High - Ivanov 1-1.2

The dry period can last up to 5 months, then evaporation is greater than the amount of precipitation, during rains precipitation> evaporation.

Vegetation:

Phytomass – 500T/ha, Productivity – 16T/ha per year

The tallest trees are 25-30m, layering is less pronounced than in constantly wet forests.

In the dry season, leaf fall is observed.

The shrub layer is better expressed than in variable-humid forests. Grasses appear in the herbaceous layer.

Soils: red feramide soils are formed. In the dry season, there is no leaching regime of soils + deciduousness + less decay = humus horizon 10-15cm. Humus is formed under conditions when the leaching regime is replaced by a non-leaching one.

Savannah landscapes.

Savannahs are called zones with a predominance of cereals in the subequatorial and tropical zones.

They are characterized by stand-alone trees.

There are 3 subzones of savannahs: wet savannahs, typical savannahs, deserted savannahs.

Savannahs are very widespread. In Africa, m / y deserts and variable-humid subequatorial forests, as well as in the east and south. South America - south of the Amazon, On the Caribbean coast (turn into woodlands), in the Orinoco Delta.

Sev. America - in the "rain shadow" of Central America and Mexico (Pacific Coast). Asia - the Hindustan Peninsula, in the interior of Thailand, Kombodia. Vast belts of savannas in Australia.

Climate characteristic:

Precipitation - 1000-1500 (for wet), 500-1000 (typical), 200-500 (desert)

Evaporation - 1500-2400 (for wet), 2400-3800 (typical), 3500-4200 (desert)

High-Ivanov coefficient 0.4-1; 02,-0.4; 0.02-0.2

Savannahs are characterized by alternating wet and dry seasons.

The maximum duration of the dry season is 10 months (in desert savannas). The minimum dry season is 3 months. Evaporation > amount of precipitation.

Vegetation:

Phytomass — 40T/ha (in typical); 15T/ha (in deserted),

Productivity - 12T/ha per year; 4t/ha per year

Characteristic sparse woody vegetation. This is due to the fact that plants compete for soil moisture.

There are areas of forests along the banks of rivers and lakes. For the savannas, a developed animal world with a large number of herbivores is typical.

Soils: Red feralite soils are common in wet savannahs. In typical and deserted - red-brown soils. All soils are formed in the process of non-leaching water regime. In humid savannahs, the humus horizon reaches 15 cm; towards desert savannahs, the humus horizon decreases.

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1) Variable rain forests grow south and north of the equatorial rain forests: in tropical Africa, America, Hindustan, Sri Lanka, Indochina, China, North and Northeast Australia.
3) They differ from their colder and drier counterparts in their red or reddish color and strong weathering of minerals.

In these areas, more than 1000 mm of precipitation falls annually in the form of rain (in some places more than 10 thousand mm), that is, a layer of water more than one meter thick.

Heat and moisture are the basis of lush vegetation, which injects organic acids into the soil all year round, and warm soil waters carry them to a great depth, dissolving the minerals of rocks. It is very important that the age of the surface layers of soil in the tropics and subtropics reaches hundreds of thousands and millions of years. With such strong and long weathering, most minerals and chemical elements are washed out and the most stable minerals remain in the soil - kaolinite, quartz, as well as a large amount of iron and aluminum oxides, for which they are called ferralite soils (from "ferrum" - "iron, aluminum" and "lithos" - "stone").

The most important iron oxides that give color to the soil are red hematite, as well as yellow limonite and brown goethite, which contain impurities of crystalline water. Differences in the color of the soils of the tropics and subtropics are also associated with the humidity of the climate and the degree of weathering of minerals.

The most humid soils of the equatorial zone are red-yellow soils (in the subtropical zone they are called krasnozems and yellow soils). In these forest soils, the litter and a small humus horizon give way to weathering horizons with red and yellow coloration. Heavily weathered, but variable wet soils of subequatorial tall grass savannahs are called red.

In them, the humus horizon is much thicker than in forest equatorial soils. In savannahs and hardwood forests, where it is still drier, the soils are less weathered, they have less red hematite and more brown goethite, therefore they are called red-brown and brown-red. Here the humus horizon is less dark in color and thinner, and calcium carbonates can appear in the soil profile.

The soils of the subtropical zone often represent, as it were, transitions between the red soils of low latitudes and the soils of the temperate zone. The wettest red and yellow soils are the closest soil
4) Among the plants of variable-moist forests, evergreen, coniferous and deciduous trees are distinguished. Evergreens include palm trees, ficuses, bamboo, all kinds of magnolia, cypress, camphor tree, tulip tree. Deciduous trees are represented by linden, ash, walnut, oak, maple. Of the evergreens, fir and spruce are often found.
5)
Among the plants of variable-moist forests, evergreen, coniferous and deciduous trees are distinguished.

Evergreens include palm trees, ficuses, bamboo, all kinds of magnolia, cypress, camphor tree, tulip tree.

Deciduous trees are represented by linden, ash, walnut, oak, maple. Of the evergreens, fir and spruce are often found. Other inhabitants of such a forest, chain-tailed monkeys, live mainly on trees. They are small in size and have a black and white color. As is clear from the name of the species, these monkeys are distinguished by a particularly tenacious tail. There are also many bats, fish and reptiles here. Note that about 2,000 species of fish live here, which is from the freshwater fauna of the whole world.
2) The climate there is very difficult, as the sun can shine and heavy rain can immediately begin.

It can rain very heavily and there is a lot of precipitation. For these forests, the most testing month is May. May is very hot, small rivers and small reservoirs dry up.

Landscapes of subtropical variable-moist forests and landscapes of broad-leaved forests of the temperate zone.

Landscapes of subtropical variable-humid (monsoon) forests are found on the eastern coasts of the continents. In Eurasia - eastern China, the southern part of Japan (to Tokyo), the south of South Korea. Here the monsoon forests are pronounced. Sev.

America is the southeastern United States. South America - the south of Brazil, the upper reaches of the Uruguay River. Africa - in South Africa (southeastern part, at the foot of the Dragon Mountains). Australia - m / y along the coast of the Tusman Sea and the Great Dividing Range; in northern New Zealand.

Climate characteristic:

Rainfall - 1000-1600

Evaporation - 750-1200

Coefficient High - Ivanov 1-1.5

Throughout the year, the amount of precipitation is greater than evaporation.

It rains in summer, there is little rain in winter. But in accordance with this, the decrease in evaporation occurs in proportion to the decrease in the amount of precipitation. Excess moisture all year round. This zone is analogous to humid equatorial forests, only with a different thermal and radiation background.

Vegetation:

Character-on polydominance - there are different types, a cat.

represent tree forests. These forests are forever green. Layering is developed, creepers are characteristic, grassy cover is developed. The fauna of Asia is diverse (a relic is a panda), many animals do not correspond to this zone. In the east of Asia, from the equator to the north, one natural zone replaces another: humid equatorial forests - subequatorial humid forests - subtropical forests - deciduous forests - taiga. This is due to the fact that the monsoon type of climate dominates here.

There is a mixing of types of zones, some penetrate into others.

All in. America exists coniferous forests, different. species of oaks, rich fauna.

South America - araucaria forests, hardwoods.

Soils: zheltozems and krasnozems are formed. Permanent decomposition of litter throughout the year, constant washing regime. Small humus horizon.

Temperate broadleaf forest zone in Zap. Europe is occupied by huge spaces (France, Ireland, Germany, etc.).

In Eurasia, there are 2 large tracts of broad-leaved forests - Zap. Europe (up to Scandinavia) and the Far East (North of Japan, Korea). All in. America - the Ohio River Basin, Fr. Michigan, in the upper reaches of the Missouri river. in Yuzh. America - south of the zone of hardwood forests. Australia - about. Tasmania, south Part of New Zealand.

Climate characteristic:

Rainfall - 600-1000

Evaporation - 500-1000

High-Ivanov coefficient 1-1.2.

Throughout the year, there is more precipitation than evaporation.

Vegetation:

Deciduous forests are formed, this is due to the negative. temperatures in winter when photosynthesis is not possible.

Under these conditions, in the north of the zone, a subtaiga zone is distinguished, where coniferous species are present in the upper tier, and broad-leaved species are present in the lower tier. Beeches, oaks, hornbeams grow in such forests.

Soils: Brown sandy soils are formed in coastal areas, sandy sulfur soils are formed in continental areas.

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Vietnam

The Socialist Republic of Vietnam is located in Southeast Asia, on the east coast of the Indochinese Peninsula. It occupies an area of ​​331,600 km2, which is comparable to the territory of Germany. Vietnam borders China in the north, Laos in the west, Cambodia in the southwest, and the South China Sea in the east. Vietnam owns two large archipelagos - Hoang Sha and Truong Sha and a large number of islands. Three-quarters of the country's territory is mountainous; there are two fertile deltas of the main water arteries of the country of the Mekong (Fig. 2.73) and Red. The coastline of Vietnam, excluding the islands, is 3444 km. Population - 92.477 million people (2013 data).

The climate, according to the Köppen classification, belongs to the types Aw (tropical savanna climate in the plains of the south of the country) and Cwa-Am (warm monsoon climate in the mountainous north).

The Vietnamese economy has been developing rapidly since 1990, when the country, following the example of China, began to combine state and private property. GDP growth varies between 5.3-8.5%.

13 large rivers and about 3,500 rivers with a length of at least 10 km flow on the territory of Vietnam. Water resources have become an important factor in ensuring food and energy security, as well as in the industrialization and modernization of the country. At the end of the 20th century, Vietnam came out on top in the world in terms of rice exports (Vietnam..., 1993) (Fig. 2.74-2.78).

Water resources are also a decisive factor in increasing the production of other agricultural and industrial crops such as tea, coffee, black pepper, etc. Currently, 70% of the water used for agricultural production comes from the Red and Mekong rivers. However, the country faces numerous challenges in the use of water resources.

The Mekong is one of the largest rivers in the world: its length is 4350 km, and its area is 795 thousand km 2. Food rain, snow and ice. Its basin is home to 250 million people from several countries (Fig. 2.73).

Rice. 2.74

Valley type of settlement. Fields and villages are located in the valleys of small rivers

The Mekong basin is the second largest biodiversity basin in the world after the Amazon. The Mekong flows through the territory of 4 states: China, Laos, Cambodia and Vietnam. The state borders of Myanmar (Burma) and Thailand pass along the right bank of the river. The cooperation of the countries to which this river is directly related, the experts have their own name - "the spirit of the Mekong." Since 1957, this cooperation has been taking place within the framework of the Commission for the river. Mekong (Rysbekov, 2009; FB.ru: http://fb.ru/article/222437/mekong).

Rice. 2.75

Rice fields of Mu Cang Chai District, Yen Bai Province

Rice. 2.76

Rice. 2.77

Rice. 2.78

On the territory of Vietnam there is only a relatively small segment (200 km long) of the lower reaches of the river. Mekong, representing a delta of two wide branches and many smaller channels (Fig. 2.79, 2.80). There are many channels dug here. 17 million Vietnamese live in the delta with an area of ​​70,000 km2. The climate within the delta is subequatorial monsoonal. The average annual temperature is 27°С; The year is divided into two seasons - wet and dry.

Rice. 2.79

The economy of the provinces in the Mekong Delta is based on agriculture (rice cultivation (Figures 2.81, 2.82)) and aquaculture. An important role in the delta is played by artificial channels, which are transport arteries and places for breeding aquatic products. The most famous canal, Vinh Te, is 87 km long and 40 to 60 m wide. It was dug by hand with shovels and hoes over a period of 5 years, from 1819 to 1824, during the reign of the Nguyen dynasty.

The fishing fleet has more than 25 thousand vessels of various tonnage. More than 1 million tons of fish (pangasius), about 300 thousand tons of saltwater shrimp and a large number of other fish, arthropods and molluscs are grown annually. About 200 factories have been built to process seafood. Tourism has been developing intensively in the last two decades.

Fig.2.80

Rice. 2.81

Rice. 2.82

The role of water resources in providing food for the population of Eurasia. Based on the completed review of the most common types of agricultural land in Eurasia, we will try to assess the role of water resources in solving the food problem on this continent. According to forecasts, by 2050 the world's population will increase to 9 billion. At the beginning of section 2.2, we outlined one of the food programs proposed by J. Foley (2014), which includes five steps. This program aims to double food production by 2050, but does not address the issue of water availability. In table. 2.4. The "steps" of the Foley program are numbered 1-5. The last column shows our estimate of the water availability of the program as a percentage of the amount that doubles food production.

The "first step" - the stabilization of the area of ​​agricultural land is accepted as feasible in all the considered territories as a necessary initial condition for the implementation of the Foley program. The “second step” (continuation of the “green revolution”) is possible on irrigated lands of countries with a warm climate, while in the zone of the northern and middle steppes it has limitations - the unsuccessful experience of introducing Italian durum wheat in the steppe zone of Russia is known.

Table 2.4

Assessing the feasibility of implementing the food program J. Foley (2014) "Five Steps", taking into account the potential of water resources

	Ecosocial systems	"Steps" of the program J. Foley
	Voronezh region
	Stavropol region
	S.-V. China
	Central Asia (Turkmenistan)
	Rajasthan (India)
	Yu.-V. China

Rice. 2.83 Map of the use of nitrogen fertilizers in Eurasia (fragment of the world map).