Variable humid forest temperatures in winter and summer. Forests of South America. Fauna of South America

For tropical wet evergreen, or, as they are sometimes called, rain forests, are characterized by a three-tier structure of the tree canopy. The tiers are poorly demarcated. The upper tier is giant trees height 45 m or more, diameter 2-2.5 m. The middle tier is represented by trees about 30 m high with a trunk diameter of up to 90 cm. The third tier grows smaller, exclusively shade-tolerant trees. There are many palm trees in these forests. Their main growing area is the Amazon basin. Here they occupy vast areas, including, in addition to the northern part of Brazil, French Guiana, Suriname, Guyana, the southern part of Venezuela, the west and south of Colombia, Ecuador and the east of Peru. In addition, this type of forest occurs in Brazil in a narrow strip along the Atlantic coast between 5 and 30° S. Similar evergreen forests also grow on the Pacific coast from the Panama border to Guayaquil in Ecuador. All species of the genus Switenia (or mahogany), rubber plants of the genus Hevea, Brazil nut (Bertolletia excelsa) and many other valuable species are concentrated here.

Tropical variable-moist deciduous forests distributed in southeastern Brazil and southern Paraguay. The tree species in them are relatively small in height, but often with thick trunks. Legumes are widely represented in forests. Subtropical deciduous broadleaf forests most common in southern Brazil and Parguay, western Uruguay and northern Argentina along the Paraná and Uruguay rivers. Mountain evergreen forests cover the slopes of the Andes from Venezuela to central Bolivia. These forests are characterized by thin-trunked trees tall trees, forming closed stands. Due to the fact that these forests occupy steep slopes and are significantly removed from populated areas, they are developed very little.

Araucaria forests are located in two areas isolated from each other. Brazilian Araucaria (Araucaria brasiliana) is dominant in the states of Paraná, Santa Catarina and Rio Grande do Sul in Brazil, as well as in Uruguay, Eastern Paraguay and Argentina. A less significant massif is formed by forests of Chilean araucaria (A. araucana), found in the Andes at 40° S. in the altitude range from 500 to 3000 m above sea level. seas. These forests are characterized by hardwood species, of which the embuya (Phoebe porosa) is the most important. In the undergrowth of Araucaria forests, the mate bush, or Paraguayan tea (Ilex paraguariensis), is widespread, also grown on plantations.

Low-growing xerophilous forests distributed in eastern Brazil, northern Argentina and western Paraguay. The most important tree species of these forests is red querbacho (Schinopsis sp.), from which tannin is obtained. Mangrove forests occupy the coastal strip of the Atlantic part of South America. These forests are dominated by the red mangrove (Rhizophora mangle), forming pure stands or mixed with Avicennia marina and Conocarpus erecta.

In addition to timber harvesting, the forests of the continent produce rubber, food products (seeds, nuts, fruits, beans, leaves, etc.), oils, medicinal substances, tannin, resins, including chicle (Zschokkea lascescens), which goes to the USA as raw materials for the production of chewing gum.

Venezuela. Evergreen (on laterites) and deciduous forests grow on the slopes of the Andes spurs and the Guiana Highlands. On the territory of the low llanos, tall grass savanna with groves of Mauritius palms is common, and in the high llanos there are xerophilous open forests and shrub communities. Around Lake Maracaibo there are mangroves, giving way to low-growing xerophilic forests, and to the south - evergreen tropical forests. In the south of the country, in the upper reaches of the river. The Orinoco and its right tributaries grow humid evergreen tropical forests, almost inaccessible for exploitation. From tree species representing economic value, characterized by mahogany, roble-colorado, baku, balsa, espave (Anacardium spp.), angelino (Ocotea caracasana), oleo-vermelho (Myroxylon balsamum), pao-roxo, guaiacum, tabebuia (Tabebuia pentaphylla), ceiba (Ceiba pentandra) , almasigo (Bursera simaruba), courbaril (Hymenaea courbaril), adobe (Samanea saman), etc.

Landscape in the center of Venezuela

Colombia. By natural conditions Two regions are distinguished: eastern (plain) and western (mountainous, where the Colombian Andes stretch). The first area is largely occupied by moist evergreen forests of the Magdalena basins and the left tributaries of the Amazon. In the north of the Guajira Peninsula and to the west of it, along the Caribbean coast, there are low-growing xerophilic forests in which divi-divi beans (Libidibia coriaria) are harvested for tannin. Guaiac wood (Guaiacum spp.) is also harvested here - this is one of the hardest and heaviest woods in the world, used for the manufacture of rollers, blocks and other mechanical engineering products.

Along the Pacific and Caribbean coasts stretch mangrove forests. In the evergreen tropical Hylaea, especially in the lower part of the Magdalena basin and along the mouth of the river. Atrato, the wood of cativo (Prioria copaifera), as well as baku, or "Colombian mahogany" (Cariniana spp.), caoba, or true mahogany (Swietenia macrophylla), roble-colorado, or Panamanian mahogany (Platymiscium spp.) is harvested for export. , purple tree, or pao-roxo (Peltogyne spp.), etc. In the eastern part of the elevated plain along the tributaries of the Orinoco, savanna-llanos with sparse trees and gallery forests with the Mauritius palm (Mauricia sp.) are common. The forests of the mountainous regions of the Andes are characterized by a peculiar altitudinal zonation. On the lower parts of the leeward slopes and on the northern ridges, deciduous forests or thorny bushes are common. In the adjacent part of the mountains (from 1000 to 2000 m) there are montane broad-leaved evergreen forests with tree ferns, wax palm (Copernicia cerifera), cinchona, coca (Erythroxylon coca) and various orchids. Cultivated plants include cocoa and coffee trees. At altitudes from 2000 to 3200 m, humid alpine hylea, which contains many species of evergreen oaks, shrubs and bamboos.

Ecuador. There are three natural areas on the territory of the country: 1) watershed plateau with humid equatorial forests - hylea, or selva(together with the upper reaches of the left tributaries of the Amazon); 2) Andes ridges; 3) Pacific forest-savanna plain and the western slopes of the Andes. Evergreen tropical forests of the first region are poorly studied and difficult to access. On the western slopes of the Andes, up to an altitude of 3000 m, evergreen mountain broad-leaved forests (hylaea) grow, largely disturbed by slash-and-burn agriculture. They produce a lot of cinchona bark, as well as balsa, kapok from ceiba fruits, and leaves of the toquilla palm, or hipihapa (Carludovica palmata), used for making Panama hats. Here you can also find the tagua palm (Phytelephas spp.), the hard endosperm of which is used to produce buttons, and various rubber plants. The lower western slopes are characterized by evergreen tropical forests. In the river valley Guayas is intensively harvested for export of balsa wood.

Guyana, Suriname, Guiana. The forests of these countries, located along the Atlantic coast and along the Guiana Highlands, are tropical evergreen with a number of valuable species. Particularly notable is the green tree, or betabaro (Ocotea rodiaei), which is exported in Guyana and Suriname. No less valuable are apomate (Tabebuia pentaphylla), canalete (Cordia spp.), pequia (Caryocar spp.), espave (Anacardium spp.), habillo (Hura crepitans), wallaba (Eperua spp.), carapa (Carapa guianensis), virola (Virola spp.), simaruba (Simaruba spp.), etc.

Brazil. The flora contains over 7 thousand species of trees and shrubs, of which in the Amazonian jungle there are over 4.5 thousand species. Tall bertholiaceae grow (producing Brazil nuts, etc.), various rubber plants, including Hevea brasiliensis, which has become a valuable plantation crop in many countries of South Asia and Africa, laurels, ficus trees, Brazilian mahogany, or “pau brazil”, which gave the country its name (Caesalpinia echinata), chocolate tree or cacao, mahogany, jacaranda or rosewood, oleo vermelho, roble colorado and sapucaya or paradise nut (Lecythis ustata), and many others. In the east, the selva turns into light palm forests, among which we note the valuable babasa palm (Orbignya speciosa), which has highly nutritious nuts. To the south of the Amazon jungle, landscapes of tropical dry woodlands are common - caatinga, in which trees grow that shed leaves during the dry season and accumulate moisture during the rainy season, for example, bottle tree (Cavanillesia arborea), thorny bushes, cacti (Cereus squamulosus). In the floodplains, the carnauba, or wax, palm (Copernicia cerifera) is found, from the leaves of which wax is collected, used in technology. To the south, palm-dominated forests and savannas are adjacent to subtropical deciduous forests. In the southeast of the country, along the Brazilian Highlands, araucaria forests of the Brazilian, or Paranan, araucaria (Pineiro, or “Brazilian pine”) extend. Along with it, embuia, tabebuia, and cordia grow, and in the undergrowth of yerbamate - Paraguayan tea is prepared from its leaves. Araucaria forests are subject to intensive exploitation.

Along the Atlantic coast and at the mouth of the Amazon, mangrove forests are dominated by red mangrove, with a mixture of black mangrove (Avicennia marina) and white mangrove (Conocarpus erecta). Tannin is extracted from the bark of these trees.

Argentina. Several stand out natural areas. In the east, evergreen forests dominate, in which more than 100 species of trees grow, having important economic importance. Among them are cabreuva (Myrocarpus frondosus), kangerana (Cabralea oblongifolia), Brazilian araucaria, tabebuia, etc. In the west, evergreen forests grow on the slopes of the Andes at an altitude of 2000-2500 m above sea level. seas. Palo blanco (Calycophyllum multiflorum), cedro salteno (Cedrela balansae), roble criolo (Amburana cearensis), nogal criolo (Juglans australis), tarco (Jacaranda mimosifolia), tipa blanco (Tipuana tipu), etc. are common in them. In the south, along the slopes of the Andes, subantarctic vegetation extends, among which several species of southern beech, alerce, “Cordilleran cypress” (Austrocedrus chilensis), etc. stand out. palosanto (Bulnesia sarmientoi), guaiacano (Caesalpinia paraguarensis), etc. To the south, on the eastern slopes of the Andes, there are xerophilic broad-leaved forests of the temperate zone with algarrobo, acacia (Acacia caven), hackberry (Celtis spinosa), quebracho blanco.

Paraguay. Forest cover 51%. In the east of the country, mixed tropical evergreen and deciduous forests are common, turning into open forests and savannas in the west (in the Gran Chaco region). The main tree species is quebracho-blanco (Aspidosperma quebracho-blanco).

Uruguay. Forests occupy a small part of the total territory of the country and are located in the lower reaches of the Rio Negro and in the valley of the river. Uruguay. The country's forest cover is 3%. Large areas are beginning to be occupied by artificial plantings - pine trees on coastal dunes and eucalyptus plantations.

Published from the monograph: A.D. Bukshtynov, B.I. Groshev, G.V. Krylov. Forests (Nature of the world). M.: Mysl, 1981. 316 p.

Variably wet forests. The zone of variable wet (including monsoon) forests extends in the east and south of Eurasia. The vegetation here is represented by both coniferous and deciduous trees (cedar, pine, oak, walnut, gingko) and evergreens (palm trees, ficus, bamboo and magnolias), which grow mainly on red-yellow soils. Animal world is also characterized by significant species diversity: monkeys, tigers, leopards, as well as endemics - bamboo bear (panda), gibbon, etc.

Geography 7th grade

“Natural zones of Eurasia” - Among the impenetrable thickets here you can find orangutans, leopards, and tapirs. Main animals: reindeer, arctic foxes, some species of birds. The latter predominates in the Asian taiga, in a cold, sharply continental climate. Zone arctic deserts. Mixed and broad-leaved forests. The desert zone stretches across three geographical zones. The fauna here is represented by elephants, tigers, and rhinoceroses. Many reptiles and reptiles, as well as various insects. Along the mountain ranges of Siberia, tundra vegetation penetrates far to the south.

“Sights of Paris” - See Paris - and die! Arc de Triomphe in 1836 by Louis-Philippe. Place de la Star is officially called Place Charles de Gaulle. The Sorbonne was founded in 1253 by Robert de Sorbonne. Georges Pompidou - Beaubourg. The Pantheon is a monument that contains the tombs of great people of France. The Eiffel Tower is the symbol of Paris. The Louvre is one of the largest and richest museums in the world fine arts. Goal: get to know the sights of Paris.

“Geographical location of the southern continents” - On plains composed of sedimentary rocks. Questions: To which oceans do the rivers of Africa and South America carry water? Why? Slide 7. Soil map. Igneous: ores of ferrous and non-ferrous metals, diamonds, noble and rare metals. General features of climate and inland waters. Slide 4. Minerals southern continents. Which climate zones have the largest network of rivers and many lakes?

“Geographic shell of the Earth” - The modern appearance of planet Earth. 1. Altitudinal zone zonality... 6. The lithosphere is... Students of class 7 A Matrosova A.E. A. state of the troposphere B. long-term weather regime C. state of the troposphere at the moment. A. on the plains B. in the mountains C. in the oceans 2. The geographical envelope is... Test work. Right answers.

“Water in the World Ocean” - Without water, a person cannot live for more than eight days. Thanks to water and in water, life arose on Earth. Next, deadly dehydration occurs. You can't grow crops without water. We begin to study the water shell of the Earth - the hydrosphere. Fundamental question: “Water! Group 2: Compare the area of ​​land and ocean. What is the temperature at different levels ocean?

“Savannahs” - Branched acacias rise like huge umbrellas among the tall grasses. Animal world. Savannah. Economic activities of people. average temperature July and January +22C. Soils. Geographical position. Climatic conditions. Umbrella acacia. Savannas are located in the subequatorial belt.

Variably wet forests, unlike constantly wet 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 dry season, they have to shed their leaves in order to protect themselves from excess evaporation in conditions of moisture deficiency. Variably humid forests grow mainly in the subequatorial climate 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, central part Madagascar, northeast Hindustan, eastern coast of Indochina and northern Australia. They are also often called deciduous moist forests or monsoon forests, as they often grow in areas with a monsoon climate. Biodiversity here is also very high, however, much less than in the equatorial rainforests. Animals and plants here have to adapt to highly variable 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. In variable humid forests it inhabits significantly more mammals, deer, many rodents, monkeys and representatives of the cat family live here. Many birds live in the trees. The soils here are also ferralitic, but predominantly red. As the amount of rain decreases, the concentration of humus in them increases. Variably humid forests, like equatorial forests, are threatened by humans. Restoring these forests is possible, however, it will take a lot of time, so it is necessary to think about their rational use.

Variably wet forests, in contrast to constantly wet 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 dry season, they have to shed their leaves in order to protect themselves from excess evaporation in conditions of moisture deficiency. Variably humid forests grow mainly in the subequatorial climate 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, the northeast of Hindustan, the eastern coast of Indochina and the north of Australia. They are also often called deciduous moist forests or monsoon forests, as they often grow in areas with a monsoon climate.

Biodiversity here is also very high, however, much less than in the equatorial rainforests.

Animals and plants here have to adapt to highly variable 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. The variable wet forests are home to significantly more mammals, deer, many rodents, monkeys and felines. Many birds live in the trees. The soils here are also ferralitic, but predominantly red. As the amount of rain decreases, the concentration of humus in them increases.

Variably humid forests, like equatorial forests, are threatened by humans. Restoring these forests is possible, however, it will take a lot of 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:

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

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

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

Climate characteristics:

Amount of precipitation – 1500-2000

Evaporation – 700-1200

Vysokogo-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 hectare.

Forests are layered and are polydominant - several plant species dominate each layer. The upper tier is trees 50-60m (characterized by diversity), the middle tier is 20-30m (well developed and closed), the lower tier is rather poorly expressed due to low radiation. There is significant shade under the forest canopy.

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

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

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 typical. The zone in Africa is presented from the north and south of the equator, the forests of the South.

America along the periphery of the Amazon rainforest, For forests Central America, in the east of the island. Java, Bali, Also in the Hindustan region (Bombay).

Climate characteristics:

Amount of precipitation – 1200-1600

Evaporation – 1200-1400

Vysokogo-Ivanov coefficient 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, the layering is less pronounced than in permanently humid forests.

During 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 ferramid soils are formed. In the dry season, there is no soil leaching regime + deciduousness + less decomposition = humus horizon 10-15 cm. Humus is formed under conditions when the leaching regime is replaced by a non-leaching one.

Savannah landscapes.

Savannas are areas with a predominance of cereals in the subequatorial and tropical zones.

They are characterized by free-standing trees.

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

Savannas are very widespread. In Africa there are deserts and variable-humid subequatorial forests, as well as in the east and south. South America - south of the Amazon, on the Caribbean coast (turning into woodlands), in the Orinoco River delta.

North America – in the “rain shadow” of Central America and Mexico (Coast Pacific Ocean). Asia - Hindustan Peninsula, in the interior of Thailand, Cambodia. Extensive savannah belts in Australia.

Climate characteristics:

Amount of precipitation – 1000-1500 (for humid), 500-1000 (typical), 200-500 (desert)

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

Vysokogo-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 desertified savannas). The minimum dry season is 3 months. Evaporation > amount of precipitation.

Vegetation:

Phytomass - 40T/Ha (typical); 15T/Ha (in deserted areas),

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. Savannahs have a developed fauna with a large number herbivores.

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

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1) Variable humid forests grow to the south and north of humid equatorial forests: in tropical Africa, America, Hindustan, Sri Lanka, Indochina, China, Northern and Northeastern 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 in the form of rain per year (in some places more than 10 thousand mm), i.e. 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 great depths, dissolving rock minerals. 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, and a large number of oxides of iron and aluminum, for which they are called ferrallitic soils (from “ferrum” - “iron, aluminum” and “litos” - “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 soils in the tropics and subtropics are also associated with climate humidity and the degree of weathering of minerals.

Wettest soils equatorial belt– these are red-yellow soils (in the subtropical zone they are called red soils and yellow soils). In these forest soils, the litter and small humus horizon are replaced by weathering horizons with red and yellow colors. The highly weathered but variably moist soils of subequatorial tall-grass savannas are called red soils.

They have a much thicker humus horizon than forest equatorial soils. In savannas and hard-leaved forests, where it is even drier, the soils are less weathered, they have less red hematite and more brown goethite, which is why they are called red-brown and brown-red. Here the humus horizon is less dark in color and less thick, and calcium carbonates may appear in the soil profile.

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

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

Deciduous trees are represented by linden, ash, walnut, oak, and maple. Among the evergreens, fir and spruce are often found. Other inhabitants of such a forest are prehensile-tailed monkeys, who live mainly in trees. They are small in size and black and white in color. As the name of the species suggests, these monkeys are distinguished by a particularly prehensile tail. There are also many bats, fish and reptiles. Note that about 2,000 species of fish live here, which is equal to the freshwater fauna of the whole world.
2) The climate there is very difficult, since the sun can shine and then pouring rain begins.

It can rain very heavily, with large amounts of precipitation falling. 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 temperate deciduous forests.

Landscapes of subtropical variable-moist (monsoon) forests meet but eastern coasts continents. In Eurasia - eastern China, southern Japan (to Tokyo), south South Korea. Monsoon forests are pronounced here. North

America - southeastern USA. South America - southern Brazil, upper reaches of the Uruguay River. Africa - in South Africa (south-eastern part, at the foot of the Drakensberg Mountains). Australia – bordered by the Tosman Sea and the Great Sea watershed ridge; in the north of New Zealand.

Climate characteristics:

Amount of precipitation – 1000-1600

Evaporation – 750-1200

Vysokogo-Ivanov coefficient 1-1.5

Throughout the year, the amount of precipitation exceeds evaporation.

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

Vegetation:

Polydominant character - found different types, cat.

represent arboreal forests. These forests are forever green. The layering is developed, the lianas are characteristic, and the herbaceous cover is developed. The fauna of Asia is diverse (a relic is the panda), many animals do not correspond to this zone. In eastern Asia, from the equator to the north, one natural zone replaces another: equatorial rain forests - subequatorial rain 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 zone types, some penetrating into others.

All in. America has coniferous forests, different. species of oak trees, rich fauna.

South America - araucaria forests, deciduous trees.

Soils: yellow soils and red soils are formed. Constant decomposition of litter throughout the year, constant leaching regime. Small humus horizon.

Temperate broadleaf forest zone in the West Europe occupies vast spaces (France, Ireland, Germany, etc.).

In Eurasia there are 2 large tracts of broad-leaved forests - Western. Europe (up to Scandinavia) and the Far East (Northern Japan, Korea). All in. America - Ohio River basin, o. Michigan, in the upper reaches of the Missouri River. in South America - south of the hard-leaved forest zone. Australia - o. Tasmania, south Part of New Zealand.

Climate characteristics:

Amount of precipitation – 600-1000

Evaporation – 500-1000

The coefficient between Vysoky and Ivanov is 1-1.2.

Throughout the year there is more precipitation than evaporation.

Vegetation:

Deciduous forests are formed, this is due to neg. 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 in the lower tier. Beeches, oaks, and hornbeams grow in such forests.

Soils: In coastal areas brown sandy soils, in continental ones - sandy sulfur.

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Geographical location, natural conditions

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

Variably humid forests occupy the most humid areas of the lower reaches of the Ganges-Brahmaputra, coastal areas of Indochina and the Philippine archipelago, and are especially well developed in Thailand, Burma, and the Malay Peninsula, where at least 1,500 millimeters of precipitation falls. On drier plains and plateaus, where precipitation does not exceed 1000-800 millimeters, seasonally wet 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. As the amount of rain decreases, the concentration of humus in them increases. They are formed as a result of ferralite weathering (the process is accompanied by the decomposition 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 silica content, high aluminum and iron content, low cation exchange and high anion absorption capacity, predominantly red and variegated yellow-red color of the soil profile, and a very acidic reaction. Humus contains mainly fulvic acids. They contain 8-10% humus.

The hydrothermal regime of seasonally humid tropical communities is characterized by constantly high temperatures and a sharp change in wet and dry seasons, which determines the specific features of the structure and dynamics of their fauna and animal population, which significantly distinguish them from humid communities. tropical forests. 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 timing of the breeding season mainly to the wet season, in the complete or partial cessation of activity during drought, in the migratory movements of animals both within the biome in question and outside it during the unfavorable dry season. Falling into complete or partial suspended animation is characteristic of many terrestrial and soil invertebrates, amphibians, and migration is characteristic of some flight-capable insects (for example, locusts), birds, chiropterans and large ungulates.

Vegetable world

Variably humid forests (Figure 1) are close in structure to hylaea, differing at the same time in a smaller number of species. In general, the same set of life forms, diversity of vines and epiphytes are preserved. Differences appear precisely in the seasonal rhythm, primarily at the level of the upper tier of the tree stand (up to 30% of the trees in 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 dicotyledons. In general, these are transitional types of communities, in some places largely reduced by humans and replaced by savannas 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 - the continuous layer B. The lower tree layer C often penetrates into layer B. Stage D is usually 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 “dwarf trees”. Finally, lower tier E is formed by grasses and tree seedlings. The boundaries between adjacent tiers can be better or worse expressed. Sometimes one tree layer imperceptibly passes into another. In monodominant communities, tree layers are better expressed than in polydominant ones.

The most common type of wood is teak wood, which is characterized by teak wood. Trees of this species can be considered an essential component of the summer green forests of India, Burma, Thailand and relatively dry areas East Java. In India, where very small areas of these natural zonal forests, along with the teak tree grow mainly ebony trees and maradu, or Indian laurel; all these species produce valuable wood. But teak wood, which has a number of valuable properties: it is hard, resistant to fungi and termites, and also weakly reacts to changes in humidity and temperature. Therefore, foresters specifically grow teak wood (in Africa and South America). Monsoon forests are best studied 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 producing bast fibers Bauhinia racemosa, Callesium grande, Ziziphus jujuba, Holarrhenia dysenteriaca with white soft wood used for turning and wood carvings. One of the bamboo species, Dendrocalamus strictus, grows in the shrub layer. The grass layer consists mainly of grasses, among which the bearded vulture dominates. Along estuaries and other storm-protected areas sea ​​coast the muddy tidal zone (littoral) is occupied by mangroves (Figure 2). Trees of this phytocenosis are characterized by thick, stilted roots extending from the trunks and lower branches like thin piles, as well as breathing roots protruding from the silt in vertical columns.

Figure 2 - Mangroves

Vast swamps stretch along the rivers in the tropical rain forest zone: heavy rains lead to regular high floods, and floodplains constantly remain flooded. Swampy forests are often dominated by palm trees and have less species diversity than in drier areas.

Animal world

The fauna of seasonally humid subtropical communities is not as rich as the fauna of moist equatorial forests due to the dry period unfavorable for animals. Although the species composition of various groups of animals in them is specific, at the level of genera and families there is a noticeable great similarity with the Gilian fauna. Only in the driest variants of these communities—in open 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 a given biome. In addition, some species of phytophagous animals are more diverse here. species composition, than in the Hylaea, due to the greater development of the herbaceous layer and, accordingly, the greater variety and richness of herbaceous food.

The layering of the animal population in seasonally wet communities is noticeably simpler than in tropical rainforests. The simplification of layering is especially pronounced in open forests and shrub communities. However, this applies mainly to the tree layer, since the tree stand itself is less dense, diverse and does not reach the same height as in the hyla. But the herbaceous layer is much more clearly expressed, since it is not so strongly shaded by woody vegetation. The population of the litter layer is also much richer here, since the deciduousness of many trees and the drying out of grasses during the dry period ensure the formation of a fairly thick layer of litter.

The presence of a layer of litter formed by leaf and grass decay ensures the existence of a trophic group of saprophagous animals that is diverse in composition. The soil-litter layer is inhabited by roundworms-nematodes, annelids-megascolecids, small and large nooses, oribatid mites, springtails-collembolas, cockroaches, and termites. All of them are involved in the processing of dead plant matter, but the leading role is played by termites, already familiar to us from the fauna of the Gila.

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 tree leaves or using herbaceous plants, many feeding on plant sap, bark, wood and roots.

The roots of plants are eaten by the larvae of cicadas and various beetles - beetles, golden beetles, and darkling beetles. The juices of living plants are sucked by adult cicadas, bugs, aphids, scale insects and scale insects. Green plant matter is consumed by butterfly caterpillars, stick insects, herbivorous beetles - beetles, leaf beetles, and weevils. The seeds of herbaceous plants are used as food by harvester ants. The green mass of herbaceous plants is eaten mainly by various locusts.

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

IN monsoon forests South Asian inhabit wild chicken(Callus gallus) and the common peacock (Pavo chstatus). Asian ring-necked parrots (Psittacula) forage for food in the treetops.

Figure 3 – Asian rathufa squirrel

Among herbivorous mammals, rodents are the most diverse. They can be found in all layers of seasonal tropical forests and woodlands. The tree layer is inhabited mainly by various representatives of the squirrel family - palm squirrels and the large ratufa squirrel (Figure 3). In the ground layer, rodents from the mouse family are common. In South Asia, large porcupines (Hystrix leucura) can be found under the forest canopy, and Rattus rats and Indian bandicotas (Bandicota indica) are common throughout.

The forest floor is home to various predatory invertebrates - large centipedes, spiders, scorpions, and predatory beetles. Many spiders that build trapping nets, for example large nephilous spiders, also inhabit the tree layer of the forest. On the branches of trees and bushes, praying mantises, dragonflies, blackflies, and predatory bugs prey on small insects.

Small predatory animals hunt rodents, lizards and birds. The most typical are various civets - civets, mongooses.

Of the large predators in seasonal forests, the leopard, which penetrates here from the Gilis, and tigers are relatively common.