Animals of variable humid forests. Zone of variable humid subtropical forests

The tundra occupies such areas as the coastal outskirts of Greenland, the western and northern outskirts of Alaska, the coast of Hudson Bay, and some areas of the Newfoundland and Labrador peninsulas. In 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 permafrost, highly acidic soils, and rocky soils. Its northernmost part 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 reaches its maximum size west of Hudson Bay. Woody forms of vegetation are already beginning to appear. This strip forms northern border 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 Alaska mountains, lowland tundra, as well as on the Scandinavian Peninsula, gives way to mountain tundra and char vegetation.

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

Coniferous forests temperate zone occupy most of North America. These forests form the second and last vegetation zone, which stretches across the entire continent from west to east and is latitudinal zone. Further to the south, latitudinal zonality is preserved only in the eastern part of the continent.

On the Pacific coast, taiga is distributed from 61 to 42° N. sh., then it passes through the lower slopes of the Cordillera and then spreads to the plain to the east. In this territory the southern border of the zone coniferous forests 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 Alaska mountains to the Labrador coast are distinguished by significant uniformity in the species composition of the species.

A distinctive feature of the coniferous forests of the Pacific coast from the forest zone of the east is their appearance and composition of species. 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 continent 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 composition of species 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 its way into technology - Canada balsam. Although conifers predominate in this zone, there are still many deciduous trees and shrubs in the Canadian taiga. And in burnt areas, of which there are many in the Canadian taiga region, even deciduous trees predominate.

Deciduous tree species in this coniferous zone include: aspen (Populus tremuloides), balsam poplar (Populus balsamifera), paper birch (Betula papyrifera). This birch tree has white and smooth bark, which the Indians used to build their canoes. It is characterized by a very diverse and rich undergrowth of berry bushes: blueberries, raspberries, blackberries, black and red currants. This zone is characterized by podzolic soils. In the north they turn into soils of permafrost-taiga composition, and in the south they become 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 broadleaf 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 sycamore (Platanus occidentalis). A characteristic feature of all these trees is that they are very powerful and tall trees. These trees are often covered with ivy and wild grapes.

Africa is the hottest continent on planet Earth. The equator line passing through the center of the Black Continent symmetrically divides its area into different natural zones. Characteristics of the natural zones of Africa allow us to form a general idea of the geographical location of Africa, the characteristics of the climate, soil, flora and fauna of each zone.

What natural areas is Africa located in?

Africa is the second largest continent on our planet. This continent is washed from different sides by two oceans and two seas. But its main feature is its symmetrical location towards the equator. In other words, the equator line horizontally divides the continent into two equal parts. The northern half is much wider than southern Africa. As a result, all natural zones of Africa are located on the map from north to south in the following order:

savannas;
variable-humid forests;
moist evergreen equatorial forests;
variable wet forests;
savannas;
tropical deserts and semi-deserts;
subtropical evergreen hard-leaved forests and shrubs.

Fig. 1 Natural areas of Africa

Equatorial rainforests

On both sides of the equator there is a zone of humid evergreen equatorial forests. It occupies a fairly narrow strip and is characterized by numerous precipitation. In addition, it is rich in water resources: the deepest Congo River flows through its territory, and the shores are washed by the Gulf of Guinea.

Constant warmth, numerous precipitation and high humidity led to the formation of lush vegetation on the red-yellow ferrallite soils. Evergreen equatorial forests surprise with their density, impenetrability and diversity of plant organisms. Their feature is multi-tiered. It became possible due to the endless struggle for sunlight, in which not only trees, but also epiphytes and climbing vines take part.

The tsetse fly lives in the equatorial and subequatorial zones of Africa, as well as in the wooded part of the savannah. Its bite is fatal to humans, as it is a carrier of sleeping sickness, which is accompanied by terrible body pain and fever.

Rice. 2 Moist evergreen equatorial forests

Savannah

The amount of precipitation is directly related to the richness of the plant world. The gradual shortening of the rainy season leads to the appearance of a dry season, and humid equatorial forests gradually give way to variable wet ones, and then turn into savannas. The last natural zone occupies the largest area of the Black Continent, and makes up about 40% of the entire continent.

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Here the same red-brown ferrallitic soils are observed, on which various herbs, cereals, and baobabs grow mainly. Low trees and shrubs are much less common.

A distinctive feature of the savannah is the dramatic changes in appearance - the rich tones of green during the rainy season fade sharply under the scorching sun during dry periods and become brownish-yellow.

Savannah is also unique in its richness of fauna. A large number of birds live here: flamingos, ostriches, marabou, pelicans and others. It amazes with the abundance of herbivores: buffalos, antelopes, elephants, zebras, giraffes, hippos, rhinoceroses and many others. They are also food for the following predators: lions, leopards, cheetahs, jackals, hyenas, crocodiles.

Rice. 3 African Savannah

Tropical deserts and semi-deserts

The southern part of the continent is dominated by the Namib Desert. But neither it nor any other desert in the world can compare with the grandeur of the Sahara, which consists of rocky, clay and sandy deserts. The total annual precipitation in the Sahara does not exceed 50 mm. But this does not mean that these lands are lifeless. The flora and fauna are quite sparse, but they exist.

Of the plants, it should be noted such representatives as sclerophids, succulents, and acacia. The date palm grows in the oases. Animals were also able to adapt to the dry climate. Lizards, snakes, turtles, beetles, and scorpions can go without water for a long time.

In the Libyan part of the Sahara there is one of the most beautiful oases in the world, in the center of which there is a large lake, the name of which literally translates as “Mother of Water”.

Rice. 4 Sahara Desert

Subtropical evergreen hard-leaved forests and shrubs

The most extreme natural zones of the African continent are subtropical evergreen hardwood forests and shrubs. They are located in the north and southwest of the mainland. They are characterized by dry, hot summers and wet, warm winters. This climate favored the formation of fertile brown soils on which cedar of Lebanon, wild olive, strawberry tree, beech and oak grew.

Table of natural zones of Africa

This table for 7th grade geography will help you compare the natural zones of the continent and figure out which natural zone predominates in Africa.

Natural area	Climate	The soil	Vegetation	Animal world
Hard-leaved evergreen forests and shrubs	Mediterranean	Brown	Wild olive, Lebanese cedar, oak, strawberry tree, beech.	Leopards, antelopes, zebras.
Tropical semi-deserts and deserts	Tropical	Desert, sandy and rocky	Succulents, xerophytes, acacias.	Scorpions, snakes, turtles, beetles.
Savannah	Subequatorial	Ferrolite red	Herbs, cereals, palms, acacias.	Buffaloes, giraffes, lions, cheetahs, antelopes, elephants, hippos, hyenas, jackals.
Variably humid and humid forests	Equatorial and subequatorial	Ferrolite brown-yellow color	Bananas, coffee, ficus, palm trees.	Termites, gorillas, chimpanzees, parrots, leopards.

What have we learned?

Today we were talking about the natural areas of the hottest continent on Earth - Africa. So, let's call them again:

subtropical evergreen hard-leaved forests and shrubs;
tropical deserts and semi-deserts;
savannas;
variable-humid forests;
moist evergreen equatorial forests.

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Variably moist forests grow in those areas of the Earth where precipitation in the form of rain does not fall all year round, but the dry season lasts a short time. They are located in Africa north and south of the equatorial rain forests, as well as in northeastern Australia.

Look geographical position zones of variable humid forests on the map of natural zones.

The life of variable wet forests is closely related to seasonal climate changes: during the dry season, under conditions of moisture deficiency, plants are forced to shed their leaves, and during the wet season, they are forced to put on foliage again.

Climate. In the summer months, the temperature in areas of variable-humid forests reaches 27 degrees Celsius; in the winter months, the thermometer rarely drops below 21 degrees. The rainy season comes after the hottest month. During the summer rainy season there are frequent thunderstorms, and there may be continuous cloud cover for several days in a row, often turning into rain. During the dry period, some areas may not receive rain for two to three months.

Variably humid forests are dominated by yellow earth and red earth forests. soil. The structure of the soil is granular-lumpy, the humus content gradually decreases downwards, on the surface - 2-4%.

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.

Animals.

The fauna of the variable humid forests is rich and varied. The lower tier is home to many rodents, large animals include elephants, tigers and leopards; monkeys, pandas, lemurs, and all kinds of felines find refuge among the tree branches. There are Himalayan bears, raccoon dogs and wild boars. The variety of birds is represented by pheasants, parrots, partridges and black grouse. Pelicans and herons live on the banks of rivers and lakes.

Man has destroyed a significant part of the variable rain forests. In place of cleared forests, rice, tea bushes, mulberries, tobacco, cotton, and citrus fruits are grown. It will take a long time to restore lost forest areas.

For tropical wet evergreens, 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 consists of giant trees with a height of 45 m or more, with a diameter of 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, low trees that form 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 xerophilic 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. Tree species of economic value include 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. According to 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.

Mangrove forests stretch along the Pacific and Caribbean coasts. 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.

Road from Calama (Chile) to La Paz (Bolivia)

Chile. The main forest area is concentrated in the southern half of the country along the Pacific slopes of the Andes. In the area of 41-42° S. there is a significant tract of araucaria forests, dominated by pure stands of pinot, or Chilean araucaria, often called “Chilean pine” (Araucaria araucana). To the south there are mixed broad-leaved deciduous forests of the temperate zone with different species of southern beech (Nothofagus spp.), representatives of the laurel trees - lingue (Persea lingue), ulmo (Beilschmiedia berteroana). In the far south there are coniferous forests of alerce (Fitzroya cupressoides) and cypres (Pilgerodendron uviferum) with an admixture of canelo (Drimys winteri). The bark of the latter contains substances with antiscorbutic properties.

Argentina. Several natural areas stand out. The east is dominated by evergreen forests, containing more than 100 species of economically important trees. 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. are distinguished. In the Gran Chaco Forest region, xerophilic forests are widespread, in which several species of quebracho, algarrobo, 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.

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 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 wet 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 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 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, the 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 the relatively dry areas of eastern Java. In India, where very small areas of these natural zonal forests still remain, the main trees that grow with teak are ebony and maradu, or Indian laurel; all these species produce valuable wood. But teak wood is in especially great demand because it 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 the shores of estuaries and in other areas of the sea coast protected from storms, 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 turn out to be more diverse in species composition here than in the 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 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, collembola springtails, 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, and 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

The monsoon forests of South Asia are home to the wild fowl (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.