Temperate monsoon forests. Forests of South America

"Peoples of Eurasia" - Romance peoples are dark-haired, swarthy. Russian Ukrainians Belarusians. Frenchwoman. Oriental. On the territory of Eurasia live peoples belonging to different language families and groups. About 3/4 of the population lives in Eurasia the globe. Slavic peoples. Religions of Eurasia. Poles, Czechs, Slovaks. The Germanic peoples are characterized by blond hair and fair skin.

"Climatic features of Eurasia" - High average annual and summer temperatures. Temperature. Definition of climate types. Climatic zones and regions of Eurasia. The climate is mild. Arctic air. January temperature. You have learned to read. Temperature and winds in January. Climate charts. Relief. Climatic features Eurasia. The largest number precipitation.

"Eurasia Geography Lesson" - To introduce students to the idea of Eurasia. Explain the effect of size on natural features. Semenov-Tan-Shansky P.P. The most high mountain in the world Chomolungma - 8848 m. Geographical position of Eurasia. General information about Eurasia. Name the names of travelers and explorers of the continent. Obruchev V.A.

"Nature of Eurasia" - Square. Minerals. Inland waters. natural areas. Climate. Eurasia. Relief. organic world. Geographical position. Mainland records.

"Lakes of Eurasia" - The correct answer. -Tectonic lakes in faults have great depth, elongated shape. Lake basin of glacial origin. Such lakes are lakes - seas: Caspian and Aral. Internal waters of Eurasia. Determination of the types of lake basins in Eurasia. Lake basin of tectonic origin.

"Natural zones of the temperate zone of Eurasia" - Flora. The flora of the taiga. Animal world taiga. Fauna: very similar to the fauna of the taiga... Animal world. In Eurasia, forest-steppes stretch in a continuous strip from west to east from the eastern foothills of the Carpathians to Altai. Taiga. In Europe and in the European part of Russia, light broadleaf forests from oak (oak), beech, linden, chestnut, ash, etc.

Introduction

Eurasia is the most big mainland on Earth, the area is 53,893 thousand square kilometers, which is 36% of the land area. The population is over 4.8 billion people.

The continent is located in the Northern Hemisphere between approximately 9° and 169° west longitude, with part of the Eurasian islands located in southern hemisphere. Most of continental Eurasia lies in the Eastern Hemisphere, although the extreme western and eastern ends of the mainland are in the Western Hemisphere. Contains two parts of the world: Europe and Asia.

All are represented in Eurasia climatic zones And natural areas.

Natural zone - part of a geographical zone with homogeneous climatic conditions.

Natural areas take their name from the vegetation found in them and other geographical features. The zones regularly change from the equator to the poles and from the oceans deep into the continents; have similar temperature and moisture conditions, which determine homogeneous soils, vegetation, wildlife and other components natural environment. Natural zones are one of the stages of physical and geographical zoning.

The main ones discussed in term paper natural zones of the subequatorial and equatorial belts of Eurasia - a zone of variable humid, including monsoon forests, zone of savannas and light forests, zone equatorial forests.

A zone of variable humid, monsoon forests develops on the plains of Hindustan, Indochina and in the northern half of the Philippine Islands, a zone of savannahs and light forests - on the Deccan Plateau and the inner parts of the Indochina peninsula, humid equatorial forests- throughout the Malay Archipelago, the southern half of the Philippine Islands, the southwest of Ceylon and the Malay Peninsula.

The course work gives a detailed description of these natural areas, reflects the geographical location, climate, soil, vegetable world his ecological features, animal population and its ecological features. Also developed topic - environmental problems equatorial and subequatorial belts of Eurasia. First of all, these include the deforestation of moist equatorial forests and the desertification of savannahs under the influence of grazing.

Zone of variable humid, including monsoon forests

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 the annual course of temperatures, landscapes of subequatorial variables develop on the plains of Hindustan, Indochina and in the northern half of the Philippine Islands. moist forests.

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 savannahs, 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 acidic reaction. Humus contains mainly fulvic acids. Humus contain 8-10%.

The hydrothermal regime of seasonally humid tropical communities is constantly characterized by high temperatures and a sharp change in the wet and dry seasons, which causes specific features structures and dynamics of their fauna and animal populations, which markedly distinguish them from communities of humid rainforest. 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 characteristic of many terrestrial and soil invertebrates, for amphibians, and migration is characteristic of some insects capable of flight (for example, locusts), birds, bats and large ungulates.

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.

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. Upper tree layer A is formed by the tallest trees, isolated or forming groups, the so-called emergents, raising "heads and shoulders" above the main canopy - a continuous tier B. The lower tree tier C often penetrates into tier 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 zoned forests still exist, mainly ebony trees and marada, or Indian laurel; 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 floodplains are constantly flooded in the floodplains. The marshy forests are often dominated by palm trees and species diversity 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 turn out to be more diverse here. species composition 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 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 applies mainly to 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. 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 litter layer 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, springtail 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.

IN monsoon forests South Asia is 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, a large porcupine (Hystrix leucura) can be found under the forest canopy; Rattus and Indian bandicots (Bandicota indica).

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.

Mainland South America is located in all geographical zones, with the exception of the subantarctic and antarctic. The wide northern part of the mainland lies in low latitudes, therefore most widespread received equatorial and subequatorial belts. hallmark continent is the wide development of forest natural zones (47% of the area). 1/4 of the world's forests are concentrated on the "green continent"(Fig. 91, 92).

South America gave humanity many cultivated plants: potatoes, tomatoes, beans, tobacco, pineapple, hevea, cocoa, peanuts, etc.

natural areas

In the equatorial geographical zone there is a zone humid equatorial forests occupying the Western Amazon. They are named by A. Humboldt hylaea, but local population- selva. The humid equatorial forests of South America are the richest in species composition of forests on Earth. They are rightfully considered the "gene pool of the planet": they have more than 45 thousand plant species, including 4000 woody ones.

Rice. 91. Endemic animals of South America: 1- giant anteater; 2- hoatzin; 3 - lama; 4 - sloth; 5 - capybaras; 6 - armadillo

Rice. 92. Typical trees of South America: 1 - Chilean araucaria; 2 - wine palm; 3 - chocolate tree (cocoa)

There are flooded, non-flooded and mountain hylaea. In river floodplains, flooded with water for a long period, depleted forests grow from low trees (10-15 m) with respiratory and stilted roots. Cecropia (“ant tree”) prevails, giant victoria-regia swim in the reservoirs.

In elevated areas, rich, dense, multi-tiered (up to 5 tiers) non-flooded forests are formed. Up to a height of 40-50 m, single-standing ceiba (cotton tree) and Bertoletia, which gives Brazil nuts, rise. The upper tiers (20-30 m) form trees with valuable wood (rosewood, pau brazil, mahogany), as well as ficus and hevea, from the milky juice of which rubber is obtained. In the lower tiers, under the canopy of palm trees, chocolate and melon trees grow, as well as ancient plants on Earth - tree ferns. The trees are densely intertwined with vines, among the epiphytes there are many brightly colored orchids.

Near the coast, mangrove vegetation is developed, poor in composition (nipa palm, rhizophora). Mangroves- these are thickets of evergreen trees and shrubs of the wetland sea tides and ebb tides of tropical and equatorial latitudes, adapted to salt water.

Moist equatorial forests form on red-yellow ferralitic soils that are poor in nutrients. Falling leaves in a hot and humid climate quickly rot, and the humus is immediately absorbed by plants, not having time to accumulate in the soil.

Hylaean animals are adapted to life on trees. Many have prehensile tails, like the sloth, the opossum, the prehensile-tailed porcupine, broad-nosed monkeys(howler monkeys, arachnids, marmosets). Pig-peccaries and tapir live near the reservoirs. There are predators: jaguar, ocelot. Turtles and snakes are numerous, including the longest - anaconda (up to 11 m). South America is the "continent of birds". Gilea is a home for macaws, toucans, hoatsins, tree chickens and the smallest birds - hummingbirds (up to 2 g).

The rivers are teeming with caimans and alligators. They are home to 2,000 species of fish, including the dangerous predatory piranha and the world's largest arapaima (up to 5 m in length and weighing up to 250 kg). Meet electric eel and the freshwater dolphin inia.

Zones stretched across three geographical zones variable-moist forests . Subequatorial variable wet forests occupy the eastern part of the Amazonian lowland and the adjacent slopes of the Brazilian and Guiana plateaus. The presence of a dry period causes the appearance of deciduous trees. Among the evergreens, cinchona, ficuses, and balsa, which have the lightest wood, predominate. In tropical latitudes, on the humid eastern outskirts of the Brazilian Plateau, rich evergreens grow on mountainous red soils. rainforests, close in composition to equatorial ones. The southeast of the plateau on the red and yellow soils is occupied by sparse subtropical variable-moist forests. They are formed by Brazilian araucaria with an undergrowth of yerba mate ("Paraguayan tea") shrub.

Zone savannas and woodlands distributed in two geographical zones. In subequatorial latitudes, it covers the Orinoc lowland and the interior regions of the Brazilian Plateau, in tropical latitudes, the Gran Chaco plain. Depending on the moisture, humid, typical and desert savannas are distinguished, under them, respectively, red, brown-red and red-brown soils develop.

Tall-grass wet savannah in the Orinoco basin is traditionally called llanos. It is flooded for up to six months, turning into an impenetrable swamp. Cereals, sedges grow; Mauritius palm dominates the trees, which is why llanos is called the "palm savannah".

On the Brazilian plateau, the savannahs are called campos. Wet shrub-tree savannah occupies the center of the plateau, typical grassy savannah occupies the south. Undersized shrubs grow against the background of grassy vegetation (bearded vultures, feather grasses). Palm trees (wax, oil, wine) dominate among the trees. The arid northeast of the Brazilian Plateau is occupied by the deserted savanna - caatinga. This is a woodland of thorny shrubs and cacti. There is a storage rain water bottle-shaped tree - bombaksovy vatochnik.

Savannahs continue in tropical latitudes, occupying the Gran Chaco plain. Only in tropical woodlands is the quebracho tree (“break the ax”) with hard and heavy wood sinking in water. Plantations of coffee tree, cotton, bananas are concentrated in the savannahs. Dry savannahs are an important pastoral area.

The animals of the savannas are characterized by a protective brown color (spicy-horned deer, red nosokha, maned wolf, ostrich nandu). Rodents are abundantly represented, including the largest in the world - the capybara. Many hylaean animals (armadillos, anteaters) also live in the savannas. Termite mounds are everywhere.

On the Laplat lowland south of 30 ° S. sh. formed subtropical steppes . In South America they are called pampas. It is characterized by rich forb-grass vegetation (wild lupine, pampas grass, feather grass). The chernozem soils of the pampas are very fertile, therefore they are heavily plowed. The Argentine pampa is the main wheat and forage grass growing area in South America. The fauna of the pampas is rich in rodents (tuco-tuco, viscacha). There are pampas deer, pampas cat, puma, ostrich rhea.

Semi-deserts and deserts South America extends into three geographical zones: tropical, subtropical and temperate. In the west of the tropics, a narrow strip along the Pacific coast and on high mountain plateaus Central Andes tropical deserts and semi-deserts extend. This is one of the driest regions on Earth: in the Atacama Desert, it may not rain for years. Dry grasses and cacti grow on the infertile sierozems of coastal deserts, receiving moisture from dews and fogs; on gravelly soils of high-mountainous deserts - creeping and pillow-shaped grasses and thorny shrubs.

Animal world tropical deserts poor. The inhabitants of the highlands are llamas, a spectacled bear, and a chinchilla with valuable fur. There is an Andean condor - the largest bird in the world with a wingspan of up to 4 m.

To the west of the pampas, in a continental climate, are common subtropical semi-deserts and deserts. On the sierozems, light forests of acacias and cacti are developed, on salt marshes - saltwort. In harsh temperate latitudes in flat Patagonia on brown semi-desert soils dry grasses and thorny shrubs grow.

The southwestern outskirts of the mainland in two belts are occupied by natural forest zones. In the subtropics in mediterranean conditions maritime climate a zone is formed dry hardwood forests and shrubs . The coast and slopes of the Chilean-Argentine Andes (between 28° and 36° S. latitude) are covered with forests of evergreen southern beeches, teak, perseus on brown and grey-brown soils.

To the south are located wet evergreens And mixed forests . In the north of the Patagonian Andes, in a subtropical humid climate, moist evergreen forests grow on mountain brown forest soils. With abundant moisture (more than 3000-4000 mm of precipitation), these rain forests differ in multi-tiered and richness, for which they received the name "subtropical hylaea". They consist of evergreen beeches, magnolias, Chilean araucaria, Chilean cedar, South American larch with a rich undergrowth of tree ferns and bamboos. In the south of the Patagonian Andes, in a temperate maritime climate, mixed forests of deciduous beech and coniferous podocarpus grow. Here you can meet a pudu deer, a Magellanic dog, an otter, a skunk.

Andean highlands occupies a vast territory with a well-defined altitudinal zonality, which is most fully manifested in equatorial latitudes. Up to a height of 1500 m common hot belt- Hylaea with an abundance of palms and bananas. Above the level of 2000 m - a temperate zone with cinchona, balsa, tree ferns and bamboos. It extends up to the mark of 3500 m cold belt- alpine hylaea from undersized crooked forests. It is replaced by a frosty belt with alpine meadows of paramos from cereals and undersized shrubs. Above 4700 m - a belt of eternal snow and ice.

Bibliography

1. Geography grade 8. Tutorial for the 8th grade of institutions of general secondary education with the Russian language of instruction / Under the editorship of Professor P. S. Lopukh - Minsk "Narodnaya Asveta" 2014

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

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

The life of variable humid forests is closely related to seasonal climate change: during the dry season, in conditions of moisture deficiency, plants are forced to shed their leaves, and during wet season dress again in foliage.

Climate. In the summer months, the temperature in areas of variable-moist forests reaches 27 degrees Celsius, in winter months the thermometer rarely drops below 21 degrees. The rainy season comes after the hottest month. Thunderstorms are common during the summer rainy season, overcast days can be observed for several days in a row, often turning into rain. During the dry season in some areas, rain may not fall for two to three months.

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

Vegetation.

Among the plants of variable humid 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.

Animals.

The animal world of variable rainforests is rich and varied. Many rodents live in the lower tier, among large animals - elephants, tigers and leopards, monkeys, pandas, lemurs, all kinds of felines have found shelter among the branches of trees. Meet Himalayan bears, raccoon dog and wild boar. A variety of birds is represented by pheasants, parrots, partridges and black grouse. Pelicans and herons are found on the banks of rivers and lakes.

Man has destroyed a significant part of the variable rainforests. Rice, tea bush, mulberry, tobacco, cotton, citrus fruits are grown on the site of cut down forests. It will take a long time to restore the lost areas of forests.