Variably humid monsoon forests vegetation. Subequatorial climatic zone. Geographical location, natural conditions
The tundra occupies such territories as the coastal outskirts of Greenland, the western and northern outskirts of Alaska, the coast of Hudson Bay, some areas of the Newfoundland and Labrador peninsulas. On Labrador, due to the severity of the climate, the tundra reaches 55 ° N. sh., and in Newfoundland it drops even further south. The tundra is part of the circumpolar Arctic subregion of the Holarctic. The North American tundra is characterized by the spread of permafrost, strong soil acidity and rocky soils. The northernmost part of it is almost completely barren, or covered only with mosses and lichens. Large areas are occupied by swamps. In the southern part of the tundra, a rich herbaceous cover of grasses and sedges appears. Some dwarf tree forms are characteristic, such as creeping heather, dwarf birch (Betula glandulosa), willow and alder.
Next comes the forest tundra. It is to the west of the Hudson Bay takes its maximum size. Woody forms of vegetation are already beginning to appear. This strip forms the northern border of forests in North America, dominated by species such as larch (Larix laricina), black and white spruce (Picea mariana and Picea canadensis).
On the slopes of the mountains of Alaska, the plain tundra, as well as on the Scandinavian Peninsula, is replaced by mountain tundra and bald vegetation.
In terms of species, the vegetation of the tundra North America almost no different from the Euro-Asian tundra. There are only some floristic differences between them.
coniferous forests temperate zone occupy most of North America. These forests form the second after the tundra and the last vegetation zone, which stretches across the entire mainland from west to east and is a latitudinal zone. Further south, latitudinal zonality is retained only in the eastern part of the mainland.
On the coast of the Pacific Ocean, taiga is distributed from 61 to 42 ° N. sh., then it crosses the lower slopes of the Cordillera and then spreads to the plain to the east. In this territory, the southern border of the coniferous forest zone rises north to a latitude of 54-55 ° N, but then it descends back to the south to the territories of the Great Lakes and the St. Lawrence River, but only its lower reaches.<
Coniferous forests along the line from the eastern slopes of the mountains of Alaska to the coast of Labrador are characterized by a significant uniformity in the species composition of the rocks.
A distinctive feature of the coniferous forests of the Pacific coast from the forest zone of the east is their appearance and composition of the rocks. So the forest zone of the Pacific coast is very similar to the eastern regions of the Asian taiga, where endemic coniferous species and genera grow. But the eastern part of the mainland is similar to the European taiga.
The “Hudson”, eastern taiga is characterized by the predominance of fairly developed coniferous trees with a high and powerful crown. This species composition includes such endemic species as white or Canadian spruce (Picea canadensis), Banks pine (Pinus banksiana), American larch, balsam fir (Abies balsamea). From the latter, a resinous substance is extracted, which finds a direction in technology - Canadian balsam. Although conifers predominate in this zone, there are still many deciduous trees and shrubs in the Canadian taiga. And in the burnt places, which are very numerous in the Canadian taiga region, even deciduous ones predominate.
Deciduous tree species of this coniferous zone include: aspen (Populus tremuloides), balsam poplar (Populus balsamifera), paper birch (Betula papyrifera). This birch has a white and smooth bark, with which the Indians built their canoes. A very diverse and rich undergrowth of berry bushes is characteristic: blueberries, raspberries, blackberries, black and red currants. Podzolic soils are characteristic of this zone. In the north, they turn into soils of permafrost-taiga composition, and in the south, these are soddy-podzolic soils.
The soil and vegetation cover of the Appalachian zone is very rich and diverse. Here, on the slopes of the Appalachians, rich broad-leaved forests grow in species diversity. Such forests are also called Appalachian forests. These forests are very similar to the genera of East Asian and European forests, in which the dominant role is dominated by endemic species of noble chestnut (Castanea dentata), May beech (Fagus grandifolia), American oak (Quercus macrocarpa), red plane tree (Platanus occidentalis). A characteristic feature of all these trees is that they are very powerful and tall trees. These trees are often entwined with ivy and wild grapes.
"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 world's population lives in Eurasia. 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 of Eurasia. The greatest amount of 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 highest 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 a great depth, an 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 of the 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 broad-leaved forests of oak (oak), beech, linden, chestnut, ash, etc. are typical.
Monsoon forests are huge green areas with lush vegetation and rich wildlife. During the rainy season, they resemble equatorial evergreen forests. Found in subequatorial and tropical climates. They attract tourists and photographers with a variety of picturesque landscapes.
Description
Moist monsoon forests are most common in the tropics. Most often they are located at an altitude of 850 meters above sea level. They are also called deciduous due to the fact that the trees lose their foliage during the drought period. Heavy rains return them to their former juiciness and color. The trees here reach a height of twenty meters, the leaves on the crowns are small. Evergreen species, many lianas and epiphytes are common in the undergrowth. Orchids grow in the monsoon zone. They are found in the Brazilian coastal mountain ranges, the Himalayas, Malaysia, Mexico, Indochina.
Peculiarities
Monsoon forests in the Far East are famous for their variety of plants and animals. Warm and humid summers, an abundance of plant foods create favorable conditions for the habitat of insects, birds, and mammals. Coniferous and broad-leaved trees are found here. Among the inhabitants of the forests, sable, squirrel, chipmunk, hazel grouse, as well as animals rare for the climatic zone of Russia were noticed. Characteristic inhabitants of the monsoon forests are the Ussuri tiger, black bear, spotted deer, wolf, and raccoon dog. There are many wild boars, hares, moles, pheasants on the territory. reservoirs subequatorial climate rich in fish. Some species are protected.
Rare orchids grow in the humid forests of Brazil, Mexico, and Indochina. About sixty percent are sympodial species, well known among flower growers. The red-yellow soils of the monsoon territories are favorable for ficuses, palm trees, valuable tree species. The most famous include teak, satin, lard, iron. For example, it is able to form a dark grove from its trunks. A huge banyan tree grows in the Indian Botanical Garden, which has almost two thousand (!) Trunks. The crown of the tree covers an area of twelve thousand square meters. Variably humid forests become a habitat for bamboo bears (pandas), salamanders, tigers, leopards, poisonous insects and snakes.
Climate
Which one dominates the monsoon forests? Winter here is mostly dry, summer is not hot, but warm. The dry season lasts three to four months. The average air temperature is lower than in the humid tropics: the absolute minimum is -25 degrees, the maximum is 35 with a "+" sign. The temperature difference is from eight to twelve degrees. A characteristic feature of the climate is prolonged heavy rains in summer and their absence in winter. The difference between the two opposite seasons is huge.
The monsoon forests are known for their morning mist and low clouds. That is why the air is so saturated with moisture. Already by noon, the bright sun completely evaporates moisture from the vegetation. In the afternoon, foggy haze forms again in the forests. High humidity and cloudiness persist for a long period of time. In winter, precipitation also falls, but rarely.
Geography
IN subequatorial belt due to the large amount of precipitation and their uneven distribution, high temperature contrast, monsoon forests develop. On the territory of Russia, they grow in the Far East, have a complex terrain, rich flora and fauna. There are humid forests in Indochina, Hindustan, the Philippine Islands, Asia, North and South America, and Africa. Despite the long rainy seasons and prolonged drought, the fauna in the monsoon forest zones is poorer than in the humid equatorial ones.
The monsoon phenomenon is most pronounced on the Indian continent, where a period of drought is replaced by heavy downpours, the duration of which can be seven months. Such a change in weather is typical for Indochina, Burma, Indonesia, Africa, Madagascar, northern and eastern Australia, and Oceania. For example, in Indochina and the Hindustan Peninsula, the dry period in the forests lasts seven months (from April to October). Trees with large crowns and an irregularly shaped vault grow in vast monsoon territories. Sometimes forests grow in tiers, which is especially noticeable from a height.
The soil
Monsoon moist soils are characterized by a red tint, a granular structure, and a low content of humus. The soil is rich in useful trace elements such as iron and silicon. Sodium, potassium, magnesium, calcium in moist soil is very small. On the territory of Southeast Asia, zheltozems and red soils predominate. Central Africa and are distinguished by dry chernozem. Interestingly, with the cessation of rain, the concentration of humus in monsoon forests increases. The reserve is one of the forms of wildlife protection on the territory rich in valuable plants and animals. It is in humid forests that many species of orchids are found.
Plants and fauna
Monsoon forests in the subequatorial climate of Hindustan, China, Indochina, Australia, America, Africa, the Far East (Russia) are characterized by a variety of fauna. For example, teak trees are common in Southeast Asia in variable humid zones, as well as Indochinese laurel and ebony. There are also bamboo, creepers, butea, cereals. Many trees in the forests are highly valued for their healthy and durable wood. For example, teak bark is dense and resistant to destruction by termites and fungi. Sal forests grow at the southern foot of the Himalayas. In the monsoon regions of Central America there are many thorny bushes. It also grows in a humid climate and is a valuable Jat tree.
In the subequatorial climate, fast-growing trees are common. Palm trees, acacias, baobab, euphorbia, cecropium, entandrophragma, ferns predominate, there are many other types of plants and flowers. The humid climate zone is characterized by a wide variety of birds and insects. In the forests there are woodpeckers, parrots, toucans, butterflies. Among terrestrial animals, marsupials, elephants, various representatives of the cat family, freshwater, amphibians, frogs, snakes are found in monsoon woodlands. This world is truly bright and rich.
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 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 climatic changes: during the dry season, under conditions of moisture deficiency, plants are forced to shed their leaves, and during the wet season, again dress in foliage.
Climate. In the summer months, the temperature in the areas of variable-moist 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, 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%.
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. There are Himalayan bears, a raccoon dog and a 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.
The continent of 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, so the equatorial and subequatorial belts are most widespread. A distinctive feature of the continent is the wide development of natural forest 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, and by the local population - the 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 the oldest 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 swampy zone of marine 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, opossum, 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). There are electric eel and freshwater dolphin iniya.
Zones stretched across three geographical zones variable-moist forests . Subequatorial variable-humid 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, on mountainous red soils, rich evergreen tropical forests grow, similar 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 bottle-shaped tree that stores rainwater - a bombaks 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 coloration (spicy-horned deer, red nosokha, maned wolf, ostrich rhea). Rodents are abundantly represented, including the largest in the world - the capybara. Many hylaea animals (armadillos, anteaters) also live in savannahs. 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, tropical deserts and semi-deserts stretch in a narrow strip along the Pacific coast and on the high plateaus of the Central Andes. 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.
The fauna of tropical deserts is 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 conditions of a continental climate, subtropical semi-deserts and deserts are widespread. On the sierozems, light forests of acacias and cacti are developed, on salt marshes - saltwort. In the harsh temperate latitudes in flat Patagonia, dry grasses and thorny shrubs grow on brown semi-desert soils.
The southwestern outskirts of the mainland in two belts are occupied by natural forest zones. In the subtropics, under the conditions of the Mediterranean climate, a zone is formed dry hardwood forests and shrubs . The coast and slopes of the Chilean-Argentine Andes (between 28° and 36° S) 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 rainforests are multi-tiered and rich, 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 deer pudu, 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 the equatorial latitudes. Up to a height of 1500 m, a hot belt is common - hylaea with an abundance of palm trees and bananas. Above the level of 2000 m - a temperate zone with cinchona, balsa, tree ferns and bamboos. Up to the level of 3500 m, the cold belt extends - an alpine hylaea from a stunted crooked forest. 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. Textbook for the 8th grade of institutions of general secondary education with the Russian language of instruction / Edited by Professor P. S. Lopukh - Minsk "Narodnaya Asveta" 2014