For tropical wet evergreens, or as they are sometimes called, rainforests are characterized by a three-tier structure of the tree canopy. The tiers are poorly demarcated. The upper tier is giant trees 45 m or more in height, 2-2.5 m in diameter. The middle tier is represented by trees about 30 m high with a trunk diameter of up to 90 cm. Smaller, extremely shade-tolerant trees grow in the third tier. There are many palm trees in these forests. The main area of \u200b\u200btheir growth 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 is found in Brazil in a narrow strip along the Atlantic coast between 5 and 30°S. Similar evergreen forests also grow along the Pacific coast from the border of Panama to Guayaquil in Ecuador. Here are concentrated all types of the genus Svitania (or mahogany), rubber-bearing genus Hevea, Brazil nut (Bertolletia excelsa) and many other valuable species.
Tropical variable-humid deciduous forests distributed in the southeast of Brazil and in the south of Paraguay. Tree species in them are relatively small in height, but often with thick trunks. Legumes are widely represented in the forests. Subtropical deciduous broadleaf forests most common in the south of Brazil and Parguay, in the west of Uruguay and in the north of Argentina along the Parana and Uruguay rivers. montane evergreen forests cover the slopes of the Andes from Venezuela to central Bolivia. These forests are characterized by thin-stemmed low trees forming dense stands. Due to the fact that these forests occupy steep slopes and are far from populated areas, they are exploited very little.
Araucaria forests located in two isolated regions. The Brazilian Araucaria (Araucaria brasiliana) is predominant 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, among which the most important is embuya (Phoebe porosa). In the undergrowth of the araucaria forests, the mate shrub, or Paraguayan tea (Ilex paraguariensis), is also widespread on plantations.
Low growing xerophilous forests distributed in the east of Brazil, in the northern part of Argentina and in the western part of Paraguay. The most important tree species in these forests is the red querbacho (Schinopsis sp.), from which tannin is obtained. mangrove forests occupy the coastal strip of the Atlantic part South America. These forests are dominated by red mangrove (Rhizophora mangle), forming pure stands or mixed with Avicenna (Avicennia marina) and Conocarpus erecta.
In addition to timber harvesting, rubber, food products (seeds, nuts, fruits, beans, leaves, etc.), oils, medicinal substances, tannins, resins, including chicle (Zschokkea lascescens), raw materials for the production of chewing gum.
Venezuela. Evergreen (on laterites) and deciduous forests grow on the slopes of the spurs of the Andes and the Guiana Highlands. On the territory of the low llanos, tall-grass savanna with groves of the Mauritian palm is common, and in the high llanos, xerophilic light forests and shrub communities are common. Mangroves stretch around Lake Maracaibo, giving way to undersized xerophilous, and to the south - evergreen tropical forests. In the south of the country, in the upper reaches of the river. Orinoco and its right tributaries, grow moist evergreen rainforests almost unusable. Of the tree species of economic value, mahogany, roble colorado, baku, balsa, espave (Anacardium spp.), angelino (Ocotea caracasana), oleo-vermelho (Myroxylon balsamum), pao-roxo, guaiacum, tabebuya (Tabebuia pentaphylla ), ceiba (Ceiba pentandra), almasigo (Bursera simaruba), kurbaril (Hymenaea courbaril), adobe (Samanea saman), etc.
Landscape in the center of Venezuela
Colombia. By natural conditions two areas are distinguished: the eastern (plain) and the western (mountainous, where the Colombian Andes stretch). The first region is largely occupied by humid evergreen forests of the Magdalena basins and the left tributaries of the Amazon. In the north of the Guajira peninsula and west of it, along the coast caribbean, low-growing xerophilous forests extend, 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 engineering products.
Mangrove forests stretch along the Pacific and Caribbean coasts. In evergreen tropical hylaea, especially in the lower part of the Magdalena basin and along the mouth of the river. Atrato, kativo wood (Prioria copaifera) is harvested for export, as well as baku, or "Colombian mahogany" (Cariniana spp.), caoba, or real mahogany (Swietenia macrophylla), roble colorado, or Panamanian mahogany (Platymiscium spp.) , purple tree, or paoroxo (Peltogyne spp.), etc. In the eastern part of the elevated plain along the tributaries of the Orinoco, savanna-llanos with rare trees and gallery forests with Mauritius palm (Mauricia sp.) are common. The forests of the mountain regions of the Andes are characterized by a peculiar altitudinal zonality. On the lower parts of the lee slopes and on the northern ridges, deciduous forests or thorny shrubs are common. In the adjacent part of the mountains (from 1000 to 2000 m) mountain broad-leaved evergreen forests grow with tree ferns, wax palm (Copernicia cerifera), cinchona, coca (Erythroxylon coca) and various orchids. Cultivated crops include cocoa and coffee trees. At an altitude of 2000 to 3200 m, humid alpine hylaea, in which there are many species of evergreen oaks, shrubs and bamboos.
Ecuador. Three natural areas are distinguished on the territory of the country: 1) a watershed plateau with moist equatorial forests - hylaea, or selva(together with the upper reaches of the left tributaries of the Amazon); 2) Andes ranges; 3) the Pacific forest-savannah plain and the western slopes of the Andes. The evergreen tropical forests of the first region are poorly studied and difficult to access. On the western slopes of the Andes, up to a height 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 the fruits of ceiba, leaves of the toquilla palm, or hipihapa (Carludovica palmata), used to make Panama hats. Tagua palm (Phytelephas spp.) is also found here, the hard endosperm of the fruits of which is used to produce buttons, and various rubber plants. The lower part of the western slopes is characterized by evergreen tropical forests. In the river valley Guayas is intensively harvested for export balsa wood.
Guyana, Suriname, Guiana. The forests of these countries, located along the coast of the Atlantic Ocean and along the Guiana Highlands, are evergreen tropical with a number of valuable species. The green tree, or betabaro (Ocotea rodiaei), which is exported in Guyana and Suriname, stands out in particular. Apomate (Tabebuia pentaphylla), canalette (Cordia spp.), pekia (Caryocar spp.), espave (Anacardium spp.), habillo (Hura crepitans), wallaba (Eperua spp.), carap (Carapa guianensis), virola are no less valuable. (Virola spp.), Simaruba (Simaruba spp.), etc.
Brazil. There are more than 7 thousand species of woody and shrubby plants in the flora, of which there are over 4.5 thousand species in the Amazonian selva. High bertholecia grow (giving brazil nuts, etc.), various rubber plants, including brazilian hevea, which has become a valuable plantation crop in many countries of South Asia and Africa, laurels, ficuses, brazilian mahogany, or "pau brazil", which gave the name to the country (Caesalpinia echinata), chocolate tree, or cocoa, mahogany, jacaranda, or rosewood, oleo vermelho, roble colorado and sapukaya, or paradise nut (Lecythis ustata), and many others. In the east, the selva turns into light palm forests, among which we note the valuable babasu palm (Orbignya speciosa), which has highly nutritious nuts. South of the Amazonian selva, landscapes of tropical dry woodlands are common - caatinga, in which trees grow that shed their leaves in the dry season and accumulate moisture in the rainy season, for example, the bottle tree (Cavanillesia arborea), thorny shrubs, cacti (Cereus squamulosus). In the floodplains, there is a carnauba, or wax, palm (Copernicia cerifera), from the leaves of which wax is collected, which is used in technology. From the south, subtropical deciduous forests adjoin forests dominated by palms and savannahs. In the southeast of the country, along the Brazilian Highlands, there are araucaria forests from the Brazilian, or Paran, araucaria (pinheiro, or "Brazilian pine"). Along with it, embuya, tabebuya, cordia grow, and in the undergrowth of yerbamate, Paraguayan tea is prepared from its leaves. Araucaria forests are involved in intensive exploitation.
Along the Atlantic coast and at the mouth of the Amazon, mangrove forests grow, dominated by red mangrove with an admixture of black mangrove (Avicennia marina) and white mangrove (Conocarpus erecta). Tannin is extracted from the bark of these trees.
Road from Calama (Chile) to LaPaz (Bolivia) | Chile. The main forest area is concentrated in the southern half of the country along the Pacific slopes of the Andes. In the region of 41-42 ° S.l. there is a significant array of araucaria forests, dominated by pure stands of pinot, or Chilean araucaria, often called "Chilean pine" (Araucaria araucana). To the south are mixed broad-leaved deciduous forests of the temperate zone with different species of southern beech (Nothofagus spp.), representatives of laurels - linge (Persea lingue), ulmo (Beilschmiedia berteroana). In the extreme south, there are coniferous forests of alerse (Fitzroya cupressoides) and sipres (Pilgerodendron uviferum) with an admixture of canelo (Drimys winteri). The bark of the latter contains substances with antiscorbutic properties. |
Argentina. There are several natural regions. The east is dominated by evergreen forests, in which more than 100 species of trees of great economic importance grow. Among them are cabreuva (Myrocarpus frondosus), kanzherana (Cabralea oblongifolia), Brazilian araucaria, tabebuya, etc. In the west, evergreen ice grows along 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 cryolo (Amburana cearensis), nogal cryolo (Juglans australis), tarco (Jacaranda mimosifolia), type blanco (Tipuana tipu), etc. In the south, along the slopes of the Andes, subantarctic vegetation extends, among which several species of southern beech, alerce, "Cordillera cypress" (Austrocedrus chilensis), etc., are distinguished. palosanto (Bulnesia sarmientoi), guaiacan (Caesalpinia paraguarensis), etc. To the south, along the eastern slopes of the Andes, there are xerophilic broad-leaved forests of the temperate zone with algarrobo, acacias (Acacia caven), carcass (Celtis spinosa), quebracho-blanco.
Paraguay. Forest cover 51%. In the east of the country, mixed tropical evergreen and deciduous forests are common, turning in the west (in the Gran Chaco region) into woodlands and savannahs. The main tree species is quebracho blanco (Aspidosperma quebracho-blanco).
Uruguay. Forests occupy an insignificant 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 forest cover of the country is 3%. Large areas are beginning to be occupied by artificial plantations - pines on coastal dunes and eucalyptus plantations.
Published according to the monograph: A.D. Bukshtynov, B.I. Groshev, G.V. Krylov. Forests (Nature of the world). M.: Thought, 1981. 316 p.
Variably humid forests. The zone of variable humid (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 evergreen trees (palms, ficuses, bamboo and magnolias), which grow mainly on red-yellow soils. Animal world it is also characterized by a significant species diversity: monkeys, tigers, leopards, as well as endemics - a bamboo bear (panda), a gibbon, etc.
slide 11 from the presentation "Natural zones of Eurasia". The size of the archive with the presentation is 643 KB.Geography Grade 7
summary other presentations"Natural zones of Eurasia" - Among the impenetrable thickets here you can meet orangutans, leopards, tapirs. Main animals: reindeer, arctic foxes, some species of birds. The latter prevails in the Asian taiga, in a cold, sharply continental climate. Arctic desert zone. Mixed and deciduous forests. The desert zone stretches through three geographical zones. The fauna here is represented by elephants, tigers, rhinos. 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 des Stars 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 in which the tombs of the great people of France are located. The Eiffel Tower is the symbol of Paris. The Louvre is one of the largest and richest museums in the world fine arts. Purpose: to get acquainted with the sights of Paris.
"The geographical position of the southern continents" - On the plains, composed of strata of sedimentary rocks. Questions: Into what 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 of the southern continents. In which climatic zones the largest network of rivers and many lakes?
"Geographical shell of the Earth" - Modern look planet Earth. 1. Altitudinal zonality zonality… 6. Lithosphere is… Pupils of the 7th grade Matrosova A.E. A. state of the troposphere B. long-term weather pattern C. current state of the troposphere. A. on the plains B. in the mountains C. in the oceans 2. Geographic envelope- this is ... Test work. Right answers.
"Water in the World Ocean" - Without water, a person cannot live more than eight days. Thanks to water and in water, life arose on Earth. Then there is deadly dehydration of the body. You can't grow crops without water. We are starting 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 of the ocean?
"Savannas" - Branched acacias rise like huge umbrellas among tall grasses. Animal world. Savannah. economic activity of people. average temperature July and January +22C. Soils. Geographical position. Climatic conditions. Umbrella acacia. Savannahs are located in the subequatorial belt.
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, so the equatorial and subequatorial belts are most widespread. 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 has given mankind many cultivated plants: potatoes, tomato, 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 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, 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). There are electric eel and freshwater dolphin iniya.
Zones stretched across three geographical zones variable-moist forests . Subequatorial variable wet forests occupy eastern part Amazonian lowland and 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 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, 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 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) 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 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 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. Tutorial 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
Vietnam
The Socialist Republic of Vietnam is located in Southeast Asia, on the east coast of the Indochinese Peninsula. It occupies an area of 331,600 km2, which is comparable to the territory of Germany. Vietnam borders China in the north, Laos in the west, Cambodia in the southwest, and the South China Sea in the east. Vietnam owns two large archipelagos - Hoang Sha and Truong Sha and a large number of islands. Three-quarters of the country's territory is mountainous; there are two fertile deltas of the main water arteries of the country of the Mekong (Fig. 2.73) and Red. Length coastline Vietnam excluding islands - 3444 km. Population - 92.477 million people (2013 data).
The climate, according to the Köppen classification, belongs to the types Aw (tropical savanna climate in the plains of the south of the country) and Cwa-Am (warm monsoon climate in the mountainous north).
The Vietnamese economy has been developing rapidly since 1990, when the country, following the example of China, began to combine state and private property. GDP growth varies between 5.3-8.5%.
13 large rivers and about 3,500 rivers with a length of at least 10 km flow on the territory of Vietnam. Water resources have become an important factor in ensuring food and energy security, as well as in the industrialization and modernization of the country. At the end of the 20th century, Vietnam came out on top in the world in terms of rice exports (Vietnam..., 1993) (Fig. 2.74-2.78).
Water resources are also a decisive factor in increasing the production of other agricultural and industrial crops such as tea, coffee, black pepper, etc. Currently, 70% of the water used for agricultural production comes from the Red and Mekong rivers. However, the country faces numerous challenges in the use of water resources.
Mekong is one of the most major rivers world: its length is 4350 km, and the area is 795 thousand km 2. Food rain, snow and ice. Its basin is home to 250 million people from several countries (Fig. 2.73).
Rice. 2.74
Valley type of settlement. Fields and villages are located in the valleys of small rivers
The Mekong basin is the second largest biodiversity basin in the world after the Amazon. The Mekong flows through the territory of 4 states: China, Laos, Cambodia and Vietnam. The state borders of Myanmar (Burma) and Thailand pass along the right bank of the river. The cooperation of the countries to which this river is directly related, the experts have their own name - "the spirit of the Mekong." Since 1957, this cooperation has been taking place within the framework of the Commission for the river. Mekong (Rysbekov, 2009; FB.ru: http://fb.ru/article/222437/mekong).
Rice. 2.75
Rice fields of Mu Cang Chai District, Yen Bai Province
Rice. 2.76
Rice. 2.77
Rice. 2.78
On the territory of Vietnam there is only a relatively small segment (200 km long) of the lower reaches of the river. Mekong, representing a delta of two wide branches and many smaller channels (Fig. 2.79, 2.80). There are many channels dug here. 17 million Vietnamese live in the delta with an area of 70,000 km2. The climate within the delta is subequatorial monsoonal. The average annual temperature is 27°С; The year is divided into two seasons - wet and dry.
Rice. 2.79
The economy of the provinces in the Mekong Delta is based on agriculture(rice cultivation (Fig. 2.81, 2.82)) and aquaculture. An important role in the delta is played by artificial channels, which are transport arteries and places for breeding aquatic products. The most famous canal, Vinh Te, is 87 km long and 40 to 60 m wide. It was dug by hand with shovels and hoes over a period of 5 years, from 1819 to 1824, during the reign of the Nguyen dynasty.
The fishing fleet has more than 25 thousand vessels of various tonnage. More than 1 million tons of fish (pangasius), about 300 thousand tons of saltwater shrimp and a large number of other fish, arthropods and molluscs are grown annually. About 200 factories have been built to process seafood. Tourism has been developing intensively in the last two decades.
Fig.2.80
Rice. 2.81
Rice. 2.82
The role of water resources in providing food for the population of Eurasia. Based on the completed review of the most common types of agricultural land in Eurasia, we will try to assess the role of water resources in solving the food problem on this continent. According to forecasts, by 2050 the world's population will increase to 9 billion. At the beginning of section 2.2, we outlined one of the food programs proposed by J. Foley (2014), which includes five steps. This program aims to double food production by 2050, but does not consider sufficiency water resources. In table. 2.4. The "steps" of the Foley program are numbered 1-5. The last column shows our estimate of the water availability of the program as a percentage of the amount that doubles food production.
The "first step" - the stabilization of the area of agricultural land is accepted as feasible in all the considered territories as a necessary initial condition for the implementation of the Foley program. The “second step” (continuation of the “green revolution”) is possible on irrigated lands of countries with a warm climate, while in the zone of the northern and middle steppes it has limitations - the unsuccessful experience of introducing Italian durum wheat in the steppe zone of Russia is known.
Table 2.4
Assessing the feasibility of implementing the food program J. Foley (2014) "Five Steps", taking into account the potential of water resources
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Ecosocial systems |
"Steps" of the program J. Foley | |||||||
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Voronezh region |
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Stavropol region |
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S.-V. China |
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Central Asia (Turkmenistan) |
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Rajasthan (India) |
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Yu.-V. China |
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Rice. 2.83 Map of the use of nitrogen fertilizers in Eurasia (fragment of the world map).
The tundra occupies such territories as the coastal outskirts of Greenland, the western and northern outskirts of Alaska, the coast of the 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.
Temperate coniferous forests cover most of North America. These forests form the second after the tundra and the last vegetation zone, which stretches across the entire continent from west to east and is a latitudinal zone. Further south latitudinal zonality preserved 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.
