South America is the fourth largest continent on Earth. This is the southern part of the land, which is called the New World, the Western Hemisphere, or simply America. The mainland has the shape of a triangle, it is wide in the north and gradually narrows towards the southern point - Cape Horn.
The continent is thought to have originated when the supercontinent Pangea broke apart several hundred million years ago. This theory says that throughout both South America and Africa were a single landmass. For this reason, both modern continents have similar mineral resources and types of rocks.
Basic geographic information
South America, together with the islands, occupies 17.3 million km². Most of its territories are located in the Southern Hemisphere. Passes through the continent. The coastline is quite indented. Pacific and Atlantic oceans, which form bays at the mouths of rivers. The southern coast with the Tierra del Fuego archipelago is more indented. :
- north - Cape Gallinas;
- south - Cape Frouard;
- west - Cape Parinas;
- east - Cape Cabo Branco.
The largest islands are Tierra del Fuego, Galapagos, Chiloe, Wellington Island and the Falkland Islands. Large peninsulas include Valdes, Paracas, Taitao and Brunswick.
South America is divided into 7 natural regions: Brazilian Plateau, Orinoco Plain, Pampas, Patagonia, Northern Andes, Central and Southern Andes. The continent consists of 12 independent countries and 3 territories without sovereignty. Most of the countries are developing countries. The largest country in terms of area is Brazil, which is Portuguese-speaking. Other countries speak Spanish. In total, about 300 million people live on the mainland, and the population continues to grow. Ethnic composition difficult due to the special settlement of the mainland. Most people live on the coast Atlantic Ocean.
Relief
Andes
The base of the continent consists of two elements: the Andes mountain belt and the South American platform. It has risen and fallen several times during its existence. Plateaus have formed in elevated places in the east. Low-lying plains formed in the troughs.
The Brazilian Highlands settled in the southeastern part of Brazil. It stretched for 1300 km. The composition includes the Serra de Mantiqueira, Serra do Paranapiataba, Serra Gerall and Serra do Mar mountain ranges. The Brazilian shield is located south of the Amazon. The Guiana Plateau, 1600 km long, stretches from Venezuela to Brazil. It is famous for its gorges and tropical forests. Here is the highest Angel Falls, 979 m high.
The Amazonian lowland was formed due to the turbulent waters of the river of the same name. The surface is filled with continental and marine sediments. In the west, heights barely reach 150 meters above sea level. The Guiana Plateau arose in the north of the continent. The longest mountain range on Earth, the Andes, is 9 thousand km. The highest peak is Mount Aconcagua, 6960 m. Mountain building continues to this day. This is evidenced by the eruptions of numerous volcanoes. The most active volcano is Cotopaxi. The mountain range is seismically active. The last major earthquake occurred in the Chile region in 2010.
desert
In the southern part of the continent, a zone and semi-deserts were formed. This is a unique territory for the temperate zone: deserts overlook the ocean coast. The proximity of the ocean creates high humidity. However, the formation of arid terrain was influenced by the Andes. They block the path of moist winds with their mountain slopes. Another factor is the cold Peruvian Current.
Atacama
Atacama Desert
The desert territory is located on the western coast of the continent, its total area is 105 thousand km². This region is considered the driest on the planet. In some areas of the Atacama, precipitation has not fallen for several centuries. The Peruvian current of the Pacific Ocean cools the lower ones. Because of this, in this desert, the lowest humidity on Earth is 0%.
The average daily temperature is cool for desert regions. It is 25 ° C. In some areas, fog can be observed in winter. Millions of years ago, the region was under water. After a while, the plain dried up, resulting in the formation of salt pools. There are a lot of active volcanoes in the desert. Red stony soils predominate.
The landscape of the Atacama is often compared to that of the moon: sandbanks and rocks alternate with dunes and hills. Evergreen forests stretch from north to south. On the western border, the desert strip gives way to thickets of shrubs. In total, there are 160 species of small cacti in the desert, as well as lichens and blue-green algae. Acacias, mesquite trees and cacti grow in the oases. Llamas, foxes, chinchillas and alpacas have adapted to the climatic conditions. 120 species of birds live on the coast.
A small population is engaged in mining. Tourists come to the desert to visit the Moon Valley, see the "Desert Hand" sculpture, and enjoy sandboarding.
Sechura
Sechura Desert
This desert area is located in the northwest of the continent. On the one hand, it is washed by the Pacific Ocean, and on the other, it borders on the Andes. The total length is 150 km. Sechura is one of the cold deserts with an average annual temperature of 22 ° C. This is due to south-west winds and ocean currents off the coast. It also contributes to the formation of fogs in winter. Fog retains moisture and gives coolness. Due to subtropical anticyclones, little precipitation falls in the region.
Sands form mobile dunes. In the central part, they form dunes 1.5 m high. Strong winds move the sand and expose the bedrock. Animal and vegetable world concentrated along streams. On the territory of Sechura there are two large cities.
Monte
Desert Monte
The desert is located in the north of Argentina. It has a hot and dry climate. Precipitation may not fall for about 9 months of the year. Weather changes are explained by the absence of mountains: the territory is open to north and south winds. Clay soils in the valleys, and stony soils in the mountains. Few rivers are fed by rain.
The territory is dominated by semi-desert steppes. There are woodlands near the water. Animal world represented by birds of prey, small mammals, including llamas. People live in oases and near water bodies. Part of the land is turned into agricultural land.
Inland waters
Amazon river
The continent receives a record amount of rainfall. Thanks to this phenomenon, many rivers were formed. Since the Andes act as the main watershed, most of the mainland belongs to the Atlantic basin. Water bodies are mainly fed by rain.
The Amazon, 6.4 thousand km long, originates in Peru. She has 500 tributaries. The rainy season increases the level of the river by 15 m. Its tributaries form waterfalls, the largest of which is called San Antonio. are poorly used. The length of the Parana River is 4380 km. Its mouth is located on the Brazilian Plateau. Rainfall is uneven because it crosses several climatic zones. In the upper reaches, due to the rapids, Parana forms waterfalls. The largest, Igausu, has a height of 72 m. Downstream, the river becomes flat.
The third largest inland body of water on the continent, the Orinoco, is 2,730 km long. It originates on the Guiana Plateau. In the upper reaches there are small waterfalls. In the lower part, the river forks, forming lagoons and channels. During floods, the depth can be up to 100 m. Due to the frequent tides, shipping becomes a risky business.
The largest lake in Venezuela is Maracaibo. It was formed as a result of the deflection of the tectonic plate. In the north, this reservoir is smaller than in the southern part. The lake is rich in algae, thanks to which various species of birds and fish live here. The south coast is represented. Tourists are attracted by a rare phenomenon called the Catatumbo Lighthouse. As a result of mixing the cold air of the Andes, the warm air of the Caribbean Sea and methane from the swamps, lightning appears. They strike 160 days a year, and silently.
Titicaca, the second largest lake South America, located between the ridges of the Andes. It has 41 inhabited islands. It is the largest navigable lake. Titicaca and the surrounding area is a national park. Rare live on its territory. Due to rarefied air, there is little species diversity. Most of the continent has large reserves of fresh water.
Climate
Subequatorial climate zone
The continent is located in five climatic zones. occupies the Pacific coast and the Amazonian lowland. During the year, 2 thousand mm of precipitation falls. The temperature throughout the year is low, about 24 ° C. It is in this belt that the equatorial forests grow, which are the largest array of wet forests on Earth.
The fight for the environment is to create national parks and reserves. Countries need to implement environmentally clean technologies and re-plant deforested areas.
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1 Ministry of Education and Science Russian Federation Pskov State University Pskov Regional Branch of the Russian Geographical Society A.I. Slinchak PHYSICAL GEOGRAPHY AND LANDSCAPES OF THE CONTAINERS AND OCEANS Practicum Pskov 2014
2 LBC C47 This textbook was published in the framework of the EU TEMPUS Joint Project TEMPUS SK-TEMPUS-JPCR Environmental Governance for Environmental Curricula with financial support from the European Union. The publication reflects the views only of the author, and the Union cannot be held responsible for any use which may be made of the information contained therein. The training manual is being printed as part of the EU project TEMPUS Environmental Governance for Environmental Curricula (TEMPUS SK-TEMPUS-JPCR). The project is funded with the support of the European Union. The content of this publication is the responsibility of the author and does not reflect the views of the European Union. Published by decision of the Academic Council of the Pskov Regional Branch of the Russian Geographical Society Reviewer: Manakov A.G. Professor of the Department of Geography of the Pskov State University, Doctor of Geography Slinchak A.I. Physical geography and landscapes of continents and oceans: workshop teaching aid for university students in the direction of "Geography" / A.I. Slinchak. Pskov: PskovGU, p. The manual contains tasks and questions for laboratory and practical work on sections of general and regional physical geography of continents and oceans, guidelines according to their implementation, a list of geographical names, Control questions(tests) for self-examination of knowledge, etc. The manual is intended for university students. ISBN Slinchak A.I., 2014 Pskov State University, 2014
3 Preface The proposed manual is intended for laboratory, practical work and organization of independent work of students on the course "Physical geography and landscapes of continents and oceans." The main objectives of the workshop: expanding and deepening the theoretical knowledge gained in the lecture course and in the study of literature on the subject; consolidation and development of skills of various forms of independent work; mastering the methods of compiling physical and geographical characteristics; detection individual characteristics major regions Earth: oceans, continents, subcontinents, physical and geographical countries. The workshop presents tasks related to human activities in nature, positive and negative assessments of anthropogenic transformations of the Earth's landscapes. The workshop includes questions and tasks that contribute to the activation of the mental activity of students, the development of their geographical, environmental thinking, stimulating them to master the ability to competently, professionally present what they have learned. educational material. In preparing the workshop, a number of tasks from authoritative publications of well-known authors were used (Eremina V.A., Pritula T.Yu., Spryalin A.N., 2005, Eramov R.A., 1987, etc.). 3
4 Topic 1. Geographical location, size, configuration of Eurasia and their geographical consequences Purpose: to identify the significance of the geographical location, size, configuration, indentation of the coastline for the formation of the nature of the mainland. 1. By physical map Eurasia and table general information on the continents in the atlas, determine the names of the extreme northern and southern points of the continental and island land of Eurasia and their geographical latitude, the distances between them in degrees of latitude and in kilometers. Using maps of the radiation balance, geographical zones and zones, determine what consequences the significant meridional extent of Eurasia leads to. Compare Eurasia in terms of a set of geographical zones with other continents. Draw conclusions. 2. Based on the physical map of Eurasia and the table of general information about the continents, determine the names and geographic longitude of the extreme western and eastern continental and island points of Eurasia, its greatest extent from west to east in degrees and kilometers along the parallels 60 0, 40 0 and 30 0 s. sh.; at what latitudes is the longitude extent of Eurasia the greatest. Determine the regions of Eurasia that are the most remote from the Atlantic and Pacific oceans, identify the consequences of a significant remoteness of the inland regions of Eurasia from the oceans. Using the map of annual precipitation, determine the differences on this basis between the oceanic and inland sectors of Eurasia. Compare Eurasia with other continents in terms of area, horizontal division, and remoteness of inland regions from the oceans. 3. On the map, determine the configuration of continental Eurasia, the areas of the greatest and least dissection of the coastline. Compare it with North America, Africa. To reveal the influence of the degree of interpenetration of the sea and land on the nature of the mainland. Identify the regions of Eurasia in which the island and peninsular land occupies the largest area. Determine the consequences of this- 4
5th. Substantiate the conclusions on specific examples, based on the analysis of thematic maps. 4. Using the maps of the atlas, trace the direction of warm and cold ocean currents near the coast of Eurasia, the position of the average border of floating ice. Determine the names of warm and cold currents off the coast of the mainland, based on the analysis of thematic maps, show the influence of each of them on the nature of the adjacent part of Eurasia. Find out the features of the influence of each of the oceans on the formation of the climate of the mainland. 5. Compare the position of Eurasia in relation to North America, Africa, Australia. What is the proximity of Eurasia to these continents in the geological past and at the present time? Substantiate your assumptions based on the analysis of thematic maps. 6. Using study guides, cartographic sources, explain what is the polar asymmetry of the Earth? How can this affect the differences in the nature of the Northern and Southern continents? 7. Compose comparative characteristic geographical location of the British and Japanese Isles. Identify their similarities and differences. 5
6 Area of continents Table 1 Remoteness Mainland Area, mln. km 2 of inland regions from oceans, km with islands without islands average greatest Eurasia 54.1 50, North America 24.1 20, South America 17.8 17, Africa 29.8 29, Australia 8.9 7, Topic 2. Relief of Eurasia: features of orography and hypsometry systems of Eurasia, to determine their role in the horizontal and vertical (spatial) differentiation of other components of the nature of the continent. 1. Based on the analysis of the physical map of Eurasia, to identify patterns in the location of large plains and mountain systems of the mainland. Analyzing the map, it is necessary to answer the following questions: A. What areas of Eurasia are large plains confined to and what are they called? B. What are the prevailing heights of these plains? Q. What areas of Eurasia are large mountain systems confined to? D. On the map, trace the main direction of the stretch of the mountain systems of the Alpine-Himalayan belt. In what direction does the height of the ridges included in this belt generally increase? Justify the conclusion with quantitative indicators. 6
7 E. Track the location of the mountains in the Pacific continental and insular parts of Eurasia. 2. Determine the role of orography and hypsometry in the differentiation of the nature of Eurasia. To do this, it is necessary to analyze a number of thematic maps, paying attention to the following questions. A. To identify the influence of plains and mountains on the climate of the mainland, on the manifestations of horizontal zonality and altitudinal zonality of landscapes. Give specific examples of these influences. B. Name the mountain systems of Eurasia that play the role of geographical barriers; to determine what exactly their differentiating role manifests itself in? Prove this with thematic map data. Q. What explains the main direction of flow of Eurasian rivers into the Arctic Ocean? D. What mountain systems of the mainland are "hydrographic nodes"? Name the regions of Eurasia, devoid of runoff into the oceans. What are the features of these regions (separately for the Aral-Caspian basin and Central Asia). Topic 3. The main stages in the development of the nature of Eurasia Purpose: to identify the features of the development of the nature of Eurasia; to consolidate interdisciplinary connections with the courses of historical geology and general geography. 1. Based on the knowledge gained in the courses of historical geology and general geography, complete following tasks. A. Find on the map the main tectonic structures within Eurasia. B. What impact did and do tectonic movements on various natural components: surface structure, climate, formation of a hydro network, development of the organic world? 2. Make a table: "The main stages in the formation of the nature of Eurasia" in the following form. 7
8 Stage of development Duration The main events in the formation of the surface in the development of the organic world Reflection of events in the modern structure of the geographical shell 3. Analyze the table by answering the following questions. A. What events in the history of the development of Eurasia had the greatest impact on the formation of relief? B. What special features in this connection does the relief of the parts of the world of Europe and Asia have? 8 Topic 4. Climate of Eurasia Purpose: to get acquainted with the manifestations of patterns of formation, seasonal and territorial differentiation of climate in Eurasia; develop skills in working with climate maps. 1. Radiation conditions What determines the distribution and mode of solar radiation? What is the radiation balance? Formulate the concepts of direct, diffuse, total, reflected radiation, albedo Analyze maps of the annual radiation balance in Eurasia. Reveal the main directions of its change and the course of the lines of equal values of the annual radiation balance. Determine which lines of the annual radiation balance approximately coincide with the southern boundaries of the Arctic, subarctic and subtropical climatic zones. Why is the radiation balance over the oceans greater than over the land? What explains the presence of maximum values of the radiation balance over the water area of the Arabian Sea? 1.3. Compare radiation balance maps for July and January in Eurasia. What are the reasons that determine the small differences in the values of the radiation balance over the territory of Eurasia in July and the large ones in January?
9 1.4. Identify areas of Eurasia with a negative radiation balance in January. How do areas with a positive and negative balance of radiation in January differ from each other in terms of the activity of the flow natural processes? Pay attention to the course of the isoline of zero radiation balance in January. 2. Winter season climate Analyze the distribution map atmospheric pressure in January. Pay attention to the prevailing pressure values over the mainland and adjacent water areas of the oceans. To identify the main climatic maxima and minima that affect the circulation of air masses over Eurasia and adjacent parts of the oceans Based on the analysis of the position of baric centers, arctic, polar fronts and fronts of the intratropical convergence zone, determine the directions of movement of cyclones, monsoons, and trade winds in January. To identify the prevailing directions of winds in the extratropical latitudes of the western, middle, eastern parts of Eurasia and in the tropical latitudes of the mainland. Based on the seasonality map of precipitation, determine the regions of Eurasia in which the winter season falls maximum amount precipitation, and areas where winter is characterized as a period of low precipitation. Give an explanation for these phenomena, based on the circulation processes and types of air masses prevailing during this period. Analyze the map of the average monthly temperature in January in Eurasia. Determine the course of January isotherms in the Atlantic, inland and Pacific sectors of the intratropical latitudes of Eurasia and in its tropical regions. To study in more detail the course of January isotherms 8 0, 0 0, C. Analyze the map of January isoanomalies (Fig. 1). Identify areas with positive and negative temperature anomalies, give explanations for temperature deviations from average latitudinal norms, using maps of atmospheric circulation, sea currents, and a physical map for this. Formulate conclusions about the horizontal transfer (advection) of heat by air masses. 9
10 Fig. 1. Map of January isoanomalies for Eurasia 10
11 3. Climate of the summer season Analyze the distribution of atmospheric pressure over Eurasia and neighboring oceans in July. Compare with the pressure distribution in January, revealing the fundamental changes that occurred between these two months, the main pressure maxima and minima, which have a major impact on the circulation of air masses over Eurasia in the summer season, their location Based on an analysis of the situation over Eurasia and adjacent water areas of the oceans of baric centers , arctic, polar fronts and fronts of the intratropical convergence zone to determine the changes that have occurred in comparison with January. To identify the main ways of movement of cyclones, trade winds, monsoons in the western, middle and eastern parts of Eurasia in extratropical latitudes and in the tropical regions of the mainland. Determine the types of circulation of air masses characteristic of these regions in summer summer time there is a maximum of precipitation, and areas where summer is characterized as a season with a minimum of precipitation To analyze the distribution of average monthly temperatures in July in the Atlantic, inland and Pacific sectors of extratropical latitudes and in tropical regions of Eurasia. Why is the distribution of mean monthly temperatures less complex in July than in January? Learn the course of the isotherms of July C and C, be able to show them on a physical map. 4. Atmospheric Precipitation and Humidity Analyze the map of annual precipitation in Eurasia and compare it with the map of annual evaporation in order to reveal the moisture balance. To this end, to determine the patterns of changes in precipitation and evaporation along the parallels 50 0, 40 0 and 20 0 N.L. Determine the patterns of changes in annual precipitation and evaporation in the meridional direction in different sectors of the mainland: along the line from the northern tip of the Scandinavian Peninsula to the island of Sicily, along the meridian 90 0 E, along the Komsomolsk-on-Amur Hanoi line. eleven
12 4.2. Analyze the map of the difference (balance) of annual precipitation and evaporation in Eurasia. Identify areas with a moisture deficit and with a positive moisture balance. Why can areas with the same or close amount of precipitation have a sharply different balance of moisture, and areas with a sharply different amount of precipitation can have similar values of the balance of moisture? Give specific examples of such areas in foreign Eurasia. Based on the seasonal precipitation map, determine the main types of precipitation regime in Eurasia and their areas of distribution. Explain the reasons for the manifestation of various types of precipitation regimes, based on the analysis of previously considered climate maps. 12 Topic 5. Agro-climatic resources of Eurasia Purpose: to determine the territorial changes in agro-climatic resources in Eurasia according to some climatic characteristics. 1. Analyze the map of the main types of annual variation in the moisture supply of agricultural crops in Eurasia (Fig. 2). 1 excessive or sufficient moisture during the growing season; 2 excessive or sufficient moisture throughout the year; 3 adequate moisture most of the year with 2-5 dry or dry months; 4 sufficient or excessive moisture in winter, dry or dry summer; 5 sufficient or excessive moisture in summer, dry in winter and spring; 6 dry during the growing season; 7 dry during the growing season; 8 dry most of the year with sufficient and excessive moisture for 2-4 months; 9 dry throughout the year; 10 the temperature of the warmest month is below C (an assessment of humidification conditions is not given). 2. To analyze the map of the duration of the growing season with a temperature of C or more (Fig. 3). The growing season with a temperature above C was chosen because this temperature is active for most cultivated plants. Continued
13 13 Fig. 2. The main types of annual variation in the moisture supply of agricultural crops in Eurasia
14, the life of the period with temperature C and better characterizes the heat resources for crops, although it is also necessary to take into account other indicators (dates of frost onset, sum of temperatures, etc.). Comparing the indicators of heat and moisture resources, indicate the regions of Eurasia: with a good combination of these resources throughout the year; with significant thermal resources at very low moisture resources; with significant moisture resources, with small thermal resources; areas in which significant thermal resources in one season are combined with sufficient moisture resources in the opposite season; areas requiring artificial irrigation of agricultural crops. 14 Topic 6. Surface waters of Eurasia Purpose: to identify patterns of territorial distribution of the river and lake network in connection with climate and relief. To identify patterns of territorial distribution of modern glaciation and conditions that contribute to the formation of glaciers. 1. Based on physical maps, determine the regions of Eurasia with a dense and underdeveloped river network. Indicate the reasons for the varying degrees of development of the river network in these areas. 2. Using physical maps, identify areas of accumulation of lakes in foreign Eurasia. Determine the types of lakes prevailing in each region according to the genesis of their basins. Highlight endorheic lakes with salt water, list the reasons for their formation. 3. Using the data of physical maps, identify the mountains of foreign Eurasia with glaciers. Formulate the patterns of the geographical distribution of modern glaciers, linking them with climate and topography.
15 Fig. 3. The duration of the growing season with a temperature of C or more (for Eurasia) 15
16 Determine which large rivers of foreign Eurasia have mountainous sections of the flow with a predominance of nutrition due to the melt waters of glaciers. 4. According to the graphs in the FGAM, on the example of the Tisza, Tiber, Yangtze rivers, compare the seasonal distribution of river runoff with a predominance of rain feeding, but located in different climatic regions. To reveal the relationship between the seasonal runoff of each of these rivers and the natural conditions of their basins. 5. Analyze table 2 "Water resources of some countries". Find in the reference literature and enter in the table the population of the countries. Explain the differences in the water availability of a number of foreign countries of the northern continents and Russia. State Area, thousand km 2 Water resources of some countries Total, thousand km 3 Per unit area, thousand m 3 / km 2 Per 1 person, m 3 / year China,8 Canada,6 India,8 USA,4 Norway, 9 France,4 Finland,2 Russia,0 Worldwide Table 2 Percentage of world resources Population, million people 16
17 Topic 7. Soils and vegetation Purpose: to find out the patterns of distribution of zonal types of soil and vegetation cover on the territory of foreign Eurasia. 1. Based on the vegetation map of the "Geographical Atlas", identify the main types of northern extratropical and tropical vegetation within Eurasia and analyze the patterns of their territorial distribution: changes in vegetation types in the meridional direction and from the outskirts to the interior of the mainland. Establish their connection with changes in thermal and pluvial characteristics. 2. Determine which climatic zones and types of climate are associated with various types of extratropical vegetation. To identify differences in the floristic composition of similar types of extratropical vegetation, but located in different sectors of the mainland: Northern European taiga, broadleaf-coniferous forests and Far Eastern dark-coniferous forests and Manchurian-North Chinese broadleaved forests; the Black Sea steppes and the Mongolian-Chinese steppes. What are the reasons for these differences? 3. Determine which climatic zones and climate types are associated with various types of tropical vegetation. 4. Determine in which parts of Eurasia and why zonal patterns in the distribution of vegetation are clearly expressed, and in which less clearly as a result of the action of regional factors, mainly orography. 5. Using the soil map of the atlas, identify the main types of soils of foreign Eurasia. Follow the directions of change in soil types and determine its causes. Give examples of zonal and sectoral patterns of soil change. 17
18 6. Give a brief description of the territorial distribution of the main types of soils in the arctic, subarctic, temperate, subtropical, tropical, subequatorial and equatorial soil belts. Identify the corresponding types of climate and vegetation cover. 7. Recall the main processes that form one or another type of soil. What genetic horizons can be observed in a number of soils? How are humus, podzolic, peat horizons formed? How does waterlogging and salinization occur? How and under what conditions does secondary soil salinization occur? Give examples. What is soil acidity? How important is acidity to soil fertility? 18 Topic 8. Land resources of Eurasia Purpose: to identify the types of land use and patterns of their distribution in foreign Eurasia. 1. Familiarize yourself with the content of the world map of land use ("Geographic Atlas"). Determine the main areas of cultivated land (arable land, vegetable gardens, orchards) and cultivated land in combination with pastures and hayfields in Europe and Asia. What natural conditions favor such land use in these areas? 2. Determine the main areas of land used for hayfields and pastures (meadows and pastures), differences within this type of land use in different climatic conditions. 3. Determine the main areas of forest lands (with pockets of cultivated land and pastures) in extratropical and separately tropical latitudes. 4. Determine the main areas of unused and underused lands. What are the reasons for the unsuitability or low suitability of these lands for economic use?
19 5. Analyze the map "Irrigation" in the "Geographical Atlas". Using the economic maps of the atlas, determine which crops are grown within the main areas of irrigated agriculture. 6. Identify the human impact on the soil cover, using the data in the following table 3. Explain the reasons for the existing differences. Table 3 Lands subjected to negative human impacts Continent, part of the world Deforestation Area, mln ha Use of improper agriculture Overgrazing Overexploitation Bioindustrial impact Africa Asia South America North America Europe Australia Worldwide map, make a cartogram (or cartogram) of the forest cover of various regions of Eurasia. Table 4 Forest cover of large regions of foreign Eurasia Region Forest cover,% cost,% Lesi Region Northern Europe 48.4 Western and Southwestern Asia 5.5 Central Europe 23.8 Central and Eastern Asia 13.1 Southern Europe 37.7 South Asia 20.8 Southeast Asia 62.6 Recommended legend gradations: regions with less than 10% forest cover; 11-20%; 21-30%; 31-40%; more than 40%. 19
20 20 Theme 9. Geographical zones and zones of Eurasia Purpose: to identify the manifestation of patterns of horizontal zonality and altitudinal zonality in Eurasia, the structure of geographical zones, to characterize the zones based on cartographic materials. 1. Analyze the map of geographical zones and zones in the atlas. List the geographical zones within which Eurasia is located. Determine what features of the climate are the basis for the allocation of geographical zones, what indicators each zone differs on this basis. On what basis are the tropical, subequatorial and equatorial climatic zones combined into a single equatorial-tropical geographical zone on the atlas map? 2. Determine what features of the climate are the basis for the allocation of geographical zones within the belts; by what indicators on this basis each zone differs from adjacent zones of this belt. 3. On the map, determine the manifestations of sectoral patterns. What are the signs of similarities and differences between forest zones of different belts within the same sector? What are the signs of similarities and differences between desert and semi-desert zones of different belts within the same sector? Why is sectoring less pronounced in the northern regions of the temperate zone than in the southern regions? 4. Give a brief description of the geographical zones of Eurasia in the form of a table, including the following information in it: the name of the geographical zone; the name of the geographic area; zone climate (temperatures, precipitation, volatility, humidity); modern geomorphological processes characteristic of the zone; features of nutrition and water regime of rivers; prevailing types of vegetation with indication of characteristic species; prevailing soil types; typical representatives of the animal world; agricultural use of the lands of the zone (with a list of crops).
21 Formulate conclusions about the features of the manifestation of horizontal zonality and altitudinal zonality in Eurasia. Topic 10. Physical and geographical regions of Eurasia Purpose: to get acquainted with the features of the spatial differentiation of the geographical envelope within Eurasia; determine the role of various factors in the spatial differentiation of the nature of Eurasia; master the scheme of the physical-geographical zoning of the continent, acquire the skills of a complex characterization of the nature of specific regions. 1. To identify the values of the main factors of spatial differentiation of the nature of Eurasia, paying special attention to the role of relief, climate, and zonal patterns. According to what leading factors are the boundaries of the subcontinents and the boundaries of the physical geographical countries of Eurasia? Identify regions in which the leading factor of differentiation is the relief, and in which the climate. 2. Draw the boundaries of subcontinents (red line) and physical-geographical countries (blue line) on the contour map. The subcontinents on the map are marked with red Roman numerals, the countries with blue Arabic numerals. In the legend, under the corresponding numbers, give the names of the regions highlighted on the map. 3. Compile an explanatory note to the zoning map with a brief comprehensive description of the regions. Include in the characteristics of subcontinents: the main feature by which this subcontinent stands out among other subcontinents of the mainland; a brief description of this feature, the composition of the territory; the main differentiating factor within the subcontinent; physical geographical countries of the subcontinent. The characteristics of physical and geographical countries should reflect: position within the subcontinent; boundaries and composition of the territory; a factor that determines the natural unity of the country; the relief of the country and the manifestation in it of the features of the geological structure; climate; surface waters and their features in connection with 21
22 climate and relief; vegetation, soils and patterns of their changes depending on the climate and relief; natural resources of the country and their economic use. Topics of messages (presentations) Physical-geographical regions and countries of Eurasia: features of nature, tourist and recreational resources, problems of management and optimization of the natural environment. Region, country 1. Northern Europe 2. Central Europe 3. Mediterranean: Iberian Peninsula and neighboring islands (Western Mediterranean) 4. Mediterranean: Apennine Peninsula and neighboring islands (Central Mediterranean) 5. Mediterranean: Balkan Peninsula and neighboring islands (Eastern Mediterranean) 6. Asia Minor highlands: Asia Minor, Armenian, Iranian 7. East Asia: Northeast and North China, peninsula Korea 8. Southeast China 9. Japanese islands 10. South Asia: Himalayas 11. South Asia: Indus and Ganges lowlands Brahmaputras 12. South Asia: the Hindustan Peninsula and the island of Sri Lanka 13. Southeast Asia: the Indochina Peninsula 14. The islands of Southeast Asia (Sunda, Moluccas, Philippine) 22 Topic 11. Man in Eurasia Purpose: to get acquainted with some features of interaction nature and man on the territory of Eurasia. 1. Prepare messages for the presentation at the seminar. Topics for messages:
23 Areas of ancient habitation of people in Eurasia. Natural conditions that existed in these areas. Centers of ancient civilizations in Eurasia. Natural conditions that existed in these areas. Features of life, culture, national character traits, economy associated with the specifics of natural conditions (on the example of one of the peoples of Eurasia). The positive and negative role of traditional features of culture and economy, formed under the influence of natural conditions (on the examples of the traditions of the peoples of Eurasia). 2. Analyze the population density map of Eurasia. What natural conditions contribute to the high population density of specific regions? Name the countries of Eurasia, whose territories are characterized by a high population density. Give examples of ecological destabilization of landscapes in these countries. Analyze table 5 and formulate conclusions. Decrease in the upper boundary of the forest belt under the influence of pastoralism Table 5 Area Natural upper boundary of the forest belt, m Actual upper boundary of the forest belt, m Scandinavian mountains to Great Britain Carpathians Alps
24 Questions for self-examination of knowledge 1. From a methodological point of view, which definition of "Physical geography of continents and oceans" is more correct: 1. An independent science in the system of Earth sciences 2. A section of geographical science that studies the Earth's biosphere regional, country level 4. The system of independent interconnected Earth sciences 2. Name the three most diverse continents in terms of tectonic structure. 1. South America, Africa, Australia 2. Eurasia, North America, South America 3. Antarctica, Africa, Australia 4. Antarctica, Australia, South America other continents? 1. Fennoskanlmya 4. Iranian Highlands 2. Hercynian Europe 5. Malay Archipelago 3. Japanese Islands 6. Central Asia 4. What soils are most typical for the zone of humid equatorial forests? 1. Brown forest 4. Chestnut 2. Brown 5. Podzolized laterites 3. Red-brown 6. Yellow soils 5. What soils are most typical for the zone of subtropical evergreen hardwood forests and shrubs? 1. Brown 4. Gray-brown 2. Forest brown 5. Red earth 3. Chestnut 6. Yellow earth 6. Which of the plant formations of the Mediterranean subtropics of Europe most emphasize the proximity and floristic influence of Africa? 1. Makvis 4. Shibljak 24
25 2. Palmitos 5. Frigana 3. Gariga 6. Tomillyars 7. What are the specific features of the most arid plants in the zone of subtropical evergreen hard-leaved forests and shrubs? 1. Wax coating on leaf blades, intense pubescence of stems and leaves, abundance of spines 2. Squat cushion-like nature of plants, long root system 3. Ability to store moisture in trunks, stems and leaves of plants 4. Lightening of leaf blades, the ability to roll them into a tube, densely soddy root system 5. Filamentous nature of leaves, abundance of thorns 8. Flora and fauna of which continents have the greatest similarities? 1. Eurasia - Australia 4. Africa - South America 2. North America - Eurasia 5. Africa - Australia 3. North America - South America 6. South America - Australia 9. Select the range of woody plants typical of Mediterranean subtropics Western Europe. 1. Cork oak, Kermes oak, Strawberry tree, Noble laurel, Olive tree 2. Herb tree, silver tree, cinnamon tree, clove tree 3. Baobab, oil palm tree, wild coffee tree, black ebony tree, equalia 4. Quebracho, southern beech, oblique beech. swamp cypress, agathis 10. Mangroves are: 1. Undergrowth of moist equatorial forests 2. Vegetation of sandy sea coasts in temperate latitudes of Western Europe 3. Plant formations of tundra swamps 4. Evergreen low-stemmed forests and shrubs in the tidal zones of the tropics 5. Wet Andean highland grasslands 6. Antarctic oasis wet grasslands 25
26 11. The origin of which physical-geographical country of Eurasia is associated exclusively with volcanic processes in the spreading zone of the mid-ocean ridge. 1. Alpine-Carpathian 4. Iceland 2. Himalayan mountains 5. Malay archipelago 3. Philippine islands 6. Iranian highlands 12. Which of the following physical and geographical countries is located in the subduction zone 1. Hindustan 4. Greenland 2. Japanese islands 5. Iceland 3. European Mediterranean 6. Fennoscandia 13. The top three countries by population include: 1. China, India, Russia 4. China, India, Indonesia 2. China, USA, Pakistan 5. China, India, Pakistan 3 China, India, USA 14. What air masses operate in the subequatorial climatic zone 1. Equatorial and tropical 3. Subequatorial 2. Tropical and temperate 4. Equatorial and subequatorial 15. What air masses operate in the subtropical climatic zone 1. Moderate and tropical 3 Temperate and subtropical 2. Equatorial and tropical 4. Subequatorial and tropical 16. What do the Scandinavian mountains, the Urals, Altai, Tien Shan have in common? 1. Altitude 3. Snow line height 2. Number and composition of altitudinal belts 4. Formation time 17. Which of the named countries is characterized by the following type of climate: “The average January temperature is above 0, in summer Precipitation falls fairly evenly throughout the year. Their number is more than 1000 mm per year”? 1. For UK 3. For Ukraine 2. For Italy 4. For India 26
27 18. The rivers of the large Sunda Islands are full of water throughout the year, as they are fed mainly by: 1. Groundwater 3. Snow melt water 2. Mountain glacier melt water 4. Rain water 19. northern islands- Iceland, Severnaya Zemlya, Svalbard? 1. They are located south of the Arctic Circle 2. Modern glaciation is common on their territory 3. There are many active volcanoes on their territory 4. They are located in the Pacific Ocean 20. The zone of mixed and broad-leaved forests is located only in the west and east of Eurasia, since broad-leaved trees : 1. They do not tolerate harsh winters and dryness 2. They are cut down by man in the central parts of Eurasia 3. They can grow only on the coasts of the oceans 4. In the central parts of Eurasia they do not receive enough heat in summer 21. Which natural zone of Eurasia is almost completely plowed up? 1. Steppes and forest-steppes 3. Taigas 2. Savannahs and light forests 4. Deserts and semi-deserts 22. Are the composition of altitudinal belts and the boundaries of their distribution on the southern and northern slopes of the Himalayas the same? Choose the answer with the correct explanation. 1. Yes, since the Himalayas are a single mountain system 2. Yes, since the northern and southern slopes receive the same amount of heat 3. No, since the northern and southern slopes are completely different in height 4. No, since the northern and southern slopes receive different amounts of moisture 23. The reason for the formation of the Caucasus and the Armenian volcanic highlands was: lithospheric plates 2. Rapprochement of the African lithospheric plate with Eurasia 3. Accession to Eurasia of the Hindustan Peninsula 4. Accession to Eurasia of the Arabian Peninsula 27
28 24. A monsoonal climate is formed in East and South Asia, because: 1. The western air transfer is replaced by the eastern one depending on the season. 2. In South and East Asia there are many mountain ranges that determine the direction of the winds 3. In summer there is practically no precipitation, and in winter their amount is very large 4. Over the vast territory of Asia and the oceans washing it, sharply different regions are formed in summer and winter pressure 25. The countries of which region are characterized by the following type of climate: “The average January temperature is from -18 in the north to -3 in the south, the average July temperatures reach +30. The average annual rainfall is 100 mm, in the mountains mm"? 1. South Asia 3. Central Asia 2. Northern Europe 4. Eastern Europe 26. Rivers flowing in areas of permafrost spread widely in spring and summer, because: 1. They are shallow 3. Water cannot seep into the ground 2. They have a very narrow channel 4. The frozen layer thaws very quickly 27. What is the difference between the Amur and Yangtze rivers? 1. The Amur floods in summer, and the Yangtze in winter 2. The Amur is fed by glaciers and rains, while the Yangtze is only glacial 3. The Amur freezes in winter, but the Yangtze does not 4. The Amur is fuller than the Yangtze 28. The main rivers of Southwest Asia are: 1 Indus and Ganges 3. Amu Darya and Syr Darya 2. Yangtze and Huang He 4. Tigris and Euphrates 29. Why do the Alps and the Scandinavian mountains have a different set of altitudinal belts? 1. They have different heights 2. They receive different amounts of rainfall 3. They receive different amounts of moisture 4. For all the above reasons 28
29 30. What is the uniqueness of Eurasia? 1. The largest continent 2. The continent is located in the Western and Eastern hemispheres 3. The continent is very diverse in nature 4. There are more plains on the continent than on other continents 31. Where is the border between Europe and Asia? 1. By state border Russia and European countries 2. By Western Siberia and the Pamir Mountains, Caucasus 3. Along the Ural Mountains, the Emba River, the northern coast of the Caspian Sea and the Kumo-Manych Depression 4. Along the Ural Mountains, the Ural River, the Caucasus Range, the Black Sea 32. Where in Eurasia are large oil and gas reserves concentrated? 1. In the mountains of Scandinavia 3. In Western Siberia 2. In the Pamirs 4. On the Great Chinese Plain 33. Along what coast of Eurasia does the zone of modern volcanism and earthquakes lie? 1. Northern 3. Western 2. Southern 4. Eastern 34. On what coasts of Eurasia does the monsoon climate form? 1. Northern 3. Western 2. Southern 4. Eastern 35. Does the Volga River belong to the basin? 1. Internal runoff 3. Pacific Ocean 2. Arctic Ocean 4. Indian Ocean 36. Oak and beech are most typical for the natural zone: 1. Taiga 2. Equatorial forests 3. Mixed and broad-leaved forests 4. Variably humid forests SE .Asia 5. Hard-leaved forests and shrubs of the Mediterranean 37. Which of the named peninsulas of Eurasia is less populated? 1. Hindustan 3. Iberian 2. Arabian 4. Indochina 29
30 38. Which of the listed animals live in Eurasia? 1. Bison, grizzly bear, raccoon, puma 2. Jaguar, tapir, lion, anaconda 3. Tiger, cheetah, orangutan, gibbon 4. Lion, leopard, gorilla, giraffe 30
31 Theme 12. The emergence and development of the oceans Purpose: to get acquainted with the patterns and processes that led to the emergence and development of the oceans. 1. Earth's tectonic plates are constantly changing. Using the knowledge gained in the course of historical geology, on the contour map show the boundaries of tectonic plates, arrows indicate the approximate direction of movement of the plates. Divergent plate boundaries can be highlighted in red, converging in blue. Think about why plates move. What could be the consequences of the movement of tectonic plates in the foreseeable geological future? 2. There are three main types of interaction between convergent boundaries of tectonic plates. Oceanic with continental. The oceanic crust is sinking under the continent; a mountain range is formed. Oceanic with oceanic. One of the plates crawls under the other; an island arc is formed. Continental with continental. There is a collision, deformation of the crust, a powerful folded area (mountain range) appears. Sketch these types of tectonic plate boundary interactions. Give concrete examples of the results of such interaction. 3. In the event of a collision, tectonic plates get processed into grandiose "factories" of subduction. The result of their work is volcanoes, earthquakes and the formation of mountain ranges. Analyze Figure 4. The Ring of Fire is a belt of intense volcanic and seismic activity almost entirely surrounding the Pacific Ocean at plate boundaries. This is the Earth's reaction to the destruction of the plates and the recycling of material through the subduction zones. Specify in which parts of the ocean the subduction zone has the most complex structure? How is it shown? In what regions of the Pacific seismic activity and volcanic activity are particularly intense? Explain the reasons for the identified patterns. 31
32 Fig. 4. Volcanic and seismic activity in the Pacific Ocean 32
33 4. In the Triassic period, there was only one supercontinent Pangea in the world, and a single, even larger ocean, called Panthalassa. Over the next 100 million years, Pangea split into parts, new continents, oceans and ocean straits were formed. Using the stratigraphic time scale (Table 6), briefly describe the history of the origin and development of the oceans. Table 6 Stratigraphic time scale (according to D. Stowe, 2007) Geological period Time (million years ago) Chervertic 0-1.8 Neogene 1.8 24 Paleogene Cretaceous Jurassic Triassic Major tectonic events Subduction of the Pacific Plate. The rifting of Africa has begun. Closing of the Tethys Sea; conflict between India and Asia. Continuation of the rifting of the Atlantic; Australia and India are drifting north. Pangea is divided into parts; The Atlantic is expanding; Tethys is shrinking. Rifting Pangea; the birth of the Atlantic. Merging of all continents into the supercontinent Pangea. Characteristic forms of Mammoth life; saber-toothed cats; modern people. Herbs; ungulate mammals; rodents; snakes; first hominins. First whales; Coral reefs; early ungulates; primates. calcareous plankton; angiosperms; placental mammals. modern fish; early mammals; first birds; dinosaurs. Sclerite (stony) corals; reptiles; first dinosaurs. 33
34 Permian Carboniferous Devonian Silurian Ordovician Cambrian Arthropods; first chordates. Proterozoic era Archean era Oceans and climate. Confluence of Gondwana and Laurasia; the birth of Siberia. The Tethys Ocean shrinks as Gondwana moves northward. Convergence of Southern Europe with the Baltic and Gondwana. Final closure of the Iapetus Ocean. Collision of the Baltic and Laurentia. The Iapetus Ocean narrows as the Baltic moves northward. Rodinia is divided into parts; the ocean of Iapetus opens. The supercontinent Rodinia is formed. The first microcontinents drift in the vast global ocean. Reefs of sponges and bryozoans; highly developed reptiles; similar to mammals. Coniferous plants; winged insects; the first highly developed reptiles (Late Carboniferous). seed plants; giant ground scorpions; the first reptiles (Early Carboniferous). Large land plants of the earth; ammonites; lungfish; sharks; amphibians. Vascular plants; jawed fish; the first land animals. Plate corals; jawless fish; spore land plants. multicellular organisms. Archaea; bacteria; cyanobacteria; stromatolites. 34
35 The oceans and atmosphere control the weather and stabilize the Earth's climate. But the modern pace global warming able to bring the planet to an extreme state. Using the data in the table, explain the mechanism of the greenhouse effect. What is the role of man in the process of unique and rapid global warming? List the possible consequences of global warming in the foreseeable future. What measures should the world community take to prevent global warming and the global ecological crisis associated with it? Table 7 Gases in the atmosphere Gas Concentration, % Contribution to the greenhouse effect, % Annual increase, % Nitrogen 78, Oxygen 20, Argon 0, Greenhouse gases Carbon dioxide Methane Chlorofluorocarbons Tropospheric ozone Nitric oxide 0.035 0.002 trace amounts trace amounts trace amounts -va,5 0.2 Theme 13. Morphometric characteristics of the oceans Purpose: based on the analysis of the maps of the "Atlas of the Oceans" to compile a comparative quantitative and qualitative morphometric characteristics of the oceans. 1. Compile a comparative morphometric description of the Atlantic, Indian, Pacific and Arctic oceans according to the following plan. 1 Underwater margin of the continents (length, dominant depths, number of volcanoes). 1 The task can be done in the form of a table. 35
36 Basins (average length, width, maximum depth, number of volcanoes). Underwater plateaus and beams (minimum depth, number of volcanoes). Mid-ocean ridges (width, depth marks in the axial part, depth rift zone, number of transform faults, volcanoes). Volcanoes (surface, underwater) and earthquake epicenters. Maximum depths of the oceans (names of trenches, basins). Islands (continental, oceanic, coral). 2. Familiarize yourself with the main morphometric parameters of the oceans presented in Table 8. Construct circular or bar charts that characterize the areas, average depths and volume of the oceans' water mass. Draw conclusions. Table 8 Morphometric parameters of the oceans (according to D. Stow, 2007) Atlantic Ocean Area km 2 Average depth m Maximum depth m (Milwaukee basin) Volume km 3 Main plates African, Eurasian, North American, South American Small plates Caribbean, Anatolian Oldest oceanic crust 175 Ma (mid-Jurassic) Gulf of Mexico Area km 2 Average depth m Maximum depth m Volume km 3 Caribbean Sea Area km 2 Average depth m Maximum depth m (Cayman Trench) Volume km 3 North Sea Area km 2 Average depth 94 m Maximum depth 700 m (Skagerrak) Volume km 3 36
37 Mediterranean Sea Area km 3 Average depth m Maximum depth m (Gellen Trench) Volume km Indian Ocean Area km 3 Average depth m Maximum depth m (Javan Trench) Volume km 3 Main plates African, Indo-Australian, Antarctic Small plates Arabian Oldest oceanic crust 120 Ma (early Cretaceous) Pacific Ocean Area km 2 Average depth m Maximum depth m (Marian Trench) Volume km 3 Main plates Pacific, Nazca, Antarctic, Indo-Australian Minor plates Philippine, Gorda, Cocos Oldest oceanic crust 150 million years (Late Jurassic) South China Sea Area km 3 Average depth 520 m Maximum depth m Volume km 3 Arctic Ocean Area km 2 Ocean Average depth 990 m Maximum depth m (Molloy Basin) Volume km 3 Main plates North American, Eurasian Oldest 55 Ma (Paleogene) oceanic crust Southern Arctic Area km 2 Ocean (Antarctic) Average depth m Maximum depth (South Sandwich Trench) Volume km 3 37
38 Main plates The oldest oceanic crust Antarctic 120 million years (beginning of the Cretaceous period) Topic 14. Quantitative and qualitative comparative characteristics of the oceans Purpose: based on the analysis of maps of the Atlases of the Oceans, to compile a quantitative and qualitative characteristic of the thermal regime, physical, chemical properties and water dynamics oceans. 1. Compile a comparative quantitative and qualitative characteristic of the oceans according to the following plan. 2 Thermal regime Total solar radiation in equatorial, tropical, temperate and subpolar latitudes. Maximum values of total solar radiation (indicate specific water areas, explain the reasons). Minimum values of total solar radiation. Radiation balance in equatorial, tropical, temperate and subpolar latitudes. Maximum values of the radiation balance. Minimum values of the radiation balance. Physical properties of water Temperature of surface waters (in January-February, July-August) in equatorial, tropical, temperate and subpolar latitudes. Maximum temperatures of surface waters (indicate water areas). Minimum surface water temperatures. Salinity of surface waters (in February, August) in equatorial, tropical, temperate and subpolar latitudes. 2 The task can be done in the form of a table. 38
39 Maximum salinity of surface waters (in February, August). Minimum salinity of surface waters (in February, August). Regularities of surface water density distribution (in February, August) in equatorial, tropical, temperate and subpolar latitudes. Maximum density of surface waters. Minimum density of surface waters. Chemical properties of water Provision of water with dissolved oxygen. Water dynamics Maximum wave height (in January, July) in equatorial, tropical, temperate and subpolar latitudes. Draw conclusions. Topic 15. Comparative characteristics of the geographical location, area and configuration of North America and Eurasia Purpose: based on the analysis of maps, to identify the significance of the geographical location, area and configuration of North America in the formation of its nature. Compare on these grounds North America with Eurasia. 1. Reveal the influence of the geographical location, area, configuration of North America on the formation of its nature. According to the physical map of North America and the table of general information about the continents in the atlas, determine the names of the extreme northern and southern points of the mainland and island land of the mainland, their geographical latitude, the distances between them in degrees of latitude and kilometers. According to the maps of the radiation balance, geographical zones and zones, determine what consequences a significant
40th meridional extent of North America. Compare North America in terms of a set of geographical zones with other continents. Draw conclusions. 2. Based on the physical map of North America and the table of general information about the continents, determine the names and geographic longitude of the extreme western and eastern continental and island points of North America, its greatest extent from west to east in degrees and kilometers. To determine the areas of North America that are the most remote from the Atlantic and Pacific oceans, to identify the consequences of the significant remoteness of the continental regions of the mainland from the oceans. Using a map of annual precipitation, determine the differences in this feature between the oceanic and inland sectors of North America. 3. On the map, determine the configuration of North America, identify areas of the greatest and least dissection of the coastline. Compare with Eurasia and Africa. To reveal the influence of the degree of interpenetration of the sea and land on the nature of the mainland. Mark the areas of North America in which the island and peninsular land occupies the largest area. Determine the implications of this. 4. Using the maps of the atlas, trace the direction of warm and cold ocean currents near the coast of North America, the position of the average boundary of floating ice. Find out the features of the influence of each of the oceans on the formation of the climate of the mainland. 5. Compare the position of North America in relation to Eurasia, South America, Antarctica. What is the proximity of North America to these continents in the geological past and at the present time? How does the mutual influence of these continents affect the nature of North America? 6. Make a comparative description of the geographical location of North America and Eurasia. 40
41 Theme 16. The relief of North America Purpose: to identify the features of the placement of various types of plains and mountains in connection with the tectonic structure of North America; reveal the role of relief in the spatial differentiation of the nature of the continent; get acquainted with the features of the manifestation of the Quaternary glaciation in North America in comparison with Eurasia and its influence on the nature of the mainland. 1. Using the physical map of the atlas, identify the features of the location of the plains and mountains of the continental and island land of North America. Compare the relative positions of plains and mountains in North America and Eurasia. 2. For flat areas, determine the main directions of surface slopes, the watershed between the basins of the Arctic Ocean and the Gulf of Mexico, the direction of change in heights and surface slopes for the Hudson Lowland, Laurentian Plain, Central, Great and Coastal Plains. What hypsometric levels are typical for these plains. To determine the influence of the orography of the Extra-Cordillera East on the circulation climate-forming processes. 3. Determine the main directions of the ranges in the Cordillera and other mountain systems of the mainland. Explain which of the mountain systems and why plays the most important role in the differentiation of the nature of the continent. What is this role? 4. Conduct an oral analysis of the tectonic map of North America. Determine the types and relative positions of tectonic structures of the highest taxonomic rank. List the main orographic units within each type of structure. According to the geological map, determine the age of the rocks of the sedimentary cover of the plates of the ancient and young platforms, the features of their occurrence. 5. Analyze the map of the Quaternary glaciation of North America (Fig. 5). In what directions was the movement 41
42 Fig. 5. Quaternary glaciation of North America ice from different centers? How are the boundaries of the Wisconsin glaciation expressed in relief, and how do they relate to the position of the lakes? Compare the area of Quaternary glaciation in North America and Eurasia, the position of the southern boundaries of the distribution of ice on both continents. Formulate an assumption about the conditions that contributed to a larger area of glaciation in North America. 42
43 Topic 17. Climate of North America Purpose: to learn the features of the formation of the climate of North America, the climatic zoning of the mainland, to identify similarities and differences in the climate of North America and Eurasia. I. Climate of the winter season 1. Conduct an oral analysis of the map of atmospheric pressure and wind directions in January over North America and adjacent parts of the ocean. Indicate the reasons why the continental pressure maximum is less clearly expressed over North America in winter than over Eurasia. 2. Using the map, determine the areas of the mainland whose climate in winter is formed under the predominant influence of cyclonic circulation on the Arctic and polar fronts. To trace the directions of movement of the trade winds flowing from the North Atlantic High, to identify the territories and water areas in the climate formation of which the trade wind circulation plays a significant role in winter. To determine which areas the influence of the North Pacific maximum is limited in winter and how it manifests itself. 3. On the map of air temperatures in January, trace the course of the isotherms, paying attention to their more southerly position in the inland regions than in the oceanic regions. What are the reasons for this pattern? Show the course of the isotherm 0 0 C, compare with its course in Eurasia, over the Atlantic and Pacific oceans. Identify areas of North America with the highest and lowest average monthly and absolute temperatures. 4. Using the January isoanomaly map (Fig. 6), determine the areas of North America with positive and negative deviations of the average monthly temperature in January from the average latitude. Compare on this basis North America with Eurasia. Determine on which of these continents in winter the influence of the systems of warm currents of the Atlantic and Pacific oceans is more pronounced. 5. Using the map of the seasonality of precipitation, determine the areas of the mainland with the winter maximum precipitation; areas with approximately equal amounts of winter and summer precipitation; areas with a pronounced minimum of precipitation. What processes and factors 43
44 Fig. 6. Map of isoanomalies in January for North America The formation of the climate of the winter season is caused by each of the listed precipitation regimes? 6. Formulate generalizing conclusions about the main processes and factors of climate formation in the winter season in Northern 44
45 America, about thermal conditions, atmospheric humidification of this season. II. Climate of the summer season 1. Conduct an oral analysis of the map of atmospheric pressure and wind directions in July over North America and adjacent ocean areas. Determine what changes have occurred in comparison with the January situation. Compare with Eurasia. What is the prevailing direction of the winds in different parts of the mainland: in high latitudes, east of the west meridian; in the Pacific sector; in Central America and the West Indies? What air masses move in these directions? To identify the main directions of movement of the trade winds flowing from the North Atlantic and North Pacific highs. Identify areas whose summer season climate is strongly influenced by the trade wind circulation. Identify areas most prone to cyclonic circulation. 2. Compare North America and Eurasia according to the position of the July isotherms. Draw conclusions. 3. Determine the areas of North America in which the summer maximum of precipitation is clearly expressed, the summer minimum of precipitation. What processes and factors of summer season climate formation are associated with these types of precipitation regime? 4. To formulate conclusions about the main processes and factors of climate formation in the summer season in North America, about thermal conditions and atmospheric humidification of this season. III. Precipitation and Humidification 1. Analyze a map of precipitation in North America. Determine the main directions of change in the amount of precipitation, sector in the humidification of the mainland. Explain the reasons for the identified patterns. Track the change in annual precipitation from north to south on the Pacific and Atlantic coasts, in the interior of the mainland. In what areas is the differentiating role of the relief in precipitation most clearly manifested? Justify the conclusions on specific examples. 45
46 2. On the map to establish patterns of changes in evapotranspiration in North America. Based on a comparison of maps of annual precipitation and evaporation, the difference in evaporation and precipitation, list the areas of the mainland with a negative and positive balance of moisture. IV. Climatic zoning of North America 1. Conduct an oral analysis of the map of climatic zoning of North America. Determine which climatic regions of the temperate and subtropical zones in North America have analogues in Eurasia; what are the similarities and what are the differences between them; on which of the northern continents monsoon climate types are better expressed; Why? To characterize the climatic regions of the tropical zone in North America and compare them with the climate of the tropical zone in Eurasia. Explain the differences in the zoning of the tropical belt on these continents. Topic 18. Surface waters of North America Purpose: to identify patterns of territorial distribution of the surface waters of the mainland. 1. Based on a physical map, determine the watersheds between the basins of the Pacific, Atlantic and Arctic oceans. To identify where the watersheds are orographically well expressed, and where weakly and why? 2. Based on the physical map, identify areas with different density of the river network, determine the reasons for the differences in its distribution. Select areas of internal flow, drainless. Explain the reasons for their occurrence. 3. To identify areas of mass accumulation of lakes, the prevailing types of lakes according to the genesis of the basins. Compare geographical position lake regions of North America and Eurasia. 46
47 Fig. 7. Annual flow of North America 4. Analyze the map of the river flow of North America (Fig. 7). To establish patterns of its distribution over the territory 47
48 mainland rii. State the reasons why the northern lowlands, with relatively little annual rainfall, have more significant runoff than most of the Great Plains, where annual rainfall is higher. What are the reasons for the low runoff in Florida, the Yucatan, the Great Basin, the Colorado Plateau? 48 Topic 19. Geographic zonality and vegetation of North America Purpose: to learn the structure of the geographical zonality of North America, compare it with the zonality structure in Eurasia, and characterize geographical zones. To identify the main types of vegetation in North America, to establish patterns of their distribution, floristic composition, to compare with similar types of Eurasia. 1. Describe the structure of zoning in North America. Explain the reasons for the sublatitudinal strike of zones in the northern part of the mainland and the submeridional strike in the southern part. Compare: in which parts of Eurasia the zones also have submeridional strike and what is it connected with. 2. Conduct an oral analysis of the vegetation map of North America. Compare patterns of vegetation change in North America and Eurasia, identify similarities and differences, and the reasons that determine them. 3. Reveal the features of the meridional change of vegetation types in the Pacific and Atlantic sectors of the continent, explain the reasons for the differences between them. Individual tasks 4. Make oral reports about the following plants of North America: giant thuja; Sitka spruce; banks and weymouth pine; balsam fir; pseudo-hemlock (Douglas fir); hickory
49 (hickory, hazel); evergreen sequoia and giant sequoia (mammoth tree); mexite shrub; creosote shrub. Plant characteristics should reflect: morphological and physiological features, plant ecology, range in North America and beyond, human use. Illustrate the messages on a multimedia projector with photographs or drawings. When preparing for reports, use articles from encyclopedic, reference publications, literary sources, the Internet. 5. Based on cartographic materials, identify landscape analogues in Eurasia of one of the following regions of North America. Mexican Lowland; Central Plains; Coast Range of Canada; Great Basin; Alaska; Laurentian Plain; the Florida peninsula; California State; Greater Antilles; Cascade Mountains; Rocky Mountains; Labrador Peninsula, Newfoundland, Colorado Plateau. Comparing physical and special maps, establish a region of Eurasia similar to a given region based on a complex of geological, geomorphological and bioclimatic features. Establish similarities and differences between analogue regions, explain their reasons. Make a conclusion about the degree of similarity of the nature of the regions: significant analogy (similarity in most of the main features); weak analogy (similarity in one of the groups of signs of geological, geomorphological or bioclimatic); lack of analogy (there is no analogue of the given region of North America in Eurasia). Theme 20. The geographical position of the southern tropical continents (Africa, South America, Australia) Purpose: to identify similarities and differences in the geographical position of Africa, South America and Australia; define it 49
50 influence on the nature of these continents; compare the geographical position of the southern tropical and northern continents. 1. Based on the analysis of physical maps and a table of general information about the continents in the atlas, identify similarities in the latitudinal position of Africa, South America and Australia. 2. Reveal the features of differences in the latitudinal position of the continents and determine the associated features of their nature. 3. Identify the main differences in the latitudinal position of the southern tropical and northern continents; causes and geographic consequences of these differences. 4. Using maps, to identify similarities and differences in the thermal features of sea currents near the western and eastern coasts of Africa, South America and Australia; consequences of the influence of these currents on the nature of adjacent land areas. 5. Determine how the latitudinal position of Africa, South America and Australia is manifested in the ratio of arid and humid landscapes on each of the continents. Which of these continents and why is the most humid, which is the least? 50 Topic 21. History of the formation and relief of the southern tropical continents Purpose: to compare the southern tropical continents in terms of their orography and hypsometry to identify similarities and differences between them, reflecting the history of the formation of the continents. Familiarize yourself with the provisions of the hypothesis of the movement of lithospheric plates about the main stages in the formation of the Gondwanan continents of Africa, South America, Australia, Antarctica. 1. Compare the continents by prevailing, maximum and minimum heights. Using tectonic maps, determine which structures are associated with the highest absolute heights for each
51 houses from the mainland. Formulate conclusions about the similarities and differences between the southern tropical continents in terms of their orographic structure and hypsometry. Using climatic maps and a map of geographical zones and zones, determine the role of relief in the territorial differentiation of nature on each of the southern tropical continents. 2. Analyze the geological and tectonic maps of the southern tropical continents in geochronological order. Using the method of comparison with physical maps, to reveal the significance of the geological structure in the formation of the modern relief. When analyzing maps within platform areas, identify protrusions (massifs, shields) and depressions (syneclises, basins) of the basement, determine the age and features of the occurrence of rocks in them; especially highlight depressions with a thick cover of Quaternary deposits. 3. Make a description of the main stages in the formation of the southern continents. 1. Formation of the Precambrian crystalline basement of the African, South American, Indian (Indo-Australian) and Antarctic platforms. 2. Paleozoic stage of development of the continents; Caledonian and Hercynian folding; marine transgressions; Permo-Carboniferous glaciation. 3. Mesozoic stage: a) formation of the supercontinent Pangea (200 million years ago); b) division of Pangea into Laurasia and Gondwana at the end of the Triassic (180 million years ago); the formation of a rift zone that separated the African-South American block from the Australo-Antarctic one; opening of the Indian Ocean and North Atlantic Ocean; rifting on land, outpouring of effusives, formation of trap covers of Parana and East Africa; d) the beginning of the opening of the southern part of the Atlantic Ocean and the drift to the west of South America at the end of the Jurassic (135 million years ago). 4. Cenozoic stage: a) separation of Australia from Antarctica; b) connection by the Isthmus of Panama of South and North America; c) the separation of the Arabian Peninsula and its attachment to Eurasia; d) accession to Eurasia of the Indian platform; e) the current position of the continents. 51
52 Determine the similarities between the southern tropical continents associated with their common origin: by configuration, dissection of the coastline, prevailing tectonic structures, floristic and faunal composition of the organic world, as a result of the former connections of these continents. 4. Among other continents, Africa is distinguished by significant reserves and extraction of certain types of mineral resources: diamonds, gold, cobalt, titanium, chromites, manganese ore, antimony, phosphorites, copper, asbestos, uranium, and to a lesser extent oil and iron ore. Conduct an analysis of a map of mineral deposits in Africa, with particular attention to the mineral resources listed above. Establish a connection between the location of each of these minerals with tectonic structures and the age of the host rocks. Identify regional features of the placement of these resources and their relationship with geological structure. 52 Topic 22. The structure of the geographical zonality of the southern tropical continents Purpose: to identify the features of the manifestation of the law of geographical zonality on tropical continents. 1. Analyze the map of geographical zones and zones within the southern tropical continents. Please note that in the "Geographical Atlas" tropical, subequatorial and equatorial climatic zones are combined into a single (equatorial-tropical) geographical zone, since the energy base of natural processes within these climatic zones, the radiation balance has very close indicators (70-75 kcal / cm 2 per year, or MJ / m 2 per year). Determine which landscapes of which geographical zones are widespread on the territory of all three continents, and which are more limited.
53 2. On the basis of literary and cartographic sources, make a brief quantitative and qualitative description of the natural zones of the southern tropical continents according to the following plan. The name of the natural area. Geographical zone. Sector Annual total solar radiation. Annual radiation balance. Average air temperature in January. Average air temperature in July. Minimum air temperature. Maximum air temperature. Sum of active temperatures. The length of the growing season. dominant air masses. Annual amount and annual course of precipitation. Evaporation. Moisture coefficient. Features of biochemical processes and the exchange of matter and energy between the organic and mineral parts of nature. The main features of the vegetation cover. Annual increase in biomass. Peculiarities of soil formation and soil cover. The main features of the animal world. Assessment of natural conditions. anthropogenic factor. Types of altitudinal zonality. Theme 23. Climate and agro-climatic resources in Africa Purpose: to identify characteristics climate of Africa, the role of heat and moisture in the spatial differentiation of its nature, to master the schemes of climatic zoning and agro-climatic resources of the mainland. 1. Reveal the influence of geographical location, configuration, relief on the formation of the climate of Africa as a whole and its various 53
54 parts. Assess the significance of the latitudinal position of the continent for the influx of solar radiation. 2. Analyze the radiation balance map; explain the small range of its indicators in Africa. Compare changes in the radiation balance in Africa and in northern continents; in Africa and South America, Australia. Determine the role of the radiation balance in the territorial differentiation of the nature of Africa. 3. Using maps of atmospheric air pressure and winds in January and July, find out how air pressure and wind directions change seasonally in Africa. What positions does the baric minimum occupy in these months within the tropical convergence zone? What is the impact on the circulation of the atmosphere over Africa of the North Atlantic, South Atlantic and South Indian subtropical maxima? Select areas of Africa, the climate of which is formed under the influence of the trade wind and equatorial-monsoon circulation of air masses. 4. Analyze a map of annual rainfall in Africa. Pay attention to the unevenness and contrast of their distribution on the mainland. Explain the reasons for this phenomenon. Determine how many times the amount of precipitation decreases from Cameroon to the Sahara. To trace the course of the 1000 mm isohyet, which outlines the humid territories of the mainland. Compare the size of the territory within the 1000 mm isohyet in Africa, South America, and Australia. Carry out similar comparisons of the areas covered by isohyets 2000 mm, 200 mm (the latter outlines arid regions). Remember, the boundaries of which natural zones are outlined by these isohyets? 5. Explain the reasons for the pronounced latitudinal zonality in the distribution of atmospheric precipitation in the Northern (Sudano-Saharan) subcontinent, which manifests itself in the west-east course of isohyets with slight deviations from this direction. 54
55 6. Identify and explain the features of the territorial distribution of precipitation in the Southern subcontinent. Compare the humidification of the western coasts of southern Africa, South America and Australia. Determine the conditions for the formation of an arid climate in these areas, which extends into Africa and South America almost to the equator. 7. Analyze maps of precipitation seasonality, evapotranspiration, the difference between precipitation and evapotranspiration. Draw conclusions about the patterns of territorial changes in these indicators in Africa. 8. According to the provision of agricultural plants with heat, most of the mainland, excluding the highlands, northern and southern outskirts, belongs to the tropical agro-climatic zone with continuous vegetation. The main differentiating agro-climatic factor is moisture, which varies greatly across Africa. Analyze the agro-climatic map of the "Geographical Atlas" and establish patterns of moisture changes in Africa. Compare them with the patterns of territorial distribution of annual precipitation amounts. 9. Based on the analysis of maps, identify climatic analogues in South America and Australia in one of the following regions of Africa: the Namib Desert; the Kalahari semi-desert; Ethiopian highlands; basin of the Congo; north coast of the Atlas; Mozambique lowlands. Theme 24. Surface waters of Africa Purpose: to determine the patterns of geographical distribution of the river and lake network in connection with the climate and topography of the mainland. 1. Based on the physical map, identify the regularities in the distribution of the river network across Africa. Reveal areas with dense 55
56 and a rare network of rivers; areas without rivers. Determine what factors in Africa are associated with the extremely uneven distribution of the river network. 2. Identify parts of the mainland where rivers have a high permanent water content; high in summer and low in winter; high water content in winter and low in summer; episodic runoff (ephemeral rivers). 3. Using a physical map, identify areas of accumulation of lakes in the Eastern, Northern and South Africa. Determine the differences between the groups of lakes according to the origin of their basins and the characteristics of the water mass. Pay attention to the location, configuration and relationship with the rifts of the East African Great Lakes group. 4. Analyze the map of the annual river runoff in Africa (Fig. 8) and identify patterns of territorial changes in the values of the annual runoff layer. Determine how they are consistent with the patterns of changes in precipitation. Theme 25. Geographical zones and zones of Africa Purpose: to identify patterns of geographical zonality in Africa, to characterize natural zones. 1. Compile a written description of each natural zone, which includes: the geographical location of the zone within the belt; composition of the territory of the zone (main orographic units); type of climate prevailing in the zone; annual precipitation; precipitation regime; duration of the wet period; duration of dry and dry periods; the type of river water regime prevailing in the zone; dominant types of vegetation and their floristic composition; dominant zonal soil types; characteristic representatives of the animal world; main types of land use; commercial crops. 56
57 Fig. 8. Africa's annual runoff 2. Learn the position of geographical zones and natural zones, be able to show them on a physical map. To formulate conclusions about the structure of geographical zonality in Africa, about the differences in this feature between the northern and southern subcontinents of the mainland, about zonality as the most important manifestation of the territorial differentiation of Africa's nature. 57
The list of skills that characterize the achievement of the planned results of mastering the main educational program in subject"Geography" in grade 7 CODE Tested skills 1. SECTION "NATURE OF THE EARTH"
Tasks A4 in geography, practice, Tasks A4 in geography 1. What natural zone is characterized by chernozem soils? 1) mixed forests 2) steppes 3) taiga 4) deciduous forests Correct answer 2. Chernozem
Calendar-thematic planning Physical geography. Continents and oceans. Grade 7 Name of the topic of the lesson Content of the topic Characteristics of species learning activities Date p / p plan fact note Section
Municipal budgetary educational institution"Average comprehensive school 1, Sovetsky "Demo version of control and measuring materials for conducting intermediate certification in geography,
Latitudinal zonality of the geographic shell Lecturer: Soboleva Nadezhda Petrovna, Associate Professor of the Department. GEHC The geographical shell has a structure that is expressed in the phenomenon of zoning. The law of geographical
Calendar-thematic planning in geography. Using the textbook Dushina I.V., Korinskaya V.A., Shchenev V.A. "Geography. Continents, oceans, peoples and countries. Moscow, "Drofa", 2009 lesson 1
calendar thematic plan Topic of the section, lesson Number Terms of p / n hours Introduction 3 What does the physical geography of the continents study. Continents and parts of the world. 2 Practical work: Learning how to work with sources
Municipal budgetary educational institution "Secondary school 10" CONSIDERED: ACCEPTED: Appendix to the order At a meeting of the MS at pedagogical council MBOU "School 10" From "23"
Factors that determine the general structure of the soil cover of the continent………………………………………………………………..………2-4
Soil-geographical zoning of South and Central America……………………………………………………………………………..5
Soil cover of equatorial and tropical humid forest areas………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………6-19
Soil cover of savanna-xerophyte-forest areas……………...20-27
South American meadow-steppe sector……………………………28-34
Southern Pacific subboreal forest sector……………...35-36
Agricultural use of the soils of South America. Agricultural crops……………………………………..……… 37
Bibliography…………………………………………………...……… ..38
FACTORS DETERMINING THE GENERAL STRUCTURE OF THE SOIL COVER OF THE CONTINENT
The general nature of the soil cover of South America is determined by: the significant length of the continent in the meridional direction; the presence of a mountain barrier along the western coasts; the predominance in the equatorial, tropical and subtropical zones of the eastern transfer of moisture from the Atlantic Ocean, the presence of the cold Peruvian Current along the Pacific coast; the predominance of the western transport of moisture in the temperate zone of South America and the presence of the cold Falkland current along the coasts of Patagonia; distribution in the equatorial and tropical belts of ancient leveling surfaces with a thick ferralitic, often strongly lateritized weathering crust; distribution in the subtropical part of the continent of alluvial plains; the presence of active volcanoes and associated volcanogenic sediments in the northern and southern Andes.
South America is the only continent in the southern hemisphere that extends into the temperate and cold temperate zones. Five geographical zones cross it: northern tropical, equatorial, southern tropical, subtropical and temperate. The largest and widest part of the continent lies in the equatorial-tropical latitudes.
The continent is protected from the west by the high barrier of the Andes, which, along with the direction of humid air masses, determines the nature of the moistening of the adjacent plains. The latter is especially pronounced in the south of the continent, where the western transfer of air masses predominates. The western slopes of the Andes in southern Chile receive 2000-5000mm precipitation, and Patagonia lying in the rain shadow - 150-250mm. The arid climate of Patagonia is aggravated by the presence of the cold Falkland Current along the Atlantic coast. Therefore, the plains of the temperate zone of South America, regardless of the fact that they lie in the eastern oceanic sector, are dominated by landscapes and soils of desert steppes and deserts.
In the subtropical zone, on the contrary, the eastern transfer of moisture from the Atlantic Ocean and the maximum amount of precipitation (1000-2000mm) falls on the east coast; inside the continent, as the sea air masses transform, the amount of precipitation decreases to 300-400mm. These are the arid regions of the inner Pampas and the province of Gran Chaco. The meridional stretch of the humidification zones determines the same direction of the landscape and soil zones: in the north of the eastern most humid part, there are subtropical moist forests on red soils and tall-grass prairies on chernozem-like soils; in the more inland regions of the dry pampas there are subtropical chernozems, and in the Andean part, in the Gran Chaco, there are subtropical dry and desert steppes on gray-brown soils in combination with solonetzes and solonchaks.
The Pacific coast and the western slopes of the Andes in the subtropical and tropical zones receive the minimum amount of precipitation, as they are under the influence of cold southeastern and southern air masses coming from the eastern periphery of the Pacific anticyclone. The dryness is exacerbated by the cold Peruvian current running along the western coasts of the continent. Desert landscapes and soils dominate here with pronounced phenomena of salt accumulation both on the low coasts and on the high uplands. Only to the north of the equator are the western slopes of the Andes moistened more than the eastern ones, due to the bringing of moisture from the Pacific Ocean by southwesterly winds.
In the equatorial zone, on the plains in the river basin. The Amazons, lying east of the Andes and receiving moisture from the Atlantic Ocean, the climate is the most humid, precipitation from 2000 to 5000mm, no significant dry period. Moist equatorial tropical forests on yellow ferralite soils predominate. To the north and south, somewhat asymmetrically with respect to the equator, are tropical regions, where 2000-1000mm rainfall and a dry period lasting from 3 to 5 months. These are zones of seasonally humid tropical forests and savannahs on red ferrallitic and alferritic soils, no less poor than the soils of permanently humid forests; they are associated in their distribution with the ancient ferrallitic weathering crust covering most of the surface of the Brazilian and Guiana highlands.
On the inland, arid plateaus somewhat isolated from the Atlantic Ocean, in the northeastern part of the Brazilian Highlands, the climate is drier, which is the reason for the appearance of xerophytic shrubs and light forests on red-brown and red-brown soils.
On the whole, in the equatorial and tropical zones, the humidification zones coincide with the direction of the thermal belts; therefore, the latitudinal zonality of landscapes and soils is expressed in this part of the continent.
The extensive alluvial plains of the Amazon and Parana river basins are associated with the distribution of modern superaquatic and paleohydrogenous landscapes and soils.
A series of mountainous soil zones are associated with the mountain ranges and uplands of the Andes, which are significantly different in the northern, central, and southern Andes.
SOIL GEOGRAPHICAL ZONING OF SOUTH AND CENTRAL AMERICA
There are seven soil sectors in the territory under consideration: the Equatorial Pacific Oceanic humid forest, the Equatorial American–African humid forest, the Southern Atlantic humid forest, the American–African savanna–xerophyte–forest, the South American meadow–steppe, the Andean–Patagonian desert, and the Southern Pacific subboreal forest. Some sectors are closed within the continent and have a small extent.
Some sectors continue in Africa and form "bridges" between the two continents. The mountainous volcanic regions of Central America and the northern Andes are part of the Equatorial Pacific humid forest sector, which includes Malaysia and New Guinea. The Southern Pacific Forest Sector links Southern Chile with New Zealand.
According to the nature of the macrostructure of the soil cover, a number of soil areas are distinguished:
1) mountainous areas of the Andean belt, with a combination of mountain zonal bioclimatogenic and volcanogenic macrostructures: Central American, Equatorial Andean, Central Andean, Chilean-Ognezemelskaya;
2) areas where a combination of elements of plain and mountain zonal bioclimatogenic structures with paleoclimatogenic and disordered lithogenic structures is observed: Caribbean, Central Brazilian, East Brazilian, Atlantic;
3) areas where plain-zonal bioclimatogenic macrostructures are combined with paleohydrogenic and modern hydrogenic ones: Amazonian, Eastern Pampa region;
4) the areas of predominance of bioclimatogenic are plain-zonalxstructures: Paraguayan-Predandian, South Argentinean-Patagonian.
SOIL COVER IN EQUATORIAL AND TROPICAL MOISTURE FOREST AREAS
South America includes, in part or in full, three humid forest sectors: the Equatorial Pacific, the Equatorial American-African, and the South Atlantic. The equatorial Pacific sector is represented by two mountainous regions: Central American and Equatorial Andean; Equatorial American-African sector - one large Amazonian region, including several soil districts; The southern Atlantic sector - the Atlantic.
Central American soil region
The narrow strip of land in Central America is characterized by a significant variety of bioclimatic and lithological-geomorphological conditions and, accordingly, soils.
According to the nature of the relief, this territory is divided into the eastern low-plain part and the western - mountainous. The highest mountain ranges of the Southern Sierra Madre and Eastern (volcanic) Sierra Madre, stretching along the coasts of the Pacific Ocean, rise to abs. high 3700-3800 l, and at the highest points exceed 4200-4500m.
The mountain ranges of Central America are composed of a complex of various Cretaceous and Paleogene sedimentary rocks, among which limestones occupy a significant place. According to the nature and structure of the soil cover, the Central American region is divided into two sub-regions: the western mountainous and the eastern mountainous-plain. The western mountainous sub-region includes the mountain ranges named above and the high plateaus of the Mexican Central Mesa, lying at 2000-2500m.
The composition and structure of the soil cover in this area are significantly different on the windward, wet, and leeward drier mountain slopes and on high intermountain plateaus.
The southwestern slopes of the Southern Sierra Madre and the eastern slopes of the Eastern Sierra Madre, covered with deciduous tropical forests, humid mixed forests and occupied by red ferrallitic tropical soils, and dark red ferrallitic soils on the rocks of the main composition, are the most moistened.
Eastern (Volcanic) Sierra Madre is a country of modern grandiose active volcanoes; the largest of them are Colima, Popocatepetl, Orizaba. Volcanic ash covers mountain slopes and highlands, basaltic lava flows and volcanic mudstone flows fill intermountain depressions. Water-soluble products of volcanic eruptions, chlorides, sulfates are removed and accumulated in local relief depressions - basins filled with lacustrine deposits. The snow line in the Eastern (Volcanic) Sierra Madre is at an altitude of 4500m. The upper vertical zone is formed by subalpine and alpine mountain meadow soils.
On better moistened mountain slopes under forest vegetation, the soils are similar to red and yellow soils. Within the Central Mesa and on the highlands in the river basin. Balsac, dark-colored soils on volcanic ash and weathering products of basic lavas are widespread. These soils contain about 5% humus, slightly acidic, neutral or slightly alkaline in the upper part, slightly clayey in the lower part of the profile, in some places with a carbonate accumulation horizon. Solonchakous dark-colored meadow soils and solonchaks of sulfate-chloride-soda and soda composition appear in local relief depressions (Gerasimov, 1968). The natural vegetation of the highlands is represented by a grassy savanna dominated by Gramme grass and aristids with acacias, cacti and agaves in the tree layer.
Central Mesa is the most populated and used agricultural region in Mexico.
The eastern mountain-plain subregion of the Central American soil region has a more humid climate. Dry periods are not expressed here, forest vegetation dominates everywhere: on the plains - tropical rainforests, on the mountain slopes - mixed, with tree ferns. Both on the plains and in the mountains, powerful ferrallitic weathering crusts with red-yellow and yellow ferrallitic soils are everywhere developed. In the higher belt of mountains, high-humus mountain ferralitic and allitic soils appear. Above 3800m - zone of acidic peaty mountain-meadow soils.
On the Yucatan Peninsula, composed of limestones, dark red ferralitic soils are more saturated and richer in humus than the rest of the soils of the piedmont plains. With a close occurrence of limestones, red-brown soils saturated with bases are formed on its eluvium. Here the slopes are terraced in places - these are traces of the ancient agricultural culture of the Mayan Indian tribe.
The coastal lowlands are occupied by groundwater sandy lateritic and bog soils, moving with sandy illuvial-ferruginous-humus podzols.
The very low economic level of development of the countries of Central America does not allow the use of even the best lands of this vast territory.
Equatorial Andean soil region
This predominantly mountainous region includes a system of mountain ranges that converge near the equator and fan out to the north. Mountains rise above 5000m; the highest peaks are volcanoes. In some places, for example, in the Eastern Cordillera, there are extensive leveled surfaces lying on the abs. high 2500-3000m. Most of the leveled surfaces are covered with thick layers of volcanic ash. There are a number of active or recently extinct volcanoes. In Ecuador, most soils, even on steep slopes, are developed on volcanic ash. They got the name "Andosols". These soils have a thick humus dark horizon, with interlayers of ash turning deeper into brownish or reddish-yellow.
Andosols are characterized by: allophane composition of the clay fraction, high absorption capacity, ability to absorb not only cations, but also anions, in particularPO4, a large number of movable Al, very low bulk density due to the porosity of volcanic glass. In a humid climate, Andosols are a stable type, especially with the periodic supply of new volcanic material.
On the plateaus of the Eastern Cordillera, at altitudes of 2200-I 3200 m near the capital of Colombia - Bogota, in a temperate warm climate, with average monthly temperatures of about 14-I16 ° C, corn, wheat, beans, potatoes are grown on Andosols.
Above 3200-3500 and up to abs. you. 4000m there is a “paramo” belt of high-mountain subalpine and alpine shrub-herbaceous vegetation. Dark-colored mountain-meadow soils with a coarse-humus and powerful humus horizon are widespread here. A colder climate, and most importantly, sharp fluctuations in daily temperatures prevent the cultivation of crops, these territories are used as pastures. On the flat surfaces of the plateau, large areas are swampy.
On the slopes of the mountains, where there is no significant accumulation of volcanic ash and falls from 3000 to 1000mm precipitation, there are a number of high-altitude zones.
Upper forest belt (tierra fria), located within 3000-2000m, represented by forests of fogs (nephelogilea). This belt is associated with mountainous brown and acidic multi-humus brown forest soils, podzolized in places. Middle forest belt (tierra-templad) - from 1000-1500 to 2000-2800m - this is a mountain gley, dominated by mountain humus allitic and mountain humus ferrallitic soils.
The lower belt of mountains and foothill plains (tierra caliente) is a special soil region extending from Guaiaquila in Ecuador to the Isthmus of Panama near the western slope of the Andes. In relief, it is an alternation of low coastal ridges and low foothills of the Andes, alluvial plains of river and sea terraces, estuaries and deltas with alluvial sediments and in places coastal sand dunes.
In the northern part of this belt, red-yellow ferralitic and red-yellow podzolic soils predominate, and podzols appear on well-drained sandy terraces. Hydromorphic, alluvial and saline soils are widespread on the coastal plain. In the central and southern parts of the territory, Andosols and accompanying alluvial and hydromorphic soils containing volcanic ash stretched in a narrow strip at the foot of the Andes. In the southern part, the soil cover is even more diverse: here, in the conditions of a hilly relief, somewhat more fertile soils are common, transitional between saturated brown forest and red-brown Mediterranean soils. Dark red ferrallitic soils are also widespread here, developing on ancient alluvium on terraces, with a high content of basic volcanic ash. The level of fertility and the need for fertilizers are very different here, and economic use is also very diverse. On the most fertile and well-drained soils on alluvium and on ash-volcanic soils (andosols), bananas and cocoa are grown, on less fertile soils ah - oil palm and fibrous crops, on poor soils of heavy mechanical composition with poor drainage - fig. In places, in the conditions of a hilly relief, the shifting culture of agriculture has still been preserved, but it is gradually being replaced by cocoa or coffee plantations, although in some places it is unsafe due to steep slopes, thin soils and possible erosion. Plots of hydromorphic soils and black merged soils are used for pastures. Significant areas of fertile soils in river estuaries are underutilized due to salinity, close brackish water horizon and lack of capital flood protection.
Amazonian soil region
This area is the largest in South America, it covers one flat equatorial soil zone of yellow and red-yellow ferralitic soils of moist equatorial and tropical forests. It stretches across the entire continent - from the eastern foothills of the Andes to the Atlantic coast. The area includes the entire Amazonian lowland, the Guiana Highlands and the northern part of the Brazilian Highlands framing the lowland from the south. Throughout the region, the climate is humid, annual moisture is uniform, sometimes with one short somewhat drier period. The most heavily moistened is the western Predian part of the region and its extreme eastern Atlantic part, where the annual precipitation ranges from 2000 to 5000mm in year. The dominant vegetation in the Amazonian soil region is moist equatorial and subequatorial forests. The main background - the selva - is interspersed with small islands of grassy savannas confined to flat surfaces experiencing seasonal flooding by atmospheric waters.
The central part of the region - the Amazonian lowland itself, is widest in the western part and narrows towards the east.
From the north and south, the lowland is framed by ancient shields: the Guiana and Brazilian highlands. In large areas of uplifted plains, the surface mantle is represented by quartz sands; along with white quartz sands, pink and red sands are common, with ferruginous films on the surface of quartz grains, often with ferruginous concretions. These sands are erosion products of the ancient weathering crust of acidic quartz-bearing rocks.
The products of erosion and redeposition of the ancient weathering crust, including quartz sands, cover large areas within the Amazonian lowland.
Only in conditions of highly dissected relief, on surfaces renewed by erosion, less poor weathering products have a fersiallitic or fersiallite-allite character. In the Amazonian soil region, yellow and red-yellow ferralitic soils dominate. They differ mainly in the amount and degree of hydration of iron oxide hydrates: yellow ferralitic ones contain less iron oxides and it is more hydrated than in red-yellow ferralitic ones. Otherwise, they have similar properties.
These soils are formed on ferralitic weathering crust or products of its erosion and redeposition, which do not contain any primary minerals except quartz.
The humus content in the upper soil horizons is about 3.0%, humus penetrates deep along the profile; at a depth of 100cm its content is about 2%. The humus is very light and, as studies by IP Gerasimov and OA Chichagova (1964) have shown, it has a pronounced fulvate composition. The profile is morphologically weakly differentiated and includes horizons: humus (Af) - brownish or yellowish black, loose, 5-10cm. Beneath it is a powerful metamorphic mountain. IN T - yellow-brown or red-brown, loose, well aggregated, riddled with termite passages, well air and water permeable, without noticeable signs of silt particles being washed into it. At a depth of 100-150cm the color becomes brighter - red or orange. The low content of humus, low absorption capacity, lack of primary minerals - the source of bases, low content of phosphorus, nitrogen and trace elements cause very low fertility of these soils and limit their use in agriculture.
Along with yellow and red-yellow ferralitic soils, other zonal types are also common in this zone, the nature of which is closely related to the composition of parent rocks and the stage of development of the relief.
Where ancient planation surfaces have been severely dissected, for example, in the Guiana Highlands, and the ancient weathering crust has been washed away, the weathering products of massive rocks appear somewhat more fertile compared to red-yellow ferrallitic soils. Dark red ferrallitic soils are formed, with a higher content of humus, a well-defined structure, a high content of iron oxides, less acidic. Groundwater laterites, soils with horizons of ferruginous concretions forming solid ferruginous slabs, are common in relief depressions with close occurrence of groundwater.
Differences in relief and soil-forming rocks lead to differentiation of the soil cover within the region and make it possible to distinguish a number of soil districts: the Amazonian lowland, the Guianan, the Brazilian, and the Atlantic.
Amazonian lowland soil district yellow ferralitic, groundwater lateritic, marsh soils and sandy podzols. This territory lies on abs. altitude below 200m and is an alluvial plain with wide terraces and wide river valleys. The degree of dissection of the relief is small, with the exception of the territories adjacent to the Brazilian Highlands. Most of the territory is covered with tropical rainforest, with small patches of grassy savannah confined to flat, poorly drained surfaces.
The soils of this district are predominantly yellow ferralitic, with a low content of iron oxides, very acidic, highly unsaturated, and often light in texture. Poor groundwater lateritic soils with accompanying hydromorphic soils are widespread. These soils are of low natural fertility. Somewhat more fertile soils are found in small massifs in places where loose deposits contain weathering products of basic rocks and limestones.
A significant part of the territory is occupied by soils on young alluvium. These are peaty-bog and humus-bog soils. Low terraces composed of quartz sandy material are occupied by very poor, acidic sandy soils.
A large amount of incoming organic residues and a high mobility of humus (mainly its fulvate composition) determine the formation of thick illuvial-humus podzols on sandy terraces, often with signs of soil moisture. The waters of many rivers and streams in the Amazon basin are so rich in organic matter that they are dark in color. In some places on high terraces they occur in the form of small, slightly elevated patches of black, relatively fertile soils. This "terrapreta"- cultural soils created during long-term agricultural cultivation by Indian tribes and currently abandoned, but have not lost the fertility created by labor. Their dark color is due to the large number of inclusions of charcoal.
Large areas on yellow ferrallitic and ferruginous-concretional (lateritized) ferrallitic soils and well-drained alluvial soils are occupied by rubber plantations; tobacco and some fiber crops are also confined to sandy ferrallitic soils.
Guiana Upland Soil District red-yellow ferrallitic and red-yellow fersiallitic podzolized soils, laterites and thin stony soils of mountain slopes.
The territory, an isolated northern section of the Brazilian Shield, has a hilly and mountainous topography, with several levels of ancient denudation surfaces well preserved from erosion and with several younger surfaces forming lower steps. Absolute altitudes in this area range from 0 to 1500m, and individual table heights reach 2000m. The natural vegetation is tropical rainforests, and on the young Denudation surfaces (Ruppini area) grassy savannahs. Small islands of herbaceous vegetation interspersed with forests, most of them of anthropogenic origin.Red-yellow ferrallitic, ferrsiallitic and podzolic soils of the region are developed on sloping and steep slopes, respectively on mudstones, siltstones and quartz sandstones. Dark red (reddish-brown) ferralitic soils occur on the main igneous rocks and their deluvium. These soils are highly valued by Indian farmers.
In the mountains, there are small areas with a relatively leveled relief, where ferrallitic soils are widespread with a high content of ferruginous nodules. Poor ground-water laterites, quartz-sandy acidic soils on pink and white sands are common on ancient denudation surfaces, some of which (especially the highest ones) have thick ancient horizons of true laterites. Thin stony soils are quite widespread in this area. Pastoralism is developed on unimproved pastures in areas of grassy savannahs, and on the slopes of mountain valleys there are small areas of shifting agriculture.
Brazilian Upland Soil District red-yellow and dark red ferralitic soils and quartz-sandy soils.
This area has a predominantly humid climate, with a short dry season; heavily forested. Absolute altitudes range from 200 to 1000m. The relief is predominantly hilly plateaus, with wide summit surfaces inclined to the north. The soils of the district are poorly studied. According to a few observations, red-yellow and dark red ferralitic soils are found here on the weathering products of shales and phyllites. On slightly undulating surfaces of uplands composed of sandstones, quartz-sandy acidic soils (quartz regosols) are common. In hilly areas, red-yellow podzolic soils form. In depressions, on loose sediments, the formation of yellow ferralitic soils is possible. Agricultural development of this territory is very weak; it is crossed by only one road. Some rivers are navigable. The mode of transportation is pedestrian or air. The indigenous population is very rare, mainly engaged in the collection of natural fruits and plants and hunting, and only in some places conducts shifting agriculture to obtain the main food crop - cassava.
Soils have a very low level of fertility; if they are used over large areas, there is a danger of erosion, especially of red-yellow podzolic soils on slopes. Soils need regular fertilization if used consistently.
Atlantic Soil District seaside acidic solonchak, marsh and sandy soils.
Most of the Primorskaya Lowland lies at altitudes of less than 50m above ur. seas; the groundwater level is high, the waters are often saline; the coast is very gentle, in many places with a strip of marches and mangrove forests. The coastal zone is built up by sediment carried by rivers, especially the Amazon and Orinoco. The climate is tropical. Natural vegetation is closely related to the nature of soils. There are mangrove swamp forests withAvicenna And Rhizophora , reed (reed) swamps, tropical forests and savannahs with rare xerophytic shrubs.
Hydromorphic soils that develop on Holocene sediments and marine sediments predominate: silt-gley, mineral gley, and coastal saline soils. These soils contain minerals of the illite-montmorillonite group, which significantly distinguishes them from most other soils of the Amazon region, which have a kaolinite composition.
Acid sulfate soils with very low pH values are a hallmark of the county. They are confined to relief elements where the water level periodically drops and oxidation of sulfides occurs, usually present in the restored undrained soils of the coasts. Acidic sulphate soils often contain a lot of mobile aluminum, which, like the high acidity of soils, makes them sterile for a number of years after drying. Most of the bog soils in the lower horizons are saline.
The belt of peaty bog soils is currently not used; their development is possible only under drainage conditions. The white and ferruginous sandy soils of the interior of the lowlands are rough pastures and forested areas. Silty-gley, mineral gley soils and coastal solonchaks of about. Marajos are occupied by good natural pastures, but they are not suitable for the cultivation of grain crops, except for some varieties of rice.
Most of the poor groundwater laterites are infertile, with many areas swampy or subject to periodic flooding. Cattle grazing on pastures with lateritic soils often suffer from a lack of minerals in feed.
Atlantic moist forest soil region
The area is located between 5 and 23 ° S. sh. It covers the eastern most elevated, up to abs. high 800-2000m, the heavily dissected part of the Brazilian Highlands and its eastern slopes facing the Atlantic Ocean. This area is well hydrated. Two soil districts are distinguished here: Northeastern Brazilian and Southwestern Parano-Uruguay.
Northeast Brazilian Soil Region . IN soil cover very poor red-yellow, ferrallitic and red-yellow podzolic ferrallitic soils under tropical rain forests predominate. At an altitude of about 2000m deciduous forests appear on humus ferrallitic acidic soils, and where the peaks reach 2100-2200m, forests disappear and are replaced by mountain peat bogs.
In the lower zone of humid tropical forests, among red-yellow ferralitic soils, somewhat more fertile dark red ferralitic soils are not uncommon, associated either with eluvium-deluvium of less acidic rocks, or with relatively dry areas where the degree of soil leaching decreases.
Alluvial and hydromorphic soils are widespread along the river valleys.
In the production of crops, this district occupies a special place, since it is located between two large cities: Rio de Janeiro and Sao Paulo. Various crops are grown here, and fertilization increases soil fertility. The remoteness makes it difficult for agricultural use of certain parts of the district, and they are occupied by natural forests. In a number of districts of the district, arable land has been abandoned due to a decline in fertility and the development of soil erosion. Soil erosion, especially of red-yellow podzolic soils, is a factor limiting the development of agriculture. These soils have a compacted horizon of poor water permeability and a less stable structure.
The soils of the river valleys were previously poorly developed due to flooding and the lack of drainage systems. In connection with the development of agricultural technology, their importance is increasing and they are currently used in agriculture and horticulture.
At the foot of the mountains stretches a narrow strip of the Atlantic coastal lowland, in some places it expands to 50km. Absolute heights range from 0 to 350m. Several geomorphological levels and associated soil combinations are distinguished here:
1) low-lying accumulative surfaces with a close level of groundwater are occupied by soddy and humus-gley low-humus gley and alluvial soils, which are often combined with well-drained soils of low hills;
2) ancient elevated sea terraces, in some places significantly dissected, in the northern part of the coastal lowland of the state of Rio de Janeiro, Espirito Santo, South Bahia and in places in Pernambuco are occupied by kaolinite yellow ferrallitic soils, very reminiscent of the soils of the Amazon basin. In the northern part of the district, on terraces, there are also poor red-yellow podzolic soils, highly unsaturated, which are transitional formations to ground-water lateritic soils and, in some places, to podzols;
3) low-hilly relief, worked out in igneous rocks and less often in clay shales, is characterized by poor red-yellow podzolic soils, in some places somewhat more saturated bases. The latter are widely used for a variety of tropical crops.
Southwestern Parano-Uruguay Soil District is located within the basalt plateau, the highest parts of which lie at an altitude of 1500m.
Low plateaus are occupied by coniferous-deciduous subtropical forests; coniferous araucaria forests dominate on high plateaus( Araucaria angustifolia ); with patches of tall grass prairie. Under the coniferous forests there are dark brown ferralitic and fersiallite soils, acidic, highly unsaturated, with a high content of absorbed aluminum, and a powerful humus horizon. Under grassy vegetation, reddish-black soils of the subtropical prairies are developed "rubrozems", as they were called by Simonson and Bromao (Simonson, Bromao).
At altitudes between 400-800m under coniferous and mixed forests and areas of prairies, dark red ferrallitic and fersiallitic soils are common on the weathering products of basalts. They are less acidic and have a higher absorption capacity than typical dark red ferrallitic soils.
In relatively drier valleys open to the west, soils of siallitic composition appear, similar to red-brown "Mediterranean"; they are more saturated, have clayey metamorphic and well-developed humus horizons. This gives them a similarity to the reddish-black soils of the prairies as well.
Poor podzolized red and yellow soils appear on acidic rocks, especially sandstones.
The agricultural use of soils is complicated by the very strong manifestation of erosion processes; and most of the territory is occupied by grazing and forest lands. In the drier valleys there are vineyards, tobacco plantations and soybean crops.
SOIL COVER OF SAVAN-XEROPHYTIC FOREST AREAS
South America includes the northern and southern branches of the horseshoe-shaped American-African savanna-xerophyte-forest sector. The northern branch includes one Carnbian soil region, the southern branch, covering the Brazilian Highlands and the Pre-Andean plains in the subtropical zone of the continent, includes three soil regions: Central Brazilian, East Brazilian and Paraguayan-Pre-Andean.
Caribbean soil region
The region occupies the northern subequatorial part of the continent - the Llanos-Orinoco plains, mountain ranges and the Greater and Lesser Antilles.
The plains are dominated by savannah and xerophyte-forest type of vegetation, which is replaced by treeless grassy groups in the lowlands, which experience periodic flooding.
Three soil districts are distinguished in the continental part of the region: the Llanos-Orinoco, the Northeastern and Caribbean Andes, and the Caribbean Lowland.
District of Llanos Orinoco is a vast treeless area covered with grassy and palm savannahs, located between the Guiana Highlands and the Caribbean Andes and encompassing the Orinoco basin. According to the nature of the relief and soil cover, the district is divided into two parts: the western lowland and the eastern elevated. Western Llanos - flat alluvial plain with abs. you. about 50m. Bog and waterlogged soils of varying degrees predominate here, groundwater laterites are widespread. The most elevated and relatively dry areas are occupied by very poor red-yellow ferralitic, often strongly lateritized soils. Agriculture is not developed, the territory is used as pasture.
Eastern Llanos - elevated plains lying on the abs. you. 200-300m, dissected by erosion into separate table remains - mezas, on the surface of which a lyinginsituferrallitic weathering crust.
Very poor red ferrallitic soils are located on the surface of the remnant hills on the ancient ferralitic weathering crust. At the outcrops of carbonate rocks, less acidic, often calcium-saturated, red-brown fersiallite soils appear. In places, poor quartz sandy soils are common. The area is used as pasture. In places, wind erosion of soils is highly developed.
Mountain District of the Northeast and Caribbean Andes receives a large amount of rainfall and is covered with forests; lower mountain belt up to a height of 1000-1500m occupied by mountain xerophyte forests on red fersiallite and red-brown soils. The higher belt is formed by mesophytic forests and tropical mountain forests on mountain red-yellow and red fersiallitic and ferrallitic humus soils. At altitudes 2500m and above, there are mountain moist forests of the cold belt on acidic mountain polyhumus brown forest soils. Soils are common in dry intermountain valleys. Soils of mountain slopes and valleys are mainly used in the mesophytic forest belt for coffee plantations. For more low levels along the terraces of the rivers are cocoa plantations.
District of the Caribbean Lowlands the northern part of Venezuela and Colombia is occupied by red ferralitic and ferritic soils of seasonally humid tropical forests and savannahs and red-brown soils of dry light forests. Large spaces in the Maracaibo depression and on the alluvial plains of the river. Magdalen is occupied by marsh soils. In many soils of the district there is a significant admixture of volcanic ash. These soils are distinguished by a higher level of fertility.
The islands of the West Indies have an equally complex and variegated soil cover, which is due to the structure of the relief (many islands are mountainous) and the variety of soil-forming rocks.
The influence of rocks on the nature of the soils of Cuba has been studied in detail by SV Zonn. Sedimentary rocks are predominantly distributed on the island: Cretaceous and Jurassic limestones, sandstones, shales, Tertiary limestones and marls, in places ultrabasic igneous rocks - serpentinites. The ancient weathering crust has been washed away in most of the territory. The products of its erosion, mixed with less weathered deluvium of rocks of different composition, compose a mantle of deluvial and alluvial Quaternary deposits on piedmont plumes and coastal plains. In some places on the plains, montmorillonite clays are common, in places carbonate and containing sulfates.
The wide development of limestones and serpentinites significantly affects the nature of the soil cover. The weathering products of these rocks are associated with slightly acidic or neutral clay red ferrallitic soils. These most fertile soils are widely used in agriculture, especially for the cultivation of sugar cane.
Red ferrallitic acidic soils are associated with gneisses, ferruginous sandstones, and marbled, quartz-bearing limestones.
Marl weathering products are associated with dark-colored humus calcareous soils effervescent from the surface - an analogue of humus-calcareous soils, or "rendzin". These soils are heavily clayed. In some places, they acquire the features of brown soils of dry forests and shrubs, characteristic of dry subtropics.
On the plains, the soil cover is also very diverse. Dark-colored merged soils (slitozems) are associated with montmorillonite clays. The composition of humus is dominated by humic acids. Slithozems are among the most fertile soils of the plains and are widely used in agriculture, mainly for the cultivation of sugar cane.
Clay plains are interspersed with sandy quartz sands formed from the surface, underlain at a shallow depth by heavier deposits, and in some places by dense rocks. Their formation is associated with the weathering products of acidic quartz-containing rocks: gneisses, sandstones.
Central Brazilian soil region
The region covers the interior of the Brazilian Highlands. The soil cover of this area is poorly studied. The vegetation is represented by alternating two types of groupings: campos-serrados tree-shrub vegetation and open savannas - campos-limpos. Within the region there are patches of rainforest associated with river valleys and some isolated, often rocky, uplands.
Dominates the Brazilian highlands campos-serrados - xerophytic shrub savannah, with a sparse grassy cover of hard turf grasses and low trees and shrubs( curatella americana , Qualea grandiflora and etc.).
Significant areas here are covered with rewashed, very poor quartz sands.
The soils of the region are represented by the so-called "serra-do phase" - red and dark red ferrallitic soils of both light and heavy mechanical composition. Another widespread group is formed by red and yellow acidic sandy soils.
The red ferrallitic soils of the savannas of the Brazilian Highlands are very similar to the red-yellow soils of tropical forests. This is due to the specific composition of parent rocks - ferralitic weathering crusts. The differences from forest soils are: a brighter red color due to dehydration of iron oxide hydrates during dry periods, a lower content of humus, similar in composition to the humus of forest soils (fulvic acids predominate), and a slightly higher absorption capacity.
Red ferrallitic soils with ferruginous concretions are widespread in the northern part of the region. In many valleys, especially in the Bananal region, there are meadow gley soils, peaty bog and groundwater laterites. In the eastern part, there are thin stony soils at the outcrops of quartzites.
Low fertility limits the agricultural use of soils. Farming is mostly primitive: with inefficient introduction of only organic residues from the "cerrado" vegetation. To improve soil fertility, it is necessary not only to apply fertilizers, but also microelements, since plants here need zinc, boron, and sulfur.
The soils of the north-eastern part of the region - district are very poor and infertile.
Laterites and ferralitic soils with a large amount of ferruginous concretions are the most widespread here. Some of these nodular ferrallites and nodular red-yellow podzolic soils are confined to ancient denudation surfaces, on which red and yellow acidic sands (quartz regosols) are also quite common. Red-yellow ferralitic soils without ferruginous concretions are encountered in places.
The soils of the southern part of the Central Brazilian soil region are somewhat fertile.
The most common soils associated with the weathering products of basalts, sandstones and shales. Dark red ferralitic soils predominate (terraroxalegitima) in places of basalt outcrops. No less common are soils of the same color, but with a clayey illuvial-metamorphic horizon -ter raroxaestructurada, or highly saturated reddish-brown ferralitic soils. They develop on younger surfaces, on traps. There are ferrallitic soils of medium mechanical composition on the weathering products of sandstones. Poorer red-yellow ferralitic soils form on gneisses, while red-yellow podzolic soils form on shales and sandstones. Most of the red-yellow podzolized soils are poor and contain little bases, but on gneisses and sandstones with carbonate cement they are richer in bases and, liketerraroxaestructurada, the most fertile soils of the region. There are massifs of acidic yellow and white sandy soils confined to ancient denudation surfaces with sandstone outcrops.
Land developed for agriculture is not permanent. Many of them, once cleared from under the forest, were used for coffee plantations, and then, as soil fertility decreased and due to lack of fertilizers, they were abandoned. Only on dark red ferrallitic soils and on some of the least poor red-yellow podzolic soils is it possible to obtain more stable crops of woody crops, such as coffee. The western part of the state of São Paulo and northern Parana is the main region for the cultivation of coffee, cotton, sugarcane, soybeans and citrus fruits in Brazil.
East Brazilian soil region
The region occupies a vast depression in the river basin. Sao Francisco in the northeastern part of the Brazilian Highlands, is outside the influence of humid equatorial air masses and is protected from the humid masses of the South Atlantic by a coastal rise. Most of the territory lies within 500m above ur. seas. The soil cover of this area is represented by combinations of relict highly alkaline poor ferralitic soils, which occupy parts of the plateau less affected by erosion, and soils corresponding to modern arid conditions. The latter in the eastern part of the region are developed on crystalline rocks and are represented mainly by red-brown soils. Soils of light mechanical composition are very widespread on the weathering products of sandstones. Sand dunes appear in places. Salt soils and dark-colored coalesced montmorillonite soils occur in relief depressions. In places, ancient lateritic crusts are exposed on the surface. In the eastern part of the region, on low river and sea terraces, subsoil laterites occur.
Lack of water is the main obstacle to agricultural development of the territory. Rare rains are torrential in nature, causing severe soil erosion on the slopes, flooding of rivers and streams. But following these short periods of flooding, the rivers dry up for a long period.
Paraguayan-Predandian soil region
This is the most southern region savanna-xerophyte-forest sector is located between 16 and 38 ° S. sh. It is elongated in the meridional direction and occupies the internal dry plains and foothills of the eastern slopes of the Andes. Two soil-bioclimatic provinces are distinguished here: the northern one is of red-brown and brown solonetsous soils and solonchaks, and the southern one is of brown and gray-brown soils.
The province of red-brown, brown solonetzic and saline soils covers the Gran Chaco plain. The surface of the plain is slightly inclined from the foot of the Andes to the east. The plain is covered with proluvial-alluvial deposits of rivers composed of weakly weathered material. There are no ancient weathering crusts so typical of the Brazilian highlands and associated relict soils here.
The El Chaco plains are an area of intracontinental accumulation of not only solid runoff products, but also readily soluble salts. On the piedmont plains, in an arid climate, salts accumulate in waters, sediments and soils. Salt lakes, often drying up and turning into vast salt marshes, are especially common in the center of the province. Strong winds, typical for this area, transfer salts from the surface of solonchaks to the surrounding elevated relief elements.
The vegetation is represented by xerophytic thorny shrubs, with a large participation of cacti. In less arid "peripheral areas" patches of herbaceous vegetation occur.
The general solonetzization of soils is facilitated by the constant aeolian accumulation of sodium salts on the soil surface and the subsequent leaching of colloids saturated with sodium at the onset of the rainy period. Therefore, strongly saline brown soils dominate even on relatively elevated relief elements.
Much of the plain is used as seasonal pasture. Agriculture requires irrigation, relief planning, and melioration of solonetsous soils.
The province of brown and grey-brown soils occupies the western part of the inner dry pampas with xerophytic shrubs. The grass cover is dominated by grasses.
Soils of relatively light texture prevail here, formed on loess-like sandy loams, with a large admixture of volcanic glass.
Soils have dark brown humus mountains. A, with a humus content of 2-3%, a well-developed clayey mountain. They are saturated with bases, have a neutral and alkaline reaction. The content of humus varies depending on the mechanical composition, but in general the soils of the eastern part of the province are more humus and can be considered as brown soils, and the western part - less humus - as gray-brown soils. Solonets and solonetzic soils are common in the western part of the province.
The main disadvantage of these soils for agricultural use is the danger of wind erosion and lack of moisture.
SOUTH AMERICAN MEADOW-STEPPE SECTOR
soil area Eastern pampas
In South America, meadow steppes are confined to the eastern Atlantic part of the continent and are limited in their distribution by the subtropical zone. The meadow-steppe sector includes only one soil region of the Eastern Pampas: brunizems, hydromorphic chernozem-like soils, and meadow slitozems, covering the most well-moistened eastern regions of the Argentine-Uruguayan pampas. The region extends north and south from the mouth of the river. La Plata and is located between 31 and 39 ° S. sh. and 57-59° E. e. This is the largest array of the most fertile soils in South America.
Almost the entire territory is covered with Quaternary deposits of considerable thickness, represented by loess-like medium and heavy silty loams up to several hundred meters thick.
Soil-forming rocks are eolian loess-like and alluvial-lacustrine deposits. The mechanical composition of the deposits is the heaviest in the east, lighter in the west. As a rule, these sediments are carbonate and rich in easily decomposable minerals, like hornblende, pyroxene, plagioclase, and contain a lot of volcanic glass; volcanic material is brought by the eolian route from the Andes, where there are a number of large active volcanoes.
The vegetation of the pampas is grassy tall-grass meadow steppes.
Currently, natural vegetation has been destroyed in large areas. Wheat, corn, sunflower, forage crops are cultivated here: oats, barley, rye, alpha, potatoes. Unplowed areas are used as highly productive natural pastures.
By the nature of the relief, the pampas are undulating, poorly drained plains with closed saucer-shaped suffusion depressions. Along the river valleys, especially along Paraguay and La Plata, low-lying alluvial plains stretch, periodically flooded. The groundwater level is very close. Many soils of the low accumulative levels of the pampa retained in their profile signs of the previous superaqueous stage. One of the most striking relics of the former hydromorphic regime is dense calcareous horizons or, as Argentinean soil scientists call them, “tosca” horizons.
The predominant soil type on relatively elevated and better drained elements in the humid eastern pampas is prairie chernozem soils, or brunizems.
Argentine brunizems have dark brown (almost black) humus mountains. And with a capacity of 35-40cm, humus content 3.0--3.4% in the upper and about 2% in the lower part, loose, with a granular structure. Below is a transitional mountain. AB, dark, grayish-brown, with a well-defined nutty structure, the humus content is about 1.5%, its lower limit runs togo-70 cm. At a depth of 70-150 cm located metamorphic mountains. Carbonate horizon up to 150-170cm absent. The soils are very slightly acidic (pH 6.1-6.2) in the upper part of the profile and neutral or slightly alkaline (pH 7.2-7.5) in the lower part. The degree of soil saturation in the mountains. And about 88-85%, in the mountains. Vsh - 94%; absorption capacity 18-20mg-eq per 100 G; in the composition of the absorbed bases 60-70% calcium, about 25% magnesium and 5-10% potassium; absorbed sodium is about 1-2%. The content of silt in the soil layer is 18-23%, while in the soil-forming rock it is only 7-10%. Silty and sandy fractions are 60-70% composed of volcanic glass.
Soil formation is accompanied by intense intrasoil clay formation, which is facilitated by constant soil moisture, a warm climate, and an abundance of roots. Enhances biochemical weathering and susceptibility to weathering processes of the source material (consisting largely of volcanic dust),
Many brunizems, located on somewhat lowered surfaces, have heavily clayey mountains.B m twith a silt content of up to 40% with a content in the rock of 10-15%, and in the mountains. A - 18-25%. This horizon has a blocky-nutty structure, is plastic when wet, and hard when dry. Clay films are observed on the surface of structural units, indicating the process of washing out the silt from the mountains. A. Absorption capacity in the illuvial horizon increases to 30-35mg-eq, what he says (as well as physical properties) about the presence of montmorillonite. These soils are also slightly acidic, slightly unsaturated, carbonate-free, and do not contain noticeable amounts of absorbed sodium. It can be assumed that the montmorillonitization of these soils is associated with weathering under conditions of longer moisture stagnation and the addition of magnesium and silica with surface and groundwater.
In closed relief depressions, on poorly drained surfaces, on river terraces, real heavy clayey, fused dark-colored montmorillonite soils (slitozems) appear, often gleyed and containing carbonates in deep horizons. Here, in areas of wet meadows subject to periodic surface waterlogging, soils classified as “planosols” are common. According to morphological and chemical properties, Argentine planosols are meadow solods. Salt licks occur in places And solonetzes, large areas are occupied by meadow gley and meadow-marsh soils. To the north, due to the increasing dryness of the climate, the areas of meadow solonetzes and solonchaks increase.
Andean-Patagonian desert-steppe sector
The sector elongated meridionally crosses the southern half of the continent from the coasts of the Pacific to the coasts of the Atlantic Ocean. It stretches from tropical to temperate latitudes and includes territories that are very diverse in terms of the nature of the relief and the structure of the soil cover. The tropical part of the sector, facing the coasts of the Pacific Ocean, covers the desert and desert-steppe highlands of the central Andes.And coastal tropical deserts of PeruAnd northern part of Chile. In the subtropical zone, the sector under consideration includes the mountainous xerophyte-forest regions of central Chile and the desert-steppe and desert central regions of Argentina, lying east of the Andes. In the temperate zone, this sector includes the desert steppes and deserts of Patagonia, stretching east from the southern Andes to the Atlantic coast. This sector is divided into two large areas: foothill-plain, South Argentine-Patagonian and mountainous Central Andean.
Central Andean soil region
The region extends from 18 to 38°S. sh. and according to the types of structure of mountain zonality it is divided into two soil districts - Puno-Atakama and Subtropical Andean.
Puno-Atakama District high-mountain and foothill desert, desert-steppe and solonchak soils occupies the Central Andes proper between 18-30 ° S. sh. and represents one of the greatest mountain deserts in the world. Eastern Cordillera (Cordillera Real) with a height of over 6000m protects the territory from humid eastern air masses. Precipitation falls on the eastern slopes of the mountains, covered with forests and xerophytic light forests.
Strong winds blow the surface of the soil, blow out fine particles, therefore, in large areas, soils have a light mechanical composition and an undeveloped profile. The areas less affected by wind erosion are occupied by reddish-brown desert soils, often saline.
In eastern Pune, the amount of precipitation slightly increases, and here high-altitude cold steppes (khalka) appear on slightly more humus high-mountain steppe soils, with a large amount of volcanic ash.
The western frame of Pune is a chain of high, active and recently extinct volcanoes, rising to a height of 5800-6800m. Their peaks are covered with snow, but the slopes, composed of lavas, volcanic tuffs and mudstone (mudflow) deposits, are devoid of vegetation in most of the territory.
On the slopes of mountains at altitudes of 2500-3500m a meager cover of xerophytic shrubs and cacti appears. Stony, thin mountainous desert soils with an unformed profile predominate here. However, in areas less exposed to erosion and burial under ash, soils have a slightly differentiated profile, in which a small, somewhat more clayey horizon stands out under a loose porous crust. All soils are carbonate, in many soils the carbonate horizon is strongly cemented and acquires the character of a calcareous slab. In the river valleys, the soils are saline. The lower part of the western slopes of the mountains and the piedmont coastal plains are just as deserted. Precipitation here is highly irregular, but some soil moisture is obtained from night dews, as the cold Humboldt current along the coast contributes to the formation of fogs.
In large areas, the surface is completely devoid of vegetation and covered with a powerful crust of salts - sulfates, chlorides and sodium nitrates (Chilean saltpeter). Intensive salt accumulation on the piedmont plains is associated with the removal of water-soluble products emitted by volcanoes and their accumulation in an extra-arid climate. Agriculture is practiced only on small areas of alluvial soils along river terraces. Irrigation is difficult due to lack of water and irregular flow.
Subtropical Andean District mountain brown, red-brown And gray-brown soils is located between 30-38 ° S. sh., covers the Coastal Cordillera abs. you. up to 2300m, Main Cordillera up to 6000-6900m and the Longitudinal Valley between them. Rainfall in the north - 300-400mm, to the south increases to 800-1000mm.
In the Longitudinal Valley and the Coastal Cordillera, brown soils of dry forests and shrubs predominate, in places there are reddish-brown soils if they form on eroded ancient red-colored weathering crust. On the most well-moistened slopes of the mountains of the Main Cordillera, mountain brown forest soils appear under mountain deciduous forests, which change with mountain meadow soils with height. The Coastal Plains and the Longitudinal Valley are centers of agriculture and horticulture. Corn, wheat, fiber crops are cultivated here. Irrigated agriculture predominates.
South Argentine-Patagonian soil region
The region is elongated meridionally and is divided into two provinces: the Central Argentinean soil of subtropical deserts and semi-deserts and the Patagonian cold, brown desert sandy and stony soils.
The southern Argentinean province of soils of subtropical deserts and semi-deserts covers piedmont plains and intermountain basins of the front ranges of the Andes (Salta, Tucuman, Catamarca, Sierra de Córdoba). The plains lie on abs. you. 1000-1500m, descending towards the east.
By the nature of the relief, these are undulating plains, representing merged fans of alluvial and proluvial material, significantly reworked by the wind. Eolian processes are highly developed, and most soils have a weakly formed profile. Soils less affected by wind erosion have the following profile: underdeveloped grayish or brownish mountains. And, where the cellular structure is well expressed, it passes into the mountains. IN T - heavier mechanical composition, brown or reddish brown, without signs of washout. Most soils are carbonate. Alkaline soils appear in relief depressions; closed drainless depressions, blind mouths of rivers are occupied by salt marshes. Agriculture is not developed here. In small areas where irrigated agriculture is carried out, soils are highly susceptible to secondary salinization.
The Patagonian province of brown desert, sandy and rocky soils covers the Patagonian plateau and lies between 34-50 ° S. sh.
Brown desert-steppe soils dominate. In large areas, the soil surface is covered with a desert shell of crushed stone or pebbles, formed as a result of very intense soil deflation. Under the stony "bridge" one can hardly distinguish a light gray thin humus horizon of various mechanical composition, usually with a well-defined cellularity. This is a carbonate-free and uninhabited horizon. Beneath it is a horizon of somewhat heavier mechanical composition, but without signs of silt illuviation. This horizon has a brown or reddish-brown color, usually carbonate-free or very low-carbonate. Carbonates and readily soluble salts are usually present in the parent rock. In the northern part of Patagonia, solonetzes and salt marshes are found in river valleys. The western high plateaus have a less desert appearance, where the vegetation cover is represented by mountainous dry shrub steppes on mountain chestnut soils.
The southernmost part of Patagonia, where the climate is more humid, is also occupied by chestnut soils with a significant proportion of sandy soils in the soil cover. Volcanic ash is present in large quantities in all soils.
The soils of the river valleys are used for grass crops and orchards, provided they are irrigated. A small amount of water and highly developed phenomena of secondary salinization of soils limit their agricultural use.
SOUTH PACIFIC SUBBOREAL FOREST SECTOR
Patagonian-Fuegoland soil region
The extreme southwestern part of the Andean mountain belt belongs to the subboreal forest sector of the southern hemisphere; in South America it is represented by only one Patagonian-Fierce soil region. It stretches from 38 to 56 ° S. sh., i.e. up to. southern tip of Tierra del Fuego. In the northern part of the Cordillera region rise to 4000m and higher, in the south they do not exceed 2000m. Powerful glaciers descend along the valleys, which in the south almost reach the sea coasts, the coast is very indented, has a fjord character and is replete with small islands. There are many active volcanoes in the northern part of the province, which determines the nature of soil-forming rocks over large areas.
The northern part of the province is dominated by high-humus, acidic ash-volcanic soils - "trumao". On ancient surfaces, on the red-colored kaolinite weathering crust of old volcanic ash deposits, red earths appear. On acid sedimentary rocks - micaceous schists and others - acid brown forest soils are formed. On terraces of rivers and alluvial fans, poorly drained, there are powerful peaty soils with interlayers of volcanic ash, called "nadis".
In the northern part of the province - between Valdivia, Puerto Montt and on about. Chiloe - significant areas of alluvial soils, volcanic soils and red soils are used in agriculture for crops of wheat, oats, potatoes, etc. Soils are poor in available phosphorus, they contain mobile aluminum, which increases acidity. Many soils of depressions have dense ferruginous horizons, which impairs their drainage and, consequently, hinders agricultural use.
In the southern part of the Patagonian Andes and in Tierra del Fuego, under deciduous forests and shrubs, peaty, acidic brown forest soils are developed, podzolized in places. On the slopes of the mountains facing the Patagonia plateau and receiving 300-250mm rainfall, under shrubby cereal steppes - mountain-steppe, chestnut soils. The steppes also cover the extreme northeastern part of Tierra del Fuego, however, most of the eastern plains of the island are occupied by damp, cryophytic meadows and low-lying sphagnum bogs, with a complex of neutral (on carbonate sediments) and acidic peaty-meadow soils, podzolized in places; on sandy deposits they are replaced by illuvial-humus podzols. Large areas in relief depressions are occupied by peat-gley soils.
These areas are used as pastures for sheep.
AGRICULTURAL USE OF SOILS OF SOUTH AMERICA. AGRICULTURAL CROPS.
In the industry structure Agriculture In the countries of the Amazon and La Plata, plantations of tropical perennial crops stand out, primarily coffee, for the production of which Brazil traditionally ranks first in the world (1.25 million tons), and sugar cane in Brazil, Guyana, Suriname and French Guiana. Among the food - corn and rice, as well as cassava. On the steppe chernozems of the Argentinean Pampa, wheat and corn are grown, and since the 60s of the XX century. - soy. The production of industrial crops - cotton, tobacco, tungu, etc. - is increasing. Brazil is the world leader in the cultivation of oranges (18.6 million tons), it provides 80% of the world's exports of orange juice and concentrate.
In many countries, monoculture of agriculture still prevails: in Brazil, Colombia, Guatemala, El Salvador, Costa Rica and Haiti, coffee is the main crop, in Ecuador (their main exporter on the world market), Honduras and Panama - bananas, Guyana and the Dominican Republic. Republic - sugar cane, Peru and Nicaragua - cotton. In many South American countries, one of the main crops is corn, for the production of which Brazil and Argentina are second only to the United States. structure
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seljskogo _ hozyajstva
South America is a continent with amazing natural diversity. Although most of it is in the equatorial and tropical zones. The natural areas of South America are unevenly distributed. This is due to the features of the relief of the mainland, the eastern part of which differs sharply from the western part.
Introduction
The climate on the mainland is warm, humid, and there are no sharp temperature changes. This is due to the fact that most of it is located in the equatorial, subtropical and tropical zones. A more moderate climate is in the south of the mainland, but in the mountains it is quite cold (each kilometer of ascent is characterized by a decrease in temperature by 6 degrees). High level humidity (especially in the eastern part of the mainland) provide air masses from the Atlantic Ocean.
Rice. 1 Map of South America
The fauna and flora are also surprisingly diverse.
Almost all known to science are mined on the mainland. minerals:
- oil;
- coal (stone and brown);
- ores (metallic and non-metallic).
Rice. 2 Geological map of South America
Geographic location of South America
The mainland is located entirely in the western hemisphere, the latitudes are equatorial and tropical. This continent includes:
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- Malvinas Islands (Atlantic Ocean);
- the island of Trinidad;
- the island of Tobago;
- Tierra del Fuego (separated from the mainland by the Strait of Magellan, whose length is 550 km).
The mainland's largest lake, Maracaibo, is connected to the Venezuelan Gulf of the Caribbean Sea.
Geology and relief of the mainland
The entire mainland, which stands on the South American Precambrian platform, can be divided into two main zones:
- mountainous;
- flat.
The mountainous zone is located in the west of the mainland. Here are the Andes - one of the highest and longest mountain ranges on Earth. Its total length is 9 tons. Km. The same mountain range and one of the most ancient, it began to form in the Paleozoic, although the movement is still going on. We can say that this zone is one of the most active, earthquakes and volcanic eruptions are constantly observed. Also located here are the Guiana and Brazilian Highlands (on shields, elevated sections of the platform) and the so-called Sierra or blocky mountains.
Where the ancient platform sags, the Amazonian, Orinokskaya and La Platskaya plains (lowlands) were formed. The Amazonian lowland is the largest. It occupies the territory from the Andes to the Atlantic Ocean, from the north and from the south it is bounded by the Guiana and Brazilian highlands.
Table of natural zones of South America and their characteristics
The main natural areas of the mainland:
- humid equatorial forests (selva);
- savannas (llanos);
- woodlands (llanos);
- subtropical steppes (pampas);
- semi-deserts (Patagonia);
- desert (Patagonia);
- temperate forests;
- zone of high zonation (Andes).
Rice. 3 Map of natural areas of South America
The main characteristics of each of the zones are presented below in the table (you can use it in the lesson). It is important to remember that all the main characteristics of the zones are interconnected. So vegetation depends on the type of soil, and the presence or absence of minerals depends on the relief.
| Zone name | Geographic location | Flora (endemic* species) | Fauna (endemic species) | The soil | Minerals |
| Selva (Gilea) | Amazonian lowland (on both sides of the equatorial belt) | ficus, ceiba (unique plants over 80 m high), melon tree, tree ferns, rubber trees, chocolate trees, creepers, orchids |
jaguar, anaconda, hummingbirds, piranhas, monkeys, tapirs, sloths, capybaras, toucans, porcupines, insects (very large, ants are the most common) |
Ferralite (wet) | oil, gas, aluminum |
| Llanos (campos) | Orinok lowland, brazilian highlands, Guiana Highlands (south and north of equatorial forests) |
palm trees, mimosa, acacias, cereals, bottle tree, legumes, forbs, araucaria forest (southeast Brazilian Highlands) |
ostrich, puma, armadillo, anteater, peccary pigs, deer, jaguars (there are many malarial mosquitoes in this area) | Ferrallitic (dry), the only exception is the southeast of the Brazilian Highlands, it is very humid here, the soils are fertile | oil, coal, iron, tin, diamonds |
| pampas | La Plata lowland | forbs, feather grass | pampas deer, rodents, pampas cat, llamas, guanaco, rhea ostrich | Chernozem (humus) | uranium, tungsten, bismuth |
| Patagonia | plateaus and plains near the Atacama Desert, Atacama Desert | cacti and cereals, date palms | rodents, magellanic dog, darwin ostrich, skunks | Brown (poor, since the Andes block the way for moist air masses) | oil, gas, iron, copper, saltpeter, iodine |
| Temperate forests (hemigeleas) | foothills of the Andes | bamboo, ferns, magnolias, southern beech, Chilean cypresses, araucaria | llamas, bears, chinchillas | Podzolic and forest brown soils | oil, gas, coal |
*endemic- the most common in this natural area animal and plant species.
* The fauna of the equatorial forest is surprisingly diverse and is placed vertically, depending on the level of illumination (some animals, for example, spend their whole lives on trees).
Since the mainland has a wide variety of topography, it is very difficult to say which of the zones has the greatest influence.
Characteristics of the zone of high zonation
The zone of high zonation is diverse. Climate and other characteristics depend on altitude:
- 1500 meters - equatorial forests or "hot land";
- 2800 meters - temperate forests or "temperate land"; this zone is characterized by rich flora, growing here: cinchona, bamboo, coca, tree-like shrubs, coniferous trees;
- 3800 meters - crooked forests and low-growing alpine forests;
- 4500 meters - alpine meadows or paramos.
At altitudes above 4500 meters there are eternal snows, many glaciers.
Spacecraft: Landsat Spatial resolution (original): 28 m and 15 m Image geographic center: 04° 34’ S, 71° 49’ W Spectral channels: 1, 8, 7 Instrument: ETM+ Date: December 29, 1999 Additional description: The image was synthesized in pseudocolors. Tropical rainforests are characterized by red-yellow soils, very poor in mineral salts, which feed on plants. This is due to the fact that most of the minerals contained in these soils are quickly weathered, destroyed, and then washed out. In the composition of the mineral mass of red-yellow soils, only kaolin, aluminum and iron hydroxides remain, often in the form of dense iron layers (the so-called lateritic crusts and layers). The forest, under which red-yellow tropical soils develop, has a yellow-green color and a small-spotted pattern. Waterlogged soils are formed in the floodplains of the rivers, the vegetation of which in the image has a red-brown color. Waterlogged soils are deciphered by the color of the vegetation, which is different from the color of the forests. The river has blue and blue colors. The oxbows of the river, turned into long lakes, are clearly visible.
