U9_Soils SAmerica

Unit 9 - Soils of South America

Read Chapter 18 in Foth, pp 439-467. Map of South American Countries; SA Countries in 1650 --Physiography of SA

For general information about South America go to South America or a trip to South America go to Diary

South America from Space NASA geomorphology

Topography and Geology- Topographically the continent is divided into three sections—the South American cordillera, the interior lowlands, and the continental shield. The continental shield, in the east, which is separated into two unequal sections (the Guiana Highlands and the Brazilian Highlands) by the Amazon geosyncline, contains the continent’s oldest rocks. Geologic studies in South America have supported the theory of continental drift and have shown that until 135 million years ago South America was joined to Africa; a Brazil-Gabon link has been established on the basis of tectonic matching.

Extending down the middle of the continent is a series of lowlands running southward from the llanos of the north, through the jungle of the great Amazon basin and the Gran Chaco, to the Pampa of Argentina.

Paralleling the Pacific shore is the great cordillera composed of the Andes ranges and high intermontane valleys and plateaus. The Andes rise to numerous snowcapped peaks; Mt. Aconcagua (22,835 ft/6,960 m) in Argentina is the highest point in the Western Hemisphere. The Andes region is seismically active and prone to earthquakes. Volcanoes are present but mostly inactive. Patagonia, a windy, semiarid plateau region, lies to the E of the Andes in S Argentina. On the Pacific coast, the land between the Andes and the sea widens northward from the islands of S Chile. In N Chile lies the barren Atacama Desert.

There are few good natural harbors along the South American coast. The continent’s great river systems empty into the Atlantic Ocean and the Caribbean Sea; from north to south they are the Magdalena, Orinoco, Amazon, and Paraguay-Paraná systems. Only short streams flow into the Pacific Ocean. Excluding Lake Maracaibo, which is actually an arm of the Caribbean Sea, Lake Titicaca, on the Peru-Bolivia border, is the largest of the continent’s lakes. South America embraces every climatic zone—tropical rainy, desert, high alpine—and vegetation varies accordingly.

Amount of Non Vegetated areas on SA http://earth.rice.edu/mtpe/bio/biosphere/latest/ndvi/samerica_ndvi.html

Climate of South America - Rainfall Rainfall2- January Temp-July Temp Temperature - Vegetation of South America SA Vegetation 2

Countries of South America

Columbia

Colombia has both torrid jungles and majestic, snowcapped mountains. By far the most prominent physical features are the three great Andean chains that fan north from Ecuador. The Andean interior is the heart of the country, where in pre-Columbian days the highly advanced Chibcha lived. It has the largest concentration of population and is the area of large-scale cultivation of coffee, Colombia’s major crop.

Of the three principal Andean ranges, the Western Cordillera is of the least economic importance. One of Colombia’s major cities, Cali, lies just east of the range, in the upper Cauca valley. The Central Cordillera has a towering chain of volcanoes (e.g., Tolima) and is the divide between the valleys of the Magdalena and the Cauca rivers. It was until the 19th cent. an undeveloped region, but with improved transportation, the introduction of coffee culture, and the exploitation of high-grade coal reserves, its cities of Medellín and Manizales have become the economic and industrial core of the republic. A third major city in the Central Cordillera is Armenia.

The Eastern Cordillera is the longest chain. Its western slopes yield coffee, and in its intermontane basins grains and cattle are raised. The area is rich in iron, coal, and emeralds. Among the leading cities of the highland basins are Tunja, Bucaramanga, and Cúcuta, in addition to Bogotá. In the eastern foothills of the Andes some hundred miles east of the capital lies a vast supply of light crude oil. Discovered in 1992, the oil fields constitute the largest find in the Americas since Alaska’s Prudhoe Bay field (1969) and have revitalized Colombia’s petroleum industry.

To the east of the Andes lies more than half of Colombia’s territory, a vast largely undeveloped lowland. The plains are crossed by navigable rivers, tributaries of the Orinoco and Amazon systems. The northern section consists of savannas (the llanos), which are devoted to a large extent to cattle and sheep grazing. Villavicencio, at the region’s western end, is its major urban center. The dense jungles of the extreme southeast are of negligible economic importance. Leticia is the country’s southernmost town, and its only port on the Amazon River. A fourth mountain chain, the Cordillera del Chocó, runs parallel to the Pacific N of Buenaventura. The range’s slopes yield dyewoods and hardwoods, rubber, tagua nuts (vegetable ivory) and other forest products, and gold and platinum.

On the Pacific are the ports of Buenaventura and Tumaco, terminus of a pipeline from the oil-rich area of Putumayo across the mountains. Colombia’s chief ocean ports, however, lie on the Caribbean coast to the north: Santa Marta, Cartagena, and Barranquilla. At Mamonal, adjacent to Cartagena, is the terminus of the pipeline from the Barrancabermeja oil fields. In the north, separating the La Guajira peninsula from the rest of the country, is the magnificent Sierra Nevada de Santa Marta, which contains Colombia’s highest peak, Pico Cristóbal (18,947 ft/5,775 m). The difficult terrain in Colombia limits the availability of road and rail transportation and makes air and water travel especially important. Administratively, the country is divided into 23 departments. From: The Columbia Encyclopedia, Sixth Edition. Copyright © 2003 Columbia University Press.

Venezuela

Geographically Venezuela is a land of vivid contrasts, with four major divisions: the Venezuelan highlands, the coastal lowlands, the basin of the Orinoco River, and the Guiana Highlands. An almost inaccessible and largely unexplored wilderness south of the Orinoco, the Guiana Highlands occupy more than half of the national territory and are noted for scenic wonders such as Angel Falls. Iron ore, gold, diamonds, and other minerals are found near Ciudad Bolívar and Ciudad Guayana. The dense forests of the region yield rubber, tropical hardwoods, and other forest products. The boundary with Brazil is mostly mountainous; its rain forests are home to thousands of indigenous inhabitants. The Orinoco, one of the great rivers of South America, has its source in this region. The Orinoco basin is a great pastoral area. North of the Orinoco and about the Apure River and its tributaries are the llanos, the vast, hot Orinoco plains, where there is a great cattle industry.

Oil is found north of the Orinoco in Anzoátequi and Monagas states. The most vital region economically, however, is an area in the coastal plains, the lowlands around Lake Maracaibo. There, since 1918, Dutch, British, and American interests have developed the astonishingly rich oil fields. The coastal lowlands are exceedingly hot, but coastal ranges rise abruptly from the Caribbean to cool altitudes of 6,000 to 7,000 ft (1,830–2,130 m). These ranges soon become a region of hills, intermontane basins, and plateaus known as the Venezuelan highlands and are a spur of the Andes. Further to the southwest, close to Barquisimeto, the mountains rise to their greatest height at Pico Bolívar (16,427 ft/5,007 m) in the Sierra Nevada de Mérida.

Densely populated, the highland region is the political and commercial hub of the nation. Coffee, the keystone of the economy before the oil boom, comes from the slopes and cocoa from the lower foothills. Valencia and Maracay are, next to Caracas, the chief cities of the mountain basins. Economically dominant in the 19th cent., they are still major urban centers, despite some loss of power because of the oil boom along the coast. Cattle from the llanos are fattened on the rich valley grasses near Lake Valencia. Field crops are intensively cultivated in the vicinity.

The politically and economically dominant landowning class is mainly of Spanish descent. About 65% of the population is mestizo, 20% white, 10% black, and 2% indigenous. Spanish is the official language. There is no established church, but nearly all Venezuelans are nominally Roman Catholic. There are 20 universities in the country. 5

Equador

The Andes, dominating the country, cut across Ecuador in two ranges and reach their greatest altitude in the snowcapped volcanic peaks of Chimborazo (20,577 ft/6,272 m) and Cotopaxi (19,347 ft/5,897 m). Within the mountains are high, often fertile valleys, where grains are cultivated, and the major urban centers, such as Quito, Cuenca, and Riobamba, are located. Earthquakes are frequent and often disastrous; in 1949 the city of Ambato was leveled. East of the Andes is a region of tropical jungle, through which run the tributaries of the Amazon River. The Pacific coast region, with hot, humid valleys north of the Gulf of Guayaquil, is the source of Ecuador’s chief exports including oil and coffee. Large deposits of oil are also located in the northeast. 2Most of the population live in the highlands. Over half of the people are mestizo, and a quarter are indigenous. Spanish is the official language, but many natives speak Quechua or Jarvo. European-descended residents, who account for about 10% of the population, are mostly landholders and play a dominant role in Equador’s unstable political life. Some 10% of the country’s inhabitants are of African descent. Roman Catholicism is the main religion, although there is no established church. Ecuador has ten universities.

Peru

Most of the population live in the highlands. Over half of the people are mestizo, and a quarter are indigenous. Spanish is the official language, but many natives speak Quechua or Jarvo. European-descended residents, who account for about 10% of the population, are mostly landholders and play a dominant role in Equador’s unstable political life. Some 10% of the country’s inhabitants are of African descent. Roman Catholicism is the main religion, although there is no established church. Ecuador has ten universities.

Peru, which varies greatly in climate and topography, falls into three main geographical regions—a narrow strip of desert along the coast, a region of high mountains in the center, and a large area of forested mountains and lowlands in the east. The desert region stretches the entire length (1,410 mi/2,269 km) of Peru’s Pacific coastline and owes its aridity to the cold Humboldt, or Peru, Current, which acts as a barrier to the moist air over the Pacific. A persistent warm current (El Niño; see El Niño–Southern Oscillation) appears off the coast every two to seven years, bringing torrential and damaging rainstorms. The coastal and mountainous regions also are frequently shaken by severe earthquakes.

Within the desert are about 40 oases where most of Peru’s commercial farming takes place; the principal oases are near Lima, Chiclayo, and Trujillo. Callao (near Lima) and Matarani, Peru’s leading ports, are also in the desert region. Near Pisco and Ica are large vineyards. Off the coast are small islands, notably the Lobos and Chincha islands, where guano (used as fertilizer) is harvested.

The central region (c.200 mi/320 km wide) is made up mostly of three ranges of the Andes Mts., the Cordillera Occidental in the west and the Cordillera Central and its continuation, the Cordillera Real, in the east. The Cordillera Occidental includes the loftiest peaks, notably Huascarán (22,205 ft/6,768 m, Peru’s highest point) and El Misti (19,150 ft/5,837 m). The rugged eastern ranges receive considerable rainfall and are drained by numerous rivers, which have cut deep canyons. Subsistence agriculture is practiced in the upper parts of the valleys. Between the eastern and western ranges of the Andes in the south, and extending into Bolivia, is the Altiplano Plateau, which includes small, scattered basins of arable land and pastureland and also part of Lake Titicaca. The central region includes about 60% of Peru’s population; its main cities are Arequipa, Huancayo, Ayacucho, and Cuzco, an old Inca center.

The eastern region includes more than half of the country’s land area. It is made up of the highly forested Cordillera Oriental of the Andes and low-lying tropical plains, covered by rain forests and drained by the Amazon River and its tributaries. The region is generally inaccessible and sparsely inhabited in the north; it is used for the illegal cultivation of coca. Iquitos is the chief city of the eastern region.

Peru ---Peru -view from space..The Andes of South America=Andes of South America

Chile

A long narrow strip of land (no more than c.265 mi/430 km wide) between the Andes and the Pacific Ocean, Chile stretches c.2,880 mi (4,630 km) from near lat. 18°S to Cape Horn (lat. 56°S), including at its southern end the Strait of Magellan and Tierra del Fuego, an island shared with Argentina. In the Pacific Ocean are Chile’s several island possessions, including Easter Island, the Juan Fernández islands, and the Diego Ramírez islands. Chile also claims a sector of Antarctica.

The country is composed of three distinct and parallel natural regions—from east to west, the Andes, the central lowlands, and the Coast Ranges. The Chilean Andes contain many high peaks and volcanoes; Ojos del Salado (22,539 ft/6,870 m high) is the second highest point of South America. Chile is located along an active zone in the earth’s crust and experiences numerous earthquakes, some of great magnitude. The rivers of Chile are generally short and swift-flowing, rising in the well-watered Andean highlands and flowing generally west to the Pacific Ocean; the Loa and Baker rivers are the longest, but those in the central portion of the country are much more important because of their use for irrigation and power production.

The climate, which varies from hot desert in the north through Mediterranean-type in the central portion to the cool and humid marine west coast type in the south, is influenced by the cold Peruvian (or Humboldt) Current along the coast of N Chile and by the Andes. Precipitation increases southward; the desert in the north is practically rainless, while S Chile receives abundant precipitation throughout the year. However, along the coast of N Chile high humidity and dense fogs modify the desert climate. The Andes are an orographic barrier, and the western slopes and the peaks receive much precipitation; permanently snowcapped mountains are found along Chile’s length.

In N Chile is the southern portion of the extensive desert zone of W South America. It is occupied mainly by the sun-baked Desert of Atacama, which, toward the south, gradually becomes a semiarid steppe with limited vegetation. The barren landscape of the north extends from the coast to the Andes, where snowcapped peaks tower above the desert. The Loa River is N Chile’s only perennial stream. The region’s scanty population is concentrated along the coast and in oases; the ports of Iquique and Antofagasta (the chief link between Bolivia and the Pacific), the mining towns of Arica and Chuquicamata, and the industrial town of La Serena are the chief population centers. The people of the region are almost totally dependent on supplies from the outside. N Chile, the economic mainstay of the nation, is rich in a variety of minerals, including copper, nitrates, iron, manganese, molybdenum, gold, and silver. Chuquicamata, one of the world’s largest copper-mining centers, produces much of Chile’s output, although a mine at Escondida possesses ample resources as well.

The middle portion of the country, roughly between lat. 30°S and 38°S, has a Mediterranean-type climate and fertile soils, and is the nation’s most populous and productive region as well as the political and cultural center. It contains Chile’s largest cities—Santiago, Valparaiso, and Concepción. Mineral deposits (in particular copper, coal, and silver) are found in central Chile, and the rivers, especially the Bío-Bío, have been harnessed to generate electricity; hydroelectricity is responsible for 70% of Chile’s power. The region, the most highly industrialized section of Chile, produces a large variety of manufactured products, especially in and around Santiago, Concepción, and Valparaiso (which is also Chile’s chief port). Between the Andes and the Coast Ranges is the Vale of Chile, a long valley divided into basins by Andean spurs. The valley is the heart of the republic, having the highest population density and the highest agricultural and industrial output.

S Chile, extending from the Bío-Bío River to Cape Horn, is cold and humid, with dense forests, heavy rainfall, snow-covered peaks, glaciers, and islands. Sections of this region, which is in the direct path of moist westerly winds, receive more than 100 in. (254 cm) of precipitation annually. Because of subsidence of the earth’s crust, the Coast Ranges and the central lowlands have been partially submerged, forming the extensive archipelago of S Chile, an area of craggy islands (notably Chiloé), numerous channels, and deep fjords. The Chilean lake district is a noted resort area. Although all of S Chile is forested, only the drier northern part has exploitable timber resources; Puerto Montt and Temuco are major timber-handling centers. The rest of the region is a wilderness of midlatitude rain forest, which has been extensively logged. Pollution and erosion have added to the environmental threat. Because of the climate, agriculture is limited; oats and potatoes are the chief crops. Livestock raising (cattle and pigs) is an important activity. A portion of extreme S Chile lies in the rain shadow of the Andes and is covered by natural grasslands; extensive sheep grazing is carried on, with wool, mutton, and skins the chief products. Cattle are also raised. This area also yields petroleum. Valdivia, a port on the Pacific Ocean, is the fourth largest industrial center of Chile; Punta Arenas on the Strait of Magellan is the world’s southernmost city.

Other Web pages on Soils of Chilehttp://www.scielo.cl/scielo.php?pid=S0716-078X2002000400015&script=sci_arttext&tlng=es
http://www.soils.kais.kyoto-u.ac.jp/worldagr/chile1.jpg
http://www.greatwinesintl.com/chile/chile.html
http://growers.avocado.org/growers/pages/growers_633.php
http://www.eco-all.com/chilean_organics.htm

Brazil -

Brazil occupies nearly half the continent of South America, stretching from the Guiana Highlands in the north, where it borders Venezuela, Guyana, Suriname, and French Guiana, to the plains of Uruguay, Paraguay, and Argentina in the south. In the west it spreads to the equatorial rain forest, bordering on Bolivia, Peru, and Colombia; in the east it juts far out into the Atlantic toward Africa. It is a federation of 26 states and Brasília, the federal district and site of the capital city of the same name. Its largest cities are São Paulo and Rio de Janeiro.

Brazil’s vast territory covers a great variety of land and climate, for although Brazil is mainly in the tropics (it is crossed by the equator in the north and by the Tropic of Capricorn in the south), the southern part of the great central upland is cool and yields the produce of temperate lands. Most of Brazil’s large cities are on the Atlantic coast or the banks of the great rivers.

The rain forests of the Amazon River basin occupy all the north and north central portions of Brazil. With the opening of the interior in the 1970s and 80s, these rain forests were heavily cut and burned for industrial purposes, farming, and grazing land. Beginning in the late 1980s, popular international movements, along with changes in government policy, began to reduce the rate of deforestation, but by the mid-1990s extensive burning was again occurring. The Amazon region includes the states of Amazonas, Pará, Acre, Amapá, Roraima, and Rondônia; its chief city is Manaus. Although it is not as developed as other parts of Brazil, the Amazon region produces timber, rubber, and other forest products such as Brazil nuts and pharmaceutical plants. Gold mining, ecotourism, and fishing are also important. At the mouth of the Amazon is the city of Belém, chief port of N Brazil.

Southeast of the Amazon mouth is the great seaward outthrust of Brazil, the region known as the Northeast. The states of Maranhão and Piauí form a transitional zone noted for its many babassu and carnauba palms. The Northeast proper—including the states of Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe, and the northern part of Bahia—was the center of the great sugar culture that for centuries dominated Brazil. The Northeast has also contributed much to the literature and culture of Brazil. In these states the general pattern is a narrow coastal plain (formerly supporting the sugarcane plantations and now given over to diversified subtropical crops) and a semiarid interior, or sertão, subject to recurrent droughts. This region has been the object of vigorous reclamation efforts by the government.

The “bulge” of Brazil reaches its turning point at the Cape of São Roque. To the northeast lie the islands of Fernando de Noronha, and to the south is the port of Natal. South of the “corner” of Brazil, the characteristic pattern of S Brazilian geography becomes notable: the narrow and interrupted coastal lowlands are bordered on the west by an escarpment, which in some places reaches the sea. Above the escarpment is the great Brazilian plateau, which tapers off in the southernmost state, Rio Grande do Sul, where it is succeeded by the plains of the Río de la Plata country. The escarpment itself appears from the sea as a mountain range, generally called the Serra do Mar [coast range], and the plateau is interrupted by mountainous regions, such as that in Bahia, which separates E Bahia from the valley of the São Francisco River.

The chief cities of the Northeast are the ports of Recife in Pernambuco and Salvador in Bahia. There are a number of excellent harbors farther south: Vitória in Espírito Santo; Rio de Janeiro, the former capital, one of the most beautiful and most capacious harbors in the world; Santos, the port of São Paulo and the one of the greatest coffee ports in the world; and Pôrto Alegre in Rio Grande do Sul.

In the east and southeast is the heavily populated region of Brazil—the states that in the 19th and 20th cent. received the bulk of European immigrants and took hegemony away from the old Northeast. The state of Rio de Janeiro, with the great steel center of Volta Redonda, is heavily industrialized. Neighboring São Paulo state has even more industry, as well as extensive agriculture. The city of São Paulo, on the plateau, has continued the vigorous and aggressive development that marked the region in the 17th and 18th cent., when the paulistas went out in the famed bandeiras (raids), searching for slaves and gold and opening the rugged interior. They were largely responsible for the development of the gold and diamond mines of Minas Gerais state, the second most populous state in Brazil, and for the building of its old mining center of Vila Rica (Ouro Prêto), succeeded by Belo Horizonte as capital. Minas has some of the finest iron reserves in the world, as well as other mineral wealth, and has become industrialized.

Settlement also spread from São Paulo southward, particularly in the 19th and early 20th cent. when coffee from São Paulo’s terra roxa [purple soil- lava plateau, one of the world's largest, lying mostly in Rio Grande do Sul and São Paulo states, southern Brazil. Its formations of solidified sheets of lava rock (diabase) also appear in Uruguay, Argentina, and Paraguay. Where the diabase is exposed at the surface, it weathers into a well-drained, dark purple soil known as terra roxa, famous as a producer of coffee.] had become the basis of Brazilian wealth, and coffee growing spread to Paraná. That state, in the west, runs out to the “corner” where Brazil, Argentina, and Paraguay meet at the natural marvel of the Iguaçu Falls on the Paraná River. The huge Itaipú dam, built from the early 1970s through the mid-1990s by Paraguay and Brazil, provides power for most of southern Brazil. The more southern states of Santa Catarina and Rio Grande do Sul, developed to a large extent by German and Slavic immigrants, are primarily cattle-raising areas with increasing industrial importance. Frontier development is continuing in central Brazil. The state of Mato Grosso is still largely devoted to stock raising. The transcontinental railroad from Bolivia spans the southern part of the state. The federal district of Brasília was carved out of the neighboring plateau state of Goiás, to the east, and the national capital was transferred to the planned city of Brasília in 1960.

The Cerrado region covers about two million sq. kilometers (0.8 million sq. miles) in the Brazilian heartland, 25% of the Brazilian territory. Go to http://www.dcs.ufla.br/cerrado/cerrado2.htm

Soil Map of Brazil (Brazil System)http://www.lba-hydronet.sr.unh.edu/statgrid/soil/

Bolivia -

Bolivia presents a sharp contrast between high, bleak mountains and plateaus in the west and lush, tropical rain forests in the east. In the southeast it merges into the semiarid plains of the Gran Chaco. The Andes mountain system reaches its greatest width in Bolivia. Two cordilleras, the western one tracing the border with Chile and the eastern running north and south across the center of the country, are divided by a high plateau (altiplano), most of it 12,000 ft (3,660 m) above sea level—barren, windswept, and segmented by mountain spurs.

Despite the harsh conditions the altiplano is the population center of Bolivia. Many sections for want of drainage have brackish lakes and salt beds, notably the extensive Salar de Uyuni in the south. In the north are Lake Titicaca, which Bolivia shares with Peru, and Lake Poopó. This region, world famous for its breathtaking scenery, was the home of one of the great pre-Columbian civilizations. Well known are the ruins of Tiahuanaco.

The eastern mountains, consisting of three major ranges, rise to the cold, forbidding heights of the Puna plateau (as high as 16,000 ft/4,880 m) and in the north to the snowcapped peaks of Illimani (21,184 ft/6,457 m) and Illampú (21,276 ft/6,485 m). In these mountains lies the source of the exploited wealth of Bolivia—its minerals. Tin is by far the most important product, but silver was once the chief metal, and tungsten, copper, wolframite, bismuth, antimony, zinc, lead, iron, and gold are also mined. The names of some mining towns, notably Potosí and Oruro, are world famous.

From the mountains, headstreams cut eastward, carving deep gorges and fingerlike valleys. In these valleys are some of Bolivia’s garden spots—Sucre, Cochabamba, and Tarija. Santa Cruz de la Sierra and La Paz are the two main cities of tropical Bolivia. In the eastern foothills headstreams gather to form the Beni, the Guaiporé, and the Mamoré (tributaries of the Madeira, in Brazil), which flow through the torrid, humid yungas, covered with dense rain forests, and inhabited mainly by indigenous South Americans. The region is the most fertile in the country, yielding cacao, coffee, and tropical fruits, and in the early 20th cent. was a major source of wild rubber and quinine. Some of the more accessible valleys, with luxuriant scenery and a pleasantly warm climate, have become popular Bolivian resort areas.

More than half the population is indigenous, although the citizens of European descent (some 5% to 15% of the people) or mixed European and native ancestry (about 25% to 30% of the population) maintain economic, political, and social hegemony. The predominant native languages are Quechua and Aymara; they and Spanish are Bolivia’s official languages. A few indigenous groups have remained isolated from European culture. Most of the population is Roman Catholic, although many people of indigenous descent retain the substance of their pre-Christian beliefs. A small but extremely active Protestant minority also exists. There are eight universities in the country.

Soil erosion in Bolivia - The causes of soil erosion in Bolivia are a function of the steep, mountainous topography and the unique cultural forces that have shaped the country throughout its history. Godoy (1984) argues that deforestation in the Andean highlands dates back to the 16th century, when indigenous farmers were drawn into a colonial taxation system designed to provide fuel for the growing mining and housing industries. Revenues were collected and paid in the form of native shrubs, dry llama dung, and many different species of grasses. Without vegetation to slow run-off, absorb excess water, and hold the soil together, massive amounts of fertile topsoil have been lost to erosion. Today the process of deforestation continues in Bolivia and the Third World. Below are some links on soil erosion in Bolivia.=http://peacecorps.mtu.edu/boliv34.ht

Argentina

Argentina is triangular in shape and stretches c.2,300 mi (3,700 km) from its broad northern region near the Tropic of Capricorn to Tierra del Fuego, an island shared with Chile, in the south. On the northeast, Argentina fronts on the Río de la Plata (an estuary and one of the major waterways of the Western Hemisphere), which separates Argentina from S Uruguay; its tributaries also act as international boundaries—the Uruguay River, with W Uruguay and S Brazil, and the Paraná, Paraguay, and Pilcomayo rivers, with Paraguay. The northwest boundary with Bolivia lies in the Gran Chaco and the Andes Mts. The western boundary with Chile follows the crestline of the Andes. The Atlantic Ocean borders Argentina on the east; there, off S Argentina, are the Falkland Islands (Islas Malvinas), and the South Georgia, South Sandwich, and South Orkney islands, all dependencies of Great Britain that are claimed by Argentina.

Argentina also claims a sector of Antarctica. The climate of Argentina varies from subtropical in the north to cold and windswept in the south, with temperate and dry areas found throughout much of the country. Precipitation, lowest along the E Andean slopes, increases markedly N and E across Argentina. The chief rivers of Argentina are the Paraná with its tributary, the Salado; the Colorado River; the Río Negro; and the Chubut.

Argentina may be divided into six geographical regions—the Paraná Plateau, the Gran Chaco, the Pampa (see under pampas), the Monte, Patagonia, and the Andes Mts. The Paraná Plateau in the extreme northeast is an extension of the highlands of S Brazil. It is the wettest part of Argentina and has a dense forest cover; tobacco, timber, and yerba maté are the chief products there. The spectacular Iguaçu Falls are in a national park located at the point where Argentina, Brazil, and Paraguay meet.

In N Argentina the Gran Chaco, with the physiographically similar Mesopotamia (between the Paraná and Uruguay rivers), is a predominantly flat alluvial plain with a subtropical climate. The region is seasonally flooded, and marshlands remain for long periods during the year because of poor drainage. Livestock, cotton, and wood from the quebracho tree are the main products.

South of the Gran Chaco is the Pampa, a vast, monotonous natural grassland that extends to the Colorado River (roughly from lat. 30°S to 40°S) and is c.400 mi (640 km) wide from the Atlantic Ocean to the Andean foothills. The Pampa’s deep, rich soil is the basic wealth of the country. The “Wet Pampa,” the more humid eastern part of the region, is Argentina’s principal agricultural area and produces most of the nation’s exports. It is the granary of South America, with wheat, alfalfa, corn, and flax the principal crops. Cattle ranching is prevalent throughout the Pampa and especially in the southeast and north; sheep are also raised there. Dairying is important in the vicinity of Buenos Aires. The Pampa has the densest transportation network of roads and railroads in South America.

Most of the principal cities of Argentina and most of its industry are found in the region. Buenos Aires, a port city on the Río de la Plata, is one of the largest cities of South America and the chief industrial center and transportation hub of S South America; it is surrounded by smaller industrial cities. Elsewhere on the Pampa are La Plata, a meatpacking and oil-refining center; Rosario, the third largest city of Argentina, an iron and steel and oil-refining center, and a huge grain port on the Paraná River; Santa Fe, a northern commercial and industrial center at the junction of the Salado and Paraná rivers; Mar del Plata, a resort and fishing center on the Atlantic Ocean; and Bahía Blanca, the largest Argentine port directly on the Atlantic Ocean, a gateway to the S Pampa and the oil fields of Neuquén prov., and a meatpacking and wool-processing center. On the western edge of the Pampa is Córdoba, the nation’s second largest city, which reflects the transition from the “Dry Pampa” to the Monte, the desolate Andean foothills.

The Monte, an arid region in the rain shadow of the Andes, has natural vegetation varying from short grasses in the east to cacti in the west. Scattered throughout the great arid stretches are small but highly productive oases such as Jujuy, Salta, Tucumán, San Juan, and Mendoza, which were settled from Peru and Upper Peru (Bolivia) in the second half of the 16th cent. The oases, whose growth and importance greatly increased after they were linked by railroad to the east coast, produce wine, sugar, fruits, and corn; stock raising is also carried on there. The varied mineral deposits of this region (especially oil, lead, zinc, tin, copper, and salt) are being exploited. Mendoza and Tucumán are major industrial areas engaged in food processing, oil refining, and chemical production.

Occupying the southern part of Argentina is Patagonia, a vast, bleak, and windswept dissected plateau. Several large rivers flow in deep valleys eastward across Patagonia to the sea. Sheep raising (chiefly for wool) and oil and natural gas production (the area around Comodoro Rivadavia is the chief oil-producing region of Argentina) are the principal economic activities of Patagonia. The poor soils of Patagonia and its cool and dry climate do not favor cultivation, although irrigated agriculture is practiced in the Negro and Colorado river valleys. Patagonia is sparsely populated and largely undeveloped, with a few small river-mouth ports on the Atlantic coast such as Viedma, Rawson, Puerto Deseado, and Río Gallegos. Ushuaia, Tierra del Fuego, on Canal Beagle, is the world’s southernmost town.

The Andes Mts. region of Argentina, broad in the north, where it is similar to the Bolivian altiplano, and becoming narrower toward the south, extends along the length of Argentina’s western border. The region, which contains some of the world’s highest elevations outside Asia—including Aconcagua (22,835 ft/6,960 m high; the highest point of the Western hemisphere), Bonete, Tupungato, Mercedario, and Llullaillaco—acts as a barrier to the moist westerly winds, thus giving the eastern slopes of the Andes a desert condition that contrasts with the heavy snowfall on the higher elevations. There are timber and mineral resources, but they are not readily exploitable because of the region’s inaccessibility. Cattle are raised on the grassy Andean foothills. There are many beautiful lakes in the region, especially where it merges with the Patagonian plateau; Lake Nahuel Huapí in Nahuel Huapí National Park, adjoining the Chilean lake district, is an attractive resort area.

The soil resources of Argentina Soils=Argentina

Paraguay

The eastern part of the country, between the Paraguay and Paraná rivers, where most of the population lives, is a lowland, rising in the east and north to a plateau region. The region was once heavily forested, but forest land has been steadily depleted. The Paraná, south of the Iguaçu River (with its magnificent falls), separates Paraguay from Argentina. The Paraguay River also forms part of the border with Argentina, from its confluence with the Paraná north to the Pilcomayo River. The section west of the Paraguay River is a dry plain, part of the Chaco (see Gran Chaco). Cattle are raised and quebracho is found in the woodlands of the Chaco Boreal. Administratively, the country is divided into 19 departments. All the important cities are in the east. Besides Asunción, they are Villarrica, Concepción, and Encarnación.

Uraguay

The land is an area of topographical transition from the humid Argentine Pampa to the uplands of S Brazil. North of the alluvial plain, known as the Banda Oriental [Span.,=east bank, i.e., of the Uruguay and the Río de la Plata], Uruguay generally has long, sweeping slopes and grasslands, wooded valleys with slow-moving rivers, and long ranges of low hills, with some huge granite blocks that stand out against the horizon. Although Uruguay is within the temperate zone, climatic variations are moderate; generally the climate is warm, with rainfall evenly distributed through the seasons, but in some years there are severe droughts.

Most of the population is concentrated in the south; over 40% live in Montevideo. Almost 90% of Uruguay’s people are of European descent, Spanish and Italian predominating; there are few pure indigenous Uruguayans. The original inhabitants, the Charrúa, were absorbed into the Spanish and Portuguese populations after long resistance; today the mestizo element (less than 10% of the total population) is found principally in N Uruguay. Spanish is the official language, but a dialect containing elements of Spanish and Portuguese is spoken along the Brazilian frontier. The majority of the population is nominally Roman Catholic. The nation has long been remarkable for its contributions to literature and the arts (see Spanish American literature). The Univ. of the Republic is in Montevideo.

Presentation on Uraguay's Soils and Nitrogen Fixation Uraguay Soil

Source: http://www.bartleby.com/65/st/SthAmer.html

Peace Corps in South America

Bolivia Kristina Owens, Frank Aragona