Interandean Valles
Encyclopedia
Dry valleys in the central Andes
of Peru
, Bolivia
, and Argentina
, known as "valles", are marked by a rain shadow
effect of the surrounding mountains, and thus rainfall is limited, and mostly falls in a brief rainy season. The interandean valles comprise most of the mid-elevation areas of the "sierra" of Peru, "los valles" of Bolivia and the "cuyo
" region of Argentina
(m.a.s.l.) or 4,000 - 13,000 feet above sea level. Much of the area features steep hillsides and deep canyons, including the world's deepest canyon, the Colca Canyon
.
Most of the major cities and towns of the valles are found in broader, open valleys with expansive flat land created by ancient lakes or floodplains that is more amenable to agriculture than the highly erodible slopes.
To the south and west, are the harsh, frigid deserts, salt flats and alpine graslands of the altiplano
. To the north and east are the lush, wet, dense cloud forests or "yungas
" of the front-range, downslope, and foothills of the Andes. Higher ridges, peaks, and plateaus, dominated by high-elevation alpine puna
grasslands, Polylepis
woodlands, or snow-capped peaks separate the valles from both of these ecoregions.
. Generally, most rainfall occurs during summer ("el verano") from December through March. These rainy seasons can in fact be cool and damp for extended periods, though it can be quite warm during dry spells. Dry seasons are substantially colder; these dry winters ("el invierno") last from April through August. Any precipitation that does occur often falls as snow at higher elevations, though snow is extremely rare below 10,000 feet above sea level (3400m.a.s.l.
). The warmest times of the year are the transitional months of Sep.-Nov.
s in the Interandean Valles:
Most of the native vegetation has been replaced by agriculture or invasive exotics that are still widely used, such as Eucalyptus spp.
, Phragmites spp.
, Pinus radiata Notable endemic plants include Schinus molle
and various cactus species, though some of those may be non-native as well.
s of their departments or countries. A longer frost-free period, and a generally warmer climate makes the valles more amenable than the higher, colder altiplano for many crops. Further, many valles feature broad plains created by river floodplains or ancient lake beds, that serve better than the steeper more formidable terrain of the yungas. And the drier climate supports fewer parasites and diseases than the yungas or tropical regions.
Of particular importance are the production of potatoes and corn
. At higher elevations, oca
and other tubers as well as quinoa
, wheat
, barley
and other grains. At lower elevations, peanuts
, grapes and numerous other varieties of fruits and vegetables are also produced.
Bolivia:
Argentina:
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
of Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
, and Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, known as "valles", are marked by a rain shadow
Rain shadow
A rain shadow is a dry area on the lee side of a mountainous area. The mountains block the passage of rain-producing weather systems, casting a "shadow" of dryness behind them. As shown by the diagram to the right, the warm moist air is "pulled" by the prevailing winds over a mountain...
effect of the surrounding mountains, and thus rainfall is limited, and mostly falls in a brief rainy season. The interandean valles comprise most of the mid-elevation areas of the "sierra" of Peru, "los valles" of Bolivia and the "cuyo
Cuyo (Argentina)
Cuyo is the name given to the wine-producing, mountainous area of central-west Argentina. Historically it comprised the provinces of San Juan, San Luis and Mendoza. The term New Cuyo is a modern one, which indicates both Cuyo proper and the province of La Rioja...
" region of Argentina
Geography
The rugged topography of the Central Andes creates the warm dry valleys that typifies the valles. Generally lying between 1,200 and 3,500 meters above sea levelAbove mean sea level
The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...
(m.a.s.l.) or 4,000 - 13,000 feet above sea level. Much of the area features steep hillsides and deep canyons, including the world's deepest canyon, the Colca Canyon
Colca Canyon
Colca Canyon is a canyon of the Colca River in southern Peru. Peru's third most-visited tourist destination with about 160,000 visitors annually, it's located about 100 miles northwest of Arequipa...
.
Most of the major cities and towns of the valles are found in broader, open valleys with expansive flat land created by ancient lakes or floodplains that is more amenable to agriculture than the highly erodible slopes.
To the south and west, are the harsh, frigid deserts, salt flats and alpine graslands of the altiplano
Altiplano
The Altiplano , in west-central South America, where the Andes are at their widest, is the most extensive area of high plateau on Earth outside of Tibet...
. To the north and east are the lush, wet, dense cloud forests or "yungas
Yungas
The Yungas is a stretch of forest along the eastern slope of the Andes Mountains from southeastern Peru through central Bolivia. It is a transitional zone between the Andean highlands and the eastern forests. Like the surrounding areas, it has characteristics of the Neotropic ecozone...
" of the front-range, downslope, and foothills of the Andes. Higher ridges, peaks, and plateaus, dominated by high-elevation alpine puna
Puna
Puna may refer to:* Puna grassland, a type of grassland in the central part of the high Andes* Puna , the king of Hiti-marama or of Vavau in the Tuamotu legend of Rata* Puna , a type of wind in the Andes...
grasslands, Polylepis
Polylepis
Polylepis is a genus containing about twenty species of shrubs or trees native to the mid- and high-elevation regions of the tropical Andes. This group is unique in the rose family in that it is predominantly wind-pollinated. They are usually gnarled in shape, but in certain areas some trees are...
woodlands, or snow-capped peaks separate the valles from both of these ecoregions.
Climate
The valles are marked by mild, wet summers, and cool dry winters. Timing of the seasons varies according to latitudeLatitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
. Generally, most rainfall occurs during summer ("el verano") from December through March. These rainy seasons can in fact be cool and damp for extended periods, though it can be quite warm during dry spells. Dry seasons are substantially colder; these dry winters ("el invierno") last from April through August. Any precipitation that does occur often falls as snow at higher elevations, though snow is extremely rare below 10,000 feet above sea level (3400m.a.s.l.
Meters above sea level
Meters above sea Level is a standard metric measurement of the elevation of a location in reference to historic mean sea level; the determination of what actually constitutes mean sea level over time however, may be determined by other parameters, such as the effects of climate history and climate...
). The warmest times of the year are the transitional months of Sep.-Nov.
Ecoregions
The World Wildlife Fund identifies several distinct tropical dry forest ecoregionEcoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...
s in the Interandean Valles:
- Bolivian montane dry forests (Bolivia)
- Cauca Valley dry forestsCauca Valley dry forestsThe Cauca Valley dry forests is a tropical dry broadleaf forest ecoregion in Colombia.-Setting:The Cauca Valley dry forests occupies an area of , extending in a long, narrow strip along the Cauca River. The Cauca Valley is nestled between the Cordillera Occidental and Cordillera Central in the...
(Colombia) - Magdalena Valley dry forests (Colombia)
- Marañón dry forests (Peru)
- Patía Valley dry forests (Colombia)
- Sinu Valley dry forests (Colombia)
Vegetation
Vegetation is often sparse or deciduous, resulting from the long dry season.Most of the native vegetation has been replaced by agriculture or invasive exotics that are still widely used, such as Eucalyptus spp.
Eucalyptus
Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
, Phragmites spp.
Phragmites
Phragmites, the Common reed, is a large perennial grass found in wetlands throughout temperate and tropical regions of the world. Phragmites australis is sometimes regarded as the sole species of the genus Phragmites, though some botanists divide Phragmites australis into three or four species...
, Pinus radiata Notable endemic plants include Schinus molle
Schinus molle
Peruvian Pepper is an evergreen tree that grows to 15 meters . It is native to the Peruvian Andes...
and various cactus species, though some of those may be non-native as well.
Human settlement and influence
The majority of the human population of the central Andes, including most major cities, large towns, and agriculture, are found in these valleys.Agriculture
Much of the land is devoted to agriculture, and the valles tend to be the breadbasketBreadbasket
The breadbasket or the granary of a country is a region which, because of richness of soil and/or advantageous climate, produces an agricultural surplus which is often considered vital for the country as a whole. Rice bowl is a similar term used in Southeast Asia...
s of their departments or countries. A longer frost-free period, and a generally warmer climate makes the valles more amenable than the higher, colder altiplano for many crops. Further, many valles feature broad plains created by river floodplains or ancient lake beds, that serve better than the steeper more formidable terrain of the yungas. And the drier climate supports fewer parasites and diseases than the yungas or tropical regions.
Of particular importance are the production of potatoes and corn
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
. At higher elevations, oca
Oca
Oxalis tuberosa is an herbaceous perennial plant that overwinters as underground stem tubers. These tubers are known as oca, oka, or New Zealand Yam. The plant was brought into cultivation in the central and southern Andes for its tubers, which are used as a root vegetable...
and other tubers as well as quinoa
Quinoa
Quinoa , a species of goosefoot , is a grain-like crop grown primarily for its edible seeds. It is a pseudocereal rather than a true cereal, or grain, as it is not a member of the grass family...
, wheat
Wheat
Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
, barley
Barley
Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...
and other grains. At lower elevations, peanuts
Peanuts
Peanuts is a syndicated daily and Sunday American comic strip written and illustrated by Charles M. Schulz, which ran from October 2, 1950, to February 13, 2000, continuing in reruns afterward...
, grapes and numerous other varieties of fruits and vegetables are also produced.
Cities and large towns in the Interandean Valles
Peru:- CajamarcaCajamarcaCajamarca may refer to:Colombia*Cajamarca, Tolima a town and municipality in Tolima DepartmentPeru* Cajamarca, city in Peru.* Cajamarca District, district in the Cajamarca province.* Cajamarca Province, province in the Cajamarca region....
- HuánucoHuánuco-Famous Natives:* Daniel Alomía Robles - Musical composer and ethnologist born in 1871, famous for El Cóndor Pasa* Johan Fano- Professional football player-External links:*** - Catholic Encyclopedia article...
- HuancayoHuancayoHuancayo with a rock') is the capital of the Junín Region, in the central highlands of Peru. It is located in Junín Province, of which it is also capital. Situated near the Mantaro Valley at an altitude of 3,271 meters, it has a population of 377,000 and is the fifth most populous city of the...
- AyacuchoAyacuchoAyacucho is the capital city of Huamanga Province, Ayacucho Region, Peru.Ayacucho is famous for its 33 churches, which represent one for each year of Jesus's life. Ayacucho has large religious celebrations, especially during the Holy Week of Easter...
- AbancayAbancayAbancay is a city in southern-central Peru. It is the most important city in the Apurímac Region, and is the capital of the Abancay Province.-Location:...
- Andahuallas
- ArequipaArequipaArequipa is the capital city of the Arequipa Region in southern Peru. With a population of 836,859 it is the second most populous city of the country...
- CuscoCuscoCusco , often spelled Cuzco , is a city in southeastern Peru, near the Urubamba Valley of the Andes mountain range. It is the capital of the Cusco Region as well as the Cuzco Province. In 2007, the city had a population of 358,935 which was triple the figure of 20 years ago...
Bolivia:
- La PazLa PazNuestra Señora de La Paz is the administrative capital of Bolivia, as well as the departmental capital of the La Paz Department, and the second largest city in the country after Santa Cruz de la Sierra...
- CochabambaCochabambaCochabamba is a city in central Bolivia, located in a valley bearing the same name in the Andes mountain range. It is the capital of the Cochabamba Department and is the fourth largest city in Bolivia with an urban population of 608,276 and a metropolitan population of more than 1,000,000 people...
- SucreSucreSucre, also known historically as Charcas, La Plata and Chuquisaca is the constitutional capital of Bolivia and the capital of the department of Chuquisaca. Located in the south-central part of the country, Sucre lies at an elevation of 2750m...
- TarijaTarija, BoliviaTarija or San Bernardo de la Frontera de Tarixa is a city in southern Bolivia. Founded in 1574, Tarija is both the capital and largest city within the Tarija Department, with an airport offering regular service to primary Bolivian cities, as well as a regional bus terminal with domestic and...
- VillazónVillazónVillazón is a town in southern Bolivia, on the border with Argentina. It sits directly across a river from La Quiaca in Argentina. The town is a busy trading hub, with large quantities of goods flowing north....
- TupizaTupizaTupiza is a city in Potosí Department, Bolivia. It is located at around at an elevation of about 3160 m. The population is 23,100...
Argentina:
- SaltaSaltaSalta is a city in northwestern Argentina and the capital city of the Salta Province. Along with its metropolitan area, it has a population of 464,678 inhabitants as of the , making it Argentina's eighth largest city.-Overview:...
- Jujuy
- CatamarcaSan Fernando del Valle de CatamarcaSan Fernando del Valle de Catamarca is a city in northwestern Argentina and capital of Catamarca Province, on the Río Valle River, at the feet of the Cerro Ambato....
- La RiojaLa Rioja, ArgentinaLa Rioja is the capital city of the Argentine province of La Rioja, located on the east of the province. The city has a population of almost 150,000 as per the ....
- San JuanSan Juan, ArgentinaSan Juan is the capital city of the Argentine province of San Juan in the Cuyo region, located in the Tulúm Valley, west of the San Juan River, at above mean sea level, with a population of around 112,000 as per the ....
- MendozaMendoza, ArgentinaMendoza is the capital city of Mendoza Province, in Argentina. It is located in the northern-central part of the province, in a region of foothills and high plains, on the eastern side of the Andes. As of the , Mendoza's population was 110,993...