The Yungas ( Aymara ''yunka'' warm or temperate

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

or earth,

Quechua Quechua may refer to: *Quechua people, several indigenous ethnic groups in South America, especially in Peru *Quechuan languages, a Native South American language family spoken primarily in the Andes, derived from a common ancestral language **So ...

''yunka'' warm area on the slopes of the Andes) is a

bioregion A bioregion is an ecologically and geographically defined area that is smaller than a biogeographic realm, but larger than an ecoregion or an ecosystem, in the World Wide Fund for Nature classification scheme. There is also an attempt to use the ...

of a narrow band of forest along the eastern slope of the

Andes Mountains The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

from

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = National seal , national_motto = "Firm and Happy f ...

and

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

, and extends into Northwest Argentina at the slope of the Andes pre-cordillera. It is a transitional zone between the Andean highlands and the eastern forests. Like the surrounding areas, the Yungas belong to the

Neotropical realm The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bioge ...

; the climate is rainy, humid, and warm.

Setting

The Yungas forests are extremely diverse, ranging from moist lowland forest to evergreen montane forest and

cloud forest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud ...

s. The terrain, formed by

valley A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams ove ...

s, fluvial mountain trails and

stream A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams ...

s, is extremely rugged and varied, contributing to the ecological diversity and richness. A complex mosaic of habitats occur with changing latitude as well as elevation. There are high levels of

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity'') ...

and species endemism throughout the Yungas regions. Many of the forests are evergreen, and the South Andean Yungas contains what may be the last evergreen forests resulting from

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million year ...

glaciations.

World Wildlife ecoregions

The

World Wide Fund for Nature The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the W ...

has delineated three yungas

ecoregions An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

along the eastern side of the Andes: * The northernmost is the Peruvian Yungas, located entirely within

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = National seal , national_motto = "Firm and Happy f ...

and stretching nearly the whole length of the country. * The Bolivian Yungas lies to the south, entirely within

. The

Cordillera Apolobamba Apolobamba ''(Cordillera (de) Apolobamba)'' is a mountain range in the South American Andes. Geographical Location It is located in the eastern borderland of Peru and Bolivia. On the Bolivian side it is situated in the La Paz Department and ...

marks the boundary between the Peruvian Yungas and Bolivian Yungas. * The Southern Andean Yungas begins in southern

and continues to the north of

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the List of South American countries by area, second-largest ...

. It is a humid forest region between the drier

Gran Chaco The Gran Chaco or Dry Chaco is a sparsely populated, hot and semiarid lowland natural region of the Río de la Plata basin, divided among eastern Bolivia, western Paraguay, northern Argentina, and a portion of the Brazilian states of Mato ...

region to the east and the dry, high altitude Puna region to the west. Yungas are transitional zones between the Andean highlands and the eastern forests. The yungas forests are extremely diverse, ranging from moist lowland forest to evergreen montane forest and cloud forests. The terrain is extremely rugged and varied, contributing to the ecological diversity and richness. A complex mosaic of habitats occur with changing latitude as well as elevation. There are high levels of biodiversity and species endemism throughout the yungas regions. Many of the forests are evergreen, and the South Andean Yungas contains what may be the last evergreen forests resulting from Quaternary glaciations.

Climate

The average temperature is 72 °F (22 °C). The climate is varied and ranges from a humid

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

to the cold of the Andes over 10,000 ft (3,000 m).

Peruvian Yungas

In Peru there is a difference between Yunga and Yungas. Yunga is considered a natural region on both sides of the Peruvian Andes, the western side towards the coast is called Sea Yunga, and the eastern side into the jungle is called Fluvial Yunga, both reach a height of 2,300 m. Instead, Yungas is the ecoregion of rain forest and montane forest from 1.000 to 3.500 m, so it is limited to the eastern side of the Andes. This concept has a closer analogy with the Bolivian Yungas. This region is considered as the most endemic biodiversity of Peru. Forest loss in the Peruvian Yungas has sharply accelerated since the 2000s, rising seven-fold between 2005 and late 2012, according to satellite analysis by Terra-i.

Sea Yunga

Sea Yunga, or Maritime Yunga, is found between 500 and 2,300 m and it is situated between the eastern part of the coastal strip and the western part of the Highlands. This subregion has a

subtropical The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° north a ...

desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...

climate with little rainfall along the central and southern coast (drier as you go south). The average year round day temperature is (max 33 °C min 8 °C). A mist-fed ecosystem called

Lomas Lomas (Spanish for "hills"), also called fog oases and mist oases, are areas of fog-watered vegetation in the coastal desert of Peru and northern Chile. About 100 lomas near the Pacific Ocean are identified between 5°S and 30°S latitude, a nort ...

is found at scattered locations among hills near the Pacific Ocean at elevations up to . The flora in the central Sea Yungas region is mainly composed by the

lucuma ''Pouteria lucuma'' is a species of tree in the family Sapotaceae, cultivated for its fruit, the lúcuma. It is native to the Andean valleys of Bolivia, Chile, Ecuador, and Peru. Description This evergreen tree is up to 20 m tall, and has greyi ...

and

cherimoya The cherimoya (''Annona cherimola''), also spelled chirimoya and called chirimuya by the Inca people, is a species of edible fruit-bearing plant in the genus ''Annona'', from the family Annonaceae, which includes the closely related sweetsop ...

trees, the casuarin, and others. Once you go north its climate becomes

in the vicinity of La Libertad, Lambayeque and Piura. Day time temperatures average between and depending on latitude (max 40 °C min 15 °C). As this area approaches the tropics, fauna differs from the rest of the coast, so that animals like the boas, larger

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates ( lizards and snakes) and rhynchocephalia ...

s and the famous

white-winged guan The white-winged guan (''Penelope albipennis'') is a bird in the chachalaca, guan and curassow family Cracidae. It is endemic to northwestern Peru. History The white-winged guan was originally known from three specimens collected in 1876 ...

(a bird species unique to this Peruvian ecoregion) occur here. Common trees in this area are the faique, the sapote, the zapayal, the '' barrigon'' and other thorny tropical savanna trees of the equatorial dry

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

s on the northern coast of

Piura Piura is a city in northwestern Peru located in the Sechura Desert on the Piura River. It is the capital of the Piura Region and the Piura Province. Its population was 484,475 as of 2017. It was here that Spanish Conqueror Francisco Pizarro ...

and Tumbes. The cooler Pacific side is more vaguely characterized. The dry and cool ''Yunga Coastal'' begins at 500 m above sea level. The Maritime Yunga begins dry, and it seems to follow

ecotone An ecotone is a transition area between two biological communities, where two communities meet and integrate. It may be narrow or wide, and it may be local (the zone between a field and forest) or regional (the transition between forest and gras ...

on ecotone until reaching the Quechua region at the Pacific side.

Fluvial Yunga

Fluvial Yunga is between the altitudes of and and is found on the eastern part of Peru. This sub-region has a

climate with ample seasonal rains. The average temperature fluctuates between 20 °C and 25 °C depending on the altitude (max 35 °C, min 11 °C). Concept: The concept of the east side of the continental divide is straightforward: 1,000 m above sea level it is 4.9 °C cooler, and the subtropical cloud forest (Fluvial Yunga) follows the tropical rainforest (Anti). At 2,300 m, the climate transitions from subtropical climate to temperate climate (

). The

Tree line The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snow ...

ends at 3,500 m and has an annual mean temperature of 10 °C. The region between the

tree line The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snow ...

and 4,000 m is called

Suni The Suni (''Nesotragus moschatus'') is a small antelope. It occurs in dense underbrush from central Kenya to KwaZulu-Natal in South Africa. Suni are around high at the shoulder and weigh . They are usually reddish brown, darker on their back t ...

or Jalca. Suni is a dry and cold region with many glacial valleys. Despite the harsh weather, crops such as

quinoa Quinoa (''Chenopodium quinoa''; , from Quechua ' or ') is a flowering plant in the amaranth family. It is a herbaceous annual plant grown as a crop primarily for its edible seeds; the seeds are rich in protein, dietary fiber, B vitamins, ...

, maca, qañiwa,

broad beans ''Vicia faba'', commonly known as the broad bean, fava bean, or faba bean, is a species of vetch, a flowering plant in the pea and bean family Fabaceae. It is widely cultivated as a crop for human consumption, and also as a cover crop. Var ...

and ulluku are cultivated here.

Flora and fauna

The flora (subtropical

) of the Yunga region is mainly composed by the Peruvian pepper tree, the Furcraea, white cabuya (Furcraea andina), the

pitahaya A pitaya () or pitahaya () is the fruit of several different cactus species indigenous to the Americas. Pitaya usually refers to fruit of the genus ''Stenocereus'', while pitahaya or dragon fruit refers to fruit of the genus ''Selenicereus'' ...

and the Peruvian torch cactus (''Echinopsis peruviana''). The

coca Coca is any of the four cultivated plants in the family Erythroxylaceae, native to western South America. Coca is known worldwide for its psychoactive alkaloid, cocaine. The plant is grown as a cash crop in the Argentine Northwest, Bolivia, ...

leaf is established in this region as well as the uña de gato ("cat's claw", '' Uncaria tomentosa''). The most attractive sites of this warm refreshing region are its many

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of floweri ...

forests and beautiful valleys. The fauna in the Yunga region is characterized by the

long-tailed mockingbird The long-tailed mockingbird (''Mimus longicaudatus'') is a species of bird in the family Mimidae. It is found in Ecuador and Peru. Taxonomy and systematics The long-tailed mockingbird has four subspecies, the nominate ''Mimus longicaudatu ...

, or chaucato.

Overview

Andean Continental Divide Mountain Top: * Mountain passes – 4,100 m *

Puna grassland The puna grassland ecoregion, of the montane grasslands and shrublands biome, is found in the central Andes Mountains of South America. It is considered one of the eight Natural Regions in Peru,Pulgar Vidal, Javier: Geografía del Perú; Las Oc ...

** Closed vegetation ** Sporadic vegetation * Andean-alpine desert *

Snow line The climatic snow line is the boundary between a snow-covered and snow-free surface. The actual snow line may adjust seasonally, and be either significantly higher in elevation, or lower. The permanent snow line is the level above which snow wil ...

– about 5,000 m *

Janca Janca is one of the eight Natural Regions of Peru (''Janq'u'' is Aymaran for “White”). It is located in the frozen heights where the condor lives. The fauna in this region is limited because of the very cold weather. The only plant that ...

– Rocks, Snow and Ice * Peak

Bolivian Yungas

Human use

In the early 20th century, the region was a major source for

rubber Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, and ...

and

quinine Quinine is a medication used to treat malaria and babesiosis. This includes the treatment of malaria due to '' Plasmodium falciparum'' that is resistant to chloroquine when artesunate is not available. While sometimes used for nocturnal leg ...

. Now,

coffee Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world. Seeds of ...

citrus ''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is native to ...

, and

are important crops. People cultivate native plants like the

canistel ''Pouteria campechiana'' (commonly known as the cupcake fruit, eggfruit, zapote amarillo or canistel) is an evergreen tree native to, and cultivated in, southern Mexico, Belize, Guatemala, and El Salvador. It is cultivated in other countries, ...

or eggfruit tree the lúcuma tree, the cherimoya or chirimoya, the guava or guayabo and the avocado or palta. The

Afro Bolivian Afro-Bolivians are Bolivian people of Sub-Saharan African heritage and therefore the descriptive "Afro-Bolivian" may refer to historical or cultural elements in Bolivia thought to emanate from their community. It can also refer to the combining of ...

community is concentrated here. The Yungas Cocalera Revolution is based in the region. Its name derives from the one applied for the same mountain level by those who study the economic system of the prehispanic Andes. The Yungas also contains one of the most deadly roads in the world, called the "camino de la muerte," or

Highway of Death The Highway of Death ( ''ṭarīq al-mawt'') is a six-lane highway between Kuwait and Iraq, officially known as Highway 80. It runs from Kuwait City to the border town of Safwan in Iraq and then on to the Iraqi city of Basra. The road was used ...

. Due to the mountainous terrain an entrepreneurial coca harvester created a network of

zip line A zip-line, zip line, zip-wire, flying fox, or death slide is a pulley suspended on a cable, usually made of stainless steel, mounted on a slope. It is designed to enable cargo or a person propelled by gravity to travel from the top to the bot ...

s that permit rapid travel from peak to peak by farmers, referred to locally as flying men or bird men, along with their harvests using zip line trollies.

Argentine Yungas

References

Other sources

* Endemic Bird Areas for th
Bolivian and Peruvian upper yungas
and th

BirdLife International, 2003. BirdLife's online World Bird Database. Version 2.0. Cambridge, UK. * * * {{Authority control Ecoregions of the Andes Andean forests Montane ecology Tropical Andes Upper Amazon Ecoregions of South America Ecoregions of Argentina Ecoregions of Bolivia Ecoregions of Peru Geography of Bolivia Physiographic regions of Peru Regions of Argentina Natural history of Argentina Natural history of Bolivia Natural history of Peru Natural regions of South America Regions of Bolivia Ecoregions Natural regions Regions of Peru