The High Monte is a

montane grasslands and shrublands Montane grasslands and shrublands are a biome defined by the World Wildlife Fund. The biome includes high elevation grasslands and shrublands around the world. The term "montane" in the name of the biome refers to "high elevation", rather than t ...

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Geography

The High Monte is located on the eastern slopes of the

Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

, extending from the vicinity of

Salta Salta () is the capital and largest city in the Provinces of Argentina, Argentine province of Salta Province, the same name. With a population of 618,375 according to the 2010 census, it is also the List of cities in Argentina, 7th most-populous ...

(24º S) south to Mendoza (32º S). It is a landscape of mountains and closed basins which lie between the

Sierras Pampeanas The Sierras Pampeanas (also called Central Sierras or Pampas Sierras) (English: Pampas Mountains) is a geographical region of Argentina. The Sierras Pampeanas are a chain of mountains that rise sharply from the surrounding pampa region of N ...

on the east and the main spine of the Andes to the west. The southern portion of the High Monte is drained by the Desaguadero River. The lower limit of soil

cryoturbation In gelisols (permafrost soils), cryoturbation (frost churning) refers to the mixing of materials from various horizons of the soil down to the bedrock due to freezing and thawing. Cryoturbation occurs to varying degrees in most gelisols. The cau ...

along the eastern slope of Andes marks the upper boundary of the High Monte, extending up to 3000 meters at the northern end of the ecoregion, and between 1500 and 1700 meters elevation in

Mendoza Province Mendoza (), officially the Province of Mendoza, is a province of Argentina, in the western central part of the country in the Cuyo region. It borders San Juan to the north, La Pampa and Neuquén to the south, San Luis to the east, and the r ...

further south. The eastern transitions to the Chaco and Low Monte are more gradual.Ojeda, Ricardo A., Solana Tabeni, and Valeria Corbalán (2011). "Mammals of the Monte Desert: from regional to local assemblages". ''Journal of Mammalogy'', 92(6):1236–1244, 2011.Abraham, Elena & Del Valle, Héctor & Roig, F. & Torres, Laura & Ares, J.O. & Coronato, Fernando & Godagnone, R.. (2009). Overview of the geography of the Monte Desert biome (Argentina). Journal of Arid Environments. 73. 144-153. 10.1016/j.jaridenv.2008.09.028.

Climate

The climate is temperate and arid to semi-arid. Mean annual rainfall varies with location and relief, from less than 100 mm to 450 mm. Much of the ecoregion is in the

rain shadow A rain shadow is an area of significantly reduced rainfall behind a mountainous region, on the side facing away from prevailing winds, known as its leeward side. Evaporated moisture from body of water, bodies of water (such as oceans and larg ...

of the Sierras Pampeanas. Most rain falls during the southern hemisphere summer, when the South American

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in Atmosphere of Earth, atmospheric circulation and precipitation associated with annu ...

system brings moist air to the ecoregion.Elías, Gabriela & Aagesen, Lone. (2016). Areas of vascular plants endemism in the Monte desert (Argentina). ''Phytotaxa''. 266. 161. 10.11646/phytotaxa.266.3.1. The High Monte is part of the

Arid Diagonal The Arid Diagonal () is a contiguous zone of arid and semi-arid climate that traverses South America from coastal Peru in the Northwest to Argentine Patagonia in the Southeast, including large swathes of Bolivia and Chile. The Arid Diagonal encom ...

, a belt of arid and semi-arid regions that extend from northwest to southeast across southern South America, from the Pacific to the Atlantic oceans.

Flora

The characteristic vegetation is shrubland. Evergreen shrub species of ''

Larrea ''Larrea'' is a genus of flowering plants in the caltrop family, Zygophyllaceae. It contains five species of evergreen shrubs that are native to the Americas. The generic name honours Bishop Juan Antonio Hernández Pérez de Larrea, a patron of ...

'', known as ''jarillas'', are predominant. There are areas of open ''algarrobo'' (''

Prosopis ''Prosopis'' is a genus of flowering plants in the family Fabaceae. The current circumscription of the genus contains three species found in northern Africa, the Middle East, Central and South Asia. Previously it also contained around 40 species ...

'') woodland where groundwater is available. ''

Prosopis alba ''Neltuma alba'' (formerly ''Prosopis alba'') is a South American tree species that grows in central Argentina, the Gran Chaco ecoregion, and part of the Argentine Mesopotamia, as well as Bolivia, Chile, Paraguay, and Peru. It is known as ''alg ...

'' and ''

Prosopis nigra ''Neltuma nigra'' (formerly ''Prosopis nigra'') is a South American leguminous tree species that inhabits the Gran Chaco ecoregion (in particular, the transition zone between the Wet Chaco and the Southern Chaco), in Argentina and Paraguay. It ...

'' are the most common ''algarrobo'' species, growing 4 to 16 meters in height.Blanco, Guillermo; Romero-Vidal, Pedro; Carrete, Martina; Chamorro, Daniel; Bravo, Carolina; Hiraldo, Fernando; Tella, José L.; Legal, Luc (2021). "Burrowing Parrots Cyanoliseus patagonus as Long-Distance Seed Dispersers of Keystone Algarrobos, Genus Prosopis, in the Monte Desert." ''Diversity'' (14242818). May 2021, Vol. 13 Issue 5, p 204. DOI: 10.3390/d13050204. Characteristic Chaco shrubs like ''

Bulnesia schickendantzii ''Bulnesia'' is a genus of flowering plants in the caltrop family, Zygophyllaceae. Species in this genus are all native to South America. The wood of some – particularly '' B. arborea'' and '' B. sarmientoi'' – is traded as verawood ( ...

'', and '' Tragia geraniifolia'' grow along the eastern boundary with the Chaco. The High Monte is home to many

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

plants, especially in the transition zone between the Monte and the humid

Southern Andean Yungas The Southern Andean Yungas is a tropical and subtropical moist broadleaf forest ecoregion in the Yungas of southwestern Bolivia and northwestern Argentina. Geography The ecoregion occurs along the eastern slope of the Andes from southern Bolivi ...

forests. Of the 505 plant species endemic to northwestern Argentina, 57 to 73 endemic species are found in the Sierra del Aconquija transition zone, the highest concentration of endemic species in Argentina's northwest.Godoy-Bürki, Ana C.; Ortega-Baes, Pablo; Sajama, Jesús M; Aagesen, Lone (2014). "Conservation priorities in the Southern Central Andes: mismatch between endemism and diversity hotspots in the regional flora". ''Biodiversity Conservation'' (2014) 23:81–107 DOI 10.1007/s10531-013-0586-1

Fauna

Native mammals include the

guanaco The guanaco ( ; ''Lama guanicoe'') is a camelid native to South America, closely related to the llama. Guanacos are one of two wild South American camelids; the other species is the vicuña, which lives at higher elevations. Etymology The gua ...

(''Lama guanicoe''), puma (''Puma concolor''),

South American gray fox The South American gray fox (''Lycalopex griseus''), also known as the Patagonian fox, the ''chilla'' or ''zorro gris'' (gray fox or gray zorro), is a South America, South American species of ''Lycalopex'' (the "false" or lesser foxes) in the Ca ...

(''Lycalopex griseus''),

Patagonian weasel The Patagonian weasel (''Lyncodon patagonicus'') is a small mustelid that is the only member of the genus ''Lyncodon''. Its geographic range is the Pampas of western Argentina and sections of Chile. An early mention of the animal is in the Journ ...

(''Lyncodon patagonicus''),

screaming hairy armadillo The screaming hairy armadillo (''Chaetophractus vellerosus'') is a species of armadillo also known as the small screaming armadillo, crying armadillo or the small hairy armadillo. It is a burrowing armadillo found in the central and southern part ...

(''Chaetophractus vellerosus''),

pink fairy armadillo The pink fairy armadillo (''Chlamyphorus truncatus'') is the smallest species of armadillo, first described by Richard Harlan in 1825. The pink fairy armadillo is long, and typically weighs about . This solitary, desert-adapted animal is ende ...

(''Chlamyphorus truncatus''),

white-eared opossum The white-eared opossum (''Didelphis albiventris''), known as the timbu and cassaco in northeast Brazil, saruê and sariguê in Bahia, micurê and mucura in northern Brazil and comadreja overa in Argentina, is an opossum species found in Argentin ...

(''Didelphis albiventris''), and

white-bellied fat-tailed mouse opossum The white-bellied fat-tailed mouse opossum (''Thylamys pallidior'') is a species of opossum in the family Didelphidae. It is found in Argentina, Bolivia, Chile and Peru. Taxonomy and etymology The white-bellied fat-tailed mouse opossum is a ...

(''Thylamys pallidior''). The

Sierra del Tontal chinchilla rat The Sierra del Tontal chinchilla rat (''Abrocoma shistacea'') is a species of chinchilla rat. Found only in Argentina, this species was once thought to be part of '' Abrocoma cinerea''. In 2002, Braun and Mares from the University of Oklahoma con ...

(''Abrocoma shistacea'') and

golden viscacha rat The golden viscacha rat or golden vizcacha rat (''Pipanacoctomys aureus'') is the single species of the genus ''Pipanacoctomys'' of the rodent family Octodontidae. It has 92 chromosomes and has been regarded as tetraploid ( 4x = 2n).Gallardo, M. ...

(''Pipanacoctomys aureus'') are endemic to the ecoregion. The

mountain viscacha rat The mountain viscacha rat or mountain vizcacha rat (''Octomys mimax''), historically viscacha rat or vizcacha rat, is a species of rodent in the family Octodontidae. It is endemic to Argentina. It is the only living species within the genus '' ...

(''Octomys mimax'') is a near-endemic, ranging into an adjacent area of the Low Monte. Other native rodents include ''

Akodon albiventer ''Akodon albiventer'', also known as the white-bellied grass mouse or white-bellied akodont,Musser and Carleton, 2005, p. 1092 is a species of rodent in the family Cricetidae. It is found in the Andean highlands from southeastern Peru to sout ...

, Akodon simulator, Akodon spegazzinii,

Andalgalomys olrogi Olrog's chaco mouse (''Andalgalomys olrogi'') is a species of South American rodent in the family Cricetidae, endemic to Argentina. The natural habitat of the species is hot deserts. Its karyotype has Diploid, 2n = 60. The species is named afte ...

Ctenomys coludo, Ctenomys famosus, Ctenomys knighti, Eligmodontia bolsonensis, Octodontomys gliroides'', and '' Salinoctomys loschalchalerosorum''. The

burrowing parrot The burrowing parrot (''Cyanoliseus patagonus''), also known as the burrowing parakeet or the Patagonian conure, is a species of parrot native to Argentina and Chile. It belongs to the Monotypic taxon, monotypic genus ''Cyanoliseus'', with four s ...

(''Cyanoliseus patagonus andinus'') is native to the ecoregion, where it is an important disperser of ''algarrobo'' seeds.

Protected areas

12.88% of the ecoregion is in protected areas. These include

Talampaya National Park Talampaya National Park () is a National Parks of Argentina, national park located in the east/centre of La Rioja Province (Argentina), La Rioja Province, Argentina. It was designated a provincial reserve in 1975, a national park in 1997, and a U ...

El Leoncito National Park El Leoncito National Park () is a federal protected area in San Juan Province, Argentina. Established on 18 September 2002, it houses a representative sample of the Central Andean Puna and the Southern Andean steppe biodiversity in good state ...

, Los Cardones National Park, and San Guillermo National Park.

References

{{reflist Ecoregions of Argentina Ecoregions of the Andes Montane grasslands and shrublands Neotropical ecoregions