Monte Desert: Argentine or Low Monte Ecoregion (South America)

Monte Desert: Argentine or Low Monte Ecoregion (South America)

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The Monte Desert is a region in South America lying entirely within Argentina. The Argentine Monte, or Low Monte, is an ecoregion of Argentina's dry thorn scrub and grasslands. It is one of the driest regions in the country. Human settlements are mainly near water supplies such as rivers or oases.

Monte Desert

The Monte Desert is a region in South America lying entirely within Argentina. It covers approximately the submontane areas of Catamarca, La Rioja, San Juan, San Luis and Mendoza provinces, the western half of La Pampa Province and the extreme north of Río Negro Province.

The desert lies southeast of the Atacama Desert in Chile, north of the larger Patagonian Desert, east of the Andes and west of the Sierra de Córdoba.

The delineations between the Monte, Atacama, and Patagonian deserts are not exact. However, the Monte seems more or less continuous with the other two nearby deserts.

The geography of the land is very similar to that of the interior Patagonian Desert, with volcanic sediments, piedmont plains, large mountain blocks and many usually dry salt lakes.

The principal river is the Río Colorado and its tributary, the Río Desaguadero, which meet in the region's south and provide the primary source of irrigation water for wine crops.

The region experiences very little rain because it lies on the eastern, or leeward, side of the Andes and west of the Sierra de Córdoba. These rain shadow effects are the primary reason for the region's aridity and the formation of the Monte and other nearby deserts.

A difference between the Monte Desert and the other two deserts is the lack of intensity of effect from the cold water currents off the South American coast, allowing the region to support a wider variety of life than the other two more extreme deserts.

The region's flora is much more diverse than the nearby Patagonian Desert (which contains mainly shrubs and grasses) and the Atacama Desert (which is pretty much devoid of life). Nevertheless, shrubs and grasses are common, and tall cacti even appear in the more hospitable areas of the desert.

The area's fauna is also very similar to that of the Patagonian Desert, only in greater diversity and number due to the Monte's more hospitable conditions. Small mammals like mice abound, and larger animals like the guanaco and burrowing owl can also be found.

Argentine or Low Monte

The Argentine Monte, or Low Monte, is an ecoregion of Argentina's dry thorn scrub and grasslands. It is one of the driest regions in the country. Consequently, human settlements are mainly near water supplies such as rivers or oases.

The Argentine Monte is in the neotropical realm, within the temperate grasslands, savannas, and shrublands biome. It is a warm scrub desert between the Puna, Patagonia, and Chaco ecoregions.

The ecoregion is located in north-central Argentina and has an area of approximately 40,896,000 ha (157,900 sq mi). It is situated east of the Andes and extends from Salta Province in the north to Chubut Province in the south. It covers the eastern foothills of the Andes.

In the north, the Argentine Monte ecoregion lies between the Dry Chaco and Southern Andean Yungas to the east and the Central Andean dry puna and Southern Andean steppe to the west.

In the south, it lies between Argentine Espinal to the east and the Patagonian steppe to the west.

The climate is temperate-arid, with annual rainfall ranging from just 80 – 250 mm (3 - 10 in). The northern and central regions of the Monte receive rains in summer, but the south is colder, and rainfall is distributed throughout the year.

Flora and Fauna

The Argentine Monte ecoregion's dominant vegetation is scrublands which can be very open. These flat open areas are formed by resinous evergreen bushes dominated by representatives of the Zygophyllaceae family, such as species from the genera Larrea, Bulnesia, and Plectocarpa.

After rains, herb plants, including moss-rose purslane, wild iris, lilies, and some grasses, will appear. Mesquite trees will form along rivers or areas with underground water.

Overall the Larrea genus is the most characteristic of the ecoregion; Larrea cuneifolia colonizes the drier parts of the Monte, while L. divaricata can only grow as riparian species, and L. nitida grows in cold environments and the slopes of the Andes.

The most characteristic mammals of the ecoregion include screaming hairy armadillo, puma, Argentine gray fox, Patagonian weasel, and guanaco. Endemics include red viscacha rat and pink fairy armadillo. In addition, two rodent species, the delicate salt flat mouse (Salinomys delicatus) and strong tuco-tuco (Ctenomys validus) are native to the ecoregion.

Reptiles found in Low Monte include the ringed hognose snake, Argentine red tegu, and the vulnerable Chaco tortoise. A characteristic amphibian, Mendoza's four-eyed frog, is also found here.

Characteristic birds include elegant crested tinamou, burrowing parrot, Darwin's nothura, warbling cinnamon finch, peregrine falcon, and the endangered crowned solitary eagle.

Protection Status

The northern parts of the Monte ecoregion, which covers large tracts of land on which many fauna species depend, are not protected.

Within the central and southern parts of the ecoregion, some of the notable protected areas (along with various other provincial reserves) include:

Map illustrating the location of the Argentine Monte (in purple)

Map illustrating the location of the Argentine Monte (in purple)