Argentine Monte
The Argentine Monte, or Low Monte, is an ecoregion of dry thorn scrub and grasslands in Argentina. It is one of the driest regions in the country.
Human settlements are mainly near water supplies such as rivers or oases.
Deforestation and over-grazing around these settlements have caused desertification.
Location
The Argentine Monte is in north-central Argentina, and has an area of.It is to the east of the Andes and extends from Salta Province in the north to Chubut Province in the south.
It extends from the eastern foothills of the Andes to the Atlantic Ocean. The ecoregion merges into the Patagonian steppe in the south and southwest. The Dry Chaco lies to the northeast, and the Espinal is to the east.
In the northwest it borders the High Monte. Some consider the High Monte a separate ecoregion, while others consider it a part of the Argentine Monte.
Physical
Elevations range from sea level on the Atlantic coast to.The region contains parts of the watersheds of the Rio Negro and Rio Colorado.
The Lagunas de Guanacache, Desaguadero y del Bebedero in Mendoza Province form the most important wetland in the ecoregion, designated a Ramsar site.
This is a long chain of lagoons and marshes covering fed by the Mendoza and San Juan rivers, which drains into the Desaguadero River. The lakes and streams are mostly seasonal or intermittent.
The ecoregion is by far the driest part of Argentina.
The Köppen climate classification is "BSk": arid, steppe, cold arid.
Annual precipitation is.
In the north and central regions there is more rain in summer.
In the colder south the monthly rainfall is more evenly distributed.
At a sample location at coordinates the mean temperature ranges from in July to in January.
The yearly average mean temperature is.
Annual precipitation is about.
Monthly precipitation ranges from in July to in October.
Ecology
The Argentine Monte is in the Neotropical realm, in the temperate grasslands, savannas, and shrublands biome.Flora
Flora are typically thorn scrub and dry grassland, with relatively low plant diversity.There are thin gallery forests along the rivers.
There are areas of cactus scrub, xerophilous open woodland, and vegetation adapted to rocky, sandy and salty conditions.
In some areas the scrub is very open.
The steppe contains resinous evergreen bushes, mainly from the family Zygophyllaceae and the genera Larrea, Bulnesia and Plectocarpa.
Other species are Monttea aphylla, Bougainvillea spinosa and Prosopis species.
In the north cacti of the genera Echinopsis and Cereus and bromeliads of the genera Dyckia, Deuterocohnia and Tillandsia are more common.
Herbaceous plants appear after rain showers, including Portulaca grandiflora, irises, lilies and grasses.
On the river edges or where there is underground water there are gallery forests of Prosopis species.
Larrea cuneifolia is found in hot and dry areas, Larrea divaricata along the streams and Larrea nitida in cooler areas and mountain slopes.
Other plants found in different conditions include Baccharis salicifolia, Tessaria dodonaefolia, Suaeda divaricata and Allenrolfea vaginata.
Several endemic species have evolved in isolation since the Oligocene such as Ramorinoa girolae and Gomphrena colosacana, found in the Sierra de las Quijadas National Park, and Halophytum ameghinoi, a succulent herbaceous plant in the Halophytaceae family.
Fauna
Common mammals include screaming hairy armadillo, pink fairy armadillo, cougar, South American gray fox, Patagonian weasel, guanaco, and southern mountain cavy.Vulnerable or endangered mammals include plains viscacha rat, pink fairy armadillo, strong tuco-tuco, viscacha rat, Roig's pericote, delicate salt flat mouse and Patagonian mara.
Endangered mammals include southern river otter.
Birds include elegant crested tinamou, cinnamon warbling finch, Darwin's nothura and burrowing parrot.
Threatened birds are peregrine falcon and Chaco eagle.
Endangered birds include yellow cardinal and Eskimo curlew.
The Guanacache, Desaguadero y Bebedero system has rich biodiversity and supports more than 50 species of waterbirds.
These include maguari stork, southern screamer, white-faced ibis, Chilean flamingo and dabbling ducks of the genus Anas.
It is also used by migratory birds such as plovers and sandpipers.
Reptiles include Argentine red tegu, false tomodon snake, Patagonian lancehead, boa constrictor, ringed hognose snake and Chaco tortoise.
Amphibians include Mendoza four-eyed frog.
Endangered amphibians include La Rioja water frog and Andalgala water frog.
In the northern region about 10% of insect genera and 35% of insect species are endemic.
Status
The World Wildlife Fund gives the ecoregion the status of "Vulnerable".The region has mostly been settled by people only in oases or areas near rivers where irrigation-based agriculture is possible.
This process began in the late 19th century and continues today.
The habitat in the settled areas has been greatly changed, with trees cleared for use as fuel and lumber and to make way for agriculture and mineral exploitation.
of the ecoregion has been affected by erosion caused by deforestation and excessive grazing by sheep, goats and cattle.
There is marked increase in desert areas, affecting the habitats of many native species.
Many species are affected by fragmentation of their habitats.
The Guanacache, Desaguadero y Bebedero system has been affected by various natural and man-made changes that have caused the area of lagoons and marshes to shrink significantly.
Some efforts are being made to rehabilitate them.
Conservation
5.37% of the ecoregion is in protected areas.Protected areas in the Low Monte include:
Protected areas in the High Monte include: