Southern Andean Steppe Ecoregion (South America)

Southern Andean Steppe Ecoregion (South America)

Thu, 06/30/2022 - 17:18
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The Southern Andean steppe ecoregion is found in the higher elevations of the Chilean and Argentine Andes, the southern portion of the Andes range, and features a cold desert climate. It is part of the Montane grasslands and shrublands biome.

Southern Andean Steppe

The Southern Andean steppe ecoregion is found in the higher elevations of the Chilean and Argentine Andes, the southern portion of the Andes range, and features a cold desert climate. It is part of the Montane grasslands and shrublands biome.

This ecoregion is found at elevations of 3,500 - 5,000 m (11,500 - 16,400 ft) in the north; to elevations of 1,800 - 3,000 m (5,900 - 9,800 ft) in the south along the border between Chile and Argentina.

Higher elevations are covered permanently with snow, glaciers and ice fields. At lower elevations, the ecoregion grades into Chilean matorral and Valdivian temperate forests in the west, High Monte in the east, Central Andean dry puna in the north and Patagonian steppe in the south.

The Southern Andean steppe ecoregion features a cold desert climate. Precipitation falls mainly in winter. This ecoregion's high elevations and harsh climate make it unsuitable for development or farming, so it has experienced little habitat loss.

The ecoregion features a high concentration of plant and fauna endemism. The flora is adapted to its cold, dry and windy climate therefore, many of the plant genera have evolved endemic species.

The flora on the western side of the ecoregion can be divided into three zones based on their growth forms and elevation.

  • lower elevations, 2,000 - 2,700 m (6,600 - 8,900 ft): large shrubs such as Chuquiraga oppositifolia and Nassauvia axillaris

  • intermediate elevations, 2,700 - 3,300 m (8,900 - 10,800 ft): small shrubs, tussock grasses and cushions, including Azorella madreporica, Laretia acaulis and Stipa spp.

  • highest elevations, extending to 3,900 m (12,800 ft): small forbs, rosettes, and grasses such as Nassauvia lagascae, Oxalis erythrorhiza, Nassauvia pinnigera and Moschopsis leyboldii

The flora on the eastern side does not grow in distinct zones.

  • lower elevations, 1,900 - 2,700 m (6,200 - 8,900 ft): plants of the genera Stipa, Adesmia, Mulinum, Nassauvia and Chuquiraga

  • intermediate elevations, 2,700 - 3,300 m (8,900 - 10,800 ft): shrubs and cushion plants of Oxalis, Junellia, Adesmia, Laretia and Azorella

  • highest elevations, 3,300 - 4,500 m (10,800 - 14,800 ft): Senecio, Nassauvia, Chaetanthera, Draba, Barneoudia, Leucheria and Moschopsis

Species of fauna include the puma (Puma concolor), the Andean fox (Lycalopex culpaeus), the vicuna (Vicugna vicugna) and the guanaco (Lama guanicoe). Rodents also stand out, such as the Andean laucha (Calomys lepidus), the Andean mouse (Akodon andinus), the chinchilla or mountain vizcacha (Lagidium viscacia) and the chinchilla rat (Abrocoma cinera).

The avifauna of the Andean steppe ecoregion includes the condor (Vultur gryphus), the ashy sleeper (Muscisaxicola cinereus), the black-fronted sleeper (Muscisaxicola frontalis), the small sleeper (Muscisaxicola maculirostris), the Andean sebo (Phrygilus gayi ), the plumbeous yal (Phrygilus unicolor), the collared snipe (Thinocorus orbignyianus), the grey-breasted monterita (Poospiza hypochondria), the Andean pigeon (Metriopelia melanoptera), the Andean gull (Chroicocephalus serranus), the Andean hummingbird (Oreotrochilus leucopleurus), the large walker (Geositta isabellina), etc.

Ecoregion NT1008 - Southern Andean steppe

Ecoregion NT1008 - Southern Andean steppe (in purple)