The Southern Andean Yungas is a tropical and subtropical moist broadleaf forest ecoregion in the yungas of southwestern Bolivia and northwestern Argentina. It contains what may be the last of the isolated evergreen forests resulting from Quaternary glaciations.
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. The ecoregion occurs in elevations ranging from 800 - 3,000 m (2,600 - 9,800 ft).
The WWF has delineated three yungas ecoregions along the eastern side of the Andes range:
The Southern Andean yungas ecoregion forms a mesic habitat between two much drier habitats. The ecoregion is loosely bordered east by the Chaco and tightly interdigitated to the west with the Bolivian Montane Dry Forest, spanning southwestern Bolivia and northwestern Argentina.
This ecoregion is fascinating from a biogeographic perspective. It may be the last of the isolated evergreen forests resulting from Quaternary glaciations (an alternating series of glacial and interglacial periods where glaciers expanded and contracted).
The Southern Andean yungas ecoregion has a subtropical highland climate. The climate is influenced by trade winds that bring about 2,500 m (98 in) of rain annually.
Flora and Fauna
The Southern Andean yungas are a mesic evergreen forest, with trees typically less than 15 m (49 ft) tall. Between 1,200 - 2,500 m (3,900 - 8,200 ft), the forest is dominated by Andean alder (Alnus acuminata) and mountain pine (Podocarpus parlatorei). These species mix with other trees at lower elevations, especially Lauraceae and Myrtaceae.
Many tropical species find the southern limit of their range in this ecoregion. Mammals that may be found here include the white-lipped peccary (Tayassu pecari), the collared peccary (Pecari tajacu), and the South American tapir (Tapirus terrestris). Cats include the jaguar (Panthera onca), puma (Puma concolor), margay (Leopardus wiedii), and jaguarundi (Puma yagouaroundi).
Like the Bolivian yungas to the north, this region is also quite strong in endemics, including approximately ten avian species that are range-restricted, including the red-faced guan (Penelope dabbenei), Rothschild's swift (Cypseloides rothschildi), and the rufous-throated dipper (Cinclus schulzi).
There are several National Parks and protected areas in this ecoregion, in Bolivia (Tariquía National Reserve) and Argentina (Calilegua National Park, Baritú National Park, El Rey National Park, and Potrero de Yala Provincial Park).
Map depicting the location of the Southern Andean Yungas (in purple)