Southern Andean steppe

Southern Andean steppe
Name	Southern Andean steppe
Biome	Montane grasslands and shrublands
Countries	Argentina, Chile

Southern Andean steppe The Southern Andean steppe is a high-elevation montane ecoregion of the Andes spanning parts of Argentina and Chile, characterized by extensive puna-like grasslands, xeric shrublands, and cold deserts. It occupies plateaus, intermontane basins, and rain-shadow zones adjacent to well-known features such as the Patagonian Andes, the Atacama Desert, and the Magellan Strait, and interacts with climatic systems influencing the Southern Cone and the Pacific Ocean.

Geography and extent

The ecoregion extends along the southern Andes between ranges associated with the Cordillera de la Costa, the Cordillera Real, and the Patagonian Ice Fields, reaching across administrative regions of Neuquén Province, Mendoza Province, Santa Cruz Province, Aysén Region, and Magallanes Region. Major geomorphological elements include the Altiplano-like plateaus, the Fagnano Lake basins, volcanoes such as Mount Fitz Roy, and passes used historically by expeditions like the Beagle Channel voyages and by indigenous groups like the Mapuche and Tehuelche. The steppe abuts biomes such as the Valdivian temperate rain forests, the Patagonian steppe, and the Sechura Desert to form ecotones recognized in inventories by the World Wide Fund for Nature and surveyed by researchers from institutions like the Universidad de Chile and the National Scientific and Technical Research Council.

Climate and environmental conditions

Climatic regimes are governed by interactions among the Humboldt Current, the Antarctic Oscillation, and orographic effects of the Andes, producing cold, arid to semi-arid conditions with large diurnal ranges recorded by stations such as those run by the Argentine National Meteorological Service and the Dirección Meteorológica de Chile. Precipitation is highly variable, influenced by phenomena like El Niño–Southern Oscillation and Southern Annular Mode, with snowpack and frost persistence shaping seasonal cycles monitored by agencies including the Intergovernmental Panel on Climate Change and programs at the National Aeronautics and Space Administration. Wind regimes associated with the Roaring Forties and regional jet streams affect aeolian processes studied in projects funded by the European Union and bilateral science agreements between Argentina and Chile.

Flora and fauna

Vegetation assemblages include tussock grasses, cushion plants, and shrubs typical of high-Andean communities catalogued by botanists at the Royal Botanic Gardens, Kew and the Smithsonian Institution. Characteristic plant genera and taxa are represented in collections at institutions like the Museo de La Plata and the Museo Nacional de Historia Natural (Chile), while faunal components include herbivores and predators such as guanaco populations monitored by the Comisión Nacional de Actividades Espaciales-associated studies, carnivores like the puma investigated by researchers affiliated with the Wildlife Conservation Society, and endemic bird species documented by the Cornell Lab of Ornithology and the Audubon Society. Endemic and relict taxa similar to those in the Patagonian steppe and the Tierra del Fuego region are subject to taxonomic revisions published in journals associated with the Royal Society and the American Museum of Natural History.

Soil, hydrology, and periglacial processes

Soils include thin, poorly developed entisols and andisols described in surveys by the Food and Agriculture Organization and national ministries such as the Ministerio de Agricultura, Ganadería y Pesca (Argentina), with cryogenic horizons and polygonal patterned ground found near periglacial zones mapped by glaciologists from the Instituto Antártico Chileno and the Universidad Nacional de La Plata. Hydrological features comprise ephemeral streams, closed-basin lagoons, and aquifers feeding rivers like the Baker River and the Gallegos River, monitored by the Comisión Nacional del Río Colorado and hydrology teams collaborating with the United Nations Environment Programme. Periglacial processes linked to thawing permafrost and seasonal freeze-thaw cycles are studied in relation to climate projections by groups at the Potsdam Institute for Climate Impact Research and the Met Office.

Human presence and land use

Human activities include extensive sheep and goat pastoralism introduced during the Patagonian colonization era, mining operations exploiting mineral belts near sites such as El Teniente and Esquel, and transportation corridors using passes like the Paso Pehuenche and the Paso de Agnia. Indigenous land use by groups including the Mapuche and legacy sites studied by archaeologists from the Instituto Nacional de Antropología y Pensamiento Latinoamericano are documented alongside contemporary resource extraction undertaken by companies like Yacimientos Petrolíferos Fiscales and multinational mining firms regulated under frameworks negotiated by the Mercosur and bilateral accords with the European Commission. Tourism associated with routes to Torres del Paine National Park, Los Glaciares National Park, and mountaineering on peaks such as Cerro Torre contributes to regional economies tracked by ministries of tourism.

Conservation and protected areas

Protected areas and conservation initiatives include national parks and reserves such as Los Glaciares National Park, Torres del Paine National Park, and private conservation efforts by organizations like Conservation International and the Wildlife Conservation Network. Transboundary cooperation frameworks involving agencies like the International Union for Conservation of Nature and academic partnerships with the National Geographic Society support biodiversity inventories, while community-based stewardship projects involve NGOs including Fundación Vida Silvestre Argentina and the Corporación Nacional Forestal (CONAF). Conservation planning aligns with commitments under conventions such as the Convention on Biological Diversity and regional strategies promoted by the Andean Community.

Threats and management strategies

Major threats include climate change impacts documented by the Intergovernmental Panel on Climate Change, overgrazing linked to historical policies during the Conquest of the Desert, mining pollution incidents similar in profile to events investigated by the Environmental Protection Agency and multinational litigation handled through tribunals like the International Court of Justice-related mechanisms. Management strategies emphasize adaptive grazing regimes developed with input from research institutes like the Facultad de Agronomía, Universidad de Buenos Aires and restoration projects funded by agencies including the Global Environment Facility and bilateral science programs with the National Science Foundation. Integrated landscape approaches coordinate stakeholders from provincial governments such as those of Santa Cruz Province and Aysén Region with conservation NGOs and international funders to reconcile development, heritage, and ecosystem integrity.

Category:Ecoregions of Argentina Category:Ecoregions of Chile