Map of the Month: Pampas and Arid Chaco

Map of the Month: Pampas, Monte, Espinal, and Arid Chaco
Map boundaries: 30 to 40 degrees South; 60 to 70 degrees West
Countries: Argentina and Chile

Overview
The Pampeanas Mountains, located between Cordoba and San Juan and extending northward beyond 30 degrees latitude, are a dry-land region of mountains and eroded rock formations in central Argentina. They are an arid extension of the Chaco region which is in more tropical areas to the north. Ecoregions covering the Pampeanas and Sierras Centrales around Cordoba are called the Arid Chaco, Cordoba montane savanna, and Argentine Monte. The region has been compared to the Great Basin of the U.S. but parts of the Sonoran Desert also sound like an appropriate comparison. The notable Ischiagualasto Provincial Park contains the most complete fossil record known from the Triassic Period, the earliest of the periods of the dinosaurs. In addition to fossils of the ancestors of mammals and dinosaurs, petrified trees up to 130 feet tall are present.

To the east of the mountains is the Argentine Espinal, located between Cordoba and Santa Fe. At the northernmost portion of the map (the most tropical), the Chaco, a tropical dry forest, extends just south of 30 degrees latitude. Lake Chiquita is a saline lake at the southern edge of the Chaco. The Espinal is the transition region between the Pampas grasslands and the dry tropical forest of the Chaco. To the south of the Espinal is the Pampas, the grassland region of Argentina. The lower Parana River cuts through the Pampas, dividing the humid Pampas into two parts.

To the west of about 63 degrees, the humid Pampas become drier as rainfall decreases in La Pampa province. Further to the west in La Pampa, the semi-arid Pampas grade into the Argentine Monte or Cuyo, an arid region at the base of the Andes along the Chilean border. The provinces of Rio Negro, Neuquen, Mendoza, and San Juan are in the Monte region. Rivers rising in the Andes discharge into marshes in the semi-arid Monte. However, larger rivers have been dammed and diverted to support irrigated agriculture in the areas to the east of the Andes.

World Wildlife Fund Ecoregions and Provinces/Political Subdivisions


Tropical and Subtropical Dry Broadleaf Forests
NT 210, Chaco. Found in Cordoba province of Argentina. Savanna and thorn forests of Prosopis and cactuses.

Temperate Broadleaf and Mixed Forests
NT 404, Valdivian temperate forests. Found in Santiago region of Chile. Nothofagus and Araucaria trees.

Tropical and Subtropical Grasslands, Savannas and Shrublands
NT 701, Arid Chaco. Found in Catamarca, Cordoba, La Rioja, San Juan, and San Luis provinces of Argentina. Aspidosperma, Prosopis and cactus in savannas; Heterostachys and bromelia in saline soils.
NT 706, Cordoba montane savanna. Found in Cordoba, La Rioja, San Luis, and San Juan provinces of Argentina. Forests of Schinopsis and Lithrea plus grasslands.
NT 708, Humid Chaco. Found in Santa Fe province of Argentina. Grasslands, bogs, and forests of Schinopsis and Apidosperma.

Temperate Grasslands, Savannas and Shrublands
NT 801, Argentine Espinal. Found in Cordoba and Santa Fe provinces of Argentina. Deciduous and xerophytic forests, palm groves and grassy savannas.
NT 802, Argentine Monte. Found in La Pampa, La Rioja, Mendoza, Neuquen, Rio Negro, San Luis, and San Juan provinces of Argentina. Thorn scrub and dry grasslands with resinous evergreen bushes such as Larrea, Bulnesia, and Plectocarpa. Also cactus scrub in the north.
NT 803. Humid Pampas. Found in Buenos Aires, Cordoba, Entre Rios, and Santa Fe provinces of Argentina. Grasslands with some Prosopis.
NT 805. Patagonian steppe. Found in Mendoza, Neuquen, and Rio Negro provinces of Argentina. Shrubs of Acantholippia, Benthamiella; cushion plants.
NT 806. Semi-arid Pampas. Found in Buenos Aires, Cordoba, La Pampa, Mendoza, Rio Negro, and San Luis provinces of Argentina. Steppe grasses with marshes.

Flooded Grasslands and Savannas
NT 908, Parana flooded savanna. Found in Buenos Aires, Entre Rios, and Santa Fe provinces of Argentina. A mosaic of wetlands and savanna with trees such as Salix, Tessaria, Victoria.
NT 909, Southern Cone Mesopotamian savanna. Found in Entre Rios province of Argentina. A mosaic of palm savanna, wetlands, and subtropical forests.

Montane Grasslands and Shrublands
NT 1008, Southern Andean steppe. Found in the Coquimbo and Santiago regions of Chile; Mendoza and San Juan provinces of Argentina. Shrubs and cushion plants.


UNESCO World Heritage Sites
Ischigualasto Provincial Park and Talampaya National Park. Ischigualasto, located in San Juan province, NT 802, and the adjoining Talampaya, located in La Rioja province, NT 706 and 802, contain gray-green rocks, petrified trees 130 feet tall, and petroglyphs. The oldest known dinosaur remains and a complete series of sediments for the Triassic Period cause Ischigualasto to be ranked first in the world in the quality, number, and importance of Triassic fossils, according to the University of California, Berkeley.

Jesuit Block and Estancias of Cordoba. The city’s colonial heritage from the 17th and 18th centuries is exceptionally preserved and ranked as a World Heritage Site. Located in Cordoba Province, NT 706.

Other points of interest
Aconcagua, the highest mountain in the Americas at 22, 835 feet elevation. Located in Mendoza province on the Chilean border, NT 1008.
Estancia Los Alamos is a European-style hotel and dude ranch with vineyards and canyonlands in the Andean foothills. Located in Mendoza Province, NT 1008 and 805.
Lihue Calel National Park is located on a small mountain range in the semi-arid Pampas (NT 806)
Predelta National Park is in the Parana delta east of Rosario, Entre Rios Province. NT 908.
Sierra las Quijadas National Park contains red sandstone ravines and fossil pterosaurs. Located in San Luis Province, NT 701 and 802.
Quebrada de Condorito National Park includes an 800-meter deep canyon and condor nesting sites. Located in Cordoba Province, NT 706.


References
Emma Beare, ed. 2006. 501 Must-Visit Natural Wonders. Bounty Books.

Moon Handbook. www.moon.com/planner/argentina/ar-overview.

National Geographic Society and World Wildlife Fund, WildWorld map. www.nationalgeographic.com/wildworld

Schultz, Patricia. 2003. 1,000 Places to See Before You Die. Workman Publishing.

University of California, Berkeley. www.ucmp.berkeley.edu/mesozoic/triassic.