Córdoba montane savanna

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March 22, 2007, 8:39 pm

Introduction This ecoregion (Córdoba montane savanna) consists of the Sierras Centrales, a group of isolated mountain chains in central Argentina. The area contains deep gorges, grasslands, woodlands and rocky areas. These isolated mountains are considered an area rich in plant endemics. The Andean condor can be found in these Sierras which constitute its easternmost habitat range.

Location and General Description

250px-Nt0706a lg.jpg Capilla de Monte, Argentina. (Photograph by Claudia Juarez)

The Córdoba Montane Savannas ecoregion is found within the provinces of Córdoba and San Juan. The northern, southern, western and eastern boundaries of this ecoregion terminate approximately at the 290 and 330 west latitudes and 660 and 630 south longitudes, respectively. Located approximately 400 kilometers (km) east of the main Andes chain, the Sierras Centrales consists of eight isolated Andean relict [[mountain]s] with more than 2,000 meters (m)in elevation. This ecoregion encompasses the Sierra Grande de Cordoba, Sierra de San Luis, Sierra de Valle Fértil, Sierra de Volasco and several smaller mountaintops, with the latter extending more than 3,000 m in elevation at Monte Corralitos. Within the mountains there are plains such as the Pampa de Achala. Annual rainfall is between 500-900 millimeters (mm), but some areas receive 1100 mm or more. Temperature ranges are variable, with a mean around 17°C.

The Sierras’ isolation from the Andes by dry lowlands is one of the unique characteristics of this ecoregion. This upland Chaco ecoregion has three basic vegetative zones. The dry sunny areas up to 1,800 m contain forest dominated by Schinopsis haenkeana, while around the same elevation on shady cooler slopes, the dominant species are Lithrea ternifolia with Fagara coco. Above 1,800 m on shallow soil, grasslands of Festuca hieronymi and species of Stipa grow. There are about 190 species found in this high elevation grassland including many rare and/or endemic species.

Biodiversity Features

Because of the isolated nature of this unique ecoregion potential speciation and endemism are high. For example, there are approximately 12 subspecies of birds endemic to this ecoregion. There are at least two species of Cinclodes (Furnariidae) endemic to this ecoregion. The Córdoba Cinclodes (Cinclodes comechingonus) is found at elevations ranging from 1,600 to 2,800 m, and it inhabits patches of Polylepsis australis that are close to water. Olrog’s Cinclodes (C. olrogi), inhabits areas slightly lower, from 1,500 to 2,400 m, where there are open, grassy rock formations that typically fringe streams and lakes. Cinclodes comprise a terrestrial group of birds that are associated with streams, and considered a striking example of parallel evolution when considering Eurasian and American Dippers in the family Cinclidae.

The Andean tinamou (Nothoprocta pentlandii), Andean condor (Vultur gryphus), olive-crowned crescentchest (Melanopareia maximiliani), cliff flycatcher (Hirundinea ferruginea), stripe-capped sparrow (Aimophila strigiceps) and black and rufous warbling finch (Poospiza nigrorufa) are just a few of the many bird species found in this ecoregion.

In terms of mammals, at least one species, the Hensel’s short-tailed opossum (Monodelphis henseli) is likely to be endemic to this region of Argentina, though current taxonomic validity is uncertain. This region exceeds the latitudes of most tropical bats (e.g., Emballonurids, Phyllostomids, etc.), with the likely exception of the common vampire bat (Desmodus rotundus) which follows cattle colonization throughout Latin America. It is likely that the more temperate families of bats (e.g., Vespertilionids and Molossids) are present.

Current Status

Primarily due to inaccessibility, this ecoregion is not currently jeopardized. The Córdoba Montane Savanna ecoregion's viability however, is of concern. The threat level is accentuated because the ecoregion is restricted to these small highland areas; therefore, any development is likely to destroy a large percentage of this ecoregion. Though not greatly threatened at present, the chief threat is moderate habitat loss due to overgrazing. At present, the only protected area in the region is the Quebrada del Condorito National Park (IUCN category II).

Types and Severity of Threats

The Córdoba Montane Savanna remains vulnerable due to high levels of endemism harbored in this unique habitat; minimal habitat disturbance can equate to major population declines of unique endemics. Populations of the Andean Condor (Vultur gryphus) for example appear to have declined since the building of roads. While overgrazing and development for grazing lands might not have a current effect on most of the endemic birds, the long-term effects remain to be seen, particularly on mammalian fauna which are also suffering from over-hunting.

Justification of Ecoregion Delineation

These elevational patches of savanna occur along the Córdoba Mountains of Argentina. Their archipelago-like distribution and isolation have resulted in a number of endemic species. The deliniations for the Córdoba Montane Savanna were derived from Daniele and Natenzon, and linework follows their Pastizales y Bosques Serranos region. Other resources consulted include Cabrera and Morello.

Additional information on this ecoregion

Further Reading

  • Anon. 1980. Time-Hammond World Atlas. Hammond, Inc., Maplewood, N.J.
  • Bucher, E.H., and M. Nores. 1988. Present status of birds in steppes and savannas of Northern and Central Argentina. ICBP Technical Publication, 7:71-79.
  • Cabrera, A.L. 1976. Regiones fitogeográficas Argentinas. Enciclopedia Argentina de Agricultura y Jardinería, Second Edition, Vol. II, Buenos Aires, Argentina.
  • Daniele, C., and C. Natenzon. 1994. Regiones Naturales de la Argentina. Draft map. Argentina National Parks Department, Buenos Aires, Argentina.
  • Davis, S.D., V.H. Heywood, O. Herrera-MacBryde, J. Villa-Lobos, and A.C. Hamilton. 1997. Centres of Plant Diversity: A guide and strategy for their conservation. Information Press, Oxford, UK. ISBN: 283170197X
  • Morello, J. 1968. La vegetación de la República Argentina, No. 10: Las grandes unidades de vegetación y ambiente del Chaco Argentino. Buenos Aires, Argentina.
  • Narosky, T., and D. Yzurieta. 1989. Birds of Argentina and Uruguay. Vazquez Mazzini Buenos Aires, Argentina. ISBN: 9509906336
  • Nores, M. 1995. Insular biogeography of birds on mountaintops in northwestern Argentina. Journal of Biogeography, 22:61-70.
  • Nores, M., and D. Yzurieta. 1983. Especiación en las Sierras Pampeanas de Córdoba y San Luis (Argentina), con descripción de siete nuevas subespecies de aves. Hornero Extr., 88-102.
  • Olrog, C. C., and M. M. Lucero. 1980. Guiá de los Mamiferos Argentinos. Fundación Miguel Lill, Tucuman, Argentina.
  • Olson, D., E. Dinerstein, P. Hedao, S. Walters, P. Allnutt, C. Loucks, Y. Kura, K. Kassem, A. Webster and M. Bookbinder. 2000. Terrestrial Ecoregions of the Neotropical Realm (map). Conservation Science Program, WWF-US, DC.
  • Stattersfield, A.J., M.J. Crosby, A.J. Long and D.C. Wege. 1998. Endemic Bird Areas of the World: Priorities for Biodiversity Conservation. The Burlington Press Ltd, Cambridge, U.K. ISBN: 1560985747



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Citation

Fund, W. (2007). Córdoba montane savanna. Retrieved from http://editors.eol.org/eoearth/wiki/Córdoba_montane_savanna