Páramo
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Páramo is a neotropical ecosystem. It is located in the high elevations, between the upper forest line (about 3100 m altitude) and the permanent snow line (about 5000 m). The ecosystem consists of accidented, mostly glacier formed valleys and plains with a large variety of lakes, peat bogs and wet grasslands intermingled with shrublands and forest patches. Nearly 57% of this ecosystem worldwide is found in Colombia.
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[edit] Location
The páramo covers the upper parts of the northern Andes, roughly between 11° north and 8° south latitude. They form a discontinuous belt between the Cordillera de Mérida in Venezuela to the Huancabamba Depression in northern Peru. Two separate complexes exist, one in the Cordillera de Talamanca of Costa Rica and Panama, and another in the Sierra Nevada de Santa Marta of Colombia.
The total area covered by páramo is estimated between 35000 and 77000 km². This discrepancy is primarily due to uncertainties in the lower limit of the páramo. The natural forest line is severely altered by human activity (logging, intensive grazing), which makes the difference between natural and artificial grasslands difficult to distinguish.
Tropical alpine grasslands similar to the páramo are abundantly present in other continents, such as the Afroalpine belt, stretching from Ethiopia and Uganda to Kenya, Tanzania and South Africa. To a smaller extent, they occur in New Guinea and Indonesia.
[edit] Vegetation
The isolated and fragmented occurrence of the páramo over the Andean highlands promotes high speciation and an exceptionally high endemism. The ecosystem hosts about 5000 different plant species. About 60% of these species is endemic, adapted to the specific physio-chemical and climatic conditions, such as the low atmospheric pressure, intense ultra-violet radiation, and the drying effects of wind. The vegetation consists mainly of tussock grasses, ground rosettes, dwarf shrubs cushion plants and conspicuous giant rosettes such as Espeletia and Puya.
In some areas, a clear altitudinal vegetation gradient is present. In the subpáramo, 2500-3100 m altitude, mosaics with shrubs and small trees alternate with grasslands. Extensive cloud forests may develop at certain places, consisting of small, twisted and gnarled trees with small and thick, notophyllous leaves and many epiphytes. In the páramo proper(3100 - 4100 m), grasslands dominate and patches of woody species such as Polylepis and Gynoxys occur only in sheltered locations and along water streams. The superpáramo is a narrow zone with scarce vegetation between the grass páramo and the snow line. In all vegetation belts, azonal vegetation types (cushion bogs, mires, aquatic vegetation) occur in flat, perhumid areas.
Ecoregions according to the World Wildlife Fund are:
- Cordillera Central páramo (Ecuador, Peru) [1]
- Cordillera de Merida páramo (Venezuela) [2]
- Northern Andean páramo (Colombia, Ecuador) [3]
- Santa Marta páramo (Colombia) [4]
- Costa Rican páramo or Talamanca páramo (Costa Rica, Panama)
[edit] Socio-economic relevance
Despite the remoteness and the cold and wet climate, human activity in the páramo is not uncommon. Human presence in the upper Andes dates from prehistorial times, but is mostly limited to extensive cattle grazing by free ranging animals. However, the páramo provides a variety of environmental services. The most important services are organic C storage and water supply. Rivers descending from the páramo are characterized by a high and sustained base flow. Given the difficulties in extracting groundwater, surface water from the páramo is intensively used for consumption, irrigation and hydropower generation.
[edit] References
- Proyecto Paramo Andino
- Hofstede, R., Segarra, P. and Mena, P. V., 2003. Los Páramos del Mundo. Global Peatland Initiative/NC-IUCN/EcoCiencia, Quito, 299 pp.
- Luteyn, J. L., 1999. Páramos: A Checklist of Plant Diversity, Geographical Distribution, and Botanical Literature. The New York Botanical Garden Press, New York, 278 pp.
