Llanos
Llanos | |
---|---|
Ecology | |
Realm | Neotropical |
Biome | tropical and subtropical grasslands, savannas, and shrublands |
Borders | List
|
Geography | |
Area | 375,786 km2 (145,092 sq mi) |
Countries | |
Conservation | |
Conservation status | Vulnerable |
Protected | 105,323 km² (28%)[1] |
The Llanos (
Geography
The Llanos occupy a lowland that extends mostly east and west. The Llanos are bounded on the west and northwest by the
The Llanos' main river is the Orinoco, which runs from west to east through the ecoregion and forms part of the border between Colombia and Venezuela. The Orinoco is the major river system of Venezuela.[3]
Climate
The ecoregion has a tropical savanna climate that grades into a tropical monsoon climate in the Colombian Llanos. Rainfall is highly seasonal, with a rainy season from April to November, and a dry season between December and March. The wettest months are typically June and July. Rainfall varies across the ecoregion, from up to 3,000 millimetres (120 in) per year in the southwest, 1,200 to 1,600 millimetres (47 to 63 in) in Apure State, and 800 to 1,200 millimetres (31 to 47 in) per year in the Llanos of Monagas State in the northeast. Mean annual temperature is 27 °C or 80.6 °F, and the average monthly temperature varies little throughout the year; the lowest-temperature months (June, July, December, and January) are only 2 °C or 3.6 °F cooler than the hottest months.[2]
Flora
The plant communities in the Llanos include open grasslands, savannas with scattered trees or clumps of trees, and small areas of forest, typically gallery forests along rivers and streams. There are seasonally flooded grasslands and savannas (llano bajo) and grasslands and savannas that remain dry throughout the year (llano alto).[2]
The llano alto grasslands and savannas are characterized by grasses and shrubs 30–100 cm high, forming
During the rainy season from May to October, parts of the Llanos can flood up to a meter. This turns some
Gallery forests include evergreen seasonally flooded forests, and semi-deciduous forests on higher ground. Morichales are seasonally flooded forests characterized by the moriche palm (Mauritia flexuosa). Vegas are seasonally flooded evergreen forests found along the Orinoco and its tributaries. Trees form a canopy 8 to 20 meters high, and include Inga spp., Combretum frangulifolium, Gustavia augusta, Pterocarpus sp., Pterocarpus dubius, Spondias mombin, and Copaifera pubiflora.[2]
Semi-deciduous forests occur above flood level, and form a canopy 12 to 15 meters high. Common trees include Tabebuia billbergii, Godmania aesculifolia, Cassia moschata, Spondias mombin, Copaifera pubiflora, Bourreria cumanensis, Cordia spp., Bursera simaruba, Cochlospermum vitifolium, Hura crepitans, and Acacia glomerosa.[2]
"Matorrales" are deciduous and semi-deciduous shrublands 5 to 8 meters high which cover large areas in the central Venezuelan llanos, and may be a form of secondary vegetation in areas that were formerly dry deciduous forest. Typical shrubs are
Fauna
Mammals of the grassland and savanna include white-tailed deer (Odocoileus virginianus), giant anteater (Myrmecophaga tridactyla), capybara (Hydrochoerus hydrochaeris), giant armadillo (Priodontes maximus), Eastern cottontail (Sylvilagus floridanus), Alston's cotton rat (Sigmodon alstoni), Hispid cotton rat (S. hispidus), Zygodontomys brevicauda, and Oecomys bicolor.[2]
The gallery forests are home to more diverse large and medium-sized mammals, including
Some of the
The Llanos long-nosed armadillo (Dasypus sabanicola) and the short-tailed opossum Monodelphis orinoci are endemic to the Llanos.[2]
The Llanos' wetlands supports around 70 species of water birds, including the scarlet ibis.[3] A large portion of the distribution of the sharp-tailed ibis (Cerbibis oxycerca) and white-bearded flycatcher (Phelpsia inornata) is in the Llanos.
Native reptiles include the Orinoco crocodile (Crocodylus intermedius), spectacled caiman (Caiman crocodilus), Green anaconda (Eunectes murinus), and Arrau turtle (Podocnemis expansa), which live in the ecoregion's wetlands.
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Spectacled caiman, Guaratico River, Venezuela
Indigenous peoples
Indigenous peoples of the Llanos include the Guahibo in the western Llanos of Colombia and Venezuela, and the Yaruro in the eastern Llanos in Venezuela.
Cattle raising and farming
The primary economic activity in the Llanos since the Spanish colonial era is the herding of millions of cattle. An 1856 watercolor by Manuel María Paz depicts sparsely populated open grazing lands with cattle and palm trees.[5] The term llanero ("plainsman") became synonymous with the cowhands that took care of the herds, and had some cultural similarities with the gauchos of the Pampas or the vaqueros of Spanish and Mexican Texas.
Decades of extensive cattle raising has altered the ecology of the Llanos. Grasslands and savannas are frequently burned to make them more suitable for grazing and eliminate trees and shrubs. Non-native grasses have been introduced for cattle fodder, including the African grass Melinis minutiflora, and now cover large areas.[2]
Agriculture, particularly rice and maize, now cover extensive areas, including rice fields in former seasonal wetlands.
Oil and gas
In Los Llanos, the governments of Venezuela and Colombia had developed a strong oil and gas industry in the zones of Arauca, Casanare, Guárico, Anzoátegui, Apure and Monagas. The
Protected areas
A 2017 assessment found that 105,323 km², or 28%, of the ecoregion, is in protected areas.
Gallery
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Colombia
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Venezuela
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The Guaratico River near Mantecal, Venezuela
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Tourist metal bongo on the Guaratico River
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The flat, expansive Llanos
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Wet season
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Sunset
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Thunderstorm tracks
Cities situated in the Llanos
In Colombia
- Acacías
- Arauca, Arauca
- Gaviotas
- Maní, Casanare
- Orocué
- Paz de Ariporo
- Puerto Carreño
- Inírida
- Puerto López, Meta
- San José del Guaviare
- Saravena
- Tame
- Villavicencio
- Yopal
- Fortul
In Venezuela
- Acarigua
- Araure
- Barinas
- Calabozo
- Caripito
- El Tigre
- Guanare
- Maturín
- Puerto Ayacucho
- Sabaneta
- San Carlos
- San Fernando de Apure
- Tucupita
- Valle de la Pascua
See also
References
- ^ a b Eric Dinerstein, David Olson, et al. (2017). An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 2017, Pages 534–545; Supplemental material 2 table S1b. [1]
- ^ a b c d e f g h i j k l m "Llanos". Terrestrial Ecoregions. World Wildlife Fund.
- ^ ISBN 1-4053-0018-3.
- ^ Jedrzejewski, W.; Abarca, M. R.; Viloria, Á.; Cerda, H.; Lew, D.; Takiff, H.; Abadia, E.; Velozo, P. (2011). "Jaguar conservation in Venezuela against the backdrop of current knowledge on its biology and evolution" (pdf). 36 (12). Interciencia: 954–966. Retrieved 2019-07-12.
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(help) - ^ Paz, Manuel María. "General View of The Plains, Province of Casanare". World Digital Library. Retrieved 2014-05-21.
- ^ UNEP-WCMC (2020). Protected Area Profile for Venezuela (Bolivarian Republic of) from the World Database of Protected Areas, September 2020. Available at: www.protectedplanet.net
External links
- (in English) "Llanos". Terrestrial Ecoregions. World Wildlife Fund.
- (in English) Dawn on the Plains Photo Feature, Havana Times, Oct 1, 2010.
- (in Spanish) The llanos music
- (in Spanish) The llanos of Colombia and Venezuela
- (in Spanish) Los Llanos de Colombia