View source for Llanos

{{Short description|Tropical grassland ecoregion in Colombia and Venezuela}}
{{About|the grassland and savanna region in South America||Llanos (disambiguation)}}
{{Infobox ecoregion
|name = Llanos
|image = Los Llanos Colombia by David.png
|caption = The Llanos in [[Colombia]]
|map = Ecoregion NT0709.svg
|map_caption = Location of the Llanos
|biogeographic_realm = [[Neotropical realm|Neotropical]]
|biome = [[tropical and subtropical grasslands, savannas, and shrublands]]
|border = [[Apure–Villavicencio dry forests]]
|border1 = [[Guianan lowland moist forests]]
|border2 = [[Guianan piedmont and lowland moist forests]]
|border3 = [[La Costa xeric shrublands]]
|border4 = [[Orinoco wetlands]]
|border5 = [[Negro-Branco moist forests]]
|country = {{COL}}
|country1 = {{VEN}}
|area = 375,786
|conservation = Vulnerable
|protected = 105,323 km² (28
|protected_ref = )<ref name = dinerstein>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. [https://doi.org/10.1093/biosci/bix014]</ref>
|embedded = 
}}

The '''Llanos''' ([[Spanish language|Spanish]] ''Los Llanos'', "The Plains"; {{IPA|es|los ˈʝanos}}) is a vast [[tropical grassland]] [[plain]] situated to the east of the [[Andes]] in [[Colombia]] and [[Venezuela]], in northwestern South America. It is an [[ecoregion]] of the [[tropical and subtropical grasslands, savannas, and shrublands]] [[biome]].

==Geography==
The Llanos occupy a lowland that extends mostly east and west. The Llanos are bounded on the west and northwest by the [[Andes]], and on the north by the [[Venezuelan Coastal Range]]. The [[Guiana Highlands]] are to the southeast, and the [[Negro-Branco moist forests]] are to the southwest. To the east the [[Orinoco wetlands]] and [[Orinoco Delta swamp forests]] occupy the [[Orinoco Delta]].<ref name = wwf>{{WWF ecoregion|id=nt0709|name=Llanos}}</ref>

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.<ref name="Llanos wetlands during the rainy season">{{cite book|title=Earth|publisher=Doring Kindersley|year=2003|pages=328|isbn=1-4053-0018-3}}</ref>

==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 {{convert|3000|mm|in|-1}} per year in the southwest, {{convert|1200|to|1600|mm|in|-0}} in [[Apure]] State, and {{convert|800|to|1200|mm|in|-0}} per year in the Llanos of [[Monagas]] State in the northeast. Mean annual temperature is {{convert|27|°C|°F|1|disp=or}}, and the average monthly temperature varies little throughout the year; the lowest-temperature months (June, July, December, and January) are only {{convert|2|C-change|F-change|1|disp=or}} cooler than the hottest months.<ref name=wwf/>

==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 forest]]s 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'').<ref name = wwf/>

The llano alto grasslands and savannas are characterized by grasses and shrubs 30–100&nbsp;cm high, forming [[tussock (grass)|tussock]]s 10 to 30&nbsp;cm apart. Soils are typically sandy and nutrient-poor. Llano alto covers approximately two-thirds of the Venezuelan llanos, and is also widespread in the Colombian llanos. Grasses of genus ''[[Trachypogon]]'' are predominant, and species include ''[[Trachypogon plumosus]], [[Trachypogon vestitus|T. vestitus]], [[Axonopus canescens]], [[Axonopus anceps|A. anceps]], [[Andropogon selloanus]], [[Aristida]]'' spp., ''[[Leptocoryphium lanatum]], [[Paspalum carinatum]], [[Sporobolus indicus]]'', and ''[[Sporobolus cubensis|S. cubensis]]'', and [[sedge]]s in the genera ''[[Rhynchospora]]'' and ''[[Bulbostylis]]''. Shrubs and herbs are most commonly [[legume]]s in the genera ''[[Mimosa]], [[Cassia (genus)|Cassia]], [[Desmodium]], [[Eriosema]], [[Galactia]], [[Indigofera]], [[Phaseolus]], [[Stylosanthes]], [[Tephrosia]]'', and ''[[Zornia]]''. The trees manteco (''[[Byrsonima crassifolia]]''),  chaparro (''[[Curatella americana]]''), and alcornoque (''[[Bowdichia virgilioides]]'') are the most common, growing either as scattered trees or in woodland patches known as ''matas'' which range in area from 12 meters in diameter up to a hectare.<ref name = wwf/>

During the rainy season from May to October, parts of the Llanos can flood up to a meter. This turns some [[savanna]]s and [[grassland]]s into temporary [[wetland]]s, comparable to the [[Pantanal]] of central South America. This flooding also creates habitat for water birds and other wildlife. These seasonally flooded grasslands and savannas, known as llano bajo, typically have richer soils. They are characterized by the grass ''[[Paspalum fasciculatum]]''. Trees include the palm ''[[Copernicia tectorum]]'' and gallery forest species.<ref name = wwf/>

Gallery forests include evergreen seasonally flooded forests, and semi-deciduous forests on higher ground. Morichales are seasonally flooded forests characterized by the [[Mauritia flexuosa|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]]''.<ref name = wwf/>

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]]''.<ref name = wwf/>

"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 ''[[Bourreria cumanensis]], [[Randia aculeata]], [[Godmania aesculifolia]], [[Pereskia guamacho]], [[Prosopis]]'' spp., ''[[Xylosma benthamii]], [[Erytroxylum]]'' sp., and ''[[Cereus hexagonus]]''.<ref name = wwf/>

==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]]''.<ref name = wwf/>

The gallery forests are home to more diverse large and medium-sized mammals, including [[collared peccary]] (''Tayassu tajacu''), [[white-lipped peccary]] (''T. pecari''), [[South American tapir]] (''Tapirus terrestris''), white-tailed deer,  [[red brocket]] (''Mazama americana''), [[wedge-capped capuchin]] (''Cebus olivaceus''), [[Venezuelan red howler]] (''Alouatta seniculus''), large rodents like the [[lowland paca]] (''Cuniculus paca''), [[agouti]]s (''[[Dasyprocta]]'' spp.), and [[Brazilian porcupine]] (''Coendou prehensilis''), and large cats like the [[cougar|puma]] (''Puma concolor''), [[jaguar]] (''Panthera onca''), and [[ocelot]] (''Leopardus pardalis''). The endangered [[giant otter]] (''Pteronura brasiliensis'') lives along the Orinoco and its tributaries.<ref name = wwf/>

Some of the [[South American jaguar#Characteristics|largest jaguars]] in the world are found in the Llanos, with average weights of over {{convert|100|kg|lb|abbr=on}} for males.<ref>{{cite journal |author1=Jedrzejewski, W. |author2=Abarca, M. R. |author3=Viloria, Á. |author4=Cerda, H. |author5=Lew, D. |author6=Takiff, H. |author7=Abadia, E. |author8=Velozo, P. |title=Jaguar conservation in Venezuela against the backdrop of current knowledge on its biology and evolution |publisher=Interciencia |format=pdf |volume=36 |issue=12 |pages=954–966 |url=https://www.researchgate.net/publication/220033215 |year=2011 |access-date=2019-07-12}}</ref>

The [[Llanos long-nosed armadillo]] (''Dasypus sabanicola'') and the short-tailed opossum ''[[Monodelphis orinoci]]'' are [[endemism|endemic]] to the Llanos.<ref name = wwf/>

The Llanos' wetlands supports around 70 species of [[water bird]]s, including the [[scarlet ibis]].<ref name="Llanos wetlands during the rainy season"/> A large portion of the distribution of the [[sharp-tailed ibis]] (''Cercibis 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.

<gallery>
File:2007 02 Capybaras 05.jpg|A group of [[capybara]]s at Hato La Fe, [[Venezuela]]
Image:guaraticocroc.jpg|[[Spectacled caiman]], Guaratico River, Venezuela
</gallery>

==Indigenous peoples==
[[Indigenous peoples]] of the Llanos include the [[Guahibo people|Guahibo]] in the western Llanos of Colombia and Venezuela, and the [[Yaruro people|Yaruro]] in the eastern Llanos in Venezuela.

==Cattle raising and farming==
The primary economic activity in the Llanos since the [[Spanish colonization of the Americas|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.<ref>{{Cite web |last=Paz |first=Manuel María |author-link=Manuel María Paz |title=General View of The Plains, Province of Casanare |work=World Digital Library |access-date=2014-05-21 |url=http://www.wdl.org/en/item/9027}}</ref> The term ''[[llanero]]'' ("plainsman") became synonymous with the cowhands that took care of the herds, and had some cultural similarities with the [[gaucho]]s of the [[Pampas]] or the ''[[Cowboy|vaqueros]]'' of [[Spanish Texas|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.<ref name = wwf/>

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 developed a strong oil and gas industry in Arauca, Casanare, Guárico, Anzoátegui, Apure, and Monagas. The [[Orinoco Belt]], entirely in Venezuelan territory, consists of large deposits of extra [[heavy crude]] ([[oil sands]]). The Orinoco Belt oil sands are known to be one of the largest, behind that of the [[Athabasca Oil Sands]] in [[Alberta]], Canada. Venezuela's non-conventional oil deposits of about {{convert|1200|Goilbbl|m3}}, found primarily in the Orinoco oil sands, are estimated to approximately equal the world's conventional oil reserves.{{citation needed|date=July 2019}}

==Protected areas==
A 2017 assessment found that 105,323&nbsp;km², or 28%, of the ecoregion, is in protected areas.<ref name = dinerstein/> Protected areas include [[Aguaro-Guariquito National Park]] (5,857.5&nbsp;km²), [[Cinaruco-Capanaparo National Park]] (5,843.68&nbsp;km²), [[Tortuga Arrau Reserve]] (98.56&nbsp;km²), and [[Caño Guaritico Wildlife Refuge]] (93.0&nbsp;km²) in Venezuela, and [[El Tuparro National Natural Park]] (5,549.08&nbsp;km²) in Colombia.<ref name = wwf/><ref>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</ref>

==Gallery==

<gallery mode="packed">
File:NP Llanos24 lo (5853385573).jpg|Colombia
File:GanadoLlanosVenezuela.jpg|Venezuela
File:Guaraticoriver.jpg|The Guaratico River near Mantecal, Venezuela
File:Llanosbongo.jpg|Tourist metal bongo on the Guaratico River
File:Llanos1.jpg|The flat, expansive Llanos
File:Llanosmarsh3.jpg|Wet season
File:Llanosnight4.jpg|Sunset
File:Llanosstorm.jpg|Thunderstorm tracks
</gallery>

==Cities situated in the Llanos==

===In Colombia===
*[[Acacías]]
*[[Arauca, Arauca]]
*[[Gaviotas]]
*[[Maní, Casanare]]
*[[Orocué]]
*[[Paz de Ariporo]]
*[[Puerto Carreño]]
*[[Inírida, Guainía|Inírida]]
*[[Puerto López, Meta]]
*[[San José del Guaviare]]
*[[Saravena]]
*[[Tame, Arauca|Tame]]
*[[Villavicencio]]
*[[Yopal]]
*[[Fortul]]

===In Venezuela===
*[[Acarigua]]
*[[Araure]]
*[[Barinas, Venezuela|Barinas]]
*[[Calabozo]]
*[[Caripito]]
*[[El Tigre]]
*[[Guanare]]
*[[Maturín]]
*[[Puerto Ayacucho]]
*[[Sabaneta, Barinas|Sabaneta]]
*[[San Carlos, Cojedes|San Carlos]]
*[[San Fernando de Apure]]
*[[Tucupita]]
*[[Valle de la Pascua]]

==See also==
* [[History of Colombia]]
* [[History of Venezuela]]

==References==
{{Reflist}}

==External links==
{{Commons category|Llanos}}
*{{in lang|en}} {{WWF ecoregion|id=nt0709|name=Llanos}}
*{{in lang|en}} [https://web.archive.org/web/20120920105047/http://www.havanatimes.org/?p=30235 Dawn on the Plains] Photo Feature, ''Havana Times'', Oct 1, 2010.
*{{in lang|es}} [http://www.llanera.com/musica/ The llanos music]
*{{in lang|es}} [https://web.archive.org/web/20100521071628/http://www.llanera.com/regiones/ The llanos of Colombia and Venezuela]
*{{in lang|es}} [https://web.archive.org/web/20180620001902/http://www.sanmartinmeta.com/ Los Llanos de Colombia]

{{Geographical Regions of Venezuela}}

{{WikidataCoord}}
{{Authority control}}

[[Category:Llanos| ]]
[[Category:Tropical and subtropical grasslands, savannas, and shrublands]]
[[Category:Plains of South America]]
[[Category:Plains of Venezuela]]
[[Category:Grasslands of Colombia]]
[[Category:Grasslands of Venezuela]]
[[Category:Geographical regions of Venezuela]]
[[Category:Ecoregions of South America]]
[[Category:Neotropical ecoregions]]
[[Category:Geography of Portuguesa (state)]]