The Llanos ( Spanish ''Los Llanos'', "The Plains"; ) is a vast tropical grassland

plain In geography, a plain, commonly known as flatland, is a flat expanse of land that generally does not change much in elevation, and is primarily treeless. Plains occur as lowlands along valleys or at the base of mountains, as coastal plains, and ...

situated to the east of the

Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

and

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

, in northwestern South America. It is an

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

of the tropical and subtropical grasslands, savannas, and shrublands

biome A biome () is a distinct geographical region with specific climate, vegetation, and animal life. It consists of a biological community that has formed in response to its physical environment and regional climate. In 1935, Tansley added the ...

Geography

The Llanos occupy a lowland that extends mostly east and west. The Llanos are bounded on the west and northwest by the

, 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 The Orinoco Delta is a vast river delta of the Orinoco River, located in eastern Venezuela. Location The Orinoco Delta is one of the eight natural regions of Venezuela. It covers the whole of Delta Amacuro State and a few square kilometers o ...

. The Llanos' main river is the

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

, 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.

Climate

The ecoregion has a

tropical savanna climate Tropical savanna climate or tropical wet and dry climate is a tropical climate sub-type that corresponds to the Köppen climate classification categories ''Aw'' (for a dry "winter") and ''As'' (for a dry "summer"). The driest month has less than ...

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 per year in the southwest, in Apure State, and per year in the Llanos of Monagas State in the northeast. Mean annual temperature is , and the average monthly temperature varies little throughout the year; the lowest-temperature months (June, July, December, and January) are only cooler than the hottest months.

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''). The llano alto grasslands and savannas are characterized by grasses and shrubs 30–100 cm high, forming tussocks 10 to 30 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'' is a small genus of African and Latin American plants in the Poaceae, grass family. Crinkleawn grass is a common name for plants in this genus. ; Species * ''Trachypogon chevalieri'' (Stapf) Jacq.-Fél. – western and central Af ...

, T. vestitus, Axonopus canescens, A. anceps, Andropogon selloanus, Aristida'' spp., '' Leptocoryphium lanatum, Paspalum carinatum, Sporobolus indicus'', and '' S. cubensis'', and sedges in the genera '' Rhynchospora'' and '' Bulbostylis''. Shrubs and herbs are most commonly

legume Legumes are plants in the pea family Fabaceae (or Leguminosae), or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consum ...

s in the genera '' Mimosa, Cassia,

Desmodium ''Desmodium'' is a genus of plants in the legume family Fabaceae, sometimes called tick-trefoil, tick clover, hitch hikers or beggar lice. There are dozens of species and the delimitation of the genus has shifted much over time. Species are distr ...

, Eriosema, Galactia, Indigofera,

Phaseolus ''Phaseolus'' (bean, wild bean) is a genus of herbaceous to woody annual and perennial vines in the family Fabaceae containing about 70 plant species, all native to the Americas, primarily Mesoamerica. It is one of the most economically importan ...

, Stylosanthes,

Tephrosia ''Tephrosia'' is a genus of flowering plants in the family Fabaceae. It is widespread in both the Eastern and Western Hemisphere, where it is found in tropical and warm-temperate regions. The generic name is derived from the Greek word τεφ ...

'', 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. During the rainy season from May to October, parts of the Llanos can flood up to a meter. This turns some

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...

s and

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

s into temporary

wetland A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

s, comparable to the

Pantanal The Pantanal () is a natural region encompassing the world's largest tropical wetland area, and the world's largest Flooded grasslands and savannas, flooded grasslands. It is located mostly within the Brazilian state of Mato Grosso do Sul, but i ...

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. 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''. 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''. "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''.

Fauna

Mammals of the grassland and savanna include

white-tailed deer The white-tailed deer (''Odocoileus virginianus''), also known Common name, commonly as the whitetail and the Virginia deer, is a medium-sized species of deer native to North America, North, Central America, Central and South America. It is the ...

(''Odocoileus virginianus''),

giant anteater The giant anteater (''Myrmecophaga tridactyla'') is an Insectivore, insectivorous mammal native to Central America, Central and South America. It is the largest of the four living species of anteaters, which are classified with sloths in the or ...

(''Myrmecophaga tridactyla''),

capybara The capybara or greater capybara (''Hydrochoerus hydrochaeris'') is the largest living rodent, native to South America. It is a member of the genus '' Hydrochoerus''. The only other extant member is the lesser capybara (''Hydrochoerus isthmi ...

(''Hydrochoerus hydrochaeris''), giant armadillo (''Priodontes maximus''),

Eastern cottontail The eastern cottontail (''Sylvilagus floridanus'') is a New World cottontail rabbit, a member of the family Leporidae. It is the most common rabbit species in North America. Distribution The eastern cottontail can be found in meadows and shrub ...

(''Sylvilagus floridanus''), Alston's cotton rat (''Sigmodon alstoni''), Hispid cotton rat (''S. hispidus''), '' Zygodontomys brevicauda'', and '' Oecomys bicolor''. 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''), agoutis ('' Dasyprocta'' spp.), and Brazilian porcupine (''Coendou prehensilis''), and large cats like the puma (''Puma concolor''), jaguar (''Panthera onca''), and

ocelot The ocelot (''Leopardus pardalis'') is a medium-sized spotted Felidae, wild cat that reaches at the shoulders and weighs between on average. It is native to the southwestern United States, Mexico, Central America, Central and South America, ...

(''Leopardus pardalis''). The endangered giant otter (''Pteronura brasiliensis'') lives along the Orinoco and its tributaries. Some of the largest jaguars in the world are found in the Llanos, with average weights of over for males. The Llanos long-nosed armadillo (''Dasypus sabanicola'') and the short-tailed opossum '' Monodelphis orinoci'' are

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the Llanos. The Llanos' wetlands supports around 70 species of water birds, including the scarlet ibis. 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 The Arrau turtle (''Podocnemis expansa''), also known as the South American river turtle, giant South American turtle, giant Amazon River turtle, Arrau sideneck turtle, Amazon River turtle or simply the Arrau, is the largest of the side-neck tu ...

(''Podocnemis expansa''), which live in the ecoregion's wetlands. File:2007 02 Capybaras 05.jpg, A group of

s at Hato La Fe,

Image:guaraticocroc.jpg, Spectacled caiman, Guaratico River, Venezuela

Indigenous peoples

Indigenous peoples There is no generally accepted definition of Indigenous peoples, although in the 21st century the focus has been on self-identification, cultural difference from other groups in a state, a special relationship with their traditional territ ...

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. The term '' llanero'' ("plainsman") became synonymous with the cowhands that took care of the herds, and had some cultural similarities with the

gaucho A gaucho () or gaúcho () is a skilled horseman, reputed to be brave and unruly. The figure of the gaucho is a folk symbol of Argentina, Paraguay, Uruguay, Rio Grande do Sul in Brazil, the southern part of Bolivia, and the south of Chilean Patago ...

s of the Pampas or the ''

vaqueros The ''vaquero'' (; , ) is a horse-mounted livestock herder of a tradition that has its roots in the Iberian Peninsula and extensively developed in what what is today Mexico (then New Spain) and Spanish Florida from a method brought to the Americ ...

'' of Spanish and

Mexican Texas Mexican Texas is the historiographical name used to refer to the era of Texan history between 1821 and 1836, when it was part of Mexico. Mexico gained independence in 1821 after winning its Mexican War of Independence, war against Spain, whi ...

. 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. 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 The Athabasca oil sands, also known as the Athabasca tar sands, are large deposits of oil sands rich in bitumen, a heavy and viscous form of petroleum, in northeastern Alberta, Canada. These reserves are one of the largest sources of unconventi ...

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

, Canada. Venezuela's non-conventional oil deposits of about , found primarily in the Orinoco oil sands, are estimated to approximately equal the world's conventional oil reserves.

Protected areas

A 2017 assessment found that 105,323 km², or 28%, of the ecoregion, is in protected areas. Protected areas include Aguaro-Guariquito National Park (5,857.5 km²), Cinaruco-Capanaparo National Park (5,843.68 km²),

Tortuga Arrau Reserve Tortuga is the Spanish word for a turtle Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the ...

(98.56 km²), and Caño Guaritico Wildlife Refuge (93.0 km²) in Venezuela, and El Tuparro National Natural Park (5,549.08 km²) in Colombia.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

Gallery

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

Cities situated in the Llanos

In Colombia

* Acacías * Arauca, Arauca * Gaviotas * Maní, Casanare *

Orocué Orocué is a town and municipality in the Department of Casanare, Colombia, located on the shore of the Meta River. Historically, it went by the name San Miguel del Macuco. It is located 180 km from Yopal, and 546 km from Bogotá. ...

* Paz de Ariporo * Puerto Carreño * Inírida * Puerto López, Meta * San José del Guaviare * Saravena * Tame * Villavicencio * Yopal * Fortul

In Venezuela

* Acarigua * Araure * Barinas *

Calabozo Calabozo, officially Villa de Todos los Santos de Calabozo, is a city in Venezuela located in Guárico state, capital of the Francisco de Miranda Municipality and former capital of the state. It has a population of 168,605, according to the Nat ...

* Caripito * El Tigre * Guanare * Maturín * Puerto Ayacucho * Sabaneta * San Carlos * San Fernando de Apure * Tucupita * Valle de la Pascua

References

External links

*
Dawn on the Plains
Photo Feature, ''Havana Times'', Oct 1, 2010.
The llanos music

The llanos of Colombia and Venezuela

Los Llanos de Colombia
{{Authority control Tropical and subtropical grasslands, savannas, and shrublands Plains of South America Plains of Venezuela Grasslands of Colombia Grasslands of Venezuela Geographical regions of Venezuela Ecoregions of South America Neotropical ecoregions Geography of Portuguesa (state)