The Llanos (Spanish Los Llanos, "The Plains"; ) 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. The Llanos' main river is the Orinoco, which runs from west to east through the ecoregion and forms part of the Colombia–Venezuela border. The Orinoco is the major river system of Venezuela.
A 2017 assessment found that 105,323 km², or 28%, of the ecoregion, is in protected areas.
Climate
The ecoregion has a tropical savanna climate that grades into a tropical monsoon climate in the Colombian Llanos. Rainfall is 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 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. The Llanos long-nosed armadillo (Dasypus sabanicola) and the short-tailed opossum Monodelphis orinoci are endemic to the Llanos. 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.