Llanos

The Llanos is a vast ecoregion of tropical grasslands, savannas, and shrublands. It is located in northwestern South America. This massive plain spans across parts of Colombia and Venezuela. To the west and northwest, the Andes mountains form a high boundary. The Venezuelan Coastal Range borders the region to the north. To the southeast lie the Guiana Highlands. To the southwest, you will find the Negro-Branco moist forests. The Orinoco River is the central feature of this landscape. It flows from west to east through the plains. This river system also helps form the border between Colombia and Venezuela.

The climate of the Llanos follows a distinct seasonal pattern. It features a tropical savanna climate. In the Colombian Llanos, this can transition into a tropical monsoon climate. Rainfall is highly seasonal. A rainy season occurs from April to November. The wettest months are typically June and July. This is followed by a dry season from December to March. Rainfall amounts vary across the region. In Apure State in the southwest, rainfall can reach high levels. Monagas State in the northeast also sees significant precipitation. The mean annual temperature remains relatively consistent throughout the year.

The landscape is divided into different types of terrain based on water levels. One type is the llano alto. These are grasslands and savannas that remain dry all year. They cover about two-thirds of the Venezuelan Llanos. These areas feature grasses and shrubs that grow between 30 and 100 cm high. They often form small clumps called tussocks. The soil here is typically sandy and low in nutrients. Another type is the llano bajo. These are seasonally flooded grasslands and savannas. During the rainy season, water can rise up to one meter. This flooding creates temporary wetlands similar to the Pantanal in South America. These flooded areas usually have richer soils.

Vegetation in the Llanos is diverse and adapts to these water changes. In the dry llano alto, grasses like Trachypogon are very common. Shrubs are often legumes from genera such as Mimosa or Cassia. Trees like the manteco or chaparro grow in scattered groups or small patches called matas. In the flooded llano bajo, you will find the Paspalum fasciculatum grass. The moriche palm is a key feature of the morichales, which are seasonally flooded forests. Along rivers, gallery forests provide more dense cover. These include evergreen forests or semi-deciduous forests on higher ground. Semi-deciduous forests have a canopy height of 12 to 15 meters. Some areas also feature matorrales, which are shrublands reaching 5 to 8 meters high.

A wide variety of animals inhabit these different environments. Mammals in the open savannas include white-tailed deer, giant anteaters, and capybaras. You might also see the giant armadillo or the Eastern cottontail. The gallery forests support more diverse large mammals. These include tapirs, peccaries, and various monkeys like the capuchin. Large cats such as the puma, jaguar, and ocelot are also present. The Llanos are home to some of the largest jaguars in the world. Male jaguars here can average over 95 kg. The Orinoco River supports the endangered giant otter. Some animals, like the long-nosed armadillo, are endemic to the Llanos. This means they are found nowhere else on Earth.

Human activity has shaped the Llanos for centuries. Since the Spanish colonial era, cattle herding has been the main economic activity. The workers who manage these herds are known as llaneros. This culture is similar to the gauchos of the Pampas. Decades of cattle raising have changed the local ecology. Grasslands are often burned to remove trees and make grazing easier. Non-native grasses, such as the African grass Melinis minutiflora, have been introduced for fodder. Agriculture has also expanded, with rice and maize being grown in large areas. Some rice fields are located in former seasonal wetlands.

The region is also vital for its natural resources. The governments of Venezuela and Colombia have developed large oil and gas industries. In Venezuela, the Orinoco Belt contains massive deposits of extra heavy crude. These oil sands are one of the largest in the world. They sit behind the Athabasca Oil Sands in Canada. Venezuela's non-conventional oil deposits are estimated at about 300 billion barrels. This amount is roughly equal to the world's conventional oil reserves. To protect this complex system, much of the land is conserved. A 2017 assessment found that 105,323 km², or 28%, of the ecoregion is in protected areas. This includes several national parks in both Colombia and Venezuela.