The Beni savanna is an ecoregion located in the Beni Department of northern Bolivia. Also known as the Llanos de Moxos, it is the third-largest savanna complex in South America and is found in the lowlands of the southwestern Amazon basin, extending northeast from the foot of the Andean ranges.
The Beni savanna is an ecoregion located in the Beni Department of northern Bolivia. Covering an area of over 128,000 sq km (49,400 sq mi), the tropical savanna covers the northern Bolivian lowlands with small portions spilling over the borders into neighboring Brazil and Peru.
The Beni savanna, also known as the Llanos de Moxos (Moxos plains), is the third-largest savanna complex in South America and is found in the lowlands of the southwestern Amazon Basin, extending northeast from the foot of the Andes.
The Llanos de Moxos is a confluence zone of four biogeographic regions:
the Chiquitanía: a region of tropical savannas in the Santa Cruz Department in eastern Bolivia
Numerous rivers that drain the eastern slopes bisect the region including the Beni, the Mamoré and the Guaporé which, at their union, form the Madeira River, the most important tributary of the Amazon Basin.
The Beni savanna ecoregion comprises a mosaic of savannas and wetlands with forest islands. Tropical forests surround it:
the Southwest Amazon moist forests ecoregion to the north, west and south
the Madeira-Tapajós moist forests ecoregion to the east
The Beni Biosphere Reserve covers approximately 135,000 ha (333,600 acres) of Beni savanna and rainforest, one of the first protected areas to be established in Bolivia.
The climate of the Beni savanna is tropical, with pronounced wet and dry seasons. During the wet season (December to May), annual rainfall ranges from 1,300 mm (51 in) in the east, to 2500 mm (98 in) in the west.
The rivers flood the plains each year during this humid season as a result of high rainfall and snowmelt in the Andes. The flooding covers 50 - 60% of the land for a period of 4 - 10 months.
The Llanos de Moxos (Archaeological Region) contains extensive remains of pre-Columbian agricultural societies that were spread throughout the tropical savanna region.
An estimated 1,500 vascular plant species are found in the Beni savanna, although few are endemic. Sedges and grasses dominate and include bent spikerush, southern cutgrass, Peruvian watergrass and brook crowngrass.
In shallow flooded areas, tree cover is limited. The most common species include silver and pink trumpet trees. In areas with better drainage, characteristic species include grugru palm, tigerwood, Tabebuia ochracea and Acacia albicorticata.
At least 146 mammals can be found in the ecoregion including the boto river dolphin, the marsh deer, the maned wolf, the puma, the jaguar and the jaguarundis. In addition, various rodent and bat species, as well as seasonal primate species can be found.
Over 500 bird species have been recorded in the Beni savanna. Restricted-range species include the white-bellied nothura (Nothura boraquira), the southern screamer (Chauna torquata) and the crowned solitary eagle or Chaco eagle (Buteogallus coronatus).
The critically endangered blue-throated macaw (Ara glaucogularis), also known as the Caninde macaw or Wagler's macaw, is endemic to the Llanos de Moxos.
Reptiles, amphibians and fish are important elements of the savannas, wetlands, lakes and rivers. Notable species include black caiman, river turtles, anacondas, giant rococo toads, spot-legged poison frogs and marsh frogs. Over 325 fish species are found in the area.
Map of Bolivia's ecoregions. The Beni savanna is shown in bright green.