Jau National Park, Amazonas, Brazil Photograph by © WWF-Canon/Juan PRATGINESTOS   Northern South America: Northwestern Brazil, into eastern Colombia and southwestern Venezuela Tropical and Subtropical Moist Broadleaf Forests   104,100 square miles (269,700 square kilometers) -- about the size of Colorado Relatively Stable/Intact

· On Solid Ground
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
More Photos

On Solid Ground

Water is abundant in this ecoregion, with extensive river systems and flooded forests. But the landscape here is actually dominated by non-flooded, or terre firme, forests. Terre firme means "solid ground," and the wildlife that lives within these forests is also on relatively solid footing, ecologically speaking. However, human activity is increasingly threatening these dense rain forests. This ecoregion is named for the three river systems that dominate the landscape: the Japurá, Solimões, and Negro Rivers.

Special Features

Situated on the lowland plateau in the north-central portion of the Amazon basin in Brazil and small sections in Colombia and Venezuela, this ecoregion constitutes much of the watershed of the Rio Negro. The topography is mostly flat and low, with elevations well under 260 feet (80 m). Valleys with steep slopes and some small hills occur in certain parts of the ecoregion. The climate is hot and humid, with annual seasonal rainfall around 100 inches (2,500 mm). All the major rivers and many tributaries flood their banks each year because of the high rainfall and runoff from the Andes. River levels have been known to rise as much as 45 feet (14 m) during the flood season. Forest types vary depending on proximity to a river, the sediment load of the river, and the topography. Tall trees and palms dominate non-flooded terre firme forests, while flooded forests have lower canopies and are less diverse. This ecoregion contains many rare and endangered plants and animals.

	Yapoks are the only species of opossum that is adapted to water. Its ears can be folded down and closed to prevent water from entering, its eyes are protected by eyelid glands, and the brooding pouch on females can be fully closed, providing an watertight seal that protects the young while the mother dives and swims.

Wild Side

In the forests, troops of red-handed tamarins and common squirrel monkeys make their way through high canopy trees and low palms, seeking insects, fruits, and small animals. A yapok, or water opossum, is one of very few species able to forage in the trees for insects and lizards and underwater for small fish, crabs, and frogs. The bright red, yellow, and black coral snake, a close relative of the cobra, has a venomous bite that quickly immobilizes a small tegus lizard. A mixed flock of Yapacana and chestnut-crested antbirds feasts on small insects, while in the canopy above a spot-backed antwren picks through a bromeliad, a relative of the pineapple, for its own meal. From atop a tall Brazil nut tree, a pair of scarlet macaws squawks a raucous chorus as they search for miriti palm nuts. Nearby, a giant river otter sits atop a log and munches on a fresh arawana fish.

Cause for Concern

This moist forest ecoregion is mostly intact, especially in the interior. But along the rivers, extensive human activities have deforested or degraded habitat, reducing populations of many plants and animals. Logging, mining, cattle ranching, uncontrolled fires, and urban development all pose serious threats to this ecoregion.

For more information on this ecoregion, go to the World Wildlife Fund Scientific Report.