Near Manaus, Amazonas, Brazil Photograph by © WWF-Canon/Edward PARKER   Northern South America: Northern central Brazil Tropical and Subtropical Moist Broadleaf Forests   25,800 square miles (66,800 square kilometers) -- about the size of West Virginia Critical/Endangered

· Dynamic Forests
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
More Photos

Dynamic Forests

The forests of this ecoregion grow in areas that stretch across the low, seasonally flooded river drainages of the central and lower Amazon River basin, much of the Madeira River basin, the mouth of the Purus River, and the tributaries of these rivers. An isolated patch of forest grows along the Mamoré River on the border of Brazil and Bolivia and is included in the Monte Alegre Várzea ecoregion. Várzea means "flooded forests" in Portuguese. The region earns this name because the sediment-laden waters of the rivers rise between 20 and 40 feet (6-12 m) and spread across the landscape for up to eight months of the year.

Special Features

Each year, the rivers of this area swell from seasonal rainfall and floodwaters heavy with sediment carving levees as they meander through swales and oxbow lakes changing the river's course across the landscape. Wherever the rivers flood, sediment deposits form islands and embankments, creating new habitats for plant communities. Swamp vegetation grows in areas that are permanently flooded. Important fruit-bearing trees such as palms, socoró, and yellow mombim thrive in the rich soils. Savannas stretch along the forests’ edges, covering the land between the várzea and the terra firma, or unflooded land. When the water recedes, new growth quickly sprouts across these areas. Lakes form in the low-lying sections of savanna, growing and shrinking along with the seasonal availability of water.

	Many beautiful fish, including the discus and angelfish, are taken from this region for the international pet trade.

Wild Side

As the rains begin, a group of small marmosets runs for cover under the fruit-laden crown of an umbrella-like tarumã palm. This palm drops its fruit in the rising floodwaters--a strategic maneuver that distributes the seeds all over the flooded basin and also supplies an important food source for fish that migrate into the understory during the floods. In the river, a kind of fish called the arawana leaps from the water to grab an insect from the trunk of a ficus tree. The ample supply of fish and invertebrates also attracts Amazon River dolphins and birds such as roseate spoonbills, herons, and egrets. While their fishing tactics preoccupy the birds, a black caiman may sneak up to grab a feathered meal. On the muddy banks, a pair of fresh prints reveals the presence of an elusive jaguar, as it quietly stalks a young tapir through the forest.

Cause for Concern

Human activities such as logging, cattle-ranching, and gold-mining all degrade and pollute this fragile flooded habitat. Few protected areas exist in this region, leaving it even more vulnerable to these pressures.

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