The Amazon River Basin is just that, a colossal but delicate apparatus encompassing various communities of organisms that interact in specific ways between each other and their physical environment. These parts, or ecosystems, play distinct roles that both wildlife and humans have evolved to use, and benefit from.
 

A unique mosaic

Far from being a monotonous expanse of trees, the Amazon River Basin is a web of landscapes and ecosystems. This unique mosaic gives the area its unmatched biological richness and hence, its global value.
 

The rivers shaping the Amazon River Basin

Rivers have played a large part in determining the diversity of ecosystems in the region. Floodplain forests and varzea (the areas close to riversides that are flooded during the rainy season), terra firma rainforest (forest that is off the floodplain) and igapo (forests lining the blackwater rivers of the Amazon) are some of the common ecosystems found in the Amazon River Basin.
 

Some of the most biodiverse ecoregions in the world

Biodiversity is not spread evenly across the Earth but follows complex patterns determined by climate, geology and the evolutionary history of the planet. These patterns are called "ecoregions".

WWF defines an ecoregion as a "large unit of land or water containing a geographically distinct assemblage of species, natural communities, and environmental conditions".

The boundaries of an ecoregion are not fixed and sharp, but rather encompass an area within which important ecological and evolutionary processes most strongly interact.

These ecoregions contain sub-ecoregions, each determined by climatic, geological and biodiversity factors.