Location and Extent
The Amazon Rainforest, also known as Amazonia, is the largest tropical rainforest on Earth, spanning approximately 6.7 million square kilometers (about 2.6 million square miles) across northern South America. It primarily occupies the Amazon River basin and extends into nine countries: Brazil (which holds about 60% of the forest), Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname, and French Guiana. This vast expanse lies between the equator and the Tropic of Capricorn, influencing its humid, tropical environment.
Key Physical Features
Geographically, the Amazon features a diverse terrain including lowland plains, Andean foothills, and extensive river systems. The Amazon River, the world's largest by water volume, stretches over 6,400 kilometers from the Peruvian Andes to the Atlantic Ocean, fed by thousands of tributaries that create floodplains known as várzeas. The region includes terra firme (non-flooded uplands), igapó (seasonally flooded blackwater forests), and white-sand savannas, with elevations ranging from sea level to over 1,000 meters in the western highlands.
Practical Example: The Amazon River Basin
The Amazon River basin exemplifies the rainforest's geography, covering 7 million square kilometers and serving as the hydrological heart of the region. For instance, during the rainy season, the river and its tributaries flood up to 150,000 square kilometers, creating dynamic aquatic habitats that support species migration and nutrient cycling. This seasonal flooding illustrates how the basin's flat topography and permeable soils interact to sustain the ecosystem's productivity.
Climate and Global Importance
The Amazon's equatorial climate is characterized by high temperatures averaging 25-28°C year-round and annual rainfall exceeding 2,000 millimeters, often reaching 4,000 millimeters in some areas, with minimal dry seasons. This geography makes it a critical global carbon sink, absorbing vast amounts of CO2, and a biodiversity hotspot housing millions of species. Its features contribute to regional weather patterns, including the generation of rainfall for much of South America through evapotranspiration.