The largest rainforest in the world is the Amazon, a vast South American ecosystem that represents the single largest remaining tract of tropical rainforest on the planet. The Amazon is a complex biological system that influences global weather patterns and harbors unparalleled biodiversity. To understand its scale and significance is to appreciate one of Earth’s most important natural environments.
Naming the World’s Largest Rainforest
The Amazon rainforest holds the undisputed title of the world’s largest tropical rainforest, defined by its immense contiguous area of forest cover. Its forested area is approximately 5.5 million square kilometers (about 2.1 million square miles). This vast expanse makes it larger than the next two largest rainforests combined, highlighting its dominance in global ecology.
The definition of a tropical rainforest hinges on factors like consistent high rainfall and year-round warm temperatures, conditions the Amazon basin fulfills. This massive area of forest cover represents over half of the total remaining rainforest area on Earth. The scale of the Amazon is so great that it constitutes roughly 40% of South America’s total land area.
Geographical Extent and Political Divisions
The Amazon rainforest stretches across the immense Amazon River basin, covering a vast territory that crosses the borders of nine nations in South America. The majority of the forest, approximately 60% of its total area, lies within the borders of Brazil. This concentration makes Brazil the primary steward of the world’s largest rainforest.
The remaining portion of the forest is shared by eight other countries, including Peru (about 13%) and Colombia (roughly 10%). Smaller areas are found in Bolivia, Ecuador, Venezuela, Guyana, Suriname, and French Guiana. This political division across nine governments presents a complex challenge for the unified conservation and management of the ecosystem.
Unique Biological and Climatic Role
The Amazon’s significance extends far beyond its physical size, playing a major role in regulating the global climate and supporting biodiversity. The forest acts as a component of the global water cycle through evapotranspiration, where trees release massive amounts of water vapor into the atmosphere. The density of vegetation contributes to the formation of atmospheric rivers, which carry rainfall to distant parts of South America.
The Amazon River, which sustains the forest, is the world’s largest river by volume, discharging more water into the ocean than the next seven largest independent rivers combined. This vast river system is home to the largest number of freshwater fish species globally. The ecosystem contains an estimated 150 to 200 billion tons of carbon stored within its vegetation and soils, making it one of the world’s most significant terrestrial carbon sinks.
Biologically, the Amazon is the most biodiverse tract of tropical rainforest in the world, containing approximately 10% of all known wildlife species on Earth. Scientists estimate the forest is home to 16,000 different tree species and an estimated 438,000 species of plants. The staggering variety of life includes unique creatures like jaguars, pink river dolphins, and thousands of bird, insect, and amphibian species.
Comparison to Other Major Rainforests
While the Amazon is the largest, other tropical rainforests also cover substantial areas globally. The second largest is the Congo Basin rainforest in Central Africa. This forest covers an area of approximately 2.87 million square kilometers (about 1.1 million square miles).
The Amazon is considerably larger, containing more than three times the primary forest area compared to the Congo Basin. Following the Congo, the rainforests of Southeast Asia, particularly those in Sundaland and the Indo-Burma region, constitute the next largest grouping of tropical forest. The vast size difference illustrates the Amazon’s unique status.