Amazon Rainforest: Biodiversity, Flying Rivers, and Deforestation

400 Billion Trees. One Forest.

The Amazon basin contains an estimated 390 billion individual trees belonging to approximately 16,000 species, according to a 2013 survey published in Science by an international team of 110 researchers. The entire Amazon rainforest covers approximately 5.5 million square kilometers across nine countries — Brazil (60%), Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname, and French Guiana — and is the largest tropical rainforest on Earth. It contains an estimated 10% of all species on the planet, including roughly 40,000 plant species, 1,300 bird species, 3,000 freshwater fish species, 430 mammal species, and an estimated 2.5 million insect species. New species are still being discovered at a rate of approximately 400 per year in the Amazon basin.

The Amazon River itself discharges approximately 20% of all freshwater entering the world's oceans — carrying more water than the next seven largest rivers combined. During the wet season, the Amazon flood plain expands to more than 350,000 square kilometers, creating the largest flooded forest ecosystem on Earth. The Pantanal, bordering the Amazon basin to the south, is the world's largest tropical wetland, covering 150,000–195,000 square kilometers across Brazil, Bolivia, and Paraguay.

Four Vertical Layers of Life

The canopy layer is the primary engine of the Amazon's biodiversity. It receives the vast majority of solar radiation, drives photosynthesis and transpiration, and provides structural habitat for the majority of the forest's species. Canopy researchers using rope access, canopy cranes, and aerial walkways have discovered that many species spend their entire lives in the canopy without ever touching the forest floor — including some orchids, ferns, and invertebrates that complete their entire life cycles in the water-filled leaf axils of bromeliads suspended 30 meters above the ground.

Flying Rivers: The Amazon's Hidden Climate Engine

The Amazon forest generates its own rainfall through a phenomenon called "flying rivers" — atmospheric water vapor transport that Brazilian meteorologist José Marengo and researchers at Brazil's National Institute for Space Research (INPE) have extensively documented. The trees of the Amazon transpire enormous volumes of water — a single large Amazonian tree can release 1,000 liters of water per day through its leaves — and this combined transpiration from 390 billion trees generates a continuous westward-flowing river of water vapor in the lower atmosphere.

• The Amazon's flying rivers transport an estimated 20 billion tons of water vapor per day westward across the continent
• This atmospheric moisture travels approximately 3,000 kilometers from the Amazon basin, rising against the Andes and falling as rain over Argentina, Paraguay, Uruguay, and southern Brazil
• The agricultural regions of southern South America — responsible for billions of dollars in soy, corn, and beef exports annually — depend on rainfall generated by the Amazon's evapotranspiration
• Computer models suggest that large-scale deforestation would reduce rainfall in these agricultural zones by 20–40%, with cascading effects on regional food security

Deforestation: Rates, Drivers, and Tipping Points

Brazil's National Institute for Space Research (INPE) uses satellite imagery to track Amazon deforestation in near-real-time. The Amazon lost approximately 11,568 square kilometers in 2022 — roughly the size of Jamaica. Cumulative deforestation since 1988 has removed approximately 800,000 square kilometers of Amazon forest — an area roughly equal to Turkey. Deforestation peaked in 2004 at 27,772 square kilometers and declined through 2012 before rising again. Under President Lula, 2023 deforestation fell to its lowest level since 2015, according to INPE data.

Scientists at INPE and Brazil's Amazon Environmental Research Institute (IPAM) have identified a potential tipping point: if the Amazon loses approximately 20–25% of its original cover (currently at ~17–18%), the southern and eastern portions of the forest may transition irreversibly from rainforest to savanna — a "dieback" driven by reduced precipitation as the flying river system weakens. The transition would release an estimated 90 billion tons of CO₂ equivalent over decades, removing one of Earth's largest carbon sinks from the global carbon cycle.