Tropical rainforests are complex ecosystems characterized by dense vegetation and high biodiversity. They are home to a wide array of plant and animal species, many found nowhere else on Earth. These forests are distinguished by their lush, multi-layered structure.
Key Global Rainforest Regions
Tropical rainforests are primarily located in three major global regions: the Amazon Basin in South America, the Congo Basin in Central Africa, and the rainforests of Southeast Asia. The Amazon rainforest spans across nine South American countries, with the majority of its area within Brazil, and significant portions also found in Peru, Colombia, Bolivia, and Ecuador. In Central Africa, the Congo Basin rainforest covers six countries, including the Democratic Republic of the Congo, the Republic of Congo, Cameroon, and Gabon. Southeast Asia’s rainforests are distributed across countries like Indonesia, Malaysia, and Papua New Guinea, with notable concentrations on islands such as Borneo and New Guinea. Smaller tropical rainforest areas also exist in Central America, parts of Australia, and on various islands in the Pacific and Caribbean.
Climatic Conditions for Rainforest Growth
The existence of tropical rainforests is directly tied to specific climatic conditions found near the Earth’s equator. These forests thrive in regions situated between the Tropic of Cancer (approximately 23.5° North latitude) and the Tropic of Capricorn (approximately 23.5° South latitude), often within 10° of the equator. This equatorial position ensures consistent high temperatures throughout the year, with mean monthly temperatures exceeding 18°C (64°F) and annual averages ranging between 20°C and 30°C (68°F and 86°F). Daily temperature variations are more pronounced than seasonal changes.
Abundant and consistent rainfall is another defining characteristic, with tropical rainforests receiving between 1,680 mm (66 inches) and 3,000 mm (120 inches) of precipitation annually, though some areas can receive up to 10 meters (390 inches). All months receive at least 60 mm (2.4 inches) of rain, indicating an absence of a true dry season. High humidity, ranging from 77% to 88% year-round, supports the lush environment. These steady, warm, and wet conditions create suitable conditions for dense plant growth and high biodiversity.
The Scale of Major Rainforests
The vastness of major rainforest regions highlights their global importance. The Amazon rainforest is the largest, encompassing approximately 6 million square kilometers (2.3 million square miles) of forest within its basin, making up over half of the Earth’s remaining rainforests. Its immense size allows it to house at least 10% of the world’s known biodiversity and play a substantial role in global carbon and water cycles. The Congo Basin is the second-largest tropical rainforest, covering around 2 million square kilometers (500 million acres) across Central Africa. This extensive forest accounts for over 70% of Africa’s tropical forests and serves as a major carbon sink.
Following these two, the rainforests of Southeast Asia collectively represent the third largest expanse. These major rainforests, particularly the Amazon and Congo, support unparalleled species diversity and influence regional and global climate patterns through evapotranspiration. These vast forests provide habitats for countless species and support the planet’s ecological balance.