Rainforests are forests characterized by high and continuous rainfall.
They cover about 6% of Earth’s surface.
Rainforests thrive on every continent except Antarctica.
They are Earth’s oldest living ecosystems, with some surviving in their present form for at least 70 million years.
Forests like this have extraordinary biodiversity. Estimates vary from 40% to 75% of all biotic species are indigenous to the rainforests.
Rainforests produce about 20% of our oxygen and store a huge amount of carbon dioxide, drastically reducing the impact of greenhouse gas emissions.
They also help maintain the world’s water cycle. More than 50% of precipitation striking a rainforest is returned to the atmosphere by evapotranspiration, helping regulate healthy rainfall around the planet.
The topography of rainforests varies considerably, from flat lowland plains marked by small rock hills to highland valleys criss-crossed by streams. Volcanoes that produce rich soils are fairly common in the humid tropical forests.
Rainforests can be tropical, subtropical, and temperate forests.
Tropical rainforests are found in the tropics; they are found primarily in South and Central America, West and Central Africa, Indonesia, parts of Southeast Asia, and tropical Australia.
Subtropical forests can be found around the edges of the tropics; they can be found in the Southern United States, Mexico, Southeast Asia, and India.
Temperate rainforests are found along coasts in temperate regions. The largest temperate rainforests are on the Pacific coast in North America, stretching from Alaska to Oregon. Other temperate rainforests are found along the coast of Chile, the United Kingdom, Norway, Japan, New Zealand, and S. Australia.
The undergrowth in some areas of a rainforest can be restricted by poor penetration of sunlight to ground level. If the leaf canopy is destroyed or thinned, the ground beneath is soon colonized by a dense, tangled growth of vines, shrubs and small trees, called a jungle. The term jungle is also sometimes applied to tropical rainforests generally.
The Amazon rainforest is the largest tropical rainforest in the world, covering over five and a half a million square kilometres (1.4 billion acres). Over half of the Amazon rainforest is located in Brazil but it is also located in other South American countries including Peru, Venezuela, Ecuador, Colombia, Guyana, Bolivia, Suriname and French Guiana.
The Congolian rainforest is the world’s second-largest tropical forest, spans six African countries, and contains a quarter of the world’s remaining tropical forest.
Rainforests provide us with many products that we use every day. Tropical woods such as teak, balsa, rosewood, and mahogany are used in flooring, doors, windows, boatbuilding, and cabinetry. Fibers such as raffia, bamboo, kapok, and rattan are used to make furniture, baskets, insulation, and cord. Cinnamon, vanilla, nutmeg, and ginger are just a few spices of the rainforest. The ecosystem supports fruits including bananas, papayas, mangoes, cocoa and coffee.
Tropical rainforests have been called the “jewels of the Earth” and the “world’s largest pharmacy”, because over one quarter of natural medicines have been discovered there.
Rainforests as well as endemic rainforest species are rapidly disappearing due to deforestation, the resulting habitat loss and pollution of the atmosphere.
They once covered about 14% of the Earth, but have been reduced in size now to only about 6% of the Earth’s surface.
A 10-hectare (25-acre) plot of rainforest in Borneo may contain more than 700 species of trees—a number equal to the total tree diversity of North America.
A single rainforest reserve in Peru is home to more species of birds than are found in the entire United States.
One single tree in Peru’s rainforest was found to harbor 43 different species of ants—a total that approximates the entire number of ant species in the British Isles.
At least 3,000 fruits are found in the rainforests; of these only 200 are now in use in the Western world. The Indians of the rainforest use over 2,000.