EcoZone: Tropical Rainforests
Tropical rainforests are found in a wide tropical belt all around the world but they are rapidly shrinking because of the expansion of human settlements, the demand for timber and the replacement of forest by agriculture.
The world's largest tropical rainforest is the Amazon jungle which boasts the most extensive number of different species of animals and plants of all the major ecosystems on earth.
Around 10% of all the mammal species, and 20% of the plant and bird species are believed to live there.
Huge numbers of Amazonian invertebrates have still not been descibed by science and, because of the rate of deforestation, are becoming extinct before they are even recorded.
The forest is drained by the mighty Amazon river which is the second longest (6276 km ) in the world (after the Nile at 6650 km). But the Amazon is the biggest river system and it alone pours out 20% of the total of all the fresh water that flows into the world’s oceans every year!
The world’s second largest rainforest lies across central Africa and includes the still mysterious Congo.
The Congo contains 6% of the world’s rainforest and almost half the total rainforest in Africa. It is the home of the pygmies but it is seriously threatened by logging and other human impacts.
Madagascar, the island home of lemurs, still has some remaining rainforest but it is critically threatened. New initiatives since the 1990s are trying to make conservation policies easier for poor local communities, who need the forest’s resources, to follow through the establishment of “Community Forests”.
A region once completely covered by rainforest, sixty-five per cent of this has been felled to make way for cattle grazing. Much has also been planted with sugar cane.
The jungles range from high altitude cloud forest to maritime mangrove swamps and, like most rainforests, contain many endemic species.
Some of the most fascinating and well studied jungle areas are in Costa Rica. It is particularly famous for its birds such as umbrella birds, toucans, trogons, guans, eagles and, of course, the quetzal.
The rainforests of southern Asia lie across Malaysia, Java and Borneo in the east to Burma and India in the west.
Constant high humidity and hot temperatures are a feature of the jungles of south-east Asia, but the mainland forests have more distinct seasons, including the famous monsoon rains.
These areas hold some of the world’s most spectacular orchids.
The world’s largest area of mangrove forest is in Bangladesh.
Another huge area of rainforest running south from Asia stretches from Papua New Guinea (home of birds of paradise) into north-east Australia. Prevailing wet winds blow from the Pacific.
Parts of Papua New Guinea are still unexplored. A recent expedition found many new species of plants, butterflies, birds and twenty new frogs!
Australia's rainforest is thought to be the oldest rainforest in the world at 100 million years old – ten times older than the Amazon forest.
The rainforest of North Queensland has the largest number of different endemic species anywhere on earth.
North Queensland is the only place in Australia where the Aborigines can trace back their culture for more than 10,000 years.