A tropical rainforest is an ecosystem distinguished by being warm and wet. To be considered a rainforest, annual rainfall in an area must be 75 inches at a minimum, and most rainforests get over 100 inches of rain every year. Moreover, temperatures in a rainforest are warm year-round. (There are other ecosystems known as “temperate rainforests,” which also get a lot of rain but have much cooler temperatures.)
Rainforests of the world:
Tropical rainforests surround the earth’s equatorial zone and are warm and humid places. They provide shelter and sustenance to an enormous variety of plant and animal species, and they are also home to 50 million Indigenous peoples. Although tropical forests cover less than 7% of the earth’s surface they are home to approximately 50% of all living things on earth.
What is Amazonia?
Amazonia is a region that includes most of Northern Brazil and parts of the bordering countries of French Guiana, Guyana, Suriname, Venezuela, Colombia, Ecuador, Peru and Bolivia. Amazonia can be visualized as a funnel (with its wide end at the Andes) draining some six million square kilometers through a complex of rivers that are tributaries of the Amazon River. The Amazon River has the greatest volume of water of any river in the world. It is navigable along its entire 4000 mile length (6,400 km). The Amazon is also extraordinarily rich in biodiversity. A very large number of Amazonian plant and animal species are “endemic”, meaning that they are found there and nowhere else. Recent estimates from Conservation International indicate that in the Amazon one can find:
- 18,000 varieties of plants (c.13, 680 endemic)
- 434 species of mammals (138 endemic)
- 239 reptile species (59 endemic)
- 225 species of amphibians (203 endemic)
- And more freshwater fish and primates than anywhere else on the planet!
Is all rainforest in Amazonia?
No! There are also very large and important tropical rainforests in Asia, Africa, Central America and the Caribbean, as well as a few temperate regions such as the Pacific Northwest. The largest expanse of rainforest in the world, however, is in Amazonia in South America.
How old is the rainforest?
Rainforests have been around for tens of millions of years. The geographical extent of this ecosystem has expanded and diminished under the effect of continental drift and glaciation.
How much rainforest is gone?
In many parts of the tropics, current forest cover is only a fraction of what it was 50 years ago. For example, only 5% of Brazil’s incomparable Atlantic coastal forest remains. While the Amazonian rainforest is still largely intact due to its great size, recent data have shown that the scale and rates of deforestation there are actually greater than many published estimates, not less.
Are rainforests the lungs of the earth?
Not exactly – they are often given this name because they produce about 20% of all the oxygen in the world. The real lungs of the planet, however, are the microorganisms in the world’s oceans which produce the other 80% of our oxygen. But rainforests do play a crucial role in many of our planet’s ecological cycles – they maintain global rainfall and regulate climate patterns worldwide. Even more importantly, mature forests such as the Amazon and elsewhere store huge amounts of carbon in their vegetation. Burning the vegetation or cutting it down and allowing it to rot releases this carbon in the form carbon dioxide – a major greenhouse gas. Keeping rainforests intact and healthy will go a long way towards combating the threat of climate change and global warming.
Will rainforests regenerate?
In some cases this is possible, but the new forest will be a much poorer habitat, home to many fewer species of plants and animals. Rainforest fragmentation leads invariably to biodiversity loss.
What do we use rainforests for?
Rainforests are crucial to all humanity. About 1.2 billion people in the world rely on the rainforest for their survival, directly or indirectly. In addition, the destruction of the rainforest creates greenhouse gases that contribute to climate change – something that impacts us all. And rainforests provide many other important benefits that we all can appreciate. For example, approximately 121 useful drugs currently on the market are obtained from plants, and over a third of these originated in tropical forests. Similarly, much of the food we eat – coffee, bananas, lemons, oranges, cacao, cashews, peanuts, pineapples, papayas, and many more! – comes from tropical forests.
Forests regulate water and protect watersheds. Without the canopy breaking the force of heavy downpours, rain can dissolve pastures and cropland into mud slides. The canopy allows rainfall to slowly trickle down, rather than rush into rivers and flood the surroundings. In 1998, for example, Hurricane Mitch left 11,000 people dead and many more homeless in Central America. The destruction was caused primarily by deforestation.
What are the major threats to the rainforest?
Uncontrolled extractive industries, such as logging, mining, and oil, as well as road development and infrastructure projects (such as roads, dams, etc.) also threaten the people that live in and rely upon the rainforest for their survival.
Indigenous and traditional peoples
The rainforests of the world are the home and a source of life and culture for many unique and diverse indigenous and traditional peoples. As the rainforests are destroyed, their ways of life can change and become poorer economically, culturally, linguistically and politically.
According to Survival International (2000), 940,000 indigenous people live in the Amazon rainforest alone. In Brazil, at the time of European contact, indigenous people numbered around 5 million. The number has since dropped to less than 200,000, and anthropologists believe that a forest dwelling tribe has been lost in Brazil every single year since 1900. In addition, there are fisherfolk, rubbertappers, Maroons, Quilombolas, and other traditional peoples who depend on a healthy Amazon for their survival.
A crucial priority for indigenous people is gaining the rights to the land they live on. Obtaining the legal right to their ancestral land enables indigenous and traditional peoples to choose for themselves how the forests will be used and to prevent unwanted development such as mining, logging, ranching and deforestation.
Indigenous lands are 20% of the preserved lands in the Brazilian Amazon, and on satellite maps, one can see that indigenous and traditional peoples’ lands are some of the best preserved zones. Indigenous people of the Amazon in Colombia control 15 million acres of land among more than 50 ethnic groups and 70,000 people. Chiribequette Park, created in 1989, protects 2.5 million acres, some of which is the indigenous peoples territory. Colombian law protects the peoples’ rights to follow their own customs and traditions and develop and organize their own health and education services. 80 % of the world’s biodiversity is found on indigenous lands!
Did you know?
- The current rate of destruction is about 1 acre each second, which is a bit less than a US football field. Expanded, that amounts to 60 acres/min, 3,600/hour, 86,400/day, 2.6 million/month, and 31.5 million acres per year.
- The natural extinction rate is approximately 1 species per year. As a result of deforestation, species will become extinct at a rate 3 to 4 times higher than that.
- Tropical forests comprise approximately 7 percent of the earth’s dry land surface (2% of total surface) and sustain over 50 percent of all species.
- The Amazon River basin contains 20% of the world’s fresh water.
Remarkable things you can find in tropical forests
- 80% of all insects live in tropical forests!
- In Borneo, 700 tree species were found in 25 acres!
- In Colombia, there are over 1,500 bird species!
- In the Tambopata Reserve in Peru, 43 ant species were found on a single tree!
- In Panama, 18,000 beetle species were found in only 2.5 acres of forest!