10 Rainforest Facts for 2017
Tropical rainforests are among the world's most important ecosystems for they role they play in sustaining life on the planet. From the Amazon to the Congo, every rainforest has a unique assemblage of plants, animals, and people.
Below are 10 quick up-to-date facts about tropical rainforests to explain what these ecosystems are, why they are important, and how they can be saved.
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The Quick List
Tropical rainforest in Sabah, Malaysia on the island of Borneo. Photo by Rhett A. Butler.
- There are several different types of rainforests
- Rainforests cover less than 3 percent of the planet
- The world's largest rainforest is the Amazon rainforest
- Rainforests house more species of plants and animals than any other terrestrial ecosystem
- Much of the life in the rainforest is found in the trees
- Many products we use on a daily basis come from rainforest plants
- Rainforest help fight global warming
- Rainforests are being destroyed at a pace of 8 million hectares per year
- We are destroying rainforests via our consumption patterns
- Bold new ideas are being proposed to save rainforests
1. There are several different types of rainforests
While tropical rainforests are the most famous, rainforests are also found in sub-tropical and temperate zones. For example, the Pacific Northwest in the United States and parts of Japan have dense forests that receive as much rainfall as parts of the Amazon, Borneo, or the Congo. Even within the tropics, rainforests have a great deal of variability depending on soils and geology, precipitation patterns, and even their resident wildlife (elephants can have a significant impact on forest structure by trampling seedings and creating meadows, for example). For that reason, a rainforest in Indonesia may look very different from a rainforest in Brazil.
2. Rainforests cover less than 3 percent of the planet
Estimates of forest cover depend on the methodology used to define a forest, including the density of canopy cover and height of trees. In dry regions, an area with ten percent canopy cover may be classified as "forest". But in the tropics, ten percent canopy cover might not look much like a conventional forest. By that broad definition, the United Nations estimated that forests covered 1.77 billion hectares or 6.8 million square miles of land in tropical countries in 2015. If the threshold of canopy cover is increased to 75 percent, forests covered about 1.3 billion hectares or 5 million square miles in 2014, according to Matthew Hansen, a researcher at the University of Maryland. Those numbers indicate that tropical forests cover at least 8 percent of Earth's land surface or 2.5 percent of its total surface area.
Temperate rainforest on the Olympic Peninsula in Washington State. Photo by Rhett A. Butler.
3. The world's largest rainforest is the Amazon rainforest
The Amazon basin contains the world's largest rainforest, which is nearly the roughly of the continental United States and covers about 40 percent of South America. Nearly two-thirds of the Amazon rainforest
lies within the borders of Brazil.
The second largest rainforest is found in Central Africa's Congo Basin
. Next is the rainforest of New Guinea.
On a country basis, Brazil ranks number one in terms of rainforest cover. It is followed by the Democratic Republic of Congo, Indonesia, Peru, and Colombia.
Chart showing biomass in tropical forests by country
4. Rainforests house more species of plants and animals than any other terrestrial ecosystem
While tropical rainforests cover less than ten percent of Earth's land mass, they are thought to house more than half the world's terrestrial species. There are several reasons why rainforests are so diverse, including their climate, their vegetation structure, and competition between species.
Rainforests can be staggeringly more species-rich than temperate forests. For example, while temperate forests may be dominated by a half dozen tree species, a tropical rainforest may have more than 480 tree species in a single hectare (2.5 acres). More than 1,300 species of butterfly has been documented in a single park in Peru, while the entire European continent has less than 400 species.
Jaguar in Colombia. Photo by Rhett A. Butler.
5. Much of the life in the rainforest is found in the trees
Compared to temperate forests, an unusually high percentage of life in the rainforest is found in the trees. Much of this is concentrated in the canopy
, the layers created well above the forest floor by the overlapping branches and leaves of rainforest trees. The conditions of the canopy are strikingly different from those on the forest floor, meaning there are orders of magnitude more ecological niches for species to inhabit. For example, many animals typically thought of as ground-dwelling are arboreal in the rainforest, including salamanders, anteaters, and even crabs.
Cock of the rock in Peru. Photo by Rhett A. Butler.
6. Many products we use on a daily basis come from rainforest plants
Many foods we eat on a daily basis originated in tropical forests, including bananas, avocados, mangos, cacao, coffee, and papaya, among others. The same is true for medicines
: indigenous shamans
have used plants for generations to diagnose
and treat illness. Some of the medicinal plants have be developed into modern drugs for treating everything from cancer to parasitic infections.
Kelumpang Sarawak (Sterculia megistophylla) in Borneo. Photo by Rhett A. Butler
7. Rainforest help fight global warming
When plants grow they sequester atmospheric carbon in their tissues via the process of photosynthesis. Because rainforests are full of large trees and other plants, they store massive amounts of carbon. But when they are burned or chopped down, much of that carbon is released into the atmosphere as carbon dioxide and other greenhouse gases (nitrous oxide, methane, and other nitrogen oxides). The clearing and burning of tropical forests and peatlands accounts for about ten percent of greenhouse gases from human activities.
Therefore rainforest protection and restoration are critical to slowing climate change. By one estimate, published in 2015 in the scientific journal Nature
, rainforests could meet half the 2050 target for reducing carbon emissions.
Rainforest in Borneo. Photo by Rhett A. Butler.
8. Rainforests are being destroyed at a pace of 8 million hectares per year
According to analysis of satellite data, tropical forests are being destroyed at a rate of at least 8 million hectares
or 31,000 square miles a year. That's an area the size of the state of South Carolina or the Czech Republic that is chopping down every year. Brazil, Indonesia, the Democratic Republic of Congo, and Malaysia had the highest rates of rainforest loss between 2012 and 2014 according to research by Matt Hansen of the University of Maryland
How many trees is that? Researchers haven't quite settled that question, but a study published in 2015
suggested that more than five billion trees are cut down across the tropics every year.
Deforestation for paper production in Sumatra, Indonesia. Photo by Rhett A. Butler.
Data from Matt Hansen and colleagues presented via Global Forest Watch. Prepared by Mongabay.com.
Data from Matt Hansen and colleagues presented via Global Forest Watch. Prepared by Mongabay.com.
9. We are destroying rainforests via our consumption patterns
Virtually all deforestation is driven by human activity
. The biggest drivers of deforestation are agriculture — both industrial and subsistence — and cattle ranching. Much of this production is not consumed locally — instead it is sent to cities or overseas. That means consumers who may live far away from rainforests are usually at least partly responsible for the destruction of these beautiful and important landscapes.
Chart: Forest loss across biomes
10. Bold new ideas are being proposed to save rainforests
Bold new ideas are being proposed to save rainforests. For example, governments and companies are finally starting to recognize the value of goods and services afforded by healthy forests, including carbon storage, buffering against flood and drought cycles, and safeguarding water supplies. Accordingly these values are being used as another justification for protecting forests.
Another recent development has been the acknowledgement that local and indigenous communities are often some of the best stewards of forests. As such, they are increasingly being viewed as partners, not adversaries in conservation. There is a growing movement to help these communities win the legal right to manage their traditional lands instead of letting the government hand out concessions to companies that clear forests for plantations and commercial farms.
Additionally, we now have a better understanding than ever before of what's happening to forests. Between "eyes in the sky" in the form of satellites and eyes on the ground in the form of camera traps and sensors, citizen journalists and scientists, and an ever-expanding network of scientists, conservationists, and environmentalists, forests are being monitored far more effectively than just a few years ago. Knowing what is happening to forests empowers us to do something about it.
Tropical rainforest in Sarawak, Malaysia on the island of Borneo. Photo by Rhett A. Butler.
And finally a secret: You can help save rainforests
As much as we're part of the problem, we're also part of the solution to saving rainforests. For example, companies respond to consumer dollars. If we demand products that are free of rainforest destruction, companies will be pressured to adopt policies that better protect forests. This is already happening: since 2013 dozens of companies have adopted zero deforestation policies for sourcing palm oil, wood pulp for paper, beef and leather, and soybeans. We're certainly not out of the woods yet, but progress is being made.
Deforestation in Malaysia for palm oil. Photo by Rhett A. Butler.
Learn more about rainforests at Mongabay's main rainforests site or our site for kids. Also take a look at our collection of rainforest photos.