RAINFOREST INFORMATION

A Place Out of Time: Tropical Rainforests and the Perils They Face - information on tropical forests, deforestation, and biodiversity

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BACKGROUND INFORMATION ON THE RAINFOREST

Rainforests are forest ecosystems characterized by high levels of rainfall, an enclosed canopy and high species diversity. While tropical rainforests are the best-known type of rainforest and the focus of this section of the web site, rainforests are actually found widely around the world, including temperate regions in Canada, the United States, and the former Soviet Union.

Tropical rainforests typically occur in the equatorial zone between the Tropic of Cancer and Tropic of Capricorn, latitudes that have warm temperatures and relatively constant year-round sunlight. Tropical rainforests merge into other types of forest depending on the altitude, latitude, and various soil, flooding, and climate conditions. These forest types form a mosaic of vegetation types which contribute to the incredible diversity of the tropics.

The bulk of the world's tropical rainforest occurs in the Amazon Basin in South America. The Congo Basin and Southeast Asia, respectively, have the second and third largest areas of tropical rainforest. Rainforests also exist on some the Caribbean islands, in Central America, in India, on scattered islands in the South Pacific, in Madagascar, in West and East Africa outside the Congo Basin, in Central America and Mexico, and in parts of South America outside the Amazon. Brazil has the largest extent of rainforest of any country on Earth.

Rainforests provide important ecological services, including storing hundreds of billions of tons of carbon, buffering against flood and drought, stabilizing soils, influencing rainfall patterns, and providing a home to wildlife and Indigenous people. Rainforests are also the source of many useful products upon which local communities depend.

While rainforests are critically important to humanity, they are rapidly being destroyed by human activities. The biggest cause of deforestation is conversion of forest land for agriculture. In the past subsistence agriculture was the primary driver of rainforest conversion, but today industrial agriculture — especially monoculture and livestock production — is the dominant driver of rainforest loss worldwide. Logging is the biggest cause of forest degradation and usually proceeds deforestation for agriculture.

Organization of this site

The rainforest section of Mongabay is divided into ten "chapters" (the original text for the site was a book, but has since been adapted for the web), with add-on content in the form of special focal sections (e.g. The Amazon, the Congo, REDD, New Guinea, Sulawesi, Forests in Brazil, etc), appendices, and other resources.

There is also a version of the site geared toward younger readers at kids.mongabay.com.

ABOUT THE RAINFOREST (SUMMARY)

RAINFOREST DISTRIBUTION AND CHARACTERISTICS

Each rainforest is unique, but there are certain features common to all tropical rainforests.

• Location: rainforests lie in the tropics.
• Rainfall: rainforests receive at least 80 inches (200 cm) of rain per year.
• Canopy: rainforests have a canopy, which is the layer of branches and leaves formed by closely spaced rainforest trees some 30 meters (100 feet) off the ground. A large proportion of the plants and animals in the rainforest live in the canopy.
• Biodiversity: rainforests have extraordinarily highs level of biological diversity or “biodiversity”. Scientists estimate that about half of Earth's terrestrial species live in rainforests.
• Ecosystem services: rainforests provide a critical ecosystem services at local, regional, and global scales, including producing oxygen (tropical forests are responsible for 25-30 percent of the world's oxygen turnover) and storing carbon (tropical forests store an estimated 229-247 billion tons of carbon) through photosynthesis; influencing precipitation patterns and weather; moderating flood and drought cycles; and facilitating nutrient cycling; among others.

The global distribution of tropical rainforests can be broken up into four biogeographical realms based roughly on four forested continental regions: the Afrotropical, the Australiasian, the Indomalayan/Asian, and the Neotropical. Just over half the world's rainforests lie in the Neotropical realm, roughly a quarter are in Africa, and a fifth in Asia.

These realms can be further divided into major tropical forest regions based on biodiversity hotspots, including:

1. Amazon: Includes parts of Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, Venezuela
2. Congo: Includes parts of Cameroon, Central African Republic, Democratic Republic of the Congo, Equatorial Guinea, Gabon, Republic of Congo
3. Australiasia: Includes parts of Australia, Indonesian half of New Guinea, Papua New Guinea
4. Sundaland: Includes parts of Brunei, Indonesia, Malaysia, Singapore
5. Indo-Burma: Includes parts of Bangladesh, Cambodia, China, India, Laos, Myanmar, Thailand, Vietnam
6. Mesoamerica: Includes parts of Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama
7. Wallacea: Sulawesi and the Maluku islands in Indonesia
8. West Africa: Includes parts of Benin, Cameroon, Côte d'Ivoire, Ghana, Guinea, Liberia, Nigeria, Sierra Leone, Togo
9. Atlantic forest: Includes parts of Argentina, Brazil, Paraguay
10. Choco: Includes parts of Colombia, Ecuador, Panama

Other countries that have large areas of rainforest include Bolivia, Cameroon, Central African Republic, Ecuador, Gabon, Guyana, India, Laos, Malaysia, Mexico, Myanmar, Papua New Guinea, Republic of Congo, Suriname, and Venezuela.

Cover and loss by rainforest region

RAINFOREST STRUCTURE

Rainforests are characterized by a unique vegetative structure consisting of several vertical layers including the overstory, canopy, understory, shrub layer, and ground level. The canopy refers to the dense ceiling of leaves and tree branches formed by closely spaced forest trees. The upper canopy is 100-130 feet above the forest floor, penetrated by scattered emergent trees, 130 feet or higher, that make up the level known as the overstory. Below the canopy ceiling are multiple leaf and branch levels known collectively as the understory. The lowest part of the understory, 5-20 feet (1.5-6 meters) above the floor, is known as the shrub layer, made up of shrubby plants and tree saplings.

RAINFOREST BIODIVERSITY

Tropical rainforests support the greatest diversity of living organisms on Earth. Although they cover less than 2 percent of Earth’s surface, rainforests house more than 50 percent of the plants and animals on the planet.

THE RAINFOREST CANOPY

In the rainforest most plant and animal life is not found on the forest floor, but in the leafy world known as the canopy. The canopy, which may be over 100 feet (30 m) above the ground, is made up of the overlapping branches and leaves of rainforest trees. Scientists estimate that more than half of life in the rainforest is found in the trees, making this the richest habitat for plant and animal life.

The conditions of the canopy are markedly different from the conditions of the forest floor. During the day, the canopy is drier and hotter than other parts of the forest, and the plants and animals that live there have adapted accordingly. For example, because the amount of leaves in the canopy can make it difficult to see more than a few feet, many canopy animals rely on loud calls or lyrical songs for communication. Gaps between trees mean that some canopy animals fly, glide, or jump to move about in the treetops. Meanwhile plants have evolved water-retention mechanisms like waxy leaves.

Scientists have long been interested in studying the canopy, but the height of trees made research difficult until recently. Today the canopy is commonly accessed using climbing gear, rope bridges, ladders, and towers. Researchers are even using model airplanes and quadcopters outfitted with special sensors — conservation drones — to study the canopy.

The rainforest floor

The rainforest floor is often dark and humid due to constant shade from the leaves of canopy trees. The canopy not only blocks out sunlight, but dampens wind and rain, and limits shrub growth.

Despite its constant shade, the ground floor of the rainforest is the site for important interactions and complex relationships. The forest floor is one of the principal sites of decomposition, a process paramount for the continuance of the forest as a whole. It provides support for trees responsible for the formation of the canopy and is also home to some of the rainforest's best-known species, including gorillas, tigers, tapirs, and elephants, among others.

Rainforest waters

Tropical rainforests support some of the largest rivers in the world, like the Amazon, Mekong, Negro, Orinoco, and Congo. These mega-rivers are fed by countless smaller tributaries, streams, and creeks. For example, the Amazon alone has some 1,100 tributaries, 17 of which are over 1,000 miles long. Although large tropical rivers are fairly uniform in appearance and water composition, their tributaries vary greatly.

Rainforest waters are home to a wealth of wildlife that is nearly as diverse as the biota on land. For example, more than 5,600 species of fish have been identified in the Amazon Basin alone.

But like rainforests, tropical ecosystems are also threatened. Dams, deforestation, channelization and dredging, pollution, mining, and overfishing are chief dangers.

Rainforest people

Tropical rainforests have long been home to tribal peoples who rely on their surroundings for food, shelter, and medicines. Today very few forest people live in traditional ways; most have been displaced by outside settlers, have been forced to give up their lifestyles by governments, or have chosen to adopt outside customs.

Of the remaining forest people, the Amazon supports the largest number of Indigenous people living in traditional ways, although these people, too, have been impacted by the modern world. Nonetheless, Indigenous peoples' knowledge of medicinal plants remains unmatched and they have a great understanding of the ecology of the Amazon rainforest.

In Africa there are native forest dwellers sometimes known as pygmies. The tallest of these people, also called the Mbuti, rarely exceed 5 feet in height. Their small size enables them to move about the forest more efficiently than taller people.

There are few forest peoples in Asia living in fully traditional ways. The last nomadic people in Borneo are thought to have settled in the late 2000's. New Guinea and the Andaman Islands are generally viewed as the last frontiers for forest people in Asia and the Pacific.

Deforestation

In recent decades there has been an important shift in deforestation trends. Today export-driven industries are driving a bigger share of deforestation than ever before, marking a shift from previous decades, when most tropical deforestation was the product of poor farmers trying to put food on the table for their families. There are important implications from this change. While companies have a greater capacity to chop down forests than small farmers, they are more sensitive to pressure from environmentalists. Thus in recent years, it has become easier—and more ethical—for green groups to go after corporations than after poor farmers.

Rainforests are also threatened by climate change, which is contributing to droughts in parts of the Amazon and Southeast Asia. Drought causes die-offs of trees and dries out leaf litter, increasing the risk of forest fires, which are often set by land developers, ranchers, plantation owners, and loggers.

Rainforest importance

While rainforests may seem like a distant concern, they are critically important for our well-being. Rainforests are often called the lungs of the planet for their role in absorbing carbon dioxide, a greenhouse gas, and producing oxygen, upon which all animals depend for survival. Rainforests also stabilize climate, house incredible amounts of plants and wildlife, and produce nourishing rainfall all around the planet.

Rainforests:

• Help stabilize the world’s climate: Rainforests help stabilize the world’s climate by absorbing carbon dioxide from the atmosphere. Scientists have shown that excess carbon dioxide in the atmosphere from human activities is contributing to climate change. Therefore, living rainforests have an important role in mitigating climate change, but when rainforests are chopped down and burned, the carbon stored in their wood and leaves is released into the atmosphere, contributing to climate change.
• Provide a home to many plants and animals: Rainforests are home to a large number of the world’s plant and animals species, including many endangered species. As forests are cut down, many species are doomed to extinction.
• Help maintain the water cycle: The role of rainforests in the water cycle is to add water to the atmosphere through the process of transpiration (in which plants release water from their leaves during photosynthesis). This moisture contributes to the formation of rain clouds, which release the water back onto the rainforest. In the Amazon, 50-80 percent of moisture remains in the ecosystem’s water cycle. When forests are cut down, less moisture goes into the atmosphere and rainfall declines, sometimes leading to drought. Rainforests also have a role in global weather patterns. For example researchers have shown that forests in South America affect rainfall in the United States, while forests in Southeast Asia influence rain patterns in southeastern Europe and China. Distant rainforests are therefore important to farmers everywhere.
• Protect against flood, drought, and erosion: Rainforests have been compared to natural sponges, moderating flood and drought cycles by slowing run-off and contributing moisture to the local atmosphere. Rainforests are also important in reducing soil erosion by anchoring the ground with their roots. When trees are cut down there is no longer anything to protect the ground, and soils are quickly washed away with rain. On steep hillsides, loss of forest can trigger landslides.
• Are a source for medicines and foods and support forest-dependent people: People have long used forests as a source of food, wood, medicine, and recreation. When forests are lost, they can no longer provide these resources. Instead people must find other places to get these goods and services. They also must find ways to pay for the things they once got for free from the forest.

Rainforest conservation

Rainforests are disappearing very quickly. The good news is there are a lot of people who want to save rainforests. The bad news is that saving rainforests will be a challenge as it means humanity will need to shift away from business-as-usual practices by developing new policies and economic measures to creative incentives for preserving forests as healthy and productive ecosystems.

Over the past decade there has been considerable progress on several conservation fronts. Policymakers and companies are increasingly valuing rainforests for the services they afford, setting aside large blocks of forests in protected areas and setting up new financial mechanisms that compensate communities, state and local governments, and countries for conserving forests. Meanwhile, forest-dependent people are gaining more management control over the forests they have long stewarded. Large international companies are finally establishing policies that exclude materials sourced via deforestation. People are abandoning rural areas, leading to forest recovery in some planes.

But the battle is far from over. Growing population and consumption means that rainforests will continue to face intense pressures. At the same time, climate change threatens to dramatically alter temperatures and precipitation patterns, potentially pushing some forests toward critical tipping points.

Thus the future of the world's rainforests in very much in our hands. The actions we take in the next 20 years will determine whether rainforests, as we currently know them, are around to sustain and nourish future generations of people and wildlife.

The Latest News on Rainforests

The people who make up the Pan-Amazonian melting pot: regional demographics (Oct 4 2024)
One reason it is possible to be optimistic about the future of the Pan Amazon is that none of the countries must deal with an impending demographic explosion. This was not always the case. In the 1970s, high birth rates and Roman Catholic traditions suggested that Latin America was facing a demographic time bomb. Populations […]

Hurricane Helene creates new hurdles for vulnerable species in southeastern US (Oct 4 2024)
Hurricane Helene recently ravaged the southeastern United States, cutting a path of destruction from the Florida coast past the mountains of North Carolina, more than 480 kilometers (300 miles) inland. The inland flooding has been catastrophic, and conservationists worry that the unprecedented storm may push some vulnerable species toward extinction. One of the most locally […]

Ant queens cannibalize their sick young to prevent disease outbreak (Oct 4 2024)
Ant queens practice a grim but effective form of childcare, eating their own sick larvae to recycle them into new, healthier eggs. A new study shows that by consuming their infected offspring, the queens protect the rest of their colonies from deadly infections while boosting their egg production with the influx of nutrients. Researchers behind […]

New conservation model calls for protecting Amazon for its archaeological riches (Oct 4 2024)
Researchers in Brazil are lobbying to register archaeological sites as national monuments, which would confer a new layer of protection status to parts of the rainforest.

Indigenous knowledge proves key in a study of plants gorillas use to self-medicate (Oct 3 2024)
For the Indigenous Vungu people living along the border of Gabon’s Moukalaba-Doudou National Park, the forest here has long been a source of traditional medicines. So when researchers set out to determine the bioactive properties of plants consumed by the park’s western lowland gorillas (Gorilla gorilla gorilla), and which the Vungu also use for medicine, […]

In Madagascar, Taniala Regenerative Camp aims to heal deforestation scars (Oct 3 2024)
The Menabe Antimena Protected Area in midwestern Madagascar is badly scarred by deforestation; farmers from the surrounding communities have encroached on this unique dry forest ecosystem in search of new and fertile land to grow crops like maize and peanuts. But amid the damage, in the village of Lambokely, is a carefully tended exception. Roland […]

EU considers postponing anti-deforestation law as pressure from agribusiness mounts (Oct 3 2024)
An ambitious anti-deforestation law in the EU could be delayed for at least a year following pressure from foreign governments and producers, who said they were struggling to meet upcoming deadlines for the new trade regulation. The EU deforestation-free products regulation (EUDR) was scheduled to go into force on January 1, requiring exporters to prove […]

‘Old ladies’ against underwater garbage and the Zen of trash picking (Oct 3 2024)
In August, a group of self-described “old ladies” fished out a toilet bowl from a pond in Massachusetts, U.S., and have gained local fame since then. The group is named Old Ladies Against Underwater Garbage (OLAUG), and so far, they’ve cleaned up 18 ponds, removing everything from tires and beer bottles to the bright blue […]

Follow the prey: How servals adapt to an industrialized landscape (Oct 3 2024)
Why did the serval go to the petrochemical complex? For the refinery rodents, of course. These swift and slender wildcats that call the marshes and reedbeds of sub-Saharan Africa home have a penchant for rats and mice, though they’ll also feed on a mix of birds, insects and reptiles. But for their preferred prey, they’ll […]

Past failures can’t stop Indonesia from clearing forests, Indigenous lands for farms (Oct 3 2024)
JAKARTA — Indigenous Papuans say they’ve been caught off guard by helicopters flying over their villages and excavators tearing down their forests in their area, all while accompanied by the Indonesian military. What they’re being subjected to is one of the largest deforestation projects in the world, which will see the development of 1 million […]

In Ecuador, booming profits in small-scale gold mining reveal a tainted industry – investigation (Oct 3 2024)
About a quarter of Ecuador’s gold exports from small-scale mining in 2023 originated from just three companies: Rockgolden, Rocadorada and Soul Metals. Their exports of $268 million in gold just to the United Arab Emirates and India was about 20 times more than the same trade the year before. A months-long investigation of their activities […]

For ranchers in Costa Rica, jaguars and pumas become unexpected allies (Oct 3 2024)
In February this year, a jaguar walked onto Wagner Durán’s family ranch, located near Tortuguero National Park in Costa Rica, and, in an unusual event, killed a calf. This area has the highest density of jaguars in Costa Rica, so it wasn’t unusual for that reason. What made it stand out was that it was […]

Cost-benefit analysis exposes ‘bogus’ promises of palm oil riches for Papuans (Oct 3 2024)
JAKARTA — A study by an Indonesian NGO challenges government claims that oil palm cultivation is a driver of economic welfare and development, showing that the environmental and social damage from plantations in the country’s Papua region vastly outweigh any benefits. Researchers at the Pusaka Bentala Rakyat Foundation carried out a cost-benefit analysis to determine […]

Bangladesh’s new government implements strong measures to eliminate single-use plastic (Oct 2 2024)
The newly formed government in Bangladesh is about to implement the existing law regarding plastic usage by strictly banning — initially — single-use plastic and, gradually, all possible plastic uses. Civil society members formed the current non-political government on Aug. 8, 2024, after former Prime Minister Sheikh Hasina and her cabinet left the country on […]

Across reforestation organizations, best practices claims abound, but details are scarce (Oct 2 2024)
Growing global interest in tree planting as a climate solution has prompted an influx of inexperienced organizations with opaque strategies, leading to numerous failures and unintended negative consequences. Awareness of this issue has inspired many reforestation organizations to follow best practices to ensure tree-planting initiatives achieve their goals. Still, far fewer report in detail the […]

In the battle against plastic pollution, Asia’s informal workers are critical allies (commentary) (Oct 2 2024)
Nguyen Thi Thanh Thuy, a waste worker from Binh Dinh, Vietnam, has worked in the waste collection industry for four decades. She has spent every day at the landfill – her home and source of income – since she was a child. Like many developing economies in the region, Vietnam has limited household waste separation. […]

UK & Dutch banks invest $55 million in controversial Cerrado tree farms (Oct 2 2024)
The U.K. government and Dutch development bank FMO committed $55 million toward commercial tree plantations primarily in Brazil’s Cerrado savanna. The agreement, announced Sep. 24, was struck with Latin America’s largest investment bank, BTG Pactual, through its forestry project, the Timberland Investment Group (TIG). However, Mongabay investigations have raised concerns about the project. The reforestation […]

Controversial US marine geoengineering test delayed until next year (Oct 2 2024)
A controversial experiment to field-test a way to quickly sequester more carbon in the world’s oceans has been pushed back until 2025, according to the Woods Hole Oceanographic Institution (WHOI). The LOC-NESS project, headed by WHOI, had planned to disseminate 20 metric tons of sodium hydroxide (commonly known as lye) along with tracer dye into […]

‘Mermaids’ dive to study and protect Mexican fishing grounds (Oct 2 2024)
Esmeralda Albañez used to be afraid of the sea. Just thinking about it would conjure up images of darkness, of how deep and unknown it was to her. Coming from a family of fishers and having grown up on Isla Natividad, in Baja California Sur, Mexico, it was clear that there was a connection between […]

Third edition of Satellites for Biodiversity Award opens for applications (Oct 2 2024)
The Airbus Foundation and the Connected Conservation Foundation have announced the third edition of the Satellites for Biodiversity Award, which aims to encourage the use of cutting-edge satellite data to monitor and protect biodiversity. The two organizations have called for applications from individuals as well as nonprofit organizations around the world that use satellite imagery […]

High CO2 levels are greening the world’s drylands, but is that good news? (Oct 1 2024)
The increased concentration of CO2 in the atmosphere since pre-industrial times isn’t just driving climate change — it’s also making much of the world’s drylands greener with increased plant growth. This is known as the CO2 fertilization effect, and politicians sometimes cite it to rhetorically downplay the negative global impacts of climate change, saying it’s […]

Brazil dredges Amazon rivers to ease drought isolation, raising environmental concerns (Oct 1 2024)
The environmental risks of dredging include ecosystem disruption, increased erosion, water contamination, and harm to aquatic species such as manatees and river dolphins.

Patent filings help scientists predict patterns in wildlife trade (Oct 1 2024)
Economists have long made the case that regulations foster greater innovation by business players. This apparently also applies to businesses involved in the wildlife trade, new research suggests. In their recently published study, researchers from the University of Oxford in the U.K. found that stricter regulations haven’t led to a reduction in patents filed for […]

In the Pacific depths, an underwater mountain hosts a bonanza of new species (Oct 1 2024)
Flying spaghetti monsters, Casper octopus, and a fish that looks like a Muppet are just a few of the rare creatures found on a previously unknown underwater mountain off the coast of Chile. During ocean expeditions in the Southeast Pacific this year, scientists found an underwater wonderland, including more than 100 potentially new-to-science species. “We […]

NGOs say EU Commission must act on Greece oil activity in whale habitat (Oct 1 2024)
Environmental NGOs are urging the European Commission to pursue their complaint about Greece’s approval of offshore oil and gas concessions in a crucial habitat for whales, after the executive body previously said the matter did not need it’s intervention. “The Greek state is persistently avoiding carrying out the required assessments on marine biodiversity and marine […]

Social media influencers’ bad behavior with marine wildlife is risky for animals, too (commentary) (Oct 1 2024)
Many of us have likely come across that viral video on social media  –  a young woman touching the back of a large, possibly pregnant, great white shark, swimming alongside it for about 10 seconds. The woman in question, Ocean Ramsey, has two million followers on Instagram and has been capturing attention by demonstrating that […]

Celestún refuge fights illegal fishing & helps revive species in Mexico’s Yucatán (Oct 1 2024)
A decade ago, the overfishing of sea cucumber (Isostichopus badionotus) was the center of controversy in Celestún, a small community in the state of Yucatán, Mexico. Extraction of the coveted species allowed local fishers to grow but also attracted ambitious businessmen and illegal fishing. Yanely Jasaai May, a biologist from the community, said violence broke […]

S. Korea dune merchant, 72, held over sand mining in Indonesia mangrove forest (Sep 30 2024)
MAKASSAR, Indonesia — Indonesian authorities have arrested a 72-year-old South Korean national for allegedly running a sand quarrying operation in a protected forest area in West Sulawesi province. The incident marks a rare instance of a foreign citizen charged with environmental crimes in the world’s largest archipelagic country. The operation involved multiple agencies, including the […]

Canada’s 2023 wildfires doubled the previous burning record (Sep 30 2024)
Canada’s 2023 wildfire season was the worst in the nation’s history. More than 15 million hectares (37 million acres), an area roughly the size of Ireland, burned between April and October, a new study found. The ferocity of the fires was fueled by unusually hot and dry conditions across the boreal forest, which spans much […]

Ever-smarter consumer electronics push world toward environmental brink (Sep 30 2024)
In recent decades, the electronics industry experienced meteoric growth as it swiftly invented and marketed a galaxy of novel products for consumers hungry for the next innovation, better performance and greater convenience. In 2024, the consumer electronics market alone is expected to top $809 billion, exceeding $1.4 trillion by 2034. But there’s a dark side […]

In Mexico, scientists race to save Marietas Islands’ corals from ocean warming (Sep 30 2024)
The corals of the Marietas Islands, a pair of small islands in Mexico’s Pacific Ocean, have survived record-high temperatures and uncontrolled tourism triggered by the sudden international fame of “the beach of love,” a picture-perfect quarry where people like to take selfies. Today, the corals of Islas Marietas National Park, created in 2005, are recovering […]

Cambodian environment minister bans logging at tycoon’s Cardamoms hydropower project (Sep 30 2024)
PHNOM PENH — In a rare move to combat forest crimes, Cambodian Environment Minister Eang Sophalleth on Sept. 2 banned all forest clearance at the site of a dam project in the country’s southwest. The ban came after multiple incidents of illegal logging inside a protected area were reported, including by Mongabay, in connection to the […]