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 Amazon’s most fertile forests are also most vulnerable to drought: Study (Jul 26 2024)
- Researchers at the University of Arizona analyzed 20 years of satellite data to understand how different Amazon forest ecosystems respond to drought. They found that variations in water-table depth, soil fertility and tree height influence forests’ response to droughts.
- In the southern Amazon, experts observed a strong relationship between groundwater availability and the forests’ drought resilience. But the situation was more complex in the northern Amazon, where drought vulnerability depended on a combination of factors, including water availability, soil fertility and tree height.
- The study suggests scientists may have overestimated the risk of drought-related tree death — and the amount of carbon released into the atmosphere as a result — in the southern Amazon. However, long droughts, like the current one across the Amazon, can push these forests to the brink of collapse.
- The researchers created a map of drought resilience across the Amazon Basin, which shows that forests at high risk of deforestation are also most vulnerable to drought. These forests also play a key role in regional weather patterns by feeding the “atmospheric river” that brings rainfall to major agricultural areas.

Indigenous midwives in Panama strive to preserve traditional medicine for maternal health (Jul 25 2024)
- An organization of midwives from Panama’s Ngäbe-Buglé Indigenous group use traditional medicinal plants endemic to the region to assist women with pregnancy and childbirth.
- Known as ASASTRAN, the organization trains midwives and traditional medicine doctors to provide health services to remote villages where hospitals and clinics aren’t accessible.
- Deforestation has reduced the availability of medicinal plants in the Ngäbe-Buglé territory, and ASASTRAN is seeking more government assistance to preserve the curative plants.
- For some Ngäbe-Buglé women, traditional curative plants are the only healing options during childbirth, as Western medicine is often unavailable.

Short on funds and long on risk, Venezuelan conservation groups worry for future (Jul 25 2024)
- Venezuela’s economic and political crises have driven away many international donors, leaving conservation groups without enough funding to sustain their operations.
- Widespread corruption and organized crime, as well as government hostility to foreign civil society organizations, has made it too dangerous for many conservation groups to carry out fieldwork in the country.
- Should President Nicolás Maduro win reelection later this month, conservation groups say the already dire situation could deteriorate even further.

In Cambodia, Indigenous villagers lose forest & land amid carbon offset project (Jul 24 2024)
- A 3,348-hectare (8,273-acre) protected forest established by a carbon credit project in Cambodia and encompassing the customary lands of several Indigenous Bunong communities has been destroyed largely by outsiders, while Indigenous community patrollers say they lack adequate law enforcement support from the REDD+ project.
- Government rangers supported by WCS are arresting and imprisoning Indigenous peoples – often the poorest and most vulnerable – for clearing land for farming amid ongoing conflicts and confusion over project boundaries.
- An Indigenous community has been blocked from receiving land ownership by the Keo Seima REDD+ project proponent and pressured by government officials to withdraw land claims without free, prior and informed consent, community leaders say.
- This reporting project received support from the Pulitzer Center’s Rainforest Journalism Fund.

What’s at stake for the environment in Venezuela’s upcoming election? (Jul 24 2024)
- President Nicolás Maduro is running for a third consecutive term despite overwhelming opposition to his regime. This time, his opponent is González Urrutia, a former diplomat.
- Under Maduro, illegal mining has spread rapidly through the rainforest, while water shortages and the trafficking and flora and fauna have only gotten worse.
- While González Urrutia has promised to address illegal mining and other environmental issues, experts say there’s little chance he can win. The current government has already taken steps to guarantee Maduro’s victory, including disqualifying opposition candidates and uninviting outside electoral observers.

Can a carbon offset project really secure Indigenous rights in authoritarian Cambodia? (Jul 22 2024)
- The Cambodian Ministry of Environment has blocked Indigenous communities from receiving ownership over thousands of hectares of customary farmlands and culturally significant forests in the Keo Seima REDD+ project zone.
- The Wildlife Conservation Society, which works with the ministry to administer the project, did not disclose these land disputes caused by the project’s activities to standard setter Verra, and its auditors failed to identify these issues.
- Indigenous peoples in the REDD+ project face arrests, imprisonment, crop destruction and property confiscation as a result of unclear boundaries and insufficient land allocated to their communities.
- This reporting project received support from the Pulitzer Center’s Rainforest Journalism Fund.

Thai plan to redraw boundaries of tiger reserve sparks concern and criticism (Jul 22 2024)
- Government-led proposals to issue land title deeds within Thailand’s Thap Lan National Park have met with heavy criticism from conservation groups and national park management.
- The plans could set a dangerous precedent for similar action in other protected areas in Thailand and might undermine the status of a flagship UNESCO World Heritage Site, critics say.
- The government says the process is necessary to settle historical boundary disputes with local communities who were living in the area long before it was established as a national park in 1981.
- While there is broad agreement that longtime residents have legitimate claims to land within the park boundaries, sections of land included in the government scheme have been encroached on by commercial developers in recent years, with critics saying the initiative risks legitimizing such illegal developments.

A Guatemalan reserve turns from civil war refuge to deforestation hotspot (Jul 22 2024)
- Illegal deforestation in Guatemala’s Sierra del Lacandón National Park is accelerating, driven by cattle ranching and drug-trafficking activities.
- The park is a critical biological corridor, home to numerous threatened species, and connects protected areas in Guatemala and Mexico.
- Indigenous communities, many of which settled in the area during the civil war, are now involved in deforestation activities under pressure from powerful political and economic figures, threatening the region’s ecological integrity.

Space mission that maps forests in 3D makes an early comeback (Jul 17 2024)
- NASA’s GEDI mission, which maps the Earth’s forests in 3D using lasers, is back in operation from a hiatus, six months earlier than expected.
- Since 2018, GEDI has used spaceborne laser altimeters to help scientists gather data on forest structure, aboveground biomass and carbon stored in forests.
- Following resumption of operations, researchers have used GEDI data along with data from other missions as well as analysis tools to estimate the aboveground carbon stored in protected areas and Indigenous territories in the Amazon Rainforest.

‘Extinct’ trees found in Tanzania spark hope for ecosystem recovery (Jul 16 2024)
- Conservationists in eastern Tanzania have found two specimens of a rare tree feared to be extinct.
- Millettia sacleuxii was only known from six specimens in forest reserves that have almost disappeared.
- Thousands of seeds have been collected and seedlings raised, and these are due to be planted out as part of a reforestation project in the Nguru Mountains.
- The two surviving Millettia “mother trees” were found near an area that conservationists hope to soon turn into a wildlife corridor.

Ugandan chimps are eating bat guano, raising concerns over human epidemics (Jul 15 2024)
- Wildlife like chimpanzees have started consuming bat excrement — guano — in the Budongo Forest, Uganda. After analyzing samples, scientists found that the guano not only held high concentrations of minerals but was also full of viruses, including a cousin to SARS-CoV-2.
- Researchers say the weird feeding behavior may be because the animals have lost a primary source of dietary minerals from native trees to tobacco farming.
- Worryingly, some of these viruses can be transmitted to humans, meaning that if wild animals become more exposed to bat-borne viruses, so could humans.
- The scientists underline that social forces like the market and resource extraction can lead to such unintended consequences.

Conservation pays and everyone’s benefitting from it (commentary) (Jul 15 2024)
- In this commentary, Diego Vincenzi, current chief of staff for the Minister of Environment and Energy in Costa Rica, highlights how Costa Rica halted deforestation, achieved 57% forest cover after reaching a low of 21% in the 1980s, and protected 25% of its land while becoming the top per capita agricultural exporter in Latin America..
- Costa Rica’s success stems from a shift in the 1990s towards greener environmental legislation, introducing the Payment for Ecosystem Services (PES) scheme funded by a fossil fuel tax, which compensates landowners for forest conservation and now includes untitled lands, benefiting native populations.
- FONAFIFO, the institution managing PES, is expanding the program to cover 182,000 hectares annually and introducing biodiversity certificates for estates, aiming to broaden conservation efforts to include mangrove ecosystems, linking land and water for a more sustainable environment.
- This is a commentary and does not necessarily reflect the views of Mongabay.

Sumatra pulp & paper giants violate zero-deforestation pledge, activists allege (Jul 12 2024)
- An investigation by an NGO coalition in Indonesia alleges that two pulp and paper giants — Asia Pulp & Paper (APP) and Asia Pacific Resources International Holdings Ltd. (APRIL) — have cleared natural forests and peatlands in violation of their zero-deforestation pledges.
- The allegations center on a concession operated by PT Riau Andalan Pulp & Paper (RAPP) in Siak district of Riau province, a concession managed by an open market supplier to APRIL, PT Selaras Abadi Utama (SAU), in Pelalawan district of Riau province, and a block of land in Riau managed by a local cooperative that has a working agreement with an APP subsidiary, PT Arara Abadi (AA).
- APRIL reiterated its commitment to sustainability and zero-deforestation and APP denied that any illegal timber had entered its supply chain.

Panama’s ‘Caribbean Corridor’ highway threatens three protected areas, critics say (Jul 11 2024)
- Several legal challenges have temporarily stalled construction on a new, controversial highway project in north-central Panama, which allegedly bypassed environmental regulations and could damage several protected areas along the Caribbean coast.
- The highway, known as the “Caribbean Corridor,” is supposed to travel 28.4 kilometers (17.6 miles) from the towns of Quebrada Ancha to María Chiquita, with the goal of increasing tourism and local commerce on the coast of Colón province.
- The $91-million project could endanger Portobelo National Park, Chagres National Park, Sierra Llorona Private Reserve and the Panama Canal watershed that includes Gatun Lake and the Panama Canal.

“Game over” for the Amazon forest and global climate if Trump wins? (commentary) (Jul 11 2024)
- Both global climate and the Amazon Forest are near tipping points beyond which irreversible processes would lead to unprecedented catastrophes. A second Trump presidency would both boost greenhouse gas emissions and would risk a critical delay in global efforts to avert a runaway greenhouse.
- The various interrelated tipping points represent thresholds where the annual probability of a catastrophic change increases sharply, after which the risk of a disaster at some point in time increases constantly.
- Climate change threatens the Amazon Forest, and if the rainforest collapses it would push global warming past a tipping point in the climate system. This risk would be greatly increased by a second Trump presidency.
- This is a commentary and does not necessarily reflect the views of Mongabay.