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

Court setback doesn’t sway Indonesian villagers fighting a mining firm (Apr 29 2022)
- Residents of remote Sangihe Island in Indonesia will mount an appeal after their lawsuit against a company planning to mine gold on their island was thrown out by a court on a technicality.
- Their case centered on concerns that the operations of PT Tambang Mas Sangihe (TMS), linked to Canada-based Baru Gold Corp., would cause widespread destruction on their island home.
- They alleged in their lawsuit that there were several administrative violations that should have nullified the contract issued to TMS by the government, but the court said the matter was out of its jurisdiction.
- The same court issued a similar dismissal in a previous case involving a coal-mining company, but an appeal by the plaintiffs in that instance led to the company’s permit being revoked; given that precedent, the Sangihe islanders say they still have a fighting chance.

As animal seed dispersers go the way of the dodo, forest plants are at risk (Apr 28 2022)
- Many plants rely on animals to reproduce, regenerate and spread. But the current sixth mass extinction is wiping out seed-dispersing wildlife that fill this role, altering entire ecosystems.
- Thousands of species help keep flora alive, from birds and bats to elephants, apes and rodents.
- Animals give plants the ability to “move,” with the need for mobility rising alongside warming temperatures and more frequent extreme weather events. Transported elsewhere, plants may be able to “outrun” a warming climate.
- There are growing efforts to restore these critical ecological relationships and processes: protecting and recovering wild lands, identifying and rewilding key animal seed dispersers, reforesting destroyed habitat, and better regulating destructive logging and agricultural practices.

2021 tropical forest loss figures put zero-deforestation goal by 2030 out of reach (Apr 28 2022)
- The world lost a Cuba-sized area of tropical forest in 2021, putting it far off track from meeting the no-deforestation goal by 2030 that governments and companies committed to at last year’s COP26 climate summit.
- Deforestation rates remained persistently high in Brazil and the Democratic Republic of Congo, home to the world’s two biggest expanses of tropical forest, negating the decline in deforestation seen in places like Indonesia and Gabon.
- The diverging trends in the different countries show that “it’s the domestic politics of forests that often really make a key difference,” says leading forest governance expert Frances Seymour.
- The boreal forests of Eurasia and North America also experienced a spike in deforestation last year, driven mainly by massive fires in Russia, which could set off a feedback loop of more heating and more burning.

Asia’s troubled trees need better conservation to reach restoration goals: Study (Apr 26 2022)
- South and Southeast Asia’s 19,000 tree species form the foundations of some of the world’s most biodiverse rainforests, as well as provide irreplaceable ecosystem services and underpin the livelihoods and diets of hundreds of millions of people.
- However, roughly three-quarters of the land deemed most important to protect regional tree diversity lies outside of protected areas, according to a new study that evaluates the distribution and threats facing 63 native tree species.
- The findings question whether countries will be able to fulfill their ambitious forest restoration targets; in particular, the researchers are concerned that crucial seed resources that could support reforestation efforts are being lost.
- The researchers recommend a more coordinated approach to conservation planning within the region, including improved cross-border collaboration and a holistic, landscape approach that integrates trees into production systems outside of protected areas.

Brazil bill seeks to redraw Amazon borders in favor of agribusiness (Apr 25 2022)
- A new bill before Brazil’s Congress proposes cutting out the state of Mato Grosso from the country’s legally defined Amazon region to allow greater deforestation there for agribusiness.
- Under the bill, known as PL 337, requirements to maintain Amazonian vegetation in the state at 80% of a rural property’s area, and 35% for Cerrado vegetation, would be slashed to just 20% for both.
- The approval of the bill would allow for an increase in deforestation of at least 10 million hectares (25 million acres) — an area the size of South Korea — and exempt farmers from having to restore degraded areas on their properties.
- Environmental law specialists warn that the departure of Mato Grosso from under the administrative umbrella of the Legal Amazon would set off a domino effect encouraging the eight other states in the region to push for similar bills.

Saving old-growth forests: Q&A with Amazon Watch’s Leila Salazar-López (Apr 22 2022)
- A new documentary called “The Last Stand,” released on Earth Day 2022, goes inside the protests against the logging of the Fairy Creek old-growth forests in British Columbia, Canada.
- Leila Salazar-López, executive director of Amazon Watch, an NGO dedicated to fighting deforestation and protecting the rights of Indigenous communities in the world’s biggest rainforest, spoke in the film about the larger implications of cutting down old-growth forests.
- In an interview with Mongabay, Salazar-López talks deforestation in the Amazon, the flaws of carbon offset policies, and the important role that Indigenous and local people play in conserving the last of Earth’s old-growth forests.

Beyond CO2, tropical forests a ‘cool’ solution to climate crisis, study finds (Apr 22 2022)
- Forests, increasingly looked to for their role in addressing climate change, can draw carbon from the atmosphere, but they also have more localized impacts on temperature and weather.
- Forests are responsible for about 0.5°C (0.9°F) of cooling globally when their ability to sequester carbon and these biophysical effects are considered, a recent study has found.
- Tropical forests, with their speedy uptake of carbon and the local cooling they provide — by humidifying the air, for example — are considered a “double win” for the climate.

Warming could nip Southeast Asian forests’ mass flowering in the bud, study finds (Apr 21 2022)
- Synchronous mass flowering is one of the most spectacular but least-understood phenomena in Southeast Asia’s tropical rainforests; crucially, scientists know very little about how flowering events might be affected by climate change.
- A new study looking at historical tree flowering in Malaysia has found that between 1976 and 2010, the proportion of flowering and fruiting species decreased as temperatures began to increase through that period.
- They also used models to predict future responses to climate change, finding that a rise of 1.2°C (2.2°F) in average global temperatures by the year 2100 could halve the flowering probability of Dipterocarp trees, an ecologically and economically important tree family in Southeast Asia.
- The researchers say we will likely see shifts in tree species composition in forests as those adapted to climate change are outcompeted by more adaptable species.

Canadian miners get high-level lobbying boost for Brazilian Amazon projects (Apr 20 2022)
- Canadian bank Forbes & Manhattan appears to be aided in pushing its mining interests in Brazil thanks to lobbying efforts by an old army acquaintance of the country’s vice president.
- F&M has been trying to secure environmental licenses for two of its companies, Belo Sun and Brazil Potash, for more than 10 years; both companies’ projects have been criticized for threatening Indigenous groups and traditional riverside communities in the Amazon.
- But F&M has managed to secure several private meetings with top government officials, which all appear to feature the same individual acting in a consulting or advisory role: Cláudio Barroso Magno Filho, a retired brigadier general in the Brazilian Army.
- Barroso Magno attended the military academy alongside Hamilton Mourão, who in 2019 took office as Brazil’s vice president in the administration of President Jair Bolsonaro.

New report pieces together toll of environmental damage in Venezuela in 2021 (Apr 20 2022)
- A report from the Political Ecology Observatory of Venezuela (OEP) lays out the worst environmental conflicts that the South American country faced in 2021.
- Among them are oil spills, deforestation, mining, and a lack of clean water in areas with degraded watersheds.
- The report notes the continuing difficulty of tracking environmental parameters in Venezuela, due to the lack of transparency by government at all levels.
- Regardless, it notes that last year’s events contributed to numerous public health crises.

History on the walls: Graffiti brings Manaus’s Indigenous roots to light (Apr 19 2022)
- Graffiti artists are painting murals recounting the history of Indigenous people and honoring their culture in the capital of Amazonas, the Brazilian state with the largest Indigenous population.
- Indigenous community leaders say they hope the movement will increase the visibility of Indigenous people living in cities, who often face poverty, housing insecurity and stigma that discourages many from maintaining their culture and identity.
- Fearing cultural erasure, Indigenous activists are urging Indigenous people to embrace their ancestry and identify themselves as Indigenous in Brazil’s next census, expected to begin in August 2022.
- As Indigenous people in cities reclaim their identities, occupying public spaces through street art is playing a key role in the fight to make Indigenous people in urban areas more visible.

Amid extinctions, forest corridors aim to save rare birds in Brazil’s northeast (Apr 18 2022)
- A project in northeastern Brazil is working to connect fragments of the Atlantic Forest in an effort to save endemic bird species from extinction.
- The Atlantic Rainforest of the Northeast Project plans to reforest 70 hectares (173 acres) in the states of Pernambuco and Alagoas by 2023.
- Monitoring in Pernambuco’s Serra do Urubu region has shown an increase in bird diversity, from 105 species recorded in 2005, to 287 in 2021.
- Despite the progress being made, the situation remains fragile, with seven bird species having gone extinct in the Atlantic Forest in recent decades, and a strong tradition of keeping birds in cages still persisting.

Plan to carve up Indonesian Papua rings alarm over fate of people and forests (Apr 18 2022)
- Activists have warned of a potential surge in deforestation under a plan to remap Indonesia’s Papua region from two provinces into five.
- Past cases of new provinces or districts being created or spun off from existing administrative regions have typically been accompanied by an increase in the issuance of licenses for extractive industries such as mining and palm oil.
- Critics of the plan have also rejected the government’s rationale that it will lead to better development outcomes for Papuans, noting that the past creation of new districts in the region has enriched local elites over the people.
- The plan has been met with widespread protests among Papuans, at least two of whom were reportedly killed by police during demonstrations.

Outcry in Malaysia as failure to replant forests sparks ‘cover-up’ accusation (Apr 15 2022)
- Critics of a government plantation scheme have slammed the program following revelations that only a fraction of forest reserves cleared for plantations over the past decade have actually been replanted.
- An investigation by environmental news site Macaranga found that only 5% of the 77,331 hectares (191,089 acres) of forest reserves cleared in Pahang state for plantations between 2012 and 2020 were replanted.
- A Pahang state opposition lawmaker has called the program a “cover-up” for a logging scheme, while an environmental activist has criticized the government for its lack of accountability.

International funding nowhere near enough for Indonesia to cut emissions: Study (Apr 15 2022)
- Indonesia will have to come up with its own funding schemes to have any chance of achieving its carbon emissions reduction target by 2030, a new study says.
- The government has calculated that it needs $323 billion in funding from the international community to slash emissions by 41%, but received just $6.4 million between 2007 and 2019, the study found.
- It found that Indonesia faced difficulties accessing international climate grants, with donors often prioritizing their own interests or preferring countries with lower incomes than Indonesia.
- A potential source of funding could be the sale of government debt that’s a combination of environmental (green) bonds and Islamic-compliant bonds, known as sukuk, the study says.