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

Indigenous communities in Peru ‘living in fear’ due to deforestation, drug trafficking (Dec 2 2022)
- Between 2021 and 2021 the territory of the Indigenous Kakataibo community of Puerto Nuevo lost 15% of its tree cover.
- Satellite data suggest forest loss in the community territory may have accelerated in 2022.
- Residents say outsiders are invading the territory and clearing forest to grow coca crops for the production of cocaine.
- The presence of armed groups is deterring government intervention.

Rare, critically endangered gecko making dramatic recovery in Caribbean (Dec 2 2022)
- The Union Island gecko (Gonatodes daudini), known for its jewel-like markings, has seen its population grow from around 10,000 in 2018 to around 18,000 today — an increase of 80%.
- The gecko’s wild population had shrunk to one-fifth its size after becoming a target for exotic pet collectors.
- Fauna & Flora International, Re:Wild and local partners like Union Island Environmental Alliance and St. Vincent and the Grenadines Forestry Department to develop a species recovery plan that included greater protected area management and expansion.

Despite 11% drop in 2022, Amazon deforestation rate has soared under Bolsonaro (Dec 2 2022)
- An area equivalent to the size of Qatar was cleared in the Brazilian Amazon between Aug. 1, 2021, and July 31, 2022, according to data from the country’s National Space Research Institute (INPE).
- Although the figure represents an 11.27% decrease in the Amazon annual deforestation rate compared with the prior year, the government of President Bolsonaro still accounts for the most Amazon destruction in the last 34 years, environmentalists say.
- Bolsonaro’s four-year term ends with a 59.5% boom in Amazon deforestation rates, the highest in a presidential term since 1988, when measurements by satellite imagery began.
- INPE’s report, dated Nov. 3 but only released 27 days later, also triggered criticism among environmentalists, who accused the Bolsonaro’s administration of omitting the annual deforestation data until the end of the UN conference on climate change, COP27, held Nov. 6-20 in Egypt.

In first for Indonesia, government recognizes Indigenous Papuans’ ancestral forests (Dec 1 2022)
- The Indonesian government has for the first time relinquished state forest into the custody of Indigenous communities in the eastern region of Papua, covering a combined area the size of New York City.
- Experts say this recognition of customary forests in Papua is significant as the region is threatened by increasing expansion of plantations, logging and mining operations, with Indigenous groups there having little to no legal protection against companies that covet their forests.
- With this official recognition, the government has essentially handed over its control over these forests to the Indigenous communities, and therefore no licenses for any kind of commercial activity can be issued for those areas.
- Activists have welcomed the move, but say it represents just a sliver of the millions of hectares of ancestral forest that are still waiting to be officially acknowledged in the Papua region.

Report calls on palm oil firms to make up for nearly 1m hectares of forest loss (Nov 29 2022)
- Palm oil companies across Southeast Asia are liable for the recovery of a Puerto Rico-sized area of forest because of their history of environmental harm, a new report shows.
- The Earthqualizer Foundation derived the figure of 877,314 hectares (2.17 million acres) based on the deforestation that the companies continued to carry out after they became aware that an increasing number of buyers had adopted sustainability policies.
- The report also calls on buyers who bought from these suppliers to shoulder some of the liability, which it said could count toward the forest restoration goals pledged by many of the buyers, including Nestlé, Kellogg’s and Unilever.
- The Earthqualizer report highlights some palm oil companies that are already undertaking recovery initiatives, but notes that these are few and far between, and any progress will need to be assessed over the long term.

What can Half or Whole Earth conservation strategies do for orangutans? (Nov 28 2022)
- In a recent study, a team of researchers attempted to predict how the application of two global conservation ideas, Half-Earth and Whole Earth, would impact orangutan conservation on the island of Borneo in Southeast Asia.
- Numbers of all three species of orangutans continue to drop due to habitat loss and killing by humans, despite an estimated $1 billion spent on conservation efforts in the past two decades.
- The researchers surveyed orangutan experts about their thoughts on the application of the two ideas on Borneo; the resulting analysis predicts continued declines for Bornean orangutans under both Half-Earth and Whole Earth paradigms, though they report that the species would fare better under Half-Earth.
- Proponents of the Whole Earth paradigm argue that the authors of the study misinterpreted some of the idea’s central tenets, however.

Indonesia’s Supreme Court rules President Widodo not liable in 2015 fires (Nov 28 2022)
- Indonesia’s highest court has ruled President Joko Widodo not liable in the 2015 fires, overturning three previous court rulings that found him to be liable for the disaster.
- The plaintiffs, a group of citizens and environmental activists affected by the 2015 fires, have lambasted the court’s decision, saying it raises questions over the government’s seriousness in tackling the annual fire problem.
- The plaintiffs also questioned the process behind the ruling, saying they hadn’t been given the chance to refute new evidence presented by the government.

Indonesia’s orangutans declining amid ‘lax’ and ‘laissez-faire’ law enforcement (Nov 25 2022)
- The widespread failure by Indonesian law enforcers to crack down on crimes against orangutans is what’s allowing them to be killed at persistently high rates, a new study suggests.
- It characterizes as “remarkably lax” and “laissez-faire” the law enforcement approach when applied to crimes against orangutans as compared to the country’s other iconic wildlife species, such as tigers.
- Killing was the most prevalent crime against orangutans, the study found when analyzing 2,229 reports from 2007-2019, followed by capture, possession or sale of infants, harm or capture of wild adult orangutans due to conflicts, and attempted poaching not resulting in death.
- The study authors call for stronger deterrence and law enforcement rather than relying heavily on rescue, release and translocation strategies that don’t solve the core crisis of net loss of wild orangutans.

Despite pledges, obstacles stifle community climate and conservation funding (Nov 23 2022)
- As science has increasingly shown the importance of conservation led by Indigenous peoples and local communities (IPLCs), donors have begun to steer funding toward supporting the work these groups do.
- In 2021, during last year’s COP26 U.N. climate conference, private and government donors committed $1.7 billion to secure the land rights of Indigenous peoples and local communities.
- But a recent assessment of the first year of the pledge shows that little of the funding goes directly to them, often going first through international NGOs, consultancies, development banks and other intermediaries.
- Most aid intended to support IPLC-led conservation work follows this path. Now, however, donors and IPLC leaders are looking for ways to ease the flow of funding and channel more of it to work that addresses climate change and the global loss of biodiversity.

2022 Amazon fires tightly tied to recent deforestation, new data show (Nov 22 2022)
- Nearly 1,000 major fires burned in the Amazon during its 2022 fire season, according to the Monitoring of the Andean Amazon Project (MAAP).
- The Brazilian Amazon accounted for the vast majority of the fires, and most burned in recently deforested areas.
- MAAP uses unique satellite data detecting aerosol emissions alongside regular heat alerts, which helps filter out small fires.
- Fires clearing logging debris are linked to soy-driven deforestation in some Brazilian Amazon areas, where many soy-trading companies have not signed zero-deforestation commitments.

Indigenous community in Peru losing forests to timber, drug, land trafficking (Nov 21 2022)
- The Indigenous community of Santa Rosillo de Yanayacu, located in northern Peru, has been facing illegal timber, drug and land trafficking for the past several years.
- Satellite data and imagery suggest deforestation associated with these incursions has increased in 2022.
- The community lacks a communal land title to their territorial forests; experts say this is opening the door to setters who are using threats to bar regional authorities from intervening.
- Santa Rosillo de Yanayacu is one of a number of Indigenous communities in the region contending with deforestation from outsiders.

In PNG, researchers find a large pigeon lost to science for 140 years (Nov 21 2022)
- After 140 years, a lost-to-science pigeon subspecies has been spotted once again on Fergusson Island, off eastern Papua New Guinea.
- After following tips from a local hunter, researchers photographed the black-naped pheasant-pigeon, a large, ground-dwelling bird, for the first time using a remote camera trap.
- Ornithologists believe the pheasant-pigeon is extremely rare and these forests on Fergusson island in the D’Entrecasteaux Archipelago could likely be the only place they exist.
- The expedition was part of the Search for Lost Birds program, a collaboration between BirdLife International, the American Bird Conservancy, and Re:wild.

Forests & Finance: Certification for deforesters, and repression for an evicted community (Nov 15 2022)
- A rule change by the Forest Stewardship Council means companies like Hevéa Sudcam, which cleared nearly 60,000 hectares (148,000 acres) of forest in Cameroon since 2011, are now eligible for the world’s leading sustainability certification.
- Two years after announcing an imminent ban on exports of raw timber, governments in the Congo Basin have again delayed its implementation, this time indefinitely, citing the need for more time to prepare for it.
- The African Commission on Human and Peoples’ Rights has called on Uganda to end its repression of the Indigenous Benet people, who are fighting for recognition and access to ancestral lands they were evicted from in 1993 for the establishment of a national park.
- Forests & Finance is Mongabay’s bi-weekly bulletin of briefs about Africa’s forests.

Stem cells may make ‘impossible possible’ for near-extinct Sumatran rhino (Nov 15 2022)
- Wildlife scientists in Germany are developing a method to produce new living cells from a dead Sumatran rhinoceros in an effort to prevent the extinction of the critically endangered species.
- They have used skin samples of the last male rhino in Malaysia, known as Kertam, who died in May 2019, to grow stem cells and mini-brains as reported in the researchers’ recently published paper.
- Fewer than 80 rhinos remain in the world, and they all currently live in Indonesia in the wild, and some in a sanctuary for captive breeding.
- The captive breeding initiative of the Sumatran rhinos began in the 1980s, but over the years, the attempts have yielded both successes and failures.

With new EU rules ahead, Indonesia adds sustainability to its timber legality system (Nov 14 2022)
- The Indonesian government is rebranding its timber legality system to include timber sustainability in anticipation of an upcoming deforestation-free regulation by the European Union.
- Right now, the EU bans only the trading of illegal timbers within Europe under its timber regulation, but it’s in the process of issuing a new regulation that will forbid not only illegal timbers, but also timbers and other commodities that are sourced from deforestation and forest degradation.
- Indonesia’s timber legality system is the only one in the world recognized by the EU, meaning the country’s timbers could enter Europe without due diligence.
- With new no-deforestation requirements to be imposed by the EU, Indonesia is adding sustainability components into its timber legality system.