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

Net-zero commitments must include more anti-deforestation policies, UN tells private sector (Jul 5 2022)
- Many companies with net-zero commitments have made little, tangible progress against tropical deforestation, according to a recent report from a U.N. climate change task force.
- Approximately a third of carbon emissions released each year are absorbed by forests, making tackling deforestation a key part of the fight to keep global temperatures below 1.5°C (2.7°F).
- Many companies, even ones that have implemented other effective net-zero commitments, have fallen short on deforestation, meaning their carbon footprint may end up being larger than they hope.

Habitat loss, climate change send hyacinth macaw reeling back into endangered status (Jul 4 2022)
- The hyacinth macaw, the world’s largest flying parrot, is closer to return to Brazil’s endangered species list, less than a decade after intensive conservation efforts succeeded in getting it off the list.
- The latest assessment still needs to be made official by the Ministry of the Environment, which is likely to publish the updated endangered species list next year.
- Conservation experts attribute the bird’s decline to the loss of its habitat due to fires in the Pantanal wetlands and ongoing deforestation in the Amazon and Cerrado biomes.
- Climate change also poses a serious threat, subjecting the birds to temperature swings that can kill eggs and hatchlings, and driving heavy rainfall that floods their preferred nesting sites.

Peru’s Amazon rainforest is threatened by an ecosystem of environment crime (commentary) (Jul 4 2022)
- While Brazil attracts more attention, deforestation is also substantial in the Peruvian Amazon, where forest clearing is on the rise.
- Carolina Andrade and Robert Muggah of Igarapé Institute, a Brazil-based think tank, write that “the scale and breadth of the assault” currently underway in Peru’s rainforest is “unprecedented”. They chalk up much of the damage to “resource pirates”.
- But while challenging, the situation isn’t without hope, argue Andrade and Muggah. “Resource pirates can be confronted,” they write. “Fostering closer cooperation between the many-layered and often competing oversight institutions could help focus government policy and action.”
- This post is a commentary. The views expressed are those of the author, not necessarily of Mongabay.

Protecting Brazil’s Amazon could be a bargain — if the government were willing to pay (Jul 4 2022)
- A new study shows that conserving 350 million hectares (865 million acres) of the Brazilian Amazon — 83% of the biome — would cost between $1.7 billion and $2.8 billion a year.
- That’s a fraction of the $5.3 billion that the European Union spends every year maintaining its 1 million hectares (2.5 million acres) of protected areas.
- Current protected areas cover 51% of the Brazilian Amazon, which experts say isn’t enough to maintain the biome’s biodiversity and must be expanded.
- While the cost for protecting the Amazon is hundreds of times cheaper, hectare for hectare, than in the EU, it’s much higher than what the Brazilian government allocates for environmental conservation.

Indigenous advocates sense a legal landmark as a guardian’s killing heads to trial (Jun 30 2022)
- For the first time in Brazil, the killing of an Indigenous land defender is expected to be tried before a federal jury — escalated to that level because of what prosecutors say was an aggression against the entire Guajajara Indigenous community and Indigenous culture.
- Paulo Paulino Guajajara, 26, was killed in an alleged ambush by illegal loggers in the Arariboia Indigenous Territory in November 2019; two people have been indicted to stand trial in the case.
- The impending trial stands out amid a general culture of impunity that has allowed violence against Indigenous individuals and the theft of their land — including the killings of more than 50 Guajajara individuals in the past 20 years — to go unpunished.
- It could also set an important legal precedent for trying those responsible for the recent killings of British journalist Dom Phillips and Brazilian Indigenous rights defender Bruno Pereira.

A conservation failure in Sumatra serves a cautionary tale for PES schemes (Jun 30 2022)
- A World Bank-funded conservation project in Indonesia led to higher rates of deforestation after the project ended, a new study shows, serving as a cautionary tale about the risks of failing to sustain such initiatives over a long enough time period.
- The payment for ecosystem services project was supposed to reward villages for halting deforestation and taking up sustainable livelihoods from 1996-2001.
- In the years after the project ended, however, participating villages that had received the payments lost up to 26% more forest cover from 2000-2016 than non-participating villages, the study shows.

Mongabay’s new-look Reforestation.app makes finding the right tree-planting project easier (Jun 28 2022)
- Mongabay has launched an upgrade to Reforestation.app, our global directory of tree-planting projects, aimed at improving transparency in the sector.
- Reforestation.app is a free online tool for people to support reforestation by providing a means to identify projects that align with their interests and motivations.
- The update features an improved project search functionality, a step-by-step guide for filtering projects, and the ability to update and add new projects. 

In Brazil, an Indigenous land defender’s unsolved killing is the deadly norm (Jun 27 2022)
- Two years after the death of Indigenous land defender Ari Uru-Eu-Wau-Wau in Brazil’s Amazonian state of Rondônia, questions about who killed him and why remain unanswered.
- Perpetrators of crimes against environmental activists are rarely brought to justice in the country, with a government report showing zero convictions for the 35 people killed in incidents of rural violence in 2021 — about a third of them in Rondônia.
- Indigenous groups and environmental activists in Rondônia say they fear for their lives as the criminal gangs that covet the Amazon’s rich resources act with impunity in threatening defenders and invading protected lands.
- Activists and experts point to a combination of the government’s anti-Indigenous rhetoric and the undermining of environmental agencies as helping incite the current surge of invasions and violence against land defenders in Rondônia and the wider Brazilian Amazon.

Pumpkin toadlets can’t jump: The frog that gave up balance for size (Jun 24 2022)
- Pumpkin toadlets are very bad at jumping, often losing balance mid-air and crash landing awkwardly.
- Researchers have determined that this is due to the size of their inner ear canals, the area of the body that regulates balance and orientation: their semicircular ear canals are the smallest recorded in vertebrates.
- The toadlets live in the leaf litter of Brazil’s Atlantic forest, where being small enough to burrow is an advantage.
- But the frogs are so small that the balancing mechanisms in their ears can’t respond to quick movements, resulting in some ungraceful antics.

Indonesian palm oil audit a chance to clean up ‘very dirty’ industry (Jun 23 2022)
- The Indonesian government plans to audit all palm oil companies operating in the country, in a bid to tackle an ongoing shortage and high prices of cooking oil.
- Experts attribute the crisis to the fact that the country’s palm oil industry is dominated by a small number of big companies.
- These companies have large concessions, in excess of the limit imposed by the government, allowing them to wield outsized power to dictate prices, policies and supplies.
- Analysts say the audit should address this land ownership issue, as well as other problems that plague the industry, such as lack of clear data and transparency.

Miners, drug traffickers and loggers: Is Costa Rica’s Corcovado National Park on the verge of collapse? (Jun 20 2022)
- Extreme polarization about what’s going on in Costa Rica’s Corcovado National Park has led to accusations of corruption, negligence, media manipulation, fights for control of the area’s management, and who does and doesn’t receive funds from international donors.
- The park suffers from artisanal gold mining, hunting, logging and drug trafficking, but officials, scientists and NGOs have very different views on how badly these things are impacting the health of the park.
- Some researchers say the populations of species like the jaguar and white-lipped peccary are on the decline, while others are optimistic about population trends and believe the park is healthy.
- Dwindling staff and budget for basic resources like food and gasoline have made it difficult to adhere to the park’s protection plan, and there’s little consensus, even on very basic things, about what the future holds for the park.

Consumer countries mull best approach to end deforestation abroad (Jun 17 2022)
- Major global consumers like the U.K., the U.S. and the EU are debating how best to reduce the amount of tropical deforestation resulting from the production of the commodities they import.
- Some experts argue that laws should restrict any products tinged with deforestation, while others say regulations should allow in imports that come from areas that were deforested legally in the countries in which they were produced.
- The debate involves questions around sovereignty, equality, and, ultimately, what strategy will best address the urgent need to stem the loss of some of the world’s most important repositories of carbon and biodiversity.

Indigenous knowledge settles question of a Bornean tree species: Study (Jun 17 2022)
- Awareness that much of the world’s biodiversity exists in lands and seas stewarded by Indigenous people and local communities has led scientists to reconsider the value of the knowledge systems that have achieved such successful results.
- But when it comes to species taxonomy, scientists often overlook the deep understanding of species relationships held within Indigenous knowledge systems.
- A new study from Malaysian Borneo found that two trees long recognized as distinct types by Indigenous Iban and Dusun communities, but classified as one species by Western taxonomists, are in fact genetically distinct species.
- The researchers recommend that scientists engage more often with IPLCs, especially in tropical biodiversity hotspots, and that Indigenous and local knowledge be recognized as complementary to modern science.

The war on journalists and environmental defenders in the Amazon continues (commentary) (Jun 16 2022)
- Journalists in Brazil and around the world are devastated about the tragic end of a 10-day search for British journalist Dom Phillips and Indigenous advocate Bruno Pereira in the Amazon rainforest near the Brazil-Peru border in northern Amazonas state. Bodies believed to be theirs were found on June 15 after a huge outcry against the federal government’s inaction following their disappearance. Indigenous patrols bravely conducted their own search while the government did little.
- The murders of Dom and Bruno are emblematic of the plight of journalists across Latin America as violence against both journalists and activists in the region escalates. It also raises an alarm for the need to protect reporters as we report on environmental crime from Nature’s frontline.
- But these crimes will not stop us: Exposing wrongdoing across Brazil’s critical biomes — from the Mata Atlantica to the Cerrado to the Amazon — is more necessary than ever now. At the same time, demanding justice for the murder of Bruno and Dom became a fight for all of us.
- This article is a commentary. The views expressed are those of the author, not necessarily of Mongabay.

For Ecuador’s A’i Cofán leaders, Goldman Prize validates Indigenous struggle (Jun 16 2022)
- Alexandra Narváez and Alex Lucitante, young leaders from the A’i Cofán community of Sinangoe in Ecaudor, led a movement to protect their people’s ancestral territory from gold mining.
- In recognition of their struggle, they were awarded the 2022 Goldman Environmental Prize, widely known as the “Green Nobel.”
- The A’i Cofán community of Sinangoe forced the Ecuadoran state to revoke 52 gold mining concessions that threatened their territory and were awarded without the prior consultation stipulated in the country’s Constitution.