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 threatened as deforestation rises in Nicaraguan reserves (Jan 30 2023)
- Nicaragua’s Bosawás and Indio Maíz biosphere reserves both experienced deforestation at the hands of illegal loggers, miners and cattle ranchers last year.
- Deforestation of the country’s largest primary forests has been a violent, ugly process for Indigenous communities, who were granted land titles and self-governance in the area in the 1980s but don’t have the resources to protect themselves.
- Indigenous leaders and environmental defenders believe the situation will only get worse moving into 2023, as gold mining accelerates and the government cracks down on opponents.

On Sumatra coast, mangrove clearing sparks scrutiny of loophole (Jan 30 2023)
- Last year, a 100-hectare patch of mangrove trees in eastern Sumatra was cleared to make way for an oil palm plantation.
- Residents say small landowners’ claims were packaged together to form a plantation, averting the need for environmental checks or permits required of a corporate concession.
- Mangrove restoration is a pillar of Indonesia’s climate change agenda, though the clearing of some intact forests has persisted.

Elephants promote jumbo trees, boosting the carbon stores in Africa’s forests (Jan 27 2023)
- The dietary habits of African forest elephants (Loxodonta cyclotis) promote the survival of large, high wood density trees better at storing carbon.
- New research finds that forest-dwelling elephants browse on trees with low wood density, making space for bigger, heftier carbon-rich trees.
- The elephants also act as seed dispersers for these larger trees.
- Cautioning that determining exactly what role local elephant extinctions have played in changing forest composition is tricky, the researchers argue that elephants may boost above-ground carbon storage in Central African forests by 6-9%.

Liberian courts rubber-stamp export shipment of illegal logs (Jan 27 2023)
- On Jan. 16, a timber company won a controversial lawsuit in Liberia, when a court ordered forestry officials there to allow a shipment of illegally harvested ekki logs to be exported overseas.
- The ruling was the latest chapter in a years-long saga that environmentalists say points to a breakdown of regulation in Liberia’s forestry sector.
- An unpublished report on the case prepared by Liberia’s Ministry of Justice and obtained by Mongabay implicates senior Liberian officials in serious violations of laws meant to protect the country’s forests.
- Sources told Mongabay the seized logs have been the subject of a heated dispute behind closed doors between President George Weah’s administration and international donors.

Even in recovery, previously logged tropical forests are carbon sources: Study (Jan 25 2023)
- Logging of tropical forests may result in more carbon being released into the atmosphere than previously thought, according to new research.
- The study conducted in Malaysian Borneo demonstrates that logged tropical forests are a significant and persistent net source of carbon emissions for at least one decade after disturbance.
- The study authors say the amount of carbon being sequestered across the world’s tropical forests may be considerably lower than currently estimated and recommend a shift toward more sustainable logging practices and better accounting of carbon emissions and uptake.
- As the body of evidence expands demonstrating how human activity is impacting the capacity of forests to mitigate climate change, experts say reducing fossil fuel emissions is paramount.

From Japan to Brazil: Reforesting the Amazon with the Miyawaki method (Jan 24 2023)
- Reforestation using the Miyawaki method seeks to restore nature to its original state with results that can be seen in around six years.
- Miyawaki works around three concepts: trees should be native, several species should be randomly planted, and the materials for the seedlings and the soil should be organic.
- The method is suitable for urban areas, which gives it a significant capacity to connect human beings with nature, with benefits for the health and well-being of the population.
- Different from other reforestation methods that may seek a financial return, like agroforestry, the motivation of the Miyawaki method is purely ecological.

Across the tropics, mammal activity doesn’t vary much, study shows (Jan 13 2023)
- A new study examines when and why mammals eat, sleep and move about, using 2.3 million camera trap photos from the Neotropics, Afrotropics, and Indo-Malayan tropics.
- The researchers found consistent patterns of daily activity across continents, with large carnivores and omnivores being more active during the day and larger herbivores being nocturnal. The main determining factors of daily activity were body size and diet.
- Insectivores were the exception, with larger species being more active during the day in the Americas, but more active at night in Africa and Asia. The activity patterns of carnivores match the activity patterns of their prey.
- The study results have important implications for conservation, the authors say: Knowing when and why different animals in a community are active is fundamental for protecting them, and can also help to mitigate conflicts between humans and animals.

For Indigenous Brazilians, capital attack was ‘scenario of war’ akin to deforestation (Jan 13 2023)
- The morning after protesters attacked government buildings in Brazil’s capital, Mongabay spoke with Indigenous Congresswoman Célia Xakriabá, who compared the act of vandalism to forest destruction: “This is this scenario of war when you deforest.”
- * Célia Xakriabá had just returned from seeing the damage to the National Congress building: “When they [the rioters] were there also in the Green Room, it made me remember that it is this scenario of war when the repossession takes place in the [Indigenous] territory.”
- One of the immediate effects of the attack was the temporary suspension of the official inauguration of longtime activist Sonia Guajajara as Brazil’s first minister of Indigenous peoples and Anielle Franco as minister for racial equality.
- The two women were finally sworn in on Jan. 11 at the Presidential Palace, despite the missing glass on the walls, the destroyed gallery of photos of former presidents, and a swath of destruction throughout the building. “[This] is the most legitimate symbol of this secular Black and Indigenous resistance in Brazil!” Sonia Guajajara said.

El Salvador poised for big year of roadbuilding, despite environmental concerns (Jan 12 2023)
- El Salvador has prioritized refurbishing and expanding its road system, in many cases destroying habitats for vulnerable species.
- 2023 looks to be yet another ambitious year for roadbuilding, with the government announcing several “large-scale” infrastructure projects throughout the country.
- One of the biggest projects, the Los Chorros Highway, requires removing thousands of trees in an area frequented by migratory birds and several endangered species. It would also relocate nearly 199 families.

Dammed, now mined: Indigenous Brazilians fight for the Xingu River’s future (Jan 12 2023)
- Canadian mining company Belo Sun wants to build a huge gold mine in the Big Bend of the Xingu River in the Brazilian Amazon, but faces opposition from Indigenous communities.
- In addition to the environmental impacts, experts warn of the risk of the proposed tailings dam rupturing, which could flood the area with 9 million cubic meters (2.4 billion gallons) of toxic waste.
- The same region is already suffering the impacts of the Belo Monte hydroelectric dam, which diverts up to 85% of the flow of the Xingu River, leading to a mass decline in fish that traditional riverside dwellers and Indigenous people rely on.  
- The Belo Sun project was legally challenged last year, prompting supporters to harass and intimidate those who oppose the mine’s construction; tensions in the region remain high.

Deforestation ‘out of control’ in reserve in Brazil’s cattle capital (Jan 11 2023)
- Forest destruction has ravaged Triunfo do Xingu, a reserve earmarked for sustainable use that has nonetheless become one of the most deforested slices of the Brazilian Amazon.
- Fires burned swaths of the reserve in recent months and forest clearing has surged, with satellite images showing even the most remote remnants of old-growth rainforest were whittled away last year.
- Advocates say the forest is mainly giving way to cattle pasture, although illegal mining and land grabbing are gaining ground.
- The destruction, facilitated by lax environmental regulation, is placing pressure on nearby protected areas and undermining agroforestry efforts in Triunfo do Xingu, advocates say.

Venezuela’s Yapacana National Park suffering increasing mining deforestation: report (Jan 11 2023)
- Satellite imagery analyzed by NGO Amazon Conservation revealed that illegal mining operations in Yapacana National Park, located in the Venezuelan state of Amazonas, are clearing protected forest much faster than previously thought.
- Over 750 hectares (1,870 acres) of deforestation took place between 2021 and 2022 in the mining area of the park.
- Although law enforcement carried out raids in the area last December, many experts believe the problem will persist amid government complacency.

Weakening of agrarian reform program increases violence against settlers in Brazilian Amazon (Jan 10 2023)
- Residents of a landless workers’ settlement in Anapu, Pará state, in Brazil’s Amazon region, accuse the federal government of favoring large landowners, land-grabbers and corporations at the expense of poor and landless peasants.
- This year, the settlers have already suffered three attacks by landowners, with houses set on fire and a school destroyed.
- In 2021, Incra, the Brazilian federal agency responsible for addressing the country’s deep inequalities in rural land use and ownership, made an agreement with the mining company Belo Sun, which ceded 2,400 hectares (5,930 acres) of an area reserved for agrarian reform for gold exploration in exchange for equipment and a percentage of mining profits.
- In protest, landless peasants occupied one of the areas included in the agreement; since then, they have been threatened and intimidated by Belo Sun supporters and armed security guards hired by the mining company.

Indonesia’s biofuel push must go beyond palm oil to reduce risk, experts say (Jan 10 2023)
- Indonesia faces deforestation, energy and security risks from its overreliance on palm oil as a feedstock for its biofuel transition program, observers say.
- The government will in February increase the biofuel blend in diesel to 35%, from the current 30%, with an eye on a 50:50 blend by 2025 — and eventually fossil-free biodiesel.
- But the program calls for a massive increase in palm oil production — and with yields largely stagnant, this will almost certainly mean clearing more land to establish new oil palm plantations.
- Experts say the government should diversify its sources of biofuel feedstock to curb the expansion of plantations into forests and to reduce the other risks that comes from relying on a single feedstock.

In Ecuador, communities protecting a ‘terrestrial coral reef’ face a mining giant (Jan 9 2023)
- For nearly 30 years, communities have worked to conserve, restore and defend the cloud forests of the Intag Valley in Ecuador, in what locals say is the longest continuous resistance movement against mining in Latin America.
- The tropical Andes are considered the world’s most biodiverse hotspot, ranking first in plant, bird, mammal and amphibian diversity; however, less than 15% of Ecuador’s original cloud forests and only 4% of all forests in northwestern Ecuador remain.
- Codelco, the world’s largest copper producer from Chile, plans to open a mine in the Intag Valley that would destroy primary forest and lie within the buffer area of Cotacachi Cayapas National Park — a plan that experts say would be ecologically devastating and not worth the cost.
- Communities are using the presence of two threatened frog species — previously thought to be extinct — at the mining site to challenge the project under the “rights of nature,” Ecuador’s constitutional guarantee that natural ecosystems have the right to exist, thrive, and evolve.