RAINFOREST INFORMATION

A Place Out of Time: Tropical Rainforests and the Perils They Face - information on tropical forests, deforestation, and biodiversity

Sections:

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

Narco activity takes heavy toll on Colombia’s protected forests, satellite data show (May 31 2024)
- Deforestation inside protected areas in central Colombia appears to be picking up pace this year, suggesting the steep drop-off from 2022-2023 was just a blip, according to satellite data.
- The most affected areas include Llanos del Yarí Yaguara II Indigenous Reserve, two national natural parks — Sierra de la Macarena and Tinigua — and the surrounding La Macarena Special Management Area.
- Threats to the region and its protected areas include agricultural expansion, along with the cultivation of illegal crops such as coca and marijuana, and illegal gold mining.
- The region’s protected areas are increasingly falling under the control of armed groups emboldened and funded by the drug industry, according to monitoring agencies and local residents interviewed by Mongabay.

‘Non-market’ solutions to deforestation need more support, advocates say (May 31 2024)
- In a report released May 29, three environmental groups called for a shift away from carbon markets and toward “non-market” solutions to deforestation.
- The Paris Agreement has a clause calling for such solutions, which the groups said could include financing for Indigenous groups, payment for ecosystem services, and debt relief.
- The report criticized carbon markets, saying incentives for brokers and project developers are misaligned with global environmental priorities.

Elusive jaguarundi inspires biologists to share data across Latin America (May 30 2024)
- The jaguarundi (Herpailurus yagouaroundi) is a little-known small felid with a range extending from northern Argentina to Mexico. The last confirmed sighting in the United States was in 1986.
- H. yagouaroundi is found in a variety of habitats, but is thought to occupy mostly rugged areas with good shrub cover, including near agricultural lands. Unlike most other felids, the jaguarundi is active during the day, which can easily bring it into conflict with farmers who don’t appreciate its habit of raiding chicken coops.
- Like most small, noncharismatic cat species, there’s little funding to learn more about the jaguarundi. But researchers are developing new tools, for example pooling sparse “bycatch” data gathered by many biologists from camera traps in widely scattered places and modeling it to predict habitat use and population size.
- An ongoing IUCN jaguarundi assessment is using a Google Forms questionnaire to reach out widely to researchers, governments and NGOs, while also using easily shared social media tools. A detailed understanding of jaguarundi behavior is needed to assure it is conserved both inside and outside protected areas.

Indigenous people and NGO grow a wildlife corridor in the world’s oldest rainforest (May 30 2024)
- Environmental charity Climate Force is collaborating with the Eastern Kuku Yalanji people and rangers to create a wildlife corridor that runs between two UNESCO World Heritage Sites in Australia: the Daintree Rainforest and the Great Barrier Reef.
- Wildlife habitats in this region have become fragmented due to industrial agriculture, and a forested corridor is expected to help protect biodiversity by allowing animals to forage for food and connect different populations for mating and migration.
- The project aims to plant 360,000 trees over an area of 213 hectares (526 acres); so far, it has planted 25,000 trees of 180 species on the land and in the nursery, which can also feed a range of native wildlife.
- The project is ambitious and organizers say they’re hopeful about it, but challenges remain, including soil regeneration and ensuring the planted trees aren’t killed off by feral pigs or flooding.

Analysis: Michelin’s no-deforestation claims in Indonesia rubber plantation a stretch (May 30 2024)
- Rubber manufacturer Michelin claims to have avoided millions of tons of carbon emissions and saved thousands of hectares of primary forest in a sustainable rubber plantation project in Indonesia.
- Michelin joined the project in 2014 after buying a stake in the Indonesian rubber company RLU, which in 2018 raised $95 million in green bonds. In 2022, Michelin became RLU’s sole shareholder, and repaid the green bonds raised by the project.
- Reporting by independent media outlet Voxeurop, published in 2022, revealed that deforestation in the RLU concession surged immediately before the company made no-deforestation commitments in 2015, resulting in the loss of critical wildlife habitat.
- In this analysis, Voxeurop reporter Stefano Valentino looks at what has happened with the project since Michelin made its no-deforestation commitments, finding ongoing loss of forest within the company’s concessions.

New bill to expand farmlands in the Amazon may derail Brazil’s green efforts (May 29 2024)
- A bill that would reduce the amount of primary forest that landowners in the Brazilian Amazon must preserve may lead to the deforestation of an area twice the size of Rio de Janeiro state.
- The bill has been tailored for the interests of the agribusiness lobby by permitting an increase in legal deforestation and would bring regulation of the Amazon closer to that of the heavily deforested Cerrado savanna biome.
- For environmental organizations, its potential approval would undermine Brazil’s stated goals of reducing carbon emissions and putting an end to deforestation by 2030.

Honduran environmental defenders hit hard by human rights crisis, report says (May 28 2024)
- A new report from the Organization of American States documents the human rights crisis in Honduras, citing threats and violence against environmental defenders as one of the most alarming problems.
- The violence tends to involve agrarian land disputes in areas populated by the over 700,000 Indigenous and Afro-descendant residents of the country, including the Miskitu, Pesh, Tawahka, Nahua, Tolupán, Chortí and Lenca, as well as Garifunas.
- The OAS recommended the government improve land titling while strengthening and better organizing institutions that hold violent aggressors accountable.

What’s at stake for the environment in Mexico’s upcoming election? (May 27 2024)
- On June 2, in addition to president, Mexico will choose all 500 deputies in the lower house of Congress and all 128 seats in the Senate.
- The main presidential candidates are left-wing Claudia Sheinbaum and right-wing Xóchitl Gálvez, with center-left Jorge Máynez representing a third, dark-horse option.
- Both Sheinbaum and Gálvez want to invest more in renewable energy, but disagree about some controversial infrastructure projects.

Governments are ramping up actions to fight environmental crime across the Amazon, but is it working? (commentary) (May 27 2024)
- In 2023, Amazon deforestation rates declined after years of record-breaking losses, thanks to efforts led by Brazil and Colombia. However, these gains are fragile, and anti-deforestation efforts show signs of weakening, with persistent risks of a tipping point, argues Robert Muggah, Co-Founder of the Igarapé Institute.
- Government measures focus on forest conservation, green development, and strengthening the rule of law but face challenges due to underfunding and limited municipal support. Public security forces are overwhelmed by environmental crimes like illegal mining and wildlife trafficking, exacerbating forest and biodiversity loss.
- Environmental crime is gaining more attention from decision-makers, law enforcement, and civil society, leading to increased media coverage and public commitments. Despite this, interventions remain fragmented, with inconsistent political backing and funding, writes Muggah.
- “Ultimately, Brazil and other countries in the Amazon Basin cannot reverse environmental crime through police and prosecutions alone,” he writes. “A comprehensive strategy that combines law enforcement with nature-based development opportunities is critical.” This post is a commentary, so the views expressed are those of the author, not necessarily Mongabay.

Collective effort monitors Amazon wildlife in heavily logged Brazil state (May 24 2024)
- Indigenous communities, the government and civil society organizations are working to identify the status and whereabouts of animals in one of the most deforested states of the Brazilian Amazon.
- Devastated by the expansion of cattle ranching and soy farming, Rondônia has seen changes in the composition of its fauna due to alterations in the landscape.
- The initiatives for surveying and monitoring Rondônia’s fauna are being carried out in conservation units, Indigenous territories and restored forest areas on private lands; the goal is to guide conservation policies.

All conservation is local: Interview with Angolan conservationist Kerllen Costa (May 23 2024)
- Kerllen Costa is the manager for a project run by the Kissama Foundation to protect Afromontane forests on Mount Moco, Angola’s highest mountain.
- Costa says he approaches conservation by looking at how communities already manage their landscapes and resources, and trying to introduce measures that recognize and enhance those systems.
- He says building on traditional ecological knowledge can help to sustain landscapes and the communities and wildlife they support, even in the absence of formally recognized protected areas.

Tracing Africa’s ‘fading biological fingerprints’ in Angola’s threatened forests (May 23 2024)
- Angola’s Afromontane forests are considered to be the country’s most threatened habitat type due to logging, wood harvesting and fire.
- Experts say the forests are relics that harbor “fading biological fingerprints” from a previous epoch.
- It’s not just species living in the closed-canopy forests that could be threatened by the loss of this ecosystem, but those that live alongside them.
- They include the Huambo cisticola, a species now known to be unique to Angola that lives in the ecotone, or transition zone, between forest patches and surrounding grasslands.

Guyana road projects spark concerns for future development on wetlands (May 21 2024)
- A series of ongoing road projects traveling over 500 kilometers (310 miles) from the capital of Georgetown to the city of Lethem, in the south, are supposed to improve access to more rural parts of Guyana while facilitating international trade, most notably with Brazil.
- But the project also crosses sensitive wetlands and Indigenous communities, raising concerns about how the government will manage future development there.
- Some of the roads cross through the Rupununi wetlands and Iwokrama Rainforest, where a unique watershed connects the Amazon River and Essequibo River basins.

Global markets and their effects on resource exploitation in the Pan Amazon (May 21 2024)
- Extractive companies operate to maximize their profits as global demand is highly fluctuating. Prior to 2000, the prices of industrial minerals were at historical lows, but jumped through the next two decades as China began its infrastructure boom.
- As of January 2023, another commodity boom appears to be underway. In part, this is due to the war in Ukraine and the (as yet unknown) dimensions and duration of the sanctions regime imposed on Russia by the United States, the European Union and their allies in Asia-Pacific.
- As minerals required by the energy transition from fossil fuels to renewable energy are plentiful in the Pan Amazon, there will be significant economic pressure to develop those resources.
- Governments in the Pan Amazon are predisposed to support the mining and hydrocarbon industries because they are export-oriented and generate revenues for the state.

Beyond deforestation, oil palm estates pose flood and water contamination risks (May 21 2024)
- Clearing of forests for oil palm plantations can increase flooding risk and water contamination for downstream communities, a new study shows.
- The research focused on the Kais River watershed in Indonesian Papua, where about 10,000 hectares (25,000 acres) of forest have been clear for plantations as of 2021.
- For the Indigenous Kais community living downstream, this period has coincided with an increase in flooding and a decline in water quality.
- The raised flooding risk comes from the fact that oil palms aren’t nearly as effective as forest trees in slowing rainwater runoff, while the water contamination has been traced to the intensive use of agrochemicals on the plantations.