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

The force is strong with space lasers helping researchers map the Amazon in 3D (Oct 4 2022)
- Since 2018, the GEDI mission has employed lasers on the International Space Station to measure the biomass density of forests on Earth.
- The information helps us understand how deforestation contributes to worsening climate change via increases in atmospheric concentration of carbon dioxide.
- In the Amazon rainforest, data from the mission have highlighted specific areas that could benefit from carbon-based conservation.

The Amazon will reach tipping point if current trend of deforestation continues (Oct 3 2022)
- A report by the Amazon Network of Georeferenced Socio-Environmental Information (RAISG) claims that 26% of Amazon forests have transformed irreversibly and show high levels of degradation.
- The savannization of the Amazon is already visible in Brazil and Bolivia, while Ecuador, Colombia and Peru seem to be heading in the same direction.
- The report also seeks to make visible the role of Indigenous peoples in protecting the Amazon, and to ensure that Indigenous people are at the center of the fight against climate change.

As Indonesia paints rosy picture for orangutans, scientists ask: Where’s the data? (Oct 3 2022)
- Foreign scientists who were apparently banned for questioning the Indonesian government’s claim that orangutans are widely increasing in number insist none of the available data support the claim.
- Erik Meijaard, Julie Sherman, Serge Wich, Marc Ancrenaz and Hjalmar Kühl were blocked from carrying out conservation-related research in the country after writing an op-ed that the forestry ministry deemed had “negative indications” that could “discredit” the government.
- “If the government says that populations are growing I assume they have data that none of us have access to,” Meijaard told Mongabay. The ministry didn’t respond to requests for comment.
- The banning of the five is the latest in a string of actions by the current government that local and foreign academics have slammed as “repressing science.”

Amazon reserve for uncontacted people moving forward amid battle over oil fields (Sep 30 2022)
- Isolated and recently contacted Indigenous peoples in the Peruvian Amazon have had their existence officially recognized after a 19-year process and are one step closer to being protected through the creation of the Napo-Tigre Indigenous Reserve.
- The reserve would prevent outsiders and extractive industries, including logging and oil companies, from entering the territory. This will prevent the spread of diseases and deforestation in the region.
- A petroleum company, Perenco, and a group of businessmen and government officials oppose the creation of the reserve. According to the group, the reserve will be an obstacle to ongoing and future development in the oil-rich region.
- Some Indigenous leaders are also against the creation of the isolated Indigenous reserve. The leaders and their communities receive infrastructure projects, transportation, health services and employment from Perenco.

Cutting down the Amazon does not build prosperity for most Brazilians (Sep 29 2022)
- Deforestation proponents in Brazil routinely argue that cutting down the Amazon is an effective way to alleviate poverty. This is especially the case with the Bolsonaro administration, which issued an official statement to the 2021 United Nations Climate Change Conference stating that “where there is a lot of forest there is also a lot of poverty.”
- Ahead of Brazil’s election this coming Sunday, a group of us led by Darren Norris of the Federal University of Amapá decided to see what the data says about links between deforestation and poverty in the Amazon.
- We found no association between forest loss and these economic indicators. Indeed, the economic indicators for municipalities with less than 40% forest cover in 1986 were no different than those of similar municipalities with more than 60% forest cover from 1986 to 2019.
- The finding thus suggests that “deforestation does not necessarily generate transformative and equitable food production systems or lead to poverty alleviation,” as we write.

In Brazil’s Mato Grosso state, deforesters foot the bill for political campaigns (Sep 28 2022)
- In Brazil’s 2018 elections, 422 candidates running in executive and legislative races at state and federal levels across the country received donations from individuals and partners of companies linked to environmental crimes in the Amazon; 156 of them won election.
- The state of Mato Grosso led in the number of candidates bankrolled by environmental violators — 62 candidates, of whom 19 won — and in the donations made: 6 million reais ($1.5 million).
- Mauro Mendes, who would go on to win the state’s election for governor, received 1 million reais ($257,000) from environmental violators, and his track record in office to date has been marked by controversies over environmental protection and natural resource administration.
- Two federal legislators from Mato Grosso, recipients of environmental violators’ money, also appear to be aligned with their donors’ interests by sponsoring a bill that would effectively free up 10 million hectares (25 million acres) of land that can be legally deforested.

Palm oil firms not acting fast enough on no-deforestation vows: Report (Sep 23 2022)
- Only 22% of companies sourcing or producing palm oil in Indonesia have public and comprehensive no-deforestation policies, a new report by London-based nonprofit CDP says.
- The report also finds that only 28% of companies have robust public no-deforestation commitments that cover 100% of production and include a cutoff date before 2020.
- In light of the report, experts are calling for more companies to adopt robust no-deforestation policies that incorporate social elements including remediation, restoration, compensation of past harms, and/or commitment to protect rights and livelihoods of local communities.

Road network spreads ‘arteries of destruction’ across 41% of Brazilian Amazon (Sep 22 2022)
- A groundbreaking study using satellite data and an artificial intelligence algorithm shows how the spread of unofficial roads throughout the Amazon is driving widespread deforestation.
- One such road is on the verge of cutting across the Xingu Socioenvironmental Corridor, posing a serious risk of helping push the Amazon beyond a crucial tipping point.
- Unprotected public lands account for 25% of the total illegal road network, with experts saying the creation of more protected areas could stem the spread and slow both deforestation and land grabs.
- Officially sanctioned roads, such as the Trans-Amazonian Highway, also need better planning to minimize their impact and prevent the growth of illegal offshoots, experts say.

Emissions and deforestation set to spike under Indonesia’s biomass transition (Sep 21 2022)
- Indonesia’s cofiring program — reducing the amount of coal used in power generation by cutting it with wood pellets — will result in massive deforestation and a net emissions surge, an energy policy think tank warns.
- Under the government’s 10% biomass cofiring plan, up to 1.05 million hectares (2.59 million acres) of forest could be cleared for acacia and eucalyptus plantations to provide wood pellets.
- This would result in up to 489 million metric tons of emissions — a vastly greater amount than the 1 million tons in reduced emissions that cofiring is expected to achieve.
- The analysis, by Trend Asia, also shows that, if anything, Indonesia’s coal consumption has only increased with higher biomass cofiring, and that this trend is expected to continue through 2030 as more new coal plants are built.

New oil refinery ‘a huge disaster’ for Nigerian forest reserve (Sep 20 2022)
- Stubbs Creek Forest Reserve comprises nearly 300 square kilometers (116 square miles) in southern Nigeria, and is home to threatened wildlife and economically valuable tree species.
- Despite its official protected status as a forest reserve, much of Stubbs Creek Forest Reserve’s tree cover has been lost due to human activities like logging and farming.
- Area residents say the construction of this new refinery has exacerbated deforestation in Stubbs Creek Forest Reserve, and a government official calls the development of the reserve “a huge disaster for the forest.”
- Residents are also concerned that the refinery will exacerbate conflicts between Local Government Areas.

How close is the Amazon tipping point? Forest loss in the east changes the equation (Sep 20 2022)
- Scientists warn that the Amazon is approaching a tipping point beyond which it would begin to transition from a lush tropical forest into a dry, degraded savanna. This point may be reached when 25% of the forest is lost.
- In a newly released report, the Monitoring of the Andean Amazon Project (MAAP) estimates that 13.2% of the original Amazon forest biome has been lost due to deforestation and other causes.
- However, when the map is divided into thirds, it shows that 31% of the eastern Amazon has been lost. Moisture cycles through the forest from east to west, creating up to half of all rainfall across the Amazon. The 31% figure is critical, the report says, “because the tipping point will likely be triggered in the east.”
- Experts say the upcoming elections in Brazil could have dramatic consequences for the Amazon, and to avert the tipping point we must lower emissions, undertake ambitious reforestation projects, and build an economy based on the standing forest. Granting and honoring Indigenous land tenure and protected areas are also key strategies.

New tech aims to track carbon in every tree, boost carbon market integrity (Sep 19 2022)
- Climate scientists and data engineers have developed a new digital platform billed as the first-ever global tool for accurately calculating the carbon stored in every tree on the planet.
- Founded on two decades of research and development, the new platform from nonprofit CTrees leverages artificial intelligence-enabled satellite datasets to give users a near-real-time picture of forest carbon storage and emissions around the world.
- With forest protection and restoration at the center of international climate mitigation efforts, CTrees is set to officially launch at COP27 in November, with the overall aim of bringing an unprecedented level of transparency and accountability to climate policy initiatives that rely on forests to offset carbon emissions.
- Forest experts broadly welcome the new platform, but also underscore the risk of assessing forest restoration and conservation projects solely by the amount of carbon sequestered, which can sometimes be a red herring in achieving truly sustainable and equitable forest management.

More droughts are coming, and the Amazon can’t keep up: Study (Sep 16 2022)
- Up to 50% of rainfall in the Amazon comes from the forest itself, as moisture is recycled from the trees to the atmosphere.
- In severe droughts, when the forest loses more water to evaporation than it receives from rain, the trees begin to die. For every three trees that die due to drought in the Amazon rainforest, a fourth tree, even if not directly affected by drought, will also die, according to a new study.
- As trees are lost and the forest dries up, parts of the Amazon will rapidly approach a tipping point, where they will transition into a degraded savanna-like ecosystem with few to no trees.
- The southern and southeastern Amazon are the most vulnerable regions to tipping. Here, deforestation and fires are at their most extreme, driven largely by cattle ranching and soy farming.

Big data monitoring tool aims to catch up to Indonesia’s booming online bird trade (Sep 16 2022)
- A web-trawling tool developed by researchers in Indonesia has identified more than a quarter of a million songbirds in online listings from a single e-commerce site between April 2020 and September 2021.
- More than 6% of these were species listed as threatened on the IUCN Red List, including the Javan pied starling (Gracupica jalla) and the straw-headed bulbul (Pycnonotus zeylanicus), both critically endangered.
- In a newly published paper, the researchers say the online bird trade is highly successful thanks to well-developed e-commerce infrastructure such as internet and shipping services.
- The researchers have proposed the adoption of their tool by Indonesian authorities to monitor the online bird trade, given the absence of any other platform to crack down on trafficking.

Eight new-to-science geckos described from biodiversity haven Madagascar (Sep 15 2022)
- Scientists have described eight new-to-science species of geckos from Madagascar, all about the length of your thumb.
- They were elevated to species level following DNA studies of what was, for decades, thought to be a single species group of dwarf gecko, Lygodactylus madagascariensis. They add there could be up to 18 distinct genetic lineages.
- Scientists have found and named at least 150 new-to-science species from Madagascar in the last 30 years, and are still finding more nearly every year. More than 90% of species in Madagascar are endemic, meaning they’re found nowhere else on Earth.
- Given ongoing threats to the forests and ecosystems in Madagascar, scientists say we may not be finding and naming species quickly enough to know what’s being lost.