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

Deforestation haunts top Peruvian reserve and its Indigenous communities (Apr 24 2024)
- Peru’s Amarakaeri Communal Reserve, considered one of the best-protected nature reserves in the world, has seen a spike in deforestation on its fringes from the expansion of illegal coca cultivation and mining, and new road construction.
- The forest loss appears to be affecting the ancestral lands of several Indigenous communities, including the Harakbut, Yine and Matsiguenka peoples, according to a new report by the Monitoring of the Andean Amazon Project (MAAP).
- The report found that 19,978 hectares (49,367 acres) of forest have been cleared in the buffer of the reserve over the past two decades.
- According to Indigenous leaders, the state is doing “practically nothing” to address deforestation drivers in the buffer zone, and they warn that if left unchecked, the activity will spread into the protected area itself.

A web of front people conceals environmental offenders in the Amazon (Apr 22 2024)
- A paper trail left by a notorious land grabber reveals how he used relatives and an employee as fronts to evade environmental fines and lawsuits, shedding light on this widespread practice in the Brazilian Amazon.
- Fronts prevent the real criminals from having their assets seized to pay for environmental fines, besides consuming time and resources from the authorities, who spend years trying to prove who the real financier of the deforestation is.
- Experts say it’s best to go after environmental offenders where it hurts the most, by seizing their assets, rather than to chase down their true identity.
- This investigation is part of a partnership between Mongabay and Repórter Brasil.

Study challenges use of charismatic wildlife as umbrella species for conservation (Apr 20 2024)
- A new study from Indonesia’s Leuser forests challenges the traditional use of charismatic “umbrella species” like tigers and rhinos to represent ecosystem biodiversity.
- Researchers found that focusing on these well-known species neglects other important wildlife and may not accurately represent overall biodiversity.
- Instead, the study proposes a data-driven approach using camera-trap data to identify the most suitable umbrella species based on their association with higher levels of community occupancy and diversity.
- The study identified the sambar deer and Sunda clouded leopard as better umbrella species than tigers and rhinos in the Leuser Ecosystem, highlighting the need for a more comprehensive approach to wildlife conservation that includes multiple species, not just the most charismatic ones.

Indonesian capital project finally gets guidelines to avoid harm to biodiversity (Apr 19 2024)
- Beset by criticism over its environmental and social impacts, the controversial project of building Indonesia’s new capital city in the Bornean jungle has finally come out with guidelines for biodiversity management.
- The country’s president has hailed the Nusantara project as a “green forest city,” but just 16% of its total area is currently intact rainforest.
- The new biodiversity master plan outlines a four-point mitigation policy of avoiding harm, minimizing any inevitable impacts, restoring damaged landscapes, and compensating for residual impacts.
- The master plan considered input from experts, but several didn’t make it into the final document, including a call for the mitigation policy to extend to a wider area beyond the Nusantara site.

Deforestation alerts in the Brazilian Amazon fall to a 5-year low (Apr 18 2024)
- Forest clearing detected by Brazil’s deforestation alert system fell to the lowest level in nearly five years.
- According to data released last week by the country’s space agency, INPE, deforestation registered over the past twelve months amounts to 4,816 square kilometers, 53% below the level this time last year.
- The drop in deforestation has occurred despite a severe drought affecting much of the Amazon basin.

Sierra Leone cacao project boosts livelihoods and buffers biodiversity (Apr 18 2024)
- The Gola rainforest in West Africa, a biodiversity hotspot, is home to more than 400 species of wildlife, including endemic and threatened species, and more than 100 forest-dependent communities living just outside the protected Gola Rainforest National Park and dependent on the forest for their livelihoods.
- In the last few decades, logging, mining, poaching and expanding agriculture have driven up deforestation rates and habitat loss for rainforest-dependent species, prompting a voluntary REDD+ carbon credit program in 2015 to incentivize conservation and provide alternative livelihoods.
- One activity under the REDD+ project is shade-grown cacao plantations, which provide a wildlife refuge while generating income for cacao farmers in the region.
- Independent evaluations have found that the REDD+ program has slowed deforestation, increased household incomes, and avoided 340,000 metric tons of CO2 emissions annually — all while enjoying support from local communities.

Protected areas bear the brunt as forest loss continues across Cambodia (Apr 17 2024)
- In 2023, Cambodia lost forest cover the size of the city of Los Angeles, or 121,000 hectares (300,000 acres), according to new data published by the University of Maryland.
- The majority of this loss occurred inside protected areas, with the beleaguered Prey Lang Wildlife Sanctuary recording the highest rate of forest loss in what was one of its worst years on record.
- A leading conservation activist says illegal logging inside protected areas is driven in part by demand for luxury timber exports, “but the authorities don’t seem to care about protecting these forests.”
- Despite the worrying trend highlighted by the data, the Cambodian government has set an ambitious target of increasing the country’s forest cover to 60% by 2050.

On the trail of Borneo’s bay cat, one of the world’s most mysterious felines (Apr 15 2024)
- The bay cat, named for its brownish-red coat, is arguably the most elusive of all the world’s wildcats. And among the most endangered.
- The bay cat is the only feline endemic to Borneo. Researchers — some of whom have never seen the cat in the wild — say it is potentially threatened by habitat loss and killings by locals, with accidental snaring another possible major cause of loss.
- But the biggest threat may be ignorance. In order to better protect this species, researchers urgently need to figure out: Why is it so rare? And why is it vanishing?
- Jim Sanderson, the world’s leading expert on wildcats, suggests research on the bay cat should focus on why it’s so uncommon, what is causing its decline, and how to reduce those threats. Then conservationists can make a viable plan to protect it.

Conservationists welcome new PNG Protected Areas Act — but questions remain (Apr 12 2024)
- In February 2024, Papua New Guinea’s parliament passed the Protected Areas Bill, first introduced two decades ago, into an act, which aims to establish a national system of protected areas to achieve the conservation target of protecting 30% of PNG’s territory by 2030.
- The act lays out a legal framework for working with customary landowners in the country to earmark protected areas, establishes regulations to manage these areas and provides provisions for alternative livelihoods to forest-dependent communities.
- The act also mandates the establishment of a long-term Biodiversity and Climate Task Fund, which communities can access to implement their management plans and conservation objectives.
- While conservationists say the act is a good step toward protecting biodiversity, they raise concerns about its implementation and whether the promised benefits of protected areas will reach landowning communities.

Traceability is no silver bullet for reducing deforestation (commentary) (Apr 12 2024)
- The European Union, UK and US have passed, or are in the process of passing, legislation which places a duty on companies to prove that products they import do not come from recently deforested land.
- Businesses and governments are ramping up efforts to address emissions and deforestation in their supply chains, but the scale at which these initiatives are being implemented limits their effectiveness in tackling deforestation.
- Investments by companies and governments in farm-level traceability must be backed up by landscape approaches that address the systemic drivers of deforestation, climate change and biodiversity loss, a new op-ed argues.
- This post is a commentary. The views expressed are those of the author, not necessarily Mongabay.

New technologies to map environmental crime in the Amazon Basin (commentary) (Apr 12 2024)
- Environmental crimes like land grabbing, illegal deforestation, and poaching hinder climate action, deter investment in sustainable practices, and threaten biodiversity across major biomes worldwide.
- Despite challenges such as vast territories difficult to police and weak rule of law, new technologies like geospatial and predictive analytics are being leveraged to enhance the detection and disruption of these activities.
- Innovative approaches, including public-private partnerships and AI tools, show promise in improving real-time monitoring and enforcement, although they require increased investment and training to be truly effective, argue Robert Muggah and Peter Smith of Instituto Igarapé, a “think and do tank” in Brazil.
- This post is a commentary. The views expressed are those of the authors, not necessarily Mongabay.

Unseen and unregulated: ‘Ghost’ roads carve up Asia-Pacific tropical forests (Apr 11 2024)
- A new study indicates that significant networks of informal, unmapped and unregulated roads sprawl into forest-rich regions of Southeast Asia and the Pacific.
- Slipping beneath the purview of environmental governance, construction of these “ghost roads” typically precede sharp spikes in deforestation and represent blind spots in zoning and law enforcement, the study says.
- The authors underscore that the relentless proliferation of ghost roads ranks among the gravest of threats facing the world’s remaining tropical forests.
- The findings bolster a growing momentum toward the development of AI-based road-mapping systems to help conservation biologists and resource managers better keep track of informal and illegal road networks and curb associated deforestation rates.

A short walk through Amazon time: Interview with archaeologist Anna Roosevelt (Apr 10 2024)
- Anna Roosevelt has been working in the Amazon for four decades and her pivotal research has changed the knowledge of the rainforest’s occupation.
- In an interview with Mongabay, she explains how her research led to evidence of much older Amazon settlements than previously thought, challenging a decades-long scientific consensus about how Indigenous people related to the forest.
- “One reason I was able to make some great discoveries is because of how opinionated archaeologists in the mid-20th century were. I only benefited from their mistakes,” she said.
- Roosevelt said the recent hype regarding the “garden cities” in Ecuador is “annoying”, as it is not a new discovery and it ignores older research from Latin American archaeologists.

Brazil’s cattle industry could suffer major losses without climate policies, report says (Apr 10 2024)
- Domestic beef production in Brazil could drop by 25% by 2050 as governments and the private sector look to step up climate change and forest conservation strategies, according to a new report from Orbitas, an initiative from Climate Advisers.
- Deforestation from cattle ranching could lead to hotter, drier conditions that worsen cattle health. It could also reduce soil productivity needed for growing animal feed, the report said.
- The industry has to invest in new technological and management techniques in order to prevent major losses.

As fires ravaged Indonesia in 2023, some positive trends emerged, data show (Apr 9 2024)
- Indonesia’s 2023 fire season saw 1.16 million hectares (2.87 million acres) of land and forest go up in flames, and while this was five times higher than in 2022, experts highlight a positive trend.
- The fires were exacerbated by an intense El Niño weather system, unlike in 2022; the last time similar conditions prevailed, in 2019, the area affected by fires was much larger, suggesting fire mitigation efforts may be working.
- Most of the burning occurred in scrubland and areas of degraded forest rather than in intact forests, meaning greenhouse gas emissions from the burning were also much lower than in 2023.
- But a worrying trend highlighted by the numbers is that severe fires are now occurring in four-year cycles, intensified and exacerbated by the impacts of a changing climate.