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

Ecuador Indigenous accuse state of crimes against humanity (20 Oct 2020 15:09:12 +0000)
- Ecuador’s Indigenous movement has declared this month “Rebel October” to commemorate the violent 11-day anti-austerity protests last year that saw 11 people killed, 63 severely injured, and more than 1,300 protesters arrested.
- Last year’s protests ended after Indigenous leaders forced the government to promise to repeal IMF-imposed austerity measures; but one year later, the government has used the pandemic as an excuse to pass the same measures and increase extractive activities, say Indigenous leaders.
- Indigenous communities also say they have been forgotten by the state during the pandemic.
- The month is also meant to show the government the Indigenous community will continue to fight for its rights.

Deforestation threatens to wipe out a primate melting pot in Indonesia (19 Oct 2020 08:39:00 +0000)
- Unique primate habitats on the Indonesian island of Sulawesi are under threat from rising deforestation, according to a new study.
- The island’s isolation has allowed macaques and tarsiers there to evolve in unique ways, leading to an “explosion” of biodiversity found nowhere else across Southeast Asia.
- But logging, expansion of farmland, and infrastructure projects are driving a growing rate of forest loss, including in the “hybridization zones” that are a key factor in the island’s rich variety of primate life.
- While protected areas exist on Sulawesi, they’re concentrated located at higher elevations, while most of the primates occur in lowland forests that can be more easily cleared and farmed.

Video: The Sumatran rhino is sliding into extinction. It doesn’t have to (19 Oct 2020 04:33:12 +0000)
- A new animated short film from Mongabay, illustrated by artist Roger Peet, depicts the Sumatran rhino’s slide toward extinction.
- No more than 80 Sumatran rhinos are believed to survive today, scattered across isolated and fragmented habitats in Indonesia.
- Driven to the brink of extinction by habitat loss and hunting, Sumatran rhinos today face an even more fundamental threat: experts fear that too few calves are being born to offset even natural deaths in the remaining populations.

‘Luckiest people’: Encountering a newborn Sumatran rhino in the wild (14 Oct 2020 04:46:34 +0000)
- In 2018, five rangers had a rare encounter with a newborn Sumatran rhinoceros in the forests of Sumatra’s Leuser Ecosystem.
- Leuser is known as one of the last strongholds of the Sumatran rhino, one of the most endangered large mammals on Earth.
- Conservationists have called for beefing up security across the Leuser Ecosystem to allow the rhinos there to feel secure enough to continue breeding.
- The species is down to no more than 80 individuals in the wild, with forest fragmentation and a low birth rate driving it toward extinction.

For Amazon’s harpy eagle, nesting trees are also coveted for timber (13 Oct 2020 10:43:22 +0000)
- A new study finds that nesting trees for the harpy eagle in the Amazon are almost all targeted by the commercial timber industry.
- The eagles were found to select trees with specific architecture to support their nests and young.
- Tightening legal logging regulations and enforcement could help with the problem, but stamping out illegal logging is a more pressing challenge.

Brazil reports lower deforestation, higher fires in September (09 Oct 2020 13:45:10 +0000)
- Brazil’s national space research institute INPE reported a third straight monthly drop in Amazon deforestation in September, but its data also showed a sharp increase in the area affect by fires.
- According to INPE’s deforestation alert system, deforestation in the “legal Amazon” during the month of September amounted to 964 square kilometers, down 34% from September 2019. That follows a 27% decline in July and a 21% decline in August relative to a year ago when deforestation in the region hit the highest level since 2008.
- However the reported decline in recent months does not match the trend reported by Imazon, an independent NGO, which reported increases of more than 30% in July and August, but hasn’t published September analysis yet. The discrepancy could be due to the different methodologies used by the two systems, though normally INPE and Imazon’s data show strong correlation.
- Since January, INPE has reported more than 7,000 square kilometers of deforestation in the Amazon, down 10% from the same period last year, but the second highest on record since 2008.

Mining covers more than 20% of Indigenous territory in the Amazon (09 Oct 2020 11:43:20 +0000)
- A new report from the World Resources Institute and the Amazon Geo-Referenced Socio-Environmental Information Network reveals that mining has impacted more than 20% of the Amazon’s Indigenous territory.
- The analysis shows that deforestation rates are as much as three times higher on Indigenous lands with mining compared to those without.
- The study’s authors suggest that improved law enforcement, greater investment in Indigenous communities and stricter environmental protections are necessary to combat the surge of mining in the Amazon.

We’re not protecting enough of the right areas to save biodiversity: Study (09 Oct 2020 11:26:12 +0000)
- In 2010, the member nations of the U.N.’s Convention on Biological Diversity (CBD), 195 countries plus the EU, agreed that at least 17% of global land and 10% of the ocean needed to be protected by 2020.
- A new global review finds that many countries have fallen short of these targets, and the expansion of protected areas over the past 10 years has not successfully covered priority areas such as biodiversity hotspots and areas providing ecosystem services.
- The research team overlaid maps of protected areas, threatened species, productive fisheries, and carbon services, and found that 78% of known threatened species do not have adequate protection.
- Adequate protection of the world’s biodiversity will require conservation areas in the right places, the involvement of Indigenous peoples and local communities in decision-making and management, ecologically connectivity between protected areas, and much more financing.

As Brazil burns, Indigenous fire brigades face an uncertain future (09 Oct 2020 07:30:37 +0000)
- More than 1,000 Indigenous people volunteer as firefighters throughout Brazil, protecting 14 million hectares (35 million acres) of Indigenous lands.
- However, in a year of record fires, the very continuity of the Indigenous fire brigades is at risk, with the government failing to provide the coordination, recognition, funding or support that they need.
- Fire-prevention measures that were supposed to start in April, before the dry season, were instead delayed to July, once the burning had already begun, with the COVID-19 pandemic one of the factors blamed for the delay.
- Insiders in the federal agencies overseeing environmental protection and Indigenous affairs also point to an official culture of neglect of Indigenous communities, which in many cases has forced Indigenous firefighters to work unpaid.

The Amazon savanna? Rainforest teeters on the brink as climate heats up (08 Oct 2020 11:17:39 +0000)
- A new study has found that 40% of the Amazon is at risk of turning into savanna due to decreases in rainfall.
- The paper’s authors used satellite data, climate simulations and hydrological models to better understand the dynamics of rainfall across the tropics and their impacts on the stability of tropical forest ecosystems.
- The team’s simulations suggest that sustained high greenhouse gas emissions through the end of the century could shrink the minimum size of the Amazon by 66%.

The murky process of licensing Amazonian meat plants (08 Oct 2020 10:33:03 +0000)
- Decades of growth in cattle ranching have meant that Pará is now the state with the largest herd nationwide. At 20.6 million heads, it has 2.5 cattle for every human inhabitant.
- 14 of the 22 Brazilian meat plants approved to export to China since 2019 are in the Amazon.

Sumatran bridge project in elephant habitat may exacerbate degradation (07 Oct 2020 06:21:44 +0000)
- Officials in Sumatra have agreed to build a bridge linking the main island to the archipelago of Bangka-Belitung, part of wider efforts to boost economic development in the region.
- The starting point for the planned bridge will be the Air Sugihan ecosystem, which is home to at least 148 wild and critically endangered Sumatran elephants.
- Conservationists say there needs to be a science-based approach to infrastructure development in the region to minimize threats to the elephant population.
- The Air Sugihan ecosystem was as recently as the 1970s home to another iconic species, the Sumatran tiger, before a government-sponsored migration program led to a boom in the human population and the clearing of large swaths of land for agriculture.

Stock indices let Brazil meatpackers shed ties to deforestation, draw investors (06 Oct 2020 09:33:49 +0000)
- The prominent placement of Brazil’s three biggest meatpackers — JBS, Marfrig and Minerva — on the country’s stock exchange indices has seen them net $121 million in investments.
- These investments are made through funds that track the various stock exchange indices, whose makeup is ostensibly determined by a company’s performance and management.
- These meatpackers, whose operations are closely associated with deforestation and land grabbing in the Amazon, receive investments even through funds geared toward environmentally and socially responsible companies.

Indonesia’s food estate program eyes new plantations in forest frontiers (06 Oct 2020 08:17:59 +0000)
- The Indonesian government says it will expand a national “food estate” program by establishing millions of hectares of new crop plantations in Sumatra and Papua.
- The program is currently centered in Indonesian Borneo, where it occupies the site of an identical project from the 1990s that failed spectacularly.
- To expand the project into North Sumatra and Papua, the government is seeking out private investors; but activists say this risks a repeat of the current corporate takeover of Indigenous and community lands.
- The government is also reportedly considering lifting the forest status of more than a million hectares of rainforest in Papua so that it can clear the area for farmland.

Forest degradation outpaces deforestation in the Brazilian Amazon: Study (05 Oct 2020 13:02:02 +0000)
- Brazilian Amazon deforestation rates have declined from, and stayed below, their 2003 peak, despite recent increases. However, this decline was offset by a trend of increased forest degradation, according to an analysis of 23 years of satellite data. By 2014, the rate of degradation overtook deforestation, driven by increases in logging and understory burning.
- During the 1992-2014 study period, 337,427 square kilometers suffered a loss of vegetation, compared to 308,311 square kilometers completely cleared, a finding that has serious implications for global greenhouse gas emissions and biodiversity loss.
- Forest degradation has been connected to outbreaks of infectious diseases as a result of increased contact between humans and displaced wildlife. Degradation can also facilitate the emergence of new diseases and some experts warn that the Amazon could be the source of the next pandemic.
- These findings could have major implications for Brazilian national commitments to the Paris Climate Agreement, as well as international agreements and initiatives such as the Aichi Biodiversity Targets and REDD+, which rely on forest degradation monitoring.