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

We’re killing those tropical trees we’re counting on to absorb carbon dioxide (24 Feb 2021 22:52:26 +0000)
- A pair of recent studies show that rising temperatures are shortening the lives of trees in tropical forests and reducing their capacity to absorb carbon dioxide from the atmosphere.
- This phenomenon is already being observed in parts of the Amazon, where the temperature has already crossed a critical threshold of 25°C (77°F); by 2050, the same may happen in the Congo Basin, the world’s second-biggest tropical rainforest.
- Forests play a major role in fighting global warming, but the authors of the recent studies say we shouldn’t be overly reliant on them as a solution, given their diminished capacity to absorb carbon dioxide.
- Instead, they say that cutting emissions is more urgent than ever.

As Amazon forest-to-savanna tipping point looms, solutions remain elusive (23 Feb 2021 17:48:12 +0000)
- Leading scientists project that if an additional 3-8% of rainforest cover is lost in the Amazon, it may overshoot a forest-to-degraded-savanna tipping point. That shift could mean mega-drought, forest death, and release of great amounts of stored carbon to the atmosphere from southern, eastern and central Amazonia.
- Despite this warning, Brazilian Amazon deforestation hit an 11-year high in 2020. Government clampdowns on environmental crime greatly decreased deforestation in the past, but Brazil is now facing a political backlash led by President Jair Bolsonaro, resulting in agribusiness and mining expansion and deforestation.
- Market efforts to create incentives have been ineffective. A public-private plan to cut deforestation led by Mato Grosso state has not met its environmental targets, even as agricultural lands increased. Amazonas, Acre and Rondônia — Bolsonaro-aligned states — are pushing for the creation of a new agriculture frontier.
- Indigenous communities, because they’re the best land stewards, should be at the forefront of public policy to conserve the Amazon, say experts, but instead they face poverty and marginalization by the institutions responsible for securing their land rights. International response to the Amazon crisis has also lagged.

Madagascar: Young farmers adopt new methods to help lemurs, forests and themselves (19 Feb 2021 16:55:47 +0000)
- Threatened by unsustainable farming methods and hunting, the forests of Mangabe-Ranomena-Sahasarotra in eastern Madagascar, and the lemurs that live there, are in danger.
- A project aims to train young villagers in the region in sustainable farming techniques and to raise their awareness of lemur protection.
- These young people are trained to be ambassadors for the protection of the environment, who will transmit their knowledge to the next generation.

U.N. report lays out blueprint to end ‘suicidal war on nature’ (19 Feb 2021 14:08:01 +0000)
- According to a new report from the United Nations Environmental Programme, the world faces three environmental “emergencies”: climate change, biodiversity loss, and air and water pollution.
- U.N. Secretary-General António Guterres said we should view nature as “an ally,” not a foe, in the quest for sustainable human development.
- The report draws on assessments that quantify carbon emissions, species loss and pollutant flows to produce what the authors call concrete actions by governments, private companies and individuals that will help address these issues.

In Malaysian Borneo’s rainforests, powerful state governments set their own rules (18 Feb 2021 18:45:32 +0000)
- Under Malaysia’s federal system, state governments hold authority over most regulations regarding land usage and environmental protection.
- In the Bornean states of Sabah and Sarawak, home to most of Malaysia’s remaining intact forests, politicians push against perceived interference from the central government, particularly when it comes to resource management.
- Since the late 1960s, Malaysian Borneo lost much of its forest: first to timber and later to palm oil and other agricultural industries.
- Both states have laws on the books aimed at protecting and managing forests, as well as sustainable forestry and palm oil certification schemes. Experts on forest management and conservation see cause for both optimism and skepticism.

Indonesian police may probe coal miners over deforestation-linked floods (18 Feb 2021 10:59:50 +0000)
- The Indonesian police say they might investigate coal companies for their alleged role in recent deadly floods that struck southern Borneo.
- Critics accuse the companies of degrading the water catchment in South Kalimantan province through deforestation and sedimentation, which they allege amplified the impact of the rain-fueled floods.
- The government, meanwhile, is under fire for issuing more permits than the previous three administrations.
- Activists warn the environmental degradation in the province will only get worse under a slate of controversial deregulation measures passed by the government last year, which they say caters to coal companies at the expense of the environment.

Podcast: Where oh where are the Sumatran rhinos? (18 Feb 2021 00:36:08 +0000)
- Sumatran rhinos are one of the most endangered large mammals on the planet, with no more than 80 left in the wild.
- Not only that but biologists are challenged to even find them in the dense rainforests they call home in order to conserve them via captive breeding.
- To shed light on the animal’s precarious situation and mysterious whereabouts, this episode of the Mongabay Explores podcast series speaks with conservation biologist Wulan Pusparini.
- This ‘rhino search and rescue’ is a big challenge she tells host Mike DiGirolamo in this episode of the podcast.

Big dream: NGO leads in creating 1,615-mile Amazon-Cerrado river greenbelt (17 Feb 2021 18:07:04 +0000)
- The Black Jaguar Foundation plans to reforest 1 million hectares (2.4 million acres) along Brazil’s Araguaia and Tocantins rivers in the Amazon and Cerrado biomes. The 2,600 kilometer (1,615 mile) long natural corridor will require the planting of around 1.7 billion trees. Tens-of-thousands have already been planted.
- This natural corridor will be established on private lands, and it will have dual ecological and economic goals, resulting in both land conservation and sustainable agroforestry production. It would cross six Brazilian states (Goiás, Mato Grosso, Mato Grosso do Sul, Tocantins, Pará and Maranhão).
- BJF is well funded and well organized, so the greatest barriers to accomplishing the NGO’s goals are many initially resistant rural property owners who need to be sold on the economic benefits of the green corridor. 24,000 privately owned lots are included in the planned green corridor.
- “Brazil has a huge liability in degraded areas, and the BJF [green corridor] initiative is a huge outdoor laboratory for ecosystem restoration in the center of the country, in the agricultural frontier region,” said one researcher.

Indigenous community wins recognition of its land rights in Panama (17 Feb 2021 10:54:01 +0000)
- A ruling by Panama’s Supreme Court of Justice in November 2020 led to the official creation of a comarca, or protected Indigenous territory, for the Naso Tjër Di people in northern Panama.
- The 1,600-square-kilometer (620-square-mile) comarca is the result of a decades-long effort to secure the Naso’s land rights.
- Panama’s former president had vetoed legislation creating the comarca in 2018, which he said was unconstitutional because it overlapped with two established protected areas.
- Other Indigenous groups in Panama with longstanding comarcas still struggle to hold back outside incursions for projects such as dams and power transmission lines.

European public roundly rejects Brazil trade deal unless Amazon protected (16 Feb 2021 18:32:15 +0000)
- The gigantic trade agreement between the European Union and the Mercosur South American bloc (Brazil, Argentina, Paraguay and Uruguay), if ratified, would be the biggest trade deal in history, totaling US $19 trillion.
- However, an extremely poor environmental record by the Mercosur nations, especially Brazil, has become a stumbling block to clinching the agreement. In new polling 75% of respondents in 12 European nations say the EU-Mercosur trade pact should not be ratified if Jair Bolsonaro’s Brazil doesn’t end Amazon deforestation.
- France, the Parliaments of the Netherlands, Austria and Belgium’s Walloon region, have announced they will not endorse the trade pact. The ratification also finds resistance by Ireland and Luxembourg. Portugal’s government appears ready to move forward with ratification without environmental safeguards put in place.

As forests shrink, mammals are stressed out— with possible fallout for humans (15 Feb 2021 18:11:52 +0000)
- Fur samples collected from small rodents and marsupials in the Atlantic Forest of Paraguay showed that the animals in the smaller forest fragments had elevated levels of stress hormones.
- While small amounts of acute stress can help an animal to get out of a bad situation, prolonged stress levels weaken the immune system, making them more susceptible to disease.
- Pathogen spillover (from animals to humans) seems more likely in all animals that are crowded together in forest fragments and stressed out, underscoring the importance of the One Health approach, which recognizes the connection between human, environment, and animal health.

Southeast Asian wild pigs confront deadly African swine fever epidemic (12 Feb 2021 04:16:16 +0000)
- A recent study in the journal Conservation Letters warns that African swine fever, responsible for millions of pig deaths in mainland Asia since 2018, now endangers 11 wild pig species living in Southeast Asia.
- These pig species generally have low populations naturally, and their numbers have dwindled further due to hunting and loss of habitat.
- The authors of the study contend that losing these species could hurt local economies and food security.
- Southeast Asia’s wild pigs are also important ecosystem engineers that till the soil and encourage plant life, and they are prey for critically endangered predators such as the Sumatran tiger and the Javan leopard.

Indonesia’s top palm oil deforesters are the usual shady suspects: Report (11 Feb 2021 10:20:37 +0000)
- Repeat offenders dominate the 2020 list of top 10 palm oil companies responsible for palm oil-linked deforestation in Indonesia, Malaysia and Papua New Guinea, according to a new analysis.
- Some of the top deforesters are shrouded in secrecy, with scant information about them publicly available.
- Overall, 2020 saw the lowest amount of palm oil-driven deforestation in three years, likely due to the COVID-19 pandemic.
- However, a resurgent domestic market in Indonesia, coupled with rallying palm oil prices, could fuel further deforestation in 2021.

Teachers create lasting change for people and other primates via clean cookstoves (commentary) (10 Feb 2021 17:30:56 +0000)
- Kibale National Park has the highest diversity of primates in the world and 300+ species of birds, but wildlife are threatened by habitat degradation from activities like firewood collection.
- Fuel-efficient cookstoves can be used to reduce wood consumption, improve cook times, and mitigate smoke inhalation associated with cooking on open fires.
- Many such projects fail over time, but a new project involves the multiplicative effect of involving teachers in educating the community about their usefulness, since a single teacher can influence many students.
- This article is a commentary and the views expressed are those of the author, not necessarily Mongabay.

Fruit-eating, seed-pooping animals can help restore degraded forests (09 Feb 2021 18:16:26 +0000)
- Restoring degraded forests can be expensive and complicated, but Brazilian researchers may have a simple technique to add to the restoration toolbox: enlisting fruit-eating animals to spread seeds.
- A new study shows that many species of mammals and birds will consume seeds inserted into fruits at feeders and then excrete the seeds over wide areas.
- This novel proof-of-concept study highlights the importance of plant and animal interactions to restore the natural ecology of forests people have destroyed or degraded.