By Rhett A. Butler Last updated July 23, 2020
A Place Out of Time: Tropical Rainforests and the Perils They Face - information on tropical forests, deforestation, and biodiversity
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, 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.
Dozens of countries have tropical forests. The countries with the largest areas of tropical forest are:
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.
|Rainforest region||Total area|
|Total tree cover (30%)|
|Total tree cover (30%)|
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.
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 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.
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.
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.
Every year an area of rainforest the size of New Jersey is cut down and destroyed, mostly the result of human activities. We are cutting down rainforests for many reasons, including:
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.
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.
- 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.
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 races for emergency infrastructure as river’s collapse threatens dam (Tue, 11 Aug 2020 11:18:17)
- The erosion has progressed at an accelerated rate and has reached other rivers, threatening a national highway and Indigenous communities.
- Studies commissioned by the Ecuadoran government call for emergency infrastructure to mitigate the erosion, which could reach the catchment dam of the Coca Codo Sinclair hydroelectric plant, with disastrous consequences.
- The Kichwa Indigenous communities affected by the oil spill four months ago say they are still waiting for justice from the government and the pipeline operators.
As Amazon tree loss worsens, political pressure grows, and Brazil hedges: Critics (Mon, 10 Aug 2020 16:07:34)
- Government data released last Friday shows that from August 1, 2019 to July 31, 2020 forest loss in the Brazilian Amazon totaled 9,205 square kilometers (3.554 square miles), an increase of 34.5% over the previous comparative period (2018/2019), when 6,844 square kilometers (2,642 square miles) were deforested.
- 1,654 square kilometers were cleared in July, 2020, a decline as compared to the 2,255 square kilometers cleared in July 2019. Brazil’s Vice President jumped on this one-month period to declare erroneously that deforestation rates are falling, and he credited this overall decline to the Army deployed to the Amazon in May.
- Meanwhile, pressure grows on the Bolsonaro government to turn away from policies that analysts say are rapidly accelerating deforestation. More than 60 organizations sent a letter to the administration, foreign investors, and Brazilian and European parliamentarians, detailing proposals to contain the deforestation crisis.
- In other news, Environment Minister Ricardo Salles met with illegal miners in the Amazon, and in response the Defense Ministry appeared to cave to their demands to stop patrolling in their area of operation. But in a reversal, the Army, after halting its patrols in the region, has reinstated them.
Life among the turtles: Traditional people struggle inside an Amazon reserve (Mon, 10 Aug 2020 08:43:10)
- The Brazilian Amazon’s Trombetas River is well known for its exceptional biodiversity, including nesting turtles. In 1979, to protect flora and fauna there, the REBIO Trombetas was founded; it’s a highly restrictive form of conservation unit where today only very limited economic activity is permitted.
- The two traditional communities inside the reserve — the Último Quilombo and Nova Esperança Quilombo (Afro-Brazilian communities of runaway slave descendants) — complain that the government has unfairly penalized them for conducting forest and river livelihoods including Brazil nut collecting and fishing.
- Local residents also contend that while they’re fined for such minor infractions, MRN, the world’s fourth largest bauxite mining company, located near the REBIO, has done extensive ecological damage due to ore ship traffic and water pollution, which severely impacts turtle populations.
- In fact, MRN’s mines, ore processing and bauxite waste lagoons are located inside the Saracá-Taquera National Forest, a protected area known as a FLONA, on the Trombetas River. MRN has been fined often for its environmental violations there, fines it has appealed and not yet paid; the firm says it’s operating within the law.
Why I stand for my tribe’s forest: It gives us food, culture, and life (commentary) (Sat, 08 Aug 2020 16:21:19)
- For the occasion of International Indigenous Peoples Day August 9, 2020, Arkilaus Kladit, a member of the Knasaimos-Tehit people in South Sorong Regency in West Papua Province, Indonesia, writes about the importance of his tribe’s customary forests.
- Arkilaus, who is a member of the Knasaimos Indigenous Peoples Council, describes his tribe’s long struggle to secure recognition of his tribe’s customary lands by the Indonesian government.
- Arkilaus explains how the Knasaimos-Tehit people are dependent on forests for food, community resilience, and cultural significance.
- This post is a commentary. The views expressed are those of the author, not necessarily Mongabay.
Amazon rainforest the size of Sao Paulo cleared in July in Brazil (Fri, 07 Aug 2020 21:46:56)
- An area of rainforest larger than the city of São Paulo was cleared during the month of July, bringing deforestation in the Brazilian Amazon to 9,205 square kilometers over the past 12 months, according to official government data released today by Brazil’s National Space Research Institute INPE.
- INPE’s satellite-based deforestation alert system registered 1,654 square kilometers of forest clearing last month, a decline from the 2,255 square kilometers detected the same month a year ago. Still, forest loss in the region puts the 2019/2020 deforestation year, which runs from August 1 to July 31, to be the highest since at least 2007.
- The sharp year-over-year rise in deforestation was confirmed by Imazon, a Brazilian NGO that independently monitors forest loss in the region, which found a 29% increase via its “SAD” system.
- Deforestation has been trending higher since 2012 but accelerated since early 2019.
Brazilian Amazon protected areas ‘in flames’ as land-grabbers invade (Fri, 07 Aug 2020 18:05:57)
- The Área de Proteção Ambiental (APA) Triunfo do Xingu spans some 1.7 million hectares (4.2 million acres). Its dense forests boast a rich diversity of plant and animal species, and it is also home to Indigenous groups and traditional peoples who rely on the forest to survive.
- But the area has come under pressure, becoming one of the most deforested regions in the Amazon in recent years. Overall, the territory has lost nearly 30% of its forest cover, with some 5% cleared in 2019 alone.
- The number of fires has soared in Triunfo do Xingu too. Over the last two months, NASA satellites picked up 3,842 fire alerts in the territory. August and September – when Brazil’s fire season is normally at its peak – are expected to bring even more intense burning.
- The area has emerged as an epicenter of land-grabbing and illegal mining, amid a surge in invaders who are betting that the Bolsonaro administration will eventually loosen or scrap protections of the land they are occupying.
Probe begins into alleged deforestation by Olam, ‘world’s largest farmer’ (Fri, 07 Aug 2020 11:34:03)
- A retrospective assessment has begun of claims that FSC-certified palm oil producer Olam razed thousands of hectares of wildlife-rich rainforest in Gabon.
- Campaigners are calling for Olam to fund compensatory forest restoration or additional protection.
- The Gabonese government says its palm oil strategy is sustainable and does not threaten the country’s rich biodiversity.
Deforestation in the Amazon is drying up the rest of Brazil: Report (Fri, 07 Aug 2020 11:06:56)
- The center-west, south and part of the southeast regions of Brazil have seen rainfall well below average in recent years.
- Agriculture is the first sector to feel the effects of the drought, with drastic losses in production. Water supply and power generation have also been impacted.
- Agribusiness suffers the consequences of drought but also causes it: Deforestation of the Amazon to clear land for livestock, farming and logging affects the rainfall regime in Brazil and other Latin American countries.
- “South America is drying up as a result of the combined effects of deforestation and climate change”, says scientist Antonio Donato Nobre.
In Colombia, a protected park is buffeted by social, environmental conflicts (Fri, 07 Aug 2020 10:58:36)
- When Serranía de Las Quinchas Regional Natural Park was established in Colombia in 2008, thousands of campesinos were already living there on land previously dominated by paramilitaries.
- Many productive activities have been restricted and residents are requesting state support.
- There have been reports that the army is eradicating illicit coca crops while disregarding health and safety protocols put in place to combat COVID-19.
- Residents of the park say they have no means of making a living and are worried about illegal logging, land ownership and oil infrastructure in the area.
Fires in the Pantanal: ‘We are facing a scenario now that is catastrophic’ (Thu, 06 Aug 2020 18:50:03)
- Devastating wildfires that burned out of control in late 2019 and early 2020 in Brazil’s Pantanal wetland are back. Around 1.2 million hectares (3 million acres) in the region have been burned so far.
- The Pantanal is the world’s largest tropical wetland and straddles the borders of Brazil, Paraguay and Bolivia – with Brazil containing the lion’s share.
- The Brazilian Pantanal has seen the number of fires more than double so far in 2020, up some 200% over the same period in 2019. Sources say the fires were started by human activity – likely to clear land for agriculture – and are difficult to control due to a lack of access to the region and because the fires are burning underground, fueled by highly combustible peat and exacerbated by drought.
- Faced with the surging number of fires in June and July, state and federal authorities moved to reinforce bans on burning. However, early signs suggest these measures are doing little to mitigate fires.
Brazil dismantles environmental laws via huge surge in executive acts: Study (Wed, 05 Aug 2020 11:54:12)
- Between March and May 2020, the government of Jair Bolsonaro published 195 infralegal acts — ordinances, normative instructions, decrees and other measures — which critics say are an indirect means of dismantling Brazil’s environmental laws and bypassing Congress. During the same period in 2019, just 16 such acts were published.
- In April, 2020 Environment Minister Ricardo Salles suggested that the administration “run the cattle” which experts say, within the context Salles used the phrase, is a euphemism for utilizing the COVID-19 crisis as a means of distracting Brazilians from the administration’s active undermining of the environmental rule of law.
- A partial study of the 195 acts has found that they, among other things, allow rural landowners who illegally deforested and occupied conserved areas in the Atlantic Forest up to July 2008 to receive full amnesty for their crimes. Another change pays indemnities to those who expropriated properties within federal conservation units.
- Shifts in administration management responsibilities have also resulted in what experts say is a weakening of regulations granting and managing national forests, and the relaxation of supervision over fisheries that could allow increased illegal trafficking in tropical fish. A study of the repercussions of all 195 acts is continuing.
New Guinea has the most plant species of any island (Wed, 05 Aug 2020 11:02:16)
- New Guinea is the planet’s most speciose island when it comes to plants, reports a comprehensive assessment of vascular plant species published in the journal Nature.
- The research concludes New Guinea has 13,634 species of plants from 1742 genera and 264 families. That gives New Guinea, the world’s second largest island, the highest plant diversity of any island on Earth, surpassing Madagascar (11,832 species), Borneo (11,165 species), and Sumatra (8,391 species).
- New Guinea’s flora is also highly unique. The study finds that more than two-thirds of its plants are endemic, meaning they are only found on the island.
- But time may be running short for New Guinea’s biodiversity, since 2002 the island lost 1.15 million hectares of primary forest and nearly 2 million hectares of total tree cover. New Guinea’s high degree of endemism makes its flora particularly vulnerable.
Vietnam approves $9 billion development within mangrove reserve (Wed, 05 Aug 2020 09:29:37)
- Vietnam’s $9.3 billion Can Gio Tourist City was recently approved for construction within the buffer zone of a UNESCO Mangrove Biosphere Reserve in Ho Chi Minh City.
- Developed by Vingroup, Vietnam’s largest private company, the project will require the reclamation of a huge amount of land along Can Gio’s coast.
- Environmentalists and activists have petitioned the government to reconsider the project, but Vingroup is a key part of the country’s drive toward industrialization and home-grown world-class companies.
‘Meaningless certification’: Study makes the case against ‘sustainable’ palm oil (Wed, 05 Aug 2020 07:59:53)
- Three-quarters of oil palm concessions in Indonesia and Malaysian Borneo certified by the Roundtable on Sustainable Palm Oil occupy land that was forest and/or wildlife habitat as recently as 30 years ago, a new study shows.
- While not the initial drivers of deforestation in those areas, these plantations shouldn’t be certified sustainable if that history is accounted for, the study authors say.
- “The fact that someone else did deforestation just a few years before does not absolve the palm oil plantation’s owner and definitely does not justify a sustainability label by a certification scheme,” says co-author Roberto Cazzolla Gatti.
- He adds the RSPO’s failure to account for past deforestation means that “every logged area ‘today’ could be certified as a sustainable plantation ‘tomorrow,’ in an infinite loop of meaningless certification.”
In Bogotá, communities weave an unlikely wetland success story (Tue, 04 Aug 2020 09:58:07)
- Around 27 years ago, a community on the northwest border of Bogotá launched a concerted campaign to defend the Conejera wetland against a city and business sector that saw it as disposable.
- The success of their efforts launched a long-standing community movement of wetland defenders in an otherwise urbanized city, where 98% of its original wetlands have been wiped out.
- Today the Colombian capital’s 15 official wetlands are home to dozens of endemic species, including 202 species of birds, and take up about 727 hectares (1,800 acres).