Rainforest
Rainforest Types
The largest rainforests in the world come in two forms: tropical and temperate.
Tropical rainforests are located near the equator, between the Tropic of Cancer at 23.5° north and the Tropic of Capricorn at 23.5° south of the equator. They are evergreen, have a warm and wet climate and receive consistent rainfall – at least 2,000mm annually.
Tropical rainforests once covered 14% of the Earth’s land surface; today, it is only 6%. Despite this, about 80% of the world’s documented species can be found in tropical rainforests.
Of all tropical rainforests, 57% are found in Latin America with a third in Brazil. Other major tropical rainforests are located in southeast Asia and the Pacific islands (25%) and west Africa (18%).
Temperate rainforests account for around 25% of the world’s forests. They are moist forests that grow on mountain ranges, usually along western coasts where westerly winds bring high precipitation.
Temperate rainforests spread much further north and south than their tropical counterparts. They still receive upwards of 2,000mm of year-round rainfall, but experience drier summers. They have less biodiversity than tropical rainforests.
It’s practically impossible to say exactly how many rainforests there are in the world as definitions, boundaries and borders are interpreted differently depending on the country and organisation.
We can, however, identify and list the world’s largest rainforests by their size, type and location.
1. AMAZON RAINFOREST
Size: 5,500,000km2
Type: Tropical
Location: Brazil, Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname, French Guiana
The world’s largest jungle, the Amazon scarcely needs an introduction. It is the world’s largest rainforest and spans nine countries in total, covering 40% of South America.
The Amazon represents over half of the planet’s remaining rainforests and is home to an estimated 390 billion individual trees divided into 16,000 species. In fact, the Amazon is home to a tenth of all known species on Earth.
However, this vast wilderness is under relentless threat from large-scale farming and ranching, development, logging, mining and climate change. With the majority (60%) of the Amazon within Brazil, the country shoulders huge responsibility.
Between 2000 and 2012, the rate of deforestation in Brazil slowed by 75%. However, data from 2017-2018 suggest there has been a 13.7% increase on the previous year with the biggest area of forest cleared since 2008. The fear is that this could continue if the policies of current Brazilian president, Jair Bolsonaro, see fruition.
2. CONGOLESE RAINFOREST
Size: 1,780,000km2
Type: Tropical
Location: Cameroon, Gabon, Republic of the Congo, Democratic Republic of the Congo, Central African Republic, Equatorial Guinea
Spanning six countries across much of the Congo Basin, the Congolese Rainforest is the second biggest rainforest in the world. A medley of rivers, forests, savannah, swamp and flooded woodland, the basin teems with life: gorillas, elephants and buffaloes all call the region home.
Central Africa’s deforestation rate since 1990 has been the lowest of any major forest region in the world. Deforestation in the Congo over the past 20 years has often been from small-scale subsistence agriculture, clearing for charcoal and fuelwood, urban expansion and mining.
All of this has indirect knock-on effects with logging roads opening up areas of the Congo to commercial poaching, leading to a 62% drop in the region’s forest elephant population in less than a decade.
3. NEW GUINEA RAINFOREST
Size: 288,000km2
Type: Tropical
Location: Indonesia, Papua New Guinea
The rainforests of New Guinea cover around 65% of the land area of the second largest island in the world. The island is home to the largest rainforest in the Asia-Pacific region and the third largest rainforest in the world.
There are few places on Earth that rival the diversity of the New Guinea Rainforest. From dense tropical rainforest to coastal mangroves, the island is home to some of the world’s most unique plants and animals. More orchid species are found here than any other place on Earth.
New Guinea’s remote location has not protected it from the usual threats. The rainforests face growing incursions from logging, mining, wildlife trade and agricultural plantations – particularly oil palm.
4. VALDIVIAN TEMPERATE RAINFOREST
Size: 248,100km2
Type: Temperate
Location: Chile, Argentina
Known as the rainforest at the end of the world, the world’s southernmost jungle of this kind, Selva Valdiviana (Valdivian Temperate Forest) is located on the west coast of southern South America.
The forest covers a narrow strip of continental land between the western slopes of the Andes mountain range and the Pacific Ocean. It is the largest temperate rainforest in the world and is characterised by dense collections of ferns, bamboos and evergreen angiosperm trees that dominate the landscape.
Threats to the Valdivian include extensive logging and the replacement of the indigenous trees by faster-growing pines and eucalyptus, which are more desirable in the pulp and paper industries.
5. HEART OF BORNEO
Borneo has lost 30% of its forest in the past 40 years
Size: 220,000km2
Type: Tropical
Location: Indonesia, Malaysia, Brunei
The rainforest on the island of Borneo – the third largest island in the world – is estimated to be around 140 million years old, making it one of the oldest rainforests in the world.
Known as Asia’s last great rainforest, it is a mix of lowland and montane rainforest located above 1,000m (3,300ft). The Borneo lowland rainforest in particular is diminishing due to logging, hunting and conversion to commercial land use – so much so that in 2007 the Heart of Borneo Initiative was launched by the WWF to save one of the largest rainforests in the world. The agreement, signed by the governments of Brunei, Indonesia and Malaysia, intends to protect a vast tract of rainforest on the island.
Like many tropical areas around the world, Borneo’s rainforests are deforested for timber, palm oil, pulp, rubber and minerals. As such, Borneo has lost 30% of its forest in the past 40 years, falling at twice the rate as the rest of the world’s rainforests. Large mammals such as orangutans and elephants are particularly at risk.
6. PACIFIC TEMPERATE RAINFOREST
Size: 60,346km2
Type: Temperate
Location: Canada, USA
Stretching over 4,000km in a narrow coastal corridor from the edge of Prince William Sound in Alaska, along coastal British Columbia in Canada, through the northwestern US states of Oregon and Washington to northern California, the Pacific Coastal Temperate Rainforest represents the world’s largest area of coastal temperate rainforest. Despite its great length, the forest is only 150km wide at its broadest.
The rainforest incorporates the Tongass National Forest in Southeast Alaska, the USA’s largest national forest, as well as Canada’s Great Bear Rainforest in British Columbia, which is home to the spirit bear, the rare white variant of the black bear.
In Tongass, logging is a genuine danger. The current US administration is trying to increase logging and road building in America’s premier temperate rainforest.
7. TROPICAL RAINFOREST HERITAGE OF SUMATRA
Size: 25,000 km2
Type: Tropical
Location: Indonesia
The Sumatran rainforest is a deeply tragic story of deforestation. The sixth largest island in the world was once covered with thick jungle from coast to coast. Now, only pockets of rainforest remain, largely within the UNESCO protected Tropical Rainforest Heritage of Sumatra. Illegal logging and palm oil production is chiefly to blame.
With almost 50% of Sumatra’s tropical rainforest lost in the last 35 years, the likelihood is that outside these protected areas all remaining rainforest in Sumatra will disappear within 20 years. Tigers, rhinos, orangutans and elephants are all severely at risk.
The Tropical Rainforest Heritage of Sumatra is spread across the national parks of Gunung Leuser, Kerinci Seblat and Bukit Barisan. Between them, they hold the island’s last hope for the long-term conservation of its varied plant life and myriad endangered species.
8. EASTERN AUSTRALIAN TEMPERATE FORESTS
Size: 222,100 km2
Type: Temperate
Location: Australia
Stretching from central coastal New South Wales up into southeast Queensland, the Eastern Australian Temperate Forests eco-region incorporates a wide variety of natural environments, microclimates and rich vegetation.
However, clearing for land and urban development since the arrival of Europeans has encroached on much of the landscape and continues today. Additionally, invasive weeds attack the native vegetation.
One of the most well known areas of the rainforest is the UNESCO World Heritage-listed Blue Mountains National Park. The region features a dramatic plateau of sandstone cliffs, deep gorges, eucalyptus forests and a profusion of rare and threatened plant and animal species.
9. BOSAWÁS BIOSPHERE RESERVE
Size: 20,000km²
Type: Tropical
Location: Nicaragua
Comprising around 5% of Nicaragua’s total land area, making it the second largest rainforest in the western hemisphere (after the Amazon), the Bosawás Biosphere Reserve has been a UNESCO biosphere reserve since 1997.
The main threat to the rainforest comes from Nicaragua’s booming livestock industry. Ranchers have migrated to the reserve en masse where they often pay land traffickers to illegally secure title to land.
10. WESTLAND TEMPERATE RAINFORESTS
Size: 11,880km2
Type: Temperate
Location: New Zealand
New Zealand’s Westland Temperate Rainforests are located along the central west coast of the country’s South Island. It is known as Te Waipounamou in Māori and nicknamed locally as the ‘wet coat’.
The narrow strip of rainforest runs between the Southern Alps and the Tasman Sea and includes the Franz Josef and Fox glaciers – one of the few places in the world where glaciers and rainforest meet.
The region is home to at least 28 species of threatened birds including the endemic Okarito brown kiwi. Much of the region is protected either by national parks or reserves making it one of the least-threatened rainforests in the world.
Threats do still exist though in the form of introduced mammal species such as stoats and rats. Additionally, substantial portions of the rainforest have been developed for pastureland and pine plantations.
11. HAINAN RAINFOREST
Size: 1,500km²
Type: Tropical
Location: China
China’s tropical rainforests were once huge. Today, however, most of China’s influence on forests exists solely on the consumption side. At home and away, China are world leaders in illegal logging operations.
China’s tropical rainforests have declined by at least 67% in the last 30 years. Abroad, Chinese firms have actively cleared huge areas of rainforests as well as sponsoring large agriculture, infrastructure and oil and mining development projects throughout the world’s rainforests.
Some good news is that Hainan Island, the country’s smallest and southernmost province, is home to the largest and best-preserved tropical rainforest in China. Much of the area is now protected and is seldom visited, even though 25 million tourists visit the island each year.
12. DAINTREE RAINFOREST
Size: 1,200km²
Type: Tropical
Location: Australia
Last on our list of the largest rainforests in the world is the Daintree Rainforest, located on the north-east coast of Queensland. The Daintree Rainforest is part of the world’s oldest continually surviving tropical rainforest. It is thought to be 6-10 times older than those found in the protected areas of the Amazon – having stood for 150 million years.
The ecosystems of the Daintree Rainforest are some of the most complex on Earth. Its plant diversity and structural complexity is unrivalled on the arid Australian continent.
Unfortunately, the UNESCO protected area does not extend to all of the Daintree with residential development, climate change and invasive plants and species all a threat.
Deforestation in Amazon Rainforest
Deforestation in the Maranhão state of Brazil, 2016
Timelapse of the deforestation 1984-2018 (bottom right)
Deforestation is the conversion of forested areas to non-forested areas. The main sources of deforestation in the Amazon are human settlement and the development of the land. In 2018, about 17% of the Amazon rainforest was already destroyed. Research suggests that upon reaching about 20–25% (hence 3–8% more), the tipping point to flip it into a non-forest ecosystem – degraded savannah – (in eastern, southern and central Amazonia) will be reached.
Prior to the early 1960s, access to the forest's interior was highly restricted, and the forest remained basically intact. Farms established during the 1960s were based on crop cultivation and the slash and burn method. However, the colonists were unable to manage their fields and the crops because of the loss of soil fertility and weed invasion. The soils in the Amazon are productive for just a short period of time, so farmers are constantly moving to new areas and clearing more land. These farming practices led to deforestation and caused extensive environmental damage. Deforestation is considerable, and areas cleared of forest are visible to the naked eye from outer space.
In the 1970s, construction began on the Trans-Amazonian highway. This highway represented a major threat to the Amazon rainforest. The highway still has not been completed, limiting the environmental damage.
Wildfires in Brazil's indigenous territory, 2017
Between 1991 and 2000, the total area of forest lost in the Amazon rose from 415,000 to 587,000 km2 (160,000 to 227,000 sq mi), with most of the lost forest becoming pasture for cattle. Seventy percent of formerly forested land in the Amazon, and 91% of land deforested since 1970, have been used for livestock pasture. Currently, Brazil is the largest global producer of soybeans. New research however, conducted by Leydimere Oliveira et al., has shown that the more rainforest is logged in the Amazon, the less precipitation reaches the area and so the lower the yield per hectare becomes. So despite the popular perception, there has been no economical advantage for Brazil from logging rainforest zones and converting these to pastoral fields.
Indigenous protesters from Vale do Javari
The needs of soy farmers have been used to justify many of the controversial transportation projects that are currently developing in the Amazon. The first two highways successfully opened up the rainforest and led to increased settlement and deforestation. The mean annual deforestation rate from 2000 to 2005 (22,392 km2 or 8,646 sq mi per year) was 18% higher than in the previous five years (19,018 km2 or 7,343 sq mi per year). Although deforestation declined significantly in the Brazilian Amazon between 2004 and 2014, there has been an increase to the present day.
Since the discovery of fossil fuel reservoirs in the Amazon rainforest, oil drilling activity has steadily increased, peaking in the Western Amazon in the 1970s and ushering another drilling boom in the 2000s. As oil companies have to set up their operations by opening roads through forests, which often contributes to deforestation in the region.
The European Union–Mercosur free trade agreement, which would form one of the world's largest free trade areas, has been denounced by environmental activists and indigenous rights campaigners. The fear is that the deal could lead to more deforestation of the Amazon rainforest as it expands market access to Brazilian beef.
2019 fires
Main article: 2019 Amazon rainforest wildfires
There have been 72,843 fires in Brazil in 2019, with more than half within the Amazon region. In August 2019 there were a record number of fires. Deforestation in the Brazilian Amazon rose more than 88% in June 2019 compared with the same month in 2018.
Sahara Desert dust windblown to the Amazon 2.6 million 40% of South America
More than 56% of the dust fertilizing the Amazon rainforest comes from the Bodélé depression in Northern Chad in the Sahara desert. The dust contains phosphorus, important for plant growth. The yearly Sahara dust replaces the equivalent amount of phosphorus washed away yearly in Amazon soil from rains and floods.
NASA's CALIPSO satellite has measured the amount of dust transported by wind from the Sahara to the Amazon: an average of 182 million tons of dust are windblown out of the Sahara each year, at 15 degrees west longitude, across 2,600 km (1,600 mi) over the Atlantic Ocean (some dust falls into the Atlantic), then at 35 degrees West longitude at the eastern coast of South America, 27.7 million tons (15%) of dust fall over the Amazon basin (22 million tons of it consisting of phosphorus), 132 million tons of dust remain in the air, 43 million tons of dust are windblown and falls on the Caribbean Sea, past 75 degrees west longitude.
CALIPSO uses a laser range finder to scan the Earth's atmosphere for the vertical distribution of dust and other aerosols. CALIPSO regularly tracks the Sahara-Amazon dust plume. CALIPSO has measured variations in the dust amounts transported – an 86 percent drop between the highest amount of dust transported in 2007 and the lowest in 2011.
A possibility causing the variation is the Sahel, a strip of semi-arid land on the southern border of the Sahara. When rain amounts in the Sahel are higher, the volume of dust is lower. The higher rainfall could make more vegetation grow in the Sahel, leaving less sand exposed to winds to blow away.
Amazon phosphorus also comes as smoke due to biomass burning in Africa.
Impact of early 21st-century Amazon droughts
In 2005, parts of the Amazon basin experienced the worst drought in one hundred years, and there were indications that 2006 may have been a second successive year of drought. A 2006 article in the UK newspaper The Independent reported the Woods Hole Research Center results, showing that the forest in its present form could survive only three years of drought. Scientists at the Brazilian National Institute of Amazonian Research argued in the article that this drought response, coupled with the effects of deforestation on regional climate, are pushing the rainforest towards a "tipping point" where it would irreversibly start to die. It concluded that the forest is on the brink of[ being turned into savanna or desert, with catastrophic consequences for the world's climate. A study published in Nature Communications in October 2020 found that about 40% of the Amazon rainforest is at risk of becoming a savanna-like ecosystem due to reduced rainfall.
According to the World Wide Fund for Nature, the combination of climate change and deforestation increases the drying effect of dead trees that fuels forest fires.
In 2010, the Amazon rainforest experienced another severe drought, in some ways more extreme than the 2005 drought. The affected region was approximately 3,000,000 km2 (1,160,000 sq mi) of rainforest, compared with 1,900,000 km2 (734,000 sq mi) in 2005. The 2010 drought had three epicenters where vegetation died off, whereas in 2005, the drought was focused on the southwestern part. The findings were published in the journal Science. In a typical year, the Amazon absorbs 1.5 gigatons of carbon dioxide; during 2005 instead 5 gigatons were released and in 2010 8 gigatons were released. Additional severe droughts occurred in 2010, 2015, and 2016.
In 2019 Brazil's protections of the Amazon rainforest were slashed, resulting in a severe loss of trees. According to Brazil's National Institute for Space Research (INPE), deforestation in the Brazilian Amazon rose more than 50% in the first three months of 2020 compared to the same three-month period in 2019.
In 2020, a 17 per cent rise was noted in the Amazon wildfires, marking the worst start to the fire season in a decade. The first 10 days of August 2020 witnessed 10,136 fires. An analysis of the government figures reflected 81 per cent increase in fires in federal reserves, in comparison with the same period in 2019. However, President Jair Bolsonaro turned down the existence of fires, calling it a "lie", despite the data produced by his own government. Satellites in September recorded 32,017 hotspots in the world's largest rainforest, a 61% rise from the same month in 2019. In addition, October saw a huge surge in the number of hotspots in the forest (more than 17,000 fires are burning in the Amazon's rainforest) - with more than double the amount detected in the same month last year.