Fast facts: the Amazon biome

A quick rundown on one of our planet’s most critical ecosystems

Lago Agrio, a lake in the Ecuadorian Amazon. Andrés Medina, Unsplash
17 August 2021
17 August 2021

This post is also available in: Español Portuguese (Brazil)

To learn more about the Amazon biome, join here for Global Landscapes Forum’s Amazonia Digital Conference: The Tipping Point (September 21-23, 2021). 

The Amazon biome is, by any measure, one of the world’s great natural wonders. It stretches across all of northern Brazil and into eight other countries, including Peru, Colombia, Bolivia, Ecuador, Venezuela, and the Guianas.

At more than 6 million square kilometers, the Amazon is the world’s largest rainforest, more than double the size of the two next-largest rainforests, those of the Congo Basin and Indonesia.

The Amazon River flows from the Andes Mountains all the way to the Atlantic Ocean and has more than 1,100 tributaries, 17 of them longer than 1,600 kilometers. Tons of suspended sediment form islands along the entire length of these rivers, and the Amazon itself deposits so much silt at its mouth that the Brazilian island of Marajó is the size of Switzerland. During highwater season, up to 18 billion cubic meters of freshwater is pumped into the Atlantic every day.

No other ecosystem on Earth can claim greater biodiversity than the Amazon biome, with between 10 percent and 30 percent of world’s known species found there. Scientists have identified some 40,000 different plant species and 16,000 tree species, many of them valuable sources of food. While most of the biome is tropical jungle, it also contains natural savannas and swamps.

A vast and amazing array of wildlife lives in the Amazon rainforest, adding up to about 2,000 different species of mammals, reptiles and amphibians. Many of them – from the pink dolphin to the grey woolly monkey to the wire-tailed manakin – are only found in this habitat, and several are endangered. The biome’s extensive canopy of trees is also home to an estimated 1,300 bird species, and its winding rivers to 3,000 freshwater fish species.

A member of the Tariana tribe in the Amazon region of Brazil. Julio Pantoja, World Bank
A member of the Tariana tribe in the Amazon region of Brazil. Julio Pantoja, World Bank

Many people also live in the Amazon biome. According to one recent study, an estimated 1.7 million people belonging to some 375 Indigenous groups live within about 3,344 indigenous territories (ITs) and about 522 protected natural areas (PNAs), spanning all eight nations and the overseas department of French Guiana. Rubber tappers, river-dwellers, and Quilombola (African-descendant) communities also live in the rainforest and, along with Indigenous peoples, have organized and fought to preserve and demarcate large tracts of the Amazon as protected Indigenous territories and extractive reserves. By now, Indigenous territories alone cover nearly one-third of the region’s land area, and together with PNAs, protect more than one-half of the Amazon rainforest.  

But since at least the 1970s, the Amazon rainforest has been under attack. In Brazil, almost one-fifth of the forest has been destroyed, with 11,000 square kilometers of forest loss in 2020 alone. Between 70 and 80 percent of the converted land is used for cattle ranching and other areas are designated for soy production. Peru has lost almost 3.4 million hectares of tree cover to small scale agriculture and other activities between 2001 and 2020. Colombia, meanwhile, is losing 200,000 hectares of forest annually to agriculture. Mining, dams, and road infrastructure projects also play a role in the environmental devastation.

As some areas of the Amazon are now seeing rainfall drop by as much as 48 percent, fires caused mostly by slash-and-burn agriculture are on the rise, the dry season has expanded over the past 50 years from four months to almost five, and three severe droughts have affected the region since 2005.

Amazon tree boa, Manu National Park, Peru
An Amazon tree boa in Manu National Park, Peru. Ulrike Langner, Unsplash

This destruction has an impact not only on Amazon Basin rainfall – which is believed to contribute to the generation of 70 percent of South America’s GDP – but also on carbon storage. A 2007 study estimated the total carbon locked up in forest biomass in the Amazon Basin was 86 billion tons. However, more recent studies have found that due to deforestation and fire, the rainforest has actually emitted more carbon (16.6 billion tons) than it has drawn in (13.9 billion tons) during the last 10 years.

Environmentalists around the world agree that more secure land rights for Indigenous peoples and local communities (IPLCs) and better protections against land-grabbing are urgently needed to stem this cascade of dire events. As one aforementioned study points out, “a growing body of evidence accumulated over the last decade suggests that IPLCs play a measurable and significant role in keeping forests intact, thereby reducing forest carbon emissions and mitigating climate change.”

Their conservation efforts tend to be “more effective and less expensive than conventional government-sponsored alternatives,” the study states, while a report from 2016 notes that deforestation rates in legally-recognized Indigenous territories are 2 to 3 times lower than in similar areas not registered to Indigenous peoples.

Along with enhancing biodiversity and controlling erosion and flooding, the report goes on to say that securing Indigenous lands in Bolivia, Brazil, and Colombia would avoid up to 59.7 million tons of carbon dioxide over 20 years, which is the equivalent of taking up to 12 million cars off the road each year.


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