Alexa Amazon: lungs of the planet

Dhaka, Monday   16 September 2019


Amazon: lungs of the planet


 Published: 11:11 PM, 23 August 2019   Updated: 04:04 PM, 25 August 2019

File Photo

File Photo

The Amazon Jungle is a wonderful place, without a doubt, whose wonder is attributed to its flora and fauna. The rainforest in South America is one of the world’s most impressive and important natural habitats. The forest encompasses an area of 5.5 million square kilometers with 60% of its total in Brazil.


The world largest forest Amazon occupies the second largest river named Amazon River, in the world. The river system is the lifeline of the forest and its history plays an important part in the development of its rainforests. 

At one time Amazon River flowed westward, perhaps as part of a Proto-Congo (Zaire) river system from the interior of present day Africa when the continents were joined as part of Gondwana. Fifteen million years ago, the Andes were formed by the collision of the South American plate with the Nazca plate. The rise of the Andes and the linkage of the Brazilian and Guyana bedrock shields blocked the river and caused the Amazon to become a vast inland sea. Gradually this inland sea became a massive swampy, freshwater lake and the marine inhabitants adapted to life in freshwater. For example, over 20 species of stingray, most closely related to those found in the Pacific Ocean, can be found today in the freshwaters of the Amazon.

About ten million years ago, waters worked through the sandstone to the west and the Amazon began to flow eastward. At this time the Amazon rainforest was born. During the Ice Age, sea levels dropped and the great Amazon Lake rapidly drained and became a river. Three million years later, the ocean level receded enough to expose the Central American isthmus and allow mass migration of mammal species between the Americas. The Ice Ages caused tropical rainforest around the world to retreat. Although debated, it is believed that much of the Amazon reverted to savanna and montage forest.

How the Amazon Rainforest got its name

It is widely believed that the Amazon got its name due to a conflict between the Spanish explorer, Francisco de Orellana, and a native Amazon tribe, known as Tapuyas.

Orellana was the first known person to sail down the Amazon River from one end to the other in 1540. He is also remembered for founding the city of Guayaquil which now is a city in Ecuador. Orellana made two expeditions in the Amazon forest; the first was when the name Amazon was coined, and the second claimed Orellana’s life.

Some historians believe Orellana was caught in conflict with the tribe Tapuyas where warriors were both female and male, although some historians argue that the male warriors may have been mistaken for women as they used makeshift grass skirts and had long hair. It was after this conflict that Orellana thought of the name Amazon, derived from the Amazons from the ancient Greek legend. In the battle of the Greeks and the Amazons, the women are often painted as beautiful, brave, and strong with shirt tunics and a bare breast. It’s likely that the warriors in the native Brazilian tribe reminded Orellana of these female warriors from the Greek stories.

One other theory is that the word Amazon came from a local indigenous word. The Amazon River was supposedly first called Rio Santa Maria de La Mar Dulce by the Spanish invaders of the 1500s. Mar dulce means freshwater sea that probably refers to the fact that the Amazon river is freshwater and so big that it seems like the sea. However, years later it was called the Amazon River, which is believed to come from the indigenous word from the Tupi or Guarani language. When translated into Portuguese, the word becomes amassona, meaning boat-breaker, which was used to describe the strong and complex root systems of local hydrophilic plants.

However, this theory is mostly speculation and it is widely believed the name of the Amazon came from Orellana and his belief that the local Amazon tribe looked like the Amazons in the Greek legend.

The biggest forest

Amazon jungle covers some 40 percent of the South American continent and it is found in nine countries of the South American continent. These includes Brazil, which boasts of 60% of the rainforest, Peru with a forest cover of 13%, Colombia with 10% and the remaining 17% divided between Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana – an overseas territory of France.

Amazon rainforest occupying the drainage basin of the Amazon River and its tributaries in northern South America and covering an area of 2,300,000 square miles (6,000,000 square km). Comprising about 40 percent of Brazil’s total area, it is bounded by the Guiana Highlands to the north, the Andes Mountains to the west, the Brazilian central plateau to the south, and the Atlantic Ocean to the east.


The tropical rainforest experiences a humid season throughout the year. In Amazon forest, there are no periodic seasons such as summer, winter, autumn and spring by virtue of the tropics. All the land and vegetation between the tropics does not experience these seasons. Evening temperatures are slightly cooler than those of the daytime. Although there is, technically, a drier season between April and September.

Instead, the rainforest experiences fairly hot temperatures of 26-30oC throughout the year. This is attributed to the imaginary Equator line which influences a consistency in the day length with 12 hours of sunlight all year round.Nevertheless, the forest is mostly damp from the constant humidity levels.


Tropical rainforests lie in a zone that has intense solar energy, which brings about convection of air thus loses of moisture to the atmosphere which is one of the factors that lead to frequent and heavy downpours. The rainfall in the rainforests range from as low as 2,000mm to as high as 10,000mm annually. Such rainfall is optimal for growth of high-end cash crops such as soy beans.


Amazon rainforest has the biggest ecosystem in the world. This ecosystem is driven by the great Amazon River which covers over thousands of miles and is the main foundation as well has a direct impact on the ecosystem.

The ecosystem of the rainforest is so big that it helps to control the entire planet’s atmospheric carbon levels. This is attributed to the Amazon basin, which is home to over ten times the annual carbon emissions from fuel consumption. The forest stabilizes the various types of soils that enhance optimal crop production in the neighboring regions.The forest also influences the pattern of rainfall such that areas that are thousands of miles away from the basin can receive adequate rainfall throughout the year.


The Amazon Rainforest is the world’s richest and most-varied biological reservoir, containing over 40,000 plant species. The luxuriant vegetation encompasses a wide variety of trees, including many species of myrtle, laurel, palm, and acacia, as well as rosewood, Brazil nut, and rubber tree. Excellent timber is furnished by the mahogany and the Amazonian cedar.


The Amazon is home to over 2,000 different animal species. These are over 427 mammal species, 1,300 bird species, 427 amphibian species, 3,000 fish species and 378 reptile species. In addition to this, there are over 2 million insect species in the Amazon rainforest. One in five of the bird species lives only in this rainforest.

Worth noting is that, there are specific animals that are only found in the Amazon. Some of these include reptiles like the anaconda and the Jesus lizard; mammals like the howler monkey, golden lion tamarin, jaguar, sloth, spider monkey and the Amazon River dolphin; birds like the toucan and the scarlet macaw; and amphibians like the poison dart frog and the glass frog.

Amazon River

The Amazon Rainforest occupies the world’s second largest river also named Amazon. It is the largest river by volume, and its basin is home to the Amazon Rainforest. Most scientists believe the South American river is at least 4,000 miles (6,400 km) long. The river is made up of over 1,100 tributaries, 17 of which are longer than 1000 miles, and two of which (the Negro and the Madeira) are larger, in terms of volume, than the Congo (formerly the Zaire) river.

Why called lungs of the earth 

The Amazon rainforest functions as a giant air machine that absorbs a large amount of carbon dioxide, and produces oxygen. The Amazon Rainforest is popularly known as the ‘Lungs of Earth’ due to its capability of absorbing about 25% of the earth’s total carbon dioxide emission. It behaves similarly to a pair of human lungs, absorbing the carbon dioxide from the atmosphere and releasing oxygen. The vast biodiversity is home to about tens of thousands of plant species and is on the verge of being destroyed by human activity and climate changes. Recent studies have been published stating that till now, the rain forest has accumulated around 11000 metric tonnes of carbon.

Why so important

The Amazon rainforest has long been recognized as a repository of ecological services not only for local tribes and communities, but also for the rest of the world.

Through transpiration, the Amazon rainforest is responsible for creating 50-75 percent of its own precipitation. But its impact extends well beyond the Amazon Basin, with Amazon rainfall and rivers feeding regions that generate 70 percent of South America's GDP.

The 390 billion trees across the Amazon rainforest locks up massive amounts of carbon in their leaves, branches and trunks. A 2007 study published in Global Change Biology estimated the forest stores some 86 billion tons of carbon or more than a third of all carbon stored by tropical forests worldwide.

The Amazon is home to more species of plants and animals than any other terrestrial ecosystem on the planet, perhaps 30 percent of the world's species are found there.

Within the Amazon Basin, tens of millions of people depend on services afforded by the forest. Rivers are the main vectors for transportation, while logging and collection of non-timber forest products are major industries in many cities, towns, and villages.

Economic Importance

The Amazon rainforest is very important to the South American economy. The Manaus region has a great electronics industry with brands like Sony, Panasonic and others. This is a result of Brazilian economic policies towards the Amazon region in the seventies. The goods produced there are exported to all South American countries and the Brazilian domestic demand.

Another important economic sector is the natural rubber industry; the Amazon rainforest is one of the most important producers of natural rubber in the world. Nowadays 25% of the medicine used by mankind comes from plants, and most plants of the planet are in the Amazon rainforest.

A substantial part of the Amazon rainforest economy comes from illegal activities, like drug dealing, biological trade and wood cutting. Most drugs that reach Europe and United States are not farmed in the region, but Amazon rainforest serves as a path to drug dealers to deliver their products.


An estimated 400-500 indigenous Amazonian Indian tribes (Amerindians) exist today in the Amazon Rainforest. Around 900,000 indigenous people live there. There are about fifty of these tribes who do not have any contact with the outside world. These groups have their own society where kids do not go to a formal school but instead, when they are old enough, are taught what they need to know from their elders. Another interesting fact is that some of the greatest threats to these tribes come from people from the outside world.

With 20,000 total members, the Yanomani tribe is the largest tribe in the Amazon Rainforest. The tribes live off the land and grow different types of fruits and vegetables such as bananas, passion fruit, papayas, corn, manioc and beans and the popular "super fruit", the acai berry.

The many tribes of the Amazon are very diverse in culture, language and heritage. There are approximately 180 different languages spoken by these indigenous people.

Both legal and illegal activities have threatened the Amazon Rainforest tribes. Some of the reasons for declining populations are due to deforestation in the Amazon, war, disease, oil development and drug trafficking. In response, Brazil has set up a type of reservation to protect the Amazonian tribes.


There has been massive reduction of the Amazon forest area by residents in the nine regions. According to the Food agriculture Organisation (FAO), there has been destruction of about 50% of the world rainforest cover. The major reasons for this are human settlement and search for agricultural land.

The increasing demand for yield per hectare of soya has dramatically resulted in forest encroachment and deforestation. 20% of the Amazon biome has already been lost due to deforestation. According to WWF, by 2030 about 27% (more than a quarter) of the Amazon biome will have no trees by if the current rate of deforestation persists.

The changing Amazon Rainforest

In the 20th century, Brazil’s rapidly growing population settled major areas of the Amazon Rainforest. The size of the Amazon forest shrank dramatically as a result of settlers’ clearance of the land to obtain lumber and to create grazing pastures and farmland. Brazil holds approximately 60 percent of the Amazon basin within its borders, and some 1,583,000 square miles (4,100,000 square km) of this was covered by forests in 1970. The amount of forest cover declined to some 1,283,000 square miles (3,323,000 square km) by 2016, about 81 percent of the area that had been covered by forests in 1970.

Why are there fires in the Amazon?

Wildfires often occur in the dry season in Brazil but they are also deliberately started in efforts to illegally deforest land for cattle ranching. Brazil's Amazon rainforest has seen a record number of fires this year.

The National Institute for Space Research (Inpe) said it had detected more than 74,000 fires between January and August - the highest number since records began in 2013. The worst recent year was 2016, with more than 68,000 fires in that period.

The dry season creates favorable conditions for the use and spread of fire, but starting a fire is the work of humans, either deliberately or by accident.

Ricardo Mello, head of the World Wide Fund for Nature (WWF) Amazon Program, said the fires were "a consequence of the increase in deforestation seen in recent figures".

Steps to protect Amazon

Many experts suggest many steps to save the Amazon and the world's rainforests that includes popularizing forest science, zero deforestation, an end to fires, smoke and soot, recover and regenerate forest, Governments and society need to wake up, reducing your paper and wood consumption, reducing your oil consumption, reduce your beef consumption, holding businesses accountable, investing in rainforest communities, supporting the grassroots etc.