The Amazon Rainforest is the world’s largest tropical rainforest. It occupies the basin of the Amazon River and its tributaries in northern South America. This basin encompasses 7,000,000 km2, of which nearly 78.5% is covered by the rainforest. The Amazon rainforest spreads across 9 countries. The majority of the forest (60%) is contained within Brazil, followed by Peru, Colombia, and minor parts in Bolivia, Ecuador, Guyana, French Guiana, Suriname, and Venezuela. 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 Amazon is the world's biggest rainforest, larger than the next two largest rainforests — in the Congo Basin and Indonesia — combined.
Other names: It is also known as Amazon jungle or Amazonia.
At one time Amazon River flowed westward. Around 15 million years ago, the Andes Mountains were formed as a result of the collision of the South American tectonic plate with the Nazca plate. The rise of the Andes and the linkage of the Brazilian and Guyana bedrock shields, blocked the Amazon River and caused it to become a vast inland sea. Gradually, this inland sea became a massive swampy, freshwater lake and the marine inhabitants adapted to freshwater life.
Then, about 10 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. Then, 3 million years later, the ocean level receded enough to expose the Central American isthmus** and allow mass migration of mammal species between the Americas.
**isthmus is a narrow strip of land with sea on either side, forming a link between two larger areas of land.
The Ice Ages divided the patches of tropical rainforest into "islands" and separated existing species for periods long enough to allow genetic differentiation. When the ice ages ended, the patches were again joined and the species that were once one had diverged significantly enough to be designated as separate species, adding to the tremendous diversity of the region. About 6000 years ago, sea levels rose about 130 meters, once again causing the river to be inundated like a long, giant freshwater lake.
Francisco de Orellana was the first European explorer to set foot in the Amazon. He was recruited by Gonzalo Pizarro, the brother of the conqueror of Peru, to join an army that in 1541 set out in search of mythical El Dorado, a city allegedly overflowing with gold. The crew never found the mythical city but suffered in the harsh and inhospitable rainforest in the east of the Andes. As the crew fruitlessly drifted along the present-day river Cosa, they found themselves without supplies.
Orellana and his crew set down the Rio Napo by boat in search of the supplies. They continued east and met the first indigenous tribe (probably the modern Ticuna), who fed them, clothed them, helped them build new boats, and dispatched them into the Amazon River itself. The group followed the Napo until its confluence with the Amazon and emerged in the Atlantic in August 1542, and eventually reached Spain via Venezuela.
This came to be known as the first-ever navigation of the Amazon Rainforest in its entirety.
Despite covering only around 1% of the planet’s surface, the Amazon is home to 10% of all the wildlife species we know about – and probably a lot that we don’t know yet. The region is home to about 2.5 million insect species, tens of thousands of plants, and some 2000 birds and mammals, over 3,000 fish species, hundreds of different amphibians and reptiles. Numerous species are discovered every year, and many have yet to even be been seen by us humans.
The vegetation comprises a wide variety of trees, including many species of myrtle, laurel, palm, and acacia, as well as rosewood, Brazil nut, and rubber tree. In rainforests, some of the highest trees on the planet shoot to the sky. Dead plants and animals quickly decompose and their organic matter is utilized by other organisms.
The tallest tree in the Amazon is the Sumaumeira. A species of the Kapok tree, the Sumaumeira can grow to heights of 200 feet and diameters of more than ten feet, towering above their neighbors high up in the jungle canopy.
These rainforests are a gigantic accumulation of biomass. Their plants grow on several levels, like floors in a building. There are tree giants that grow to a height of 60 to 80 meters. Then, there is the middle tree level. Below, it is very dark and humid, because the crowns of the trees are so close together that they act as a green blanket.
Sunlight hardly gets through to the ground. But it is quite bright near the treetops, where most animals live — monkeys, birds, insects, but also snakes and amphibians.
Major wildlife includes jaguar, manatee, tapir, red deer, capybara, and many other types of rodents, and several types of monkeys.
Amazon plants and trees play critical roles in regulating the global climate and sustaining the local water cycle. The forests they form are home to the huge variety of animals found in the Amazon. But their greatest riches lie in the compounds they produce, some of which are used for medicine and agriculture. For Amazon people, both indigenous and recent arrivals, plants are a food source and raw matter for non-timber forest products.
Unfortunately, there are a number of endangered animals in the Amazon Rainforest. Some of the most endangered animals in the Amazon Rainforest are:
It is estimated that 80 percent of the world's green flowering plants are in the Amazon rain forest. About 1,500 species of higher plants (ferns and conifers) and 750 types of trees can be found in the Amazon rain forest.
Some of the endangered plants are:
Treetops form a vast canopy that is characterized by large, thick, overlapping leaves that absorb a lot of sunlight. Most of the sunlight is blocked by this layer and this shades the plants below. This blocked sunlight is converted into energy matter through photosynthesis. Underneath the vibrant canopy, light is scarce and because of that growth is limited. In some places, however, light does come through, such as in the forest gaps, which can be created by falling trees.
Amazon rainforest receives abundant rainfall. In one year, a patch of rainforest will receive between 1500mm - 3000 mm of rainfall. This creates the typical tropical atmosphere of a rainforest with an average temperature of around 24oC or more.
In this rainforest "universe," there are infinite niches for animals — thanks to an abundance of food, like leaves, seeds, fruits, and nutrients. Everything is in the plants. As is the CO2 the trees extract from the atmosphere and store as they grow. All the while, they produce oxygen.
The rain forest also acts as a key climate regulator, producing 20% of the world's oxygen and acting as a carbon sink. However, human activity, in the form of logging, mining, and resource extraction, threatens this critical ecosystem.
The soil in the Amazon rainforest is the poorest and most infertile in the world. The rainforest feeds itself. Most nutrients are absorbed by the plants and do not get into the soil at all. The few plant remains that do reach the ground — leaves or branches — are decomposed in no time by fungi and bacteria thanks to the year-round warm and humid climate. The nutrients released, such as potassium, calcium, and magnesium, are immediately reabsorbed by the roots.
There is virtually nothing left for the soil. Nor can a fertile layer of humus ever form. Just a few centimeters below the top layer of soil, there is nothing more than sand or clay. All nutrients in the rainforest are stored in the plants themselves, not in the soil.
Because of the incessant rain that beats down on the Amazon rainforest, soils are generally poor in nutrients. If one cuts down the forest, it is irretrievably lost. The humus layer is quickly washed out.
Apart from lush green canopies and exotic wildlife, the Amazon Rainforest is home to more than 30 million people. Some 1.6 million of these inhabitants are indigenous, and they belong to more than 400 different indigenous groups. The indigenous tribes live in settled villages by the rivers, or as nomads deep inside the forest.
Before the arrival of explorers in the 16th century, there was a much bigger native population living in the Amazon rainforest. Slowly, the native population begin to decline. This happened due to disease. Explorers brought with them illnesses like smallpox, measles, and the common cold that the native group had no immunity to.
The Yanomami are the largest relatively isolated tribe in South America. They live in the rainforests and mountains of northern Brazil and southern Venezuela. The Yanomami live in large, circular, communal houses called yanos or shabonos. Some can house up to 400 people. The central area is used for activities such as rituals, feasts, and games. The Yanomami have a huge botanical knowledge and use about 500 plants for food, medicine, house building, and other artefacts. They provide for themselves partly by hunting, gathering, and fishing, but crops are also grown in large gardens cleared from the forest. As Amazonian soil is not very fertile, a new garden is cleared every two or three years.
Huge areas of the Amazon Rainforest are destroyed by clearing for farming, timber, roads, hydropower dams, mining, house-building, or other development. Following five major threats are facing the amazon rainforest:
1. Ranching and agriculture - The rainforest is continuously cut down to make room for raising crops and cattle farming.
2. Commercial fishing - Amazon river fish are the main source of food and income for many Amazonian people. The amount of fish needed to feed a growing population, however, may lead to over-fishing, especially if large industries are harvesting fish in order to export to foreign markets.
3. Bio-piracy and smuggling - People take plants and animals from the Amazon to sell abroad as pets, food, and medicine. This leads to a decline in wild populations, normally affecting animals already threatened by habitat destruction and pollution.
4. Poaching - Many people illegally hunt animals to sell as food and raw materials for finished products. Animals, like the giant Amazon river turtle, the Paiche fish, and the Amazon manatee are vanishing from the wild.
5. Damming - Large hydroelectric projects have led to widespread forest loss. This kills off local wildlife, destroys aquatic habitats and affects fish populations, displaces indigenous peoples, and adds carbon to the atmosphere.
Earlier the Amazon rainforest acted as a 'carbon sink' when it absorbed more carbon dioxide than is released through land-use changes and forest destruction. For generations, the rainforest has stored an immense amount of carbon in its soil and enormous trees, playing an important role in keeping the global environment stable.
However, due to deforestation and forest fires, along with warmer temperatures and markedly drier conditions, it is fast losing its ability to absorb carbon dioxide. Certain parts of the Amazon are becoming a source of emissions. Not only does the destruction of rainforest add to carbon dioxide in the atmosphere, but it also creates a 'positive feedback loop' - where increased deforestation causes a rise in temperatures which in turn can bring about drying of tropical forests and increase the risk of forest fires.
1. Buy sustainably sourced products - These are food products that have been produced through responsible practices, from planting down to the selling of these goods. This simply means that the environment was not harmed or negatively affected in making the food. For this reason, buying sustainable food products like bananas and coffee is one step in helping save our rainforests.
2. Use less paper - paper is made from trees. Because of this, whenever we use less paper in whatever way possible is already a huge deal for the rainforests around the globe. Using less paper and recycling the ones that we use can save a ton of trees in the rainforest, which means the ecosystem of our forests will continue to be preserved.
3. Choose products that give back - It’s best to buy less. But when you do buy, choose products from companies that donate to environmental causes.
4. Support indigenous communities - Buying artisanal and fair trade products made by indigenous people is a unique and effective way to protect rainforests and sustainable livelihoods.
5. Reduce your carbon footprint - Your carbon footprint is the amount of carbon dioxide released into the air because of your own energy needs. You need transportation, electricity, food, clothing, and other goods. Your and your family's choices can make a difference.
