The Amazon, by the numbers

– The Amazon is the largest of all rain forests.  It covers 5.5 million square kilometers (2.1 million square miles) and makes up roughly half of all rain forest territory in the world today.  (According to National Geographic Kids, the UK and Ireland would fit into the Amazon 17 times.)

– The Amazon River basin covers 40% of the South American continent.

– The Amazon River is the world’s second longest river, after the Nile River.  It’s nearly 4,000 miles (6,437 km) long and has more than 1,100 tributaries (= smaller rivers that branch off of a main river).  Seventeen of these tributaries are themselves gigantic waterways, longer than 1,000 miles (1,609 km).

– The Amazon is densely packed with life.  One Amazonian shrub will likely have more species of ant in it than exist on the British Isles.  Just 2.5 acres of rain forest could have 500 different species of tree.  It would be impossible, of course, to count the trees in the Amazon, but there are estimates: around 390 billion, scientists say!

– More species inhabit the forests of the Amazon than any other land area on Earth.  Scientists estimate that 30% of the world’s plant and animal species live in the Amazon, including some 40,000 plant species, 16,000 tree species, 2,400 freshwater fish species, 370 reptile types, 1,300 bird types, 430 mammal types, 1,000 amphibian types, and 2.5 million species of insect!  These are only approximate numbers; scientists continually discover new species in the Amazon, which means there are many, many more that are not yet named or described.

The Forest

– The highest part of the forest is called the canopy.  This is made up of the lush tops of trees that grow so close together that they form a solid rainforest “roof.”  Within this part of the forest there is a universe of life so rich that scientists have yet to discover many of the species, which live up there.  The top of the canopy – called the overstory – towers more than 100 feet (30 meters) above the ground.

– The understory is the part of the forest that lies below the canopy.  Here shrubs thrive, as well as young trees, just starting to grow.

– The forest floor is almost black because only 1% of the sunlight is able to permeate the massive green cover of the canopy.  It can take ten minutes for raindrops to make it through all the rain forest layers and finally reach the ground.

– The plants and animals of the rain forest exist within complicated systems of relationships that have been evolving for millions of years.  The living things in these systems are interdependent, meaning that if one species vanishes, there is a domino effect: all the species that are linked to it, plus all the species that are linked to each of those species, will be affected.  If a so-called “keystone species” – a plant or animal to which many other species are linked – collapses, then a whole ecosystem could die.

The Wildlife

-The diversity of species in the Amazon is mind-boggling, and scientists are discovering new ones every day.  Many of the animals that live in the Amazon cannot be found anywhere else on Earth. 

– Some better-known species include (mammals) jaguars, pumas, spider monkeys, giant river otters, pink river dolphins, two-toed sloths, (birds) macaws, toucans, many species of hummingbird, (reptiles and amphibians) anacondas, tree frogs, iguanas, (fish) piranhas, neon tetras, giant catfish, and electric eels. 

– But over 90% of the wildlife in the Amazon consists of insects!  There are some 2,000 species of butterfly. (All of Europe has about 321.)  One square mile of the rain forest is home to about 50,000 different insect species.  Ants are the tiny kings of the Amazon.  Some researchers say that if you would amass all the ants of the rain forest, they would weigh more than a collection of any other animal species.

The River

– Without the Amazon River, there would be no Amazon rain forest.  The size of this mighty river is difficult to fathom.  During certain points in the year, its mouth can be up to 300 miles (483 km) wide.  It discharges enormous quantities of water into the Atlantic Ocean in powerful surges.  The current’s force is so strong, that the water from the Amazon River continues to flow for over 100 miles (160 km) before it even starts to mix with the salty waters of the Atlantic.  There are accounts of sailors from long ago who could drink fresh water from the ocean before they even caught sight of South America.  This was Amazon River water they were drinking, that maintained its freshness even far out at sea.

– As you might imagine, such a powerful river carries lots of dirt, sand, and rock along with it.  This collection of loose material from the land is called, “sediment.”  The Amazon carries tons of it all the way from the Andes Mountains to the river’s mouth where much of the sediment collects.  It has formed a river island called Majaro Island, which is the size of Switzerland!

The People

– The Amazon is home to many indigenous people — between 400 and 500 tribes have been living and thriving there for thousands of years.  These groups are deeply integrated into the life of the forest, meaning that they get whatever they need to survive from the forest.  At the same time, they do not disrupt the ecosystems within which they live.  Many of these groups lead lives completely separate from the world outside the forest.

– In Spanish and Portuguese, the Amazon River is called Rio Amazonas.  “Amazonas” comes from the name of a group of women warriors found in ancient Greek mythology.  When Spanish conquistador, Francisco de Orellana, and his men were attacked on the river by a group of indigenous people with long hair (either women or men with long hair), he named the river “Amazonas.”  

The Destruction

– The awe-inspiring vibrancy of the Amazon rain forest is at risk due to human activity.  Every time a tree is cut down, the ecosystem of interdependent organisms that lived on and around that tree is destroyed.  Millions of trees are being cut down at a faster and faster rate.

– 80% of the land that was once rain forest, but is now cleared of trees, is used as cattle pasture.  Most of these cattle are raised for beef consumption around the world, but also for leather and other products.  Brazil in particular is making huge profits from its billion-dollar cattle industry.  Besides the loss of the forest, there are other ruinous environmental consequences that result from the raising of cattle.  The waste from cattle runs off into waterways and contaminates them.  The fires that are used to maintain the grazing lands often spread uncontrollably into nearby forests, burning up acres and acres of trees.  

– Besides cattle ranching – which is by far the biggest driver of deforestation in the Amazon – there are other forms of commercial activity that are destroying the forest, such as soybean farming, mining for oil and gas, and the expansion of cities. 

– The Amazon is a crucial part of a water cycle that influences weather patterns far and wide.  Trees take water from the ground.  This water then releases into the atmosphere, through a process called transpiration, and falls back down to the ground as rain.  When forests are burning or lands are cleared of trees, this cycle is disrupted, and, scientists say, will soon be broken beyond repair if the destruction doesn’t stop.  Much of the lush forest that exists today will turn into hot, dry savanna. 

– 17% of the Amazon rain forest has been lost.  Scientists say that once 20% of the forest is gone, there will be a domino effect of ever-escalating forest loss.  And if climate change is not curbed, it will mean that in the near future, most of the rain forest regions in the central, eastern, and southern parts of the Amazon will become arid land where little can grow.