You wipe the sweat off your brow as you try to breathe more deeply. But the air is heavy, still, and hot, and you’re finding it difficult. Your body is covered in perspiration. As you close your eyes, your ears pick up hundreds of different sounds, from the cawing of toucans up above in the treetops to the rustling of hundreds of insects on the ground below. A smile slowly creeps across your face as you remember where you are: the Amazon Rain Forest—otherwise known as the lungs of Mother Earth!
Why is the Amazon Rain Forest often called the lungs of our planet? The Amazon converts carbon dioxide produced on Earth into oxygen. In fact, it releases approximately 20 percent of the oxygen for the entire planet. It is able to do this because the rain forest is a huge, concentrated area of trees, which, like all plants, produce oxygen. The oxygen released from the rain forest is used by people and other species around the globe.
The Amazon Rain Forest is one of the most significant biospheres on our planet. So what is a rain forest? What makes the Amazon Rain Forest so special? And what can we do to help preserve this resource?
A rain forest is exactly what the name suggests: a forest in which rain falls almost constantly. The average annual rainfall in the Amazon is between 130 to 445 centimeters, while the daily temperature ranges from 20 to 34 degrees Celsius. Humidity within the forest hovers between 77 and 88 percent. These conditions make it ideal for plants to grow. It is no wonder Darwin called the Amazon "nature’s hothouse."
The rain forest is made up of distinct layers that contribute to the climate inside. Emergent trees grow to fifty meters and thrust out above the rest of the forest. The next level of plant life is known as the canopy, and it captures the vast majority of the sunlight and rain. Trees in the canopy grow thirty to forty meters tall, with branches that spread out to form a dense cover of foliage that the sunlight rarely penetrates. As a result plants such as younger trees and shrubs growing under the canopy—in a layer called the understory—have a hard time getting enough sun to grow. On the other hand, the canopy prevents moisture, which all plants and animals need, from evaporating.
The scarcity of light results in a fierce fight among the species living in the rain forest. It also means that the majority of movement and activity is seen at the top layer. Rainbow-colored macaws and harpy eagles fly overhead while three-toed sloths hang by their feet, spider monkeys jump from branch to branch, and huge snakes hang from tree limbs. Many animals spend their entire lives high above the ground.
Even though the wildlife lives mainly in the canopy, the floor of the forest is not dead. On the contrary scientists are still cataloging the insects that inhabit the forest floor—some experts claim as many as thirty million species exist. Many of these insects are scavengers, helping in the decomposition of dead plants and animals and providing nutrients for new growth.
The Amazon has long been viewed as an economic gold mine. It is no wonder that people are constantly devising ways to exploit the Amazon Rain Forest’s natural resources for financial advantage. People originally became aware of this forest’s importance because of its rubber trees. In the nineteenth century, rubber was found only in this area. In time, however, the land itself would become the desirable commodity.
In the 1960s the Brazilian government put a tragic policy into effect. The government built the Trans-Amazon Highway and encouraged people to settle deeper in the forest. Many poorer people were lured by offers of free land. Settlers, ignorant of the precarious balance within the rain forest, began a slash-and-burn policy that continues to this day. They cut down all the vegetation in an area, and then burn it in order to clear the land for farming or cattle grazing. Sadly the infertile soil in the rain forest is not suitable for agriculture and is exhausted of its nutrients within a few years. As a result people have to constantly clear more and more land in order to survive. In 1997 satellites recorded 45,000 fires in the Amazon. These fires release carbon dioxide into the air and reduce the number of plants available to replace carbon dioxide with oxygen, doubly worsening the greenhouse effect.
However, the fastest-growing threat to the Amazon Rain Forest is logging. Often huge trees are linked with many smaller trees by vines. When a tree is cut down, the network of vines drags several other trees down with it, causing unnecessary destruction. Added to this tragedy is the fact that logging companies can log much faster than trees can recover. Logged areas need at least seventy years to grow back.
Furthermore logging endangers the rain forest’s delicate ecosystem because it disturbs the intricate web of dependence among species. As scientists began classifying the planet’s species, they discovered that half of them were found in the Amazon and other tropical rain forests. Biologists and botanists alike warn that continued indiscriminate logging will result in the loss of many species that have never been classified, and whose extinctions will have far-reaching effects. For instance, plants called bromeliads, many of which grow on trees, have cup-shaped leaves capable of holding pools of water far above the ground. These pools become a feeding and breeding ground for birds, animals, and insects. If the trees on which bromeliads grow are cut down, the creatures that rely on the pools of water have to struggle that much more for their survival.
Modern medicine also relies a great deal on the plants found within the Amazon Rain Forest. One study shows that 25 percent of the medicines used in the United States and other countries come from rain forest plants. For example, curare, a medicine derived from a vine, has been useful in cardiac surgery. Another drug, called quinine, is a key ingredient in the treatment of malaria. The study also states that 70 percent of the plants shown to be effective against cancer have been found in tropical rain forests. Fewer than 1 percent of the world’s estimated 250,000 tropical plants have been analyzed, so scientists are frantically trying to collect data that may result in cures for the diseases that plague the human race.
In addition, as developers steadily encroach on the Amazon, loss of habitat may destroy another valuable resource for medical development: the native people. Researchers that study the relationships between people and plants hope to be able to record traditional native treatments in order to find out about drugs that can be used to cure modern diseases. However, these native tribes are disappearing at an alarming rate.
What can we do to combat this destruction? In 1987 children from Sweden started to collect money through a variety of fund-raising activities. They were able to raise $100,000 and buy a section of rain forest near the Costa Rican village of Monteverde. This spurred children from countries around the world to do the same. Within a few years, about 42,000 acres had been bought for what came to be called the Children’s Rain Forest. Let’s learn from these children and the many others working to protect the Amazon: If we combine our efforts, we can save this precious resource—the lungs of planet Earth!