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Rain Forests: Why Are Rain Forests Important?

Rain Forests. Online ed. 2012. Lexile Measure: 750L.
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The world needs rain forests. Without its green jungles, doctors would lose a valuable source of new medicines. People would have fewer kinds of foods to eat. Rain forests also clean Earth’s water and air. And they keep the planet cool. When forests are cut down, the world’s climate could change.

Earth’s Natural Regulator

Rain forests play an important part in Earth’s ecological health. These forests have been called the “lungs of the world.” Like all plants and trees, those in rain forests take in large amounts of a gas known as carbon dioxide (CO2). It occurs naturally in the atmosphere. It is also produced when living things die and decay. And it is breathed out by humans and other animals. Plants make food by a process known as photosynthesis (foh-toh-SIN-thuh-sis). They take in CO2 from the air. They then mix it with water and minerals from the soil and with sunlight. Oxygen is left over from this process. The plants do not need the oxygen. They “breathe” it out into the air. Animals and people breathe the oxygen in. Plants help keep the air clean and breathable.

Rain forests also help regulate Earth’s climate. For that reason, they are sometimes called the “air conditioners of the world.” The green plants of the rain forest soak up heat from the sun. Without the forest cover, the sun’s heat would bounce back off the land. It would go into Earth’s atmosphere. This would result in a warmer world. The world’s climate would be different without forests.

Nature’s Rainmaker

Rain forests provide another important good for the planet. They make clean water for humans and other living things. This is because a rain forest serves as nature’s rainmaker. A rain forest has its own water cycle. Almost every day rain falls over a rain forest. Most drops do not reach the ground. Instead, the leaves of the upper canopy trees catch much of the water. The rest of the rain evaporates in the bright sunlight and forms water vapor. This is why rain forests are usually misty.

As the water vapor rises into cooler air, it gathers together in small droplets and forms clouds or a steamy mist. Soon, bigger drops form. They are too heavy to stay in the air. They fall back into the forest as rain. Some rain forests are almost always wrapped in clouds and mist. These rain forests are also called cloud forests. The Monteverde cloud forest in the Central American country of Costa Rica is an example.

The breathtaking Monteverde Cloud Forest in Costa Rica.

The breathtaking Monteverde Cloud Forest in Costa Rica.
Peter Essick/Aurora/Getty Images

This blanket of wet air and clouds keeps the rain forest from drying out. The soil on the forest floor is thin and poor. All the soil’s minerals have been taken out by the many plants there. Sometimes there are spots where trees have fallen or been cut down. There, the sun makes the forest floor hard and cracked. The hard soil keeps seeds from sprouting. Seeds that do sprout have no shade to protect them. This makes it hard to grow.

The World’s Medicine Cabinet

The rain forest is not only a source of clean water and air. It also produces lifesaving medicines. A group of people called the Rainforest Alliance says: “There’s a reason why rainforests are called the ‘world’s largest pharmacies [drugstores]’! We have already developed medicines such as those used to fight cancer, diabetes and heart disease from rainforest plants. More cures might be found here one day!”1 About one-fourth of all medicines used in the United States contain ingredients from rain forest plants and even animals.

Native people of the rain forest have long used the bark, roots, flowers, and leaves of plants to cure illnesses. They also make poisons such as curare (kyoo-RAHR-ee) to hunt animals. Amazon rain forest people make curare from the skin of a tree frog. They dip the tips of hunting darts in the curare. They use a blowgun to shoot the dart into an animal high up in a tree. The curare causes the animal’s muscles to relax so much it cannot breathe. Soon, it faints and falls to the ground. The hunters can then easily capture it.

In the 1800s, doctors noticed a strange thing about animals shot with curare darts. Their breathing stopped, but their hearts kept beating. Surgeons now give a little curare to people having an operation. The drug keeps their muscles from moving. This makes the surgeon’s work easier.

Other rain forest plants have also been lifesavers. One is a pretty flowering plant called the rosy periwinkle. It helps cure some forms of cancer. The rosy periwinkle grows in Madagascar. Madagascar is an island country near Africa. Important medicines are made from the little plant. Some help children survive a blood cancer known as leukemia. Nearly all children with leukemia used to die. That is no longer the case. A drug made from the rain forest periwinkle now helps more than nine out of ten children survive leukemia.

The rosy periwinkle, a plant found only in Madagascar, is used in the treatment of childhood leukemia.

The rosy periwinkle, a plant found only in Madagascar, is used in the treatment of childhood leukemia.
© David Muench/Corbis

An aerial view of the tropical rain forest and beach at Masoala National Park in Madagascar.

An aerial view of the tropical rain forest and beach at Masoala National Park in Madagascar.
© Frans Lanting/Corbis

Scientists and doctors have been experimenting with rain forest plants for 200 years now. Their discoveries have saved millions of lives. They have found treatments for cancers, high blood pressure, asthma, and many other illnesses. But only a few rain forest plants have been studied. If the rain forests are destroyed, these plants may be lost forever. Also lost will be life-saving plants that have not even been found yet.

The World’s Grocery Store

Rain forest plants also provide foods that people eat every day. Chocolate is one of them. It comes from the bean-like fruits of the cacao tree. These trees grow in Central and South American rain forests. Fruits like bananas, oranges, grapefruit, papayas, and pineapple also come from tropical rain forests. Common baking spices such as cinnamon, vanilla, and nutmeg come from rain forests, too. Many of the foods found in grocery stores have at least one ingredient that came from a rain forest. Some meals can be made from all rain forest foods.

Chocolate is made from the beans of the cacao tree.

Chocolate is made from the beans of the cacao tree.
© Frans Lanting/Corbis

Breakfast foods such as cereal, milk, eggs, and coffee have roots in the rain forest. Corn and some other grains are used to make breakfast cereal. They came from South America. Dairy cattle were first tamed in the rain forests of Southeast Asia. Long ago people learned to raise chickens that once roamed wild in the Asian jungles. Coffee came from Ethiopia in Africa. Ethiopia is mostly desert now. But it once was covered with thick green forests where coffee plants thrived. Coffee now is grown in Central and South American rain forests.

The rain forest is important to food production. New kinds of plants and animals need to be added to crops and livestock herds. This keeps them healthy. The rain forest can supply the variety needed to keep them strong. Here is an example: A Mexican scientist named Rafael Guzmán discovered a new species of rain forest grass. The grass is related to modern corn (maize). This new grass can fight off many of the diseases that attack and destroy corn crops each year. Teams of scientists are using the new grass to develop a type of corn that can resist disease.

A Precious Resource

The world relies on rain forests for clean air, medicines, and foods. But millions of acres/hectares are being cut down. Scientists are afraid that new medicines might never be discovered. Farmers may lose the chance to grow better crops. Scientists study the causes of rain forest destruction. They want to better understand why this is happening. They can then find ways to stop the loss.

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Words to Know

Changes over time that help a living thing better survive where it lives.
The number and variety of plants and animals found within a specified geographic region.
A large area where plants and animals have adapted to live in a certain climate.
Preserving and protecting rivers, forests, and other natural resources through careful management.
carbon dioxide (CO2:
A gas that occurs naturally in the atmosphere. It is also produced when living things die and decay and when humans and other animals breathe it out.
The Cutting down or clearing of forests.
Travelers who vacation in places where they can see, be with, and learn about nature.
The disappearance forever of a species of plant or animal from the planet.
Water supplies that exist deep beneath Earth’s surface.
indigenous people:
Native people who first lived in a particular region.
The process by which plants use carbon dioxide, water and minerals from the soil, and sunlight to make their own food.
Rain, snow, sleet, or hail that falls to the ground.
A place set aside for a special use only; the place might be for worship or a place where animals or people are safe from harm.
A method of farming used in the tropics in which trees and bushes are cut down and then burned so that crops can be planted.
The practice of using natural resources without using them up or harming the environment.
Having a mild climate that is not very hot or very cold.
water cycle:
The continuous movement of water on, above, and below the surface of the Earth.
Footnotes:1. Rainforest Alliance, “What Are Rainforests?”
Source Citation   (MLA 8th Edition)
Jackson, Kay, and Peggy J. Parks. "Rain Forests: Why Are Rain Forests Important?" Rain Forests, by Peggy J. Parks, Gale, 2012. Our Environment. Kids InfoBits, Accessed 13 Dec. 2019.

Gale Document Number: GALE|SKYGTX156963138