STRUGGLING TO SURVIVE: TROPICAL RAIN FOREST

Transcription

1 STRUGGLING TO SURVIVE: TROPICAL RAIN FOREST 1 videocassette minutes Copyright MCMXCVI Rainbow Educational Media 4540 Prelyn Drive Raleigh, NC Distributed by: United Learning 1560 Sherman Ave., Suite 100 Evanston, IL

2 CREDITS Author /Executive Producer: Peter Cochran Costa Rica Production Team: Audiovisuales Chirripo Producers: Drew Irwin Werner Andre Videographer: Roberto Miranda Music: Habitas Content Consultant: Werner Andre United States Production Team Videographer: Peter Scheer Graphics: Roger Meyer Narrators: Richard Cassell Randye Kaye Curriculum Consultant: Michael Worosz Post Production: North Country Media Audio Sweetening: Acme Recording Studios Produced for Rainbow Educational Media by Cochran Communications and Audiovisuales Chirripo

3 Table of Contents Introduction... 4 Objectives... 5 Program Summary...5 Review Questions... 9 Activities Glossary Bibliography Appendix: Organizations to Contact Script... 20

4 Introduction Tropical rain forests occupy only 2% of the earth's surface, but they are disproportionately important to our planet's ecology. They are home to a majority of the earth's species of plant and animal life. Many of these species live only in rain forests. These forests have an important but still poorly understood impact on the world's climate. They also are rich in resources such as food, latex, and timber, and it is estimated that seventy percent of all plants identified as having cancer-fighting properties come from tropical rain forests. Despite their obvious importance, tropical rain forests are seriously threatened by human activity. Half of the rain forests have been destroyed since 1945 as land has been cleared for timber, farming and ranching. As rain forests are destroyed, plant and animal species are becoming extinct at an alarming rate. At the current rate of destruction, we risk losing these treasuries of biological diversity forever within the next few decades. This video program provides an overview of what makes tropical rain forests special, how they are threatened, and what can be done to save them. Grade level: The video is designed for students in grades five through eight, but older and younger students can effectively use the program as well.

5 Objectives After viewing this program, students will be able to: - describe the characteristics of tropical rain forests - name and describe different animals and plants of the rain forest - describe the layers of the rain forest - describe effects of rain forest on climate - name products of the rain forest - discuss causes and effects of destruction of the rain forests - discuss ways people can help to protect and conserve rain forests Program Summary The opening shows different images of rain forests, including shots of colorful animals and plants. The title then appears. After the title, the video shows leaf cutter ants marching in a long file back to their nest. The program then

6 describes how these ants are just one of millions of species of insects found in tropical rain forests and how rain forests also have an unmatched diversity of plants, reptiles, mammals and amphibians. A map of the world shows how tropical rain forests cover just 2% of the earth's surface but contain over 21 3 of its plant and animal species, including many that can be found only in tropical rain forests. The program describes the basic characteristics of tropical rain forests: they are located near the equator, receive a large amount of rain, and exist in lowland areas. The program next shows how a rain forest consists of different layers. The floor gets the least light and has relatively little vegetation except where light gaps have been created by a fallen tree. The soil is shallow because dead organisms are quickly decomposed and their nutrients taken up by plants. The next layer, the understory, consists of the trunks of tall trees, and plants like lianas, woody vines that grow up from the forest floor. The canopy is the top of the rain forest and gets most of the light. Here most of the species of animals and plants live. The emergent layer consists of individual trees that poke up from the canopy and can reach heights of 160 feet or more. The program describes some of the animals and plants found in rain forests. Among the animals shown are tapirs, deer, iguanas, poison dart frogs, toucans, scar-

7 let macaws, sloths, and caimans. Among the plants described are epiphytes such as bromeliads and orchids. Next, the video shows a variety of products that come from the rain forest, including different fruits, chocolate, vanilla, sugar, and cashews The program shows how rubber tappers in the Amazon get latex from rubber trees, and how indigenous people coat their arrows in curare, a drug that doctors use to relax muscles during surgery. The program notes that many useful drugs come from rain forest plants. The program then discusses how teak, mahogany, and other tropical woods are taken from rain forests. However, lumbering has resulted in the destruction of large areas of forest. Rain forests also have been cleared for farms and cattle. The program explains that this is a very inefficient use of the land because the soil is good for only a few years. Such destruction also often leads to erosion. The program goes on to note the effects of deforestation on indigenous people who have lived in the forests for centuries. The program describes how rain forests affect the water cycle by absorbing huge amounts of moisture that they then release back into the atmosphere. When forests are cut down, there is much less rain. The destruction of rain forests may affect global climate in other ways. Burning trees releases large amounts of

8 carbon dioxide, and increased levels of this gas in the atmosphere may contribute to global warming. The program explains that saving the rain forests requires understanding the needs of local people. Economic conditions, for example, often force people to seek short term solutions that result in temporary profit from cutting down forests. The video shows how one country, Costa Rica, is trying to promote economic development while at the same time protecting its forests. The video notes that we, too, have had a role in the destruction of rain forests. For example, the beef in many hamburgers comes from cattle raised in Central America on land that used to be forested. Also, much of the timber cut down is exported to other countries. Finally the program gives specific ideas about what students themselves can do to save the rain forests that remain.

9 Review Questions 1) What are some of the features that distinguish tropical rain forests? They are near the equator. They lie in low elevations and get most of their moisture from a great deal of rain. 2) What are the main layers of the rain forest? They are the forest floor, understory, canopy, and emergent layer. 3) Why has the rain forest canopy become so interesting to scientists? The canopy has probably the most complex communities of life on earth. 4) Name and describe some of the plants that can be found in a rain forest. Plants described in the program include bromeliads, epiphytes, lianas, and orchids. Students may think of other examples. 5) Name and describe some of the animals that can be found in the rain forest. There are numerous examples in the program, including monkeys, tapirs, iguanas, leaf cutter ants, deer, toucans, poison dart frogs and sloths. Encourage students to give other examples.

10 6) Name some of the foods and products we use that came originally from tropical rain forests. Examples in the video include fruits such as oranges, grapefruit, bananas, mangoes, and pineapple; coffee; vanilla; ginger; cashew nuts; rubber; chemicals that can be used as drugs. Students should be encouraged to think of other examples as well. 7) How are tropical rain forests threatened? Rainforests are being cut for timber and to clear land for farming and ranching. 8) How do tropical rain forests affect climate? Tropical rain forests absorb huge amounts of moisture. Much of this moisture is released back into the atmosphere through a process called transpiration. 9) How might the burning of rain forests affect the world's climate? Burning wood releases large amounts of carbon dioxide. Carbon dioxide and other gases in the atmosphere trap heat from the sun. Some scientists think that the burning of rain forests causes the buildup of carbon dioxide in the atmosphere and leads to global warming. 10

11 10) What is meant by sustainable use of rain forest resources? Things taken from the rainforest grow back at a rate at least equal to the rate at which they are taken. Examples of things that can be used in a sustainable way include latex from rubber trees; fruits, and nuts. 11) Why can the loss of one species of plant or animal lead to the loss of others? In the rain forest there is great interdependence among different species. The loss of one can start a domino effect leading to the loss of others. 12) What are some ways that people from other parts of the world, including the United States, contribute to the destruction of rain forests? Examples in the program include fast food hamburgers that may contain beef from cattle raised in Central America on land cleared from forests. Much of the timber from rainforests is exported to other countries, particularly Japan and the United States. 13)What are some ways we can help save the rain forests? We can be environmentally aware consumers and not buy products that promote deforestation. We can write to our elected officials to encourage 11

12 them to pass laws that help protect forests. We can recycle. We can contribute to organizations that help protect the forests that remain. Activities 1) Not everyone can actually visit a rain forest, but many of us can see examples of rain forest life at a zoo. The New York Zoological Society and the San Diego Zoo, for example, have extensive exhibits focused on rain forest life. 2) Ask students to compare tropical rain forests to other kinds of forests, including tropical cloud forests and different kinds of temperate forests. As part of the project, they should collect data on temperature, humidity, amount of sunlight and rain fall. They should also note differences in the types and variety of vegetation and wildlife. 3) The video gives the examples of monkeys and fruit trees to illustrate plant and animal partnerships. Ask students to research and report on other examples. Azteca ants, for example, live on the acacia tree which provides them food, water, and other things they need for survival. The ants, in return, protect the tree by attacking anything that brushes against it. Other possible examples include plants and their pollinators, and leaf cutter ants and the fungus they cultivate. 12

13 4) Ask students to research and report on different native people who have lived in tropical rain forests. Examples include the Mayan of Central America, the Mbuti pygmies of central Africa, the Amerindians of South America, the Lua' of Thailand, and the Penan of Borneo. As part of their report, students could report on how the people hunt or farm to survive, rituals and traditions that reflect where they live, and the effects of encroachment from outside people. 5) The United States has some small tropical rain forests in Hawaii and Puerto Rico. Ask students to research and report on these forests. How large are they now compared to 200 years ago? What, if anything, now threatens their survival? What is being done to protect them? 6) Students can organize a rain forest awareness week. Exhibits could include maps of the world's rain forests, samples of fruits and nuts and other sustainable products we get from rain forests, posters with pictures of rain forest plants and animals, a description of medicines from the forests, and information about the causes of the destruction of rain forests and ways students themselves can help protect them. Students can arrange for a local naturalist to speak about various issues concerning rain forests. 13

14 7) Students can do a survey at home and at school of products whose extraction from rain forests may damage the forests. Examples include furniture made from tropical woods. 8) The Rain Forest Action Network of San Francisco (see Appendix) has established a program that aims to provide funding to help forest people "secure communal land title, guarantee land rights by marking boundaries, and implement projects that maintain the ecological balance of the forest and strengthen the rights and livelihood of its inhabitants". The Rain Forest Action League argues that this is better than "buy-an-acre" programs because they say these programs do not take into account the needs of the indigenous people living in the forest. Students and others who wish to participate in this program can contact the Rain Forest Action Network. 14

15 Glossary bromeliads: any of various, mostly epiphytic tropical plants. They often grow on the trunks and limbs of trees. buttress root: flared base of a tree trunk that helps support the tree in shallow soil canopy: uppermost layer of a forest, formed by the crowns of the trees deforestation: cutting down or clearing away of trees or forests emergent layer: individual trees that rise above the rain forest canopy epiphyte: plant such as an orchid or bromeliad that grows on another plant but does not draw nutrients from it. Epiphytes draw moisture directly from the air. global warming: warming of the earth's atmosphere caused by an increase in carbon dioxide and other gases that trap the sun's heat liana: woody, tropical vine light gap: gap in the forest canopy that allows light to reach the floor 15

16 orchid: type of flowering plant found in tropical rain forests. Many orchids are epiphytic. poison dart frog: kind of frog that lives in Central and South America. It has glands that secrete highly toxic chemicals that are used by native people to coat the tips of their arrows and darts. sustainable use: use of a resource that allows them to regenerate transpiration: process by which plants give off water vapor into the atmosphere tropical rain forest: evergreen forest that lies in low elevations between the Tropics of Cancer and Capricorn and gets most of its moisture from rain understory: forest layer that lies between the floor and canopy and consists of small trees, shrubs and vines 16

17 Bibliography Caulfield, Catherine. In the Rainforest: Report from a Strange, Beautiful, Imperiled World. Chicago; University of Chicago Press: 1984 Crowell, Adrian. The Decade of Destruction. New York; Henry Holt: Forsyth, Adrian. Journey Through a Tropical Jungle, New York; Simon and Schuster: George, Jean Craighead. One Day in the Tropical Rain Forest. New York; Thomas Y. Crowell: Goodman, Billy. The Rain Forest. New York; Tern Enterprise: Lewis, Scott. The Rain forest Book. Los Angeles; Living Planet Press: Mitchell, Andrew W. The Enchanted Canopy. New York; Macmillan: Perry, Donald. Life Above the Jungle Floor. New York; Simon& Schuster: Steger, Will and Bowermaster, Jon. Saving the Earth: A Citizen's Guide to Environmental Action. New York; Knopf:

18 Appendix: Organizations to Contact Environmental Defense Fund 1616 P Street, NW Washington, DC Environmental Project on Central America 349 Church Street San Francisco, CA (415) Friends of the Earth 218 D Street, SE Washington, DC (202) National Resources Defense Council 40 W. 20th St. New York, NY The Nature Conservancy 1800 North Kent Street Arlington, VA (703) Rain Forest Action Network 301 Broadway San Francisco, CA (415)

19 Rain Forest Alliance 270 Lafayette St. Suite 512 New York, NY The Rain Forest Foundation, Inc Broadway New York, NY Sierra Club 30 Polk Street San Francisco, CA

20 Script Male Narrator: Deep in a rain forest in Costa Rica, leaf cutter ants snip the vegetation with their scissors-like jaws. Tens of thousands of these insects then carry their loads back to their nest while others return in the opposite direction to harvest more leaves. Long columns of ants form two-way highways that run for hundreds of yards. The ants don't eat the leaves, however. They use them to cultivate a fungus. This fungus becomes their food. Female Narrator: Leaf cutter ants are only one of millions of species of insects that thrive in tropical rain forests. Most of these species haven't even been identified; and insects provide only a part of the picture. In a single acre of rain forest there may be more kinds of plants than are found in most countries. In tiny Costa Rica about the size of West Virginia you can find over 500 species of birds, more than in all of Canada and the United States. Rain forests also contain an abundant diversity of reptiles, amphibians and mammals. 20

21 Male Narrator: Tropical rain forests have a unique combination of traits that make them ideal incubators of life. In part, these traits are determined by their location. Tropical rain forests lie along the equator in a band of vegetation that includes forests in Malaysia and Africa. The largest forests are in the Amazon region of South America, but there also are important patches in Central America. Their location along the equator insures that tropical rain forests are exposed to strong sunlight all year round. On average, the temperature is around 80 degrees Fahrenheit, and the temperature varies little between January and August. Female Narrator: There are other kinds of forests in the tropics, including tropical cloud forests that are in mountainous areas. These get most of their moisture directly from mist and clouds. Rain forests lie at lower elevations, and get most of their moisture from rain lots of rain from 160 to 400 inches of rain a year. In comparison, New York gets on average about 43 inches a year, and San Francisco gets only 20 inches. 21

22 The combination of strong sunlight and abundant rain supports a diversity of plant and animal life unmatched anywhere else in the world. Altogether, tropical rain forests occupy only about 2% of the earth's surface. Yet, they contain over half of all the earth's species of plants and animals, many of which do not exist anywhere else. Male Narrator: A rain forest is not just one environment but several, each with its own characteristics. In a way, a rain forest is like the different layers of an ocean. Most marine life exists near the surface where there is the most light and it is warmest. The deep ocean floor, on the other hand, is cold and dark; and much less life exists here. The rain forest, too, consists of layers that are as different from each another as the ocean floor is from its surface. Like the ocean bottom, the rain forest floor gets the least light. Even at noon on a sunny day it is dark, and the air is still and humid. The lack of light also means that the floor is relatively clear of vegetation. Only plants that don't need a lot of sunlight grow here. The rain forest floor is covered by only a thin layer of soil. 22

23 Plants and animals that die in the rain forest are quickly decomposed. Most of the nutrients they contain are taken up by the roots of nearby plants rather than becoming part of the soil. Roots lie close to the surface of the ground or simply run along the top. Such roots may not support the weight of a tree very well. So, many trees have large buttresses, finlike growths that extend out from the trunk and help keep the tree from falling over. Sometimes, a large tree does fall over, creating a light gap, a hole in the forest roof through which sunlight can reach the floor. When this happens, trees that were only small, slowly growing saplings shoot up rapidly toward the newly available light. Rivers and streams also are places where sunlight can reach the forest floor. For this reason, you can often find luxuriant plant growth along their banks. Female Narrator: Above the floor is the forest understory. Part of the understory consists of the trunks of the forest's tallest trees. Here, too, you might see a variety of vines, including lianas that start as seeds on the forest floor and grow 23

24 toward the forest ceiling where they spread from tree to tree. Above the understory is the canopy. Seen from below, the canopy forms a kind of umbrella that blocks most of the light from reaching the floor. From above, the canopy is like a lush green carpet. A few trees, called the emergent layer, poke out of the top of the canopy. These emergent trees are the winners in the race for light and can reach 160 feet or more in height. Male Narrator: Some animals in the forest move freely from layer to layer. Iguanas are vegetarians that feed on leaves and spend most of their time in trees, but you may also find them sunning themselves along a river bank. Other animals, such as deer, spend their entire lives on the forest floor. Tapirs, a mammal related to horses and rhinoceroses, are also floor dwellers and like to cool themselves in rivers and ponds. But many species spend almost all their lives in the trees, like the white-faced monkey, which is among the most intelligent of all monkeys, 24

25 and this toucan, which uses its unusual bill to pick fruit. Another tree dweller is the sloth, a mammal that is legendary for being slow and inactive. Female Narrator: The rain forest canopy probably contains the most complex communities of life on earth. Until recently, however, these communities were largely hidden from human view. In Costa Rica, an aerial tram now makes it possible for almost anyone to observe the canopy, including these Costa Rican students. As they travel up from the floor through the canopy, the students enter a very different world, full of an incredible variety of vegetation. While a forest in other places like the United States might contain five or six different species of trees, here there are hundreds of species existing next to each other. As you go higher, the climate changes. While just above the sheltered floor the air is still and the temperature relatively constant, in the canopy there are greater changes of humidity and temperature and more wind. 25

26 Male Narrator: A single rain forest tree illustrates the complexity of life in the treetops. A closer look shows that its branches are covered with plants called epiphytes. Epiphytes don't have roots that go to the ground. Instead they attach themselves to trees without harming them, and get their nourishment from the air and rain. There are many kinds of epiphytes including different types of bromeliads. Bromeliads have overlapping leaves that form a kind of tank that stores water. These water tanks serve as a home to a variety of animals, such as frogs and insects. Many kinds of orchids are also epiphytes. There are thousands of different species of orchids, whose colorful flowers make them among the most beautiful plants of the earth's rain forests Female Narrator: Tropical rain forests may seem far removed from our own lives, but in many ways we reap the benefits of the abundance and diversity of the rain forest life. Many of the foods we eat were originally discovered in rain forests, particularly fruits like oranges, grapefruit, bananas and pineapple. 26

27 And fruits are only part of the story. Chocolate comes from the cocoa plant and sugar from sugar cane. Vanilla, coffee beans, ginger, and cashews are all from rain forest plants. Male Narrator: Rubber comes from a whitish sap, called latex, that comes from rubber trees. In the Amazon, rubber tappers still collect this sap by cutting the bark and letting the sap run into cups. Native people in the Amazon have discovered other uses for rain forest plants. They tip their arrows and spears with curare, a poisonous chemical which conies from a vine and causes paralysis. Scientists have found that this same chemical can be used for medical purposes to relax muscles during surgery. Medical researchers have obtained useful drugs from hundreds of different rain forest plants. Among other things, some of these drugs have been used to treat different kinds of cancer. Researchers are also studying substances produced by animals. In Central and South America colorful poison dart frogs secrete extremely powerful toxins that affect nerves and muscles. 27

28 Another resource from the rain forest is timber. Tropical woods, such as teak and mahogany, are used for products from furniture to chop sticks. Female Narrator: But logging this timber poses a serious threat. Rain forests throughout the world are being cut at an alarming rate, not only for timber, but to clear land for farming and ranching. In Brazil, for example, a highway has been built through the Amazon, opening up previously inaccessible areas to thousands of farmers. The effects have been devastating. From 1979 to 1990 over five million acres of forest in the Amazon were cleared each year. Among other consequences of this destruction, tribes of native people that have lived in harmony with the rain forest for centuries are being displaced. They may soon have nowhere to go. In Central America, much of rain forest has been cut to create pasture for cattle.the soil is so thin, however, that it may be able to support grazing or farming for only a few years. Erosion also has become a problem. Without trees to protect the soil from torrential rains, the exposed soil washes away. 28

29 Male Narrator: The effects of destruction of rain forests can be farreaching. Life in the rain forests is diverse, but it is also fragile. In a given section of forest, there may be many species of animals and plants, but very few individuals of any one species. Destroying even a small part of a rain forest may mean that all the individuals of a species are lost. There are also intricate relationships between different species, including partnerships between specific plants and animals. For example, monkeys like this howler monkey eat fruit, and in turn many fruit trees depend on monkeys to disperse their seeds. While such partnerships are not unique to rain forests, the destruction of just one species of plant or animal can threaten the survival of many others. This is Werner Andre, a Costa Rican naturalist. Werner Andre: This enormous biodiversity that you find in the neotropics is very badly affected when you lose some individuals of different species, because everybody depends on everybody else. Once you lose one you may start a chain reaction that will go step by step, creating a domino effect. 29

30 Female Narrator: Destruction of rain forests has other consequences. Rain forests receive almost half of the earth's rainfall. Much of the water is absorbed by plants. These plants then release moisture back into the air through a process called transpiration. This moisture collects in clouds, and returns again as rain. But as rain forests are cut down, this cycle is disrupted. When it rains, there are few trees and plants to capture and absorb the water. In some areas, the climate has become drier because the water isn't being recycled back into the atmosphere. Some scientists even think that this has an effect on weather patterns worldwide. The burning of rain forests may affect the world's climate in other ways. Burning wood releases large amounts of carbon dioxide into the atmosphere. Carbon dioxide and other gases trap heat from the sun. There is disagreement among scientists, but some are concerned that the burning of rain forests will contribute to global warming, an increase in the temperature of the earth's atmosphere that results from greater levels of carbon dioxide and other gases. 30

31 Male Narrator: There are many reasons for preserving the earth's rain forests, but it is also important to understand the needs of the countries that contain these forests. Take Costa Rica. In many ways, this small country has done much to preserve its natural environment. It has established an extensive system of national parks that protect many of its rain forests and cloud forests. Costa Rica also devotes over 25 per cent of its national budget to education. As part of their schooling, students learn about the importance of the country's ecology. But Costa Rica's population is rapidly growing, and many of its people are poor. This puts continuing pressure on the forests that remain unprotected. For many, cutting down forests in order to farm or raise cattle seems the only way to make a living. Also, Costa Rica is burdened with a large debt owed to other countries and desperately needs to find ways to raise money. Some see selling timber as a way of raising muchneeded cash. With such problems in mind, the Costa Rican government and some non-government organizations are looking for solutions. 31

32 This is Irene Araya Ortiz, a lawyer with the Ministry of Natural Resources, Energy, and Mines. Irene Araya Ortiz: Our country is now trying to achieve an equilibrium between the development of the forest and preservation of its natural resources. For this purpose, we have established a judicial department that is responsible for farmers. One of its aims is to find ways for small landowners, to use the land, that are acceptable so that we can still protect the natural environment. Female Narrator: In one approach, agricultural experts are teaching farmers how to plant trees where rain forests have already been cut down. Here farmers are being shown an experimental tree farm. While such places can not come close to matching the diversity of plant life in a rain forest, the trees can later be harvested for timber and the land replanted again. This reduces the pressure to cut down trees in the forests that remain undamaged. Costa Rica is also trying to promote ways of logging in the rain forests themselves that protect them from long term and possibly irreversible damage. One method they are experimenting with involves cutting selected trees only in narrow strips of land. The 32

33 unaffected forest next to these strips provides seeds that will regenerate the cleared areas with hundreds of different species. Eventually, it is hoped, the land will return to its original state. Male Narrator: The rubber tappers in the Amazon provide another model for using the resources of the rain forests. Tapping the rubber trees for their latex sap doesn't damage the trees. The sap is an example of a sustainable rain forest product. "Sustainable" means that it can be obtained over and over again without causing harm. Other examples of sustainable products include fruits like mangoes and different kinds of nuts. Female Narrator: Several countries have started to promote tourism to rain forests. By attracting visitors from around the world, protected parks in these countries provide income and jobs for local people as rangers, researchers, and guides. There is a risk, however, that poorly managed tourism will damage the environment. The aerial tram in Costa Rica is an example of how this risk can be avoided. 33

34 This is Donald Perry, who was among the first scientists to explore the canopy and who is responsible for building the tram. Donald Perry: We expect that in the future there will be more and more people wanting to see sensitive habitats. We want to keep these habitats open to people, but we don't want them to affect nature. So, we have designed a system that takes people into nature without causing damage to the habitat. We like to say here that we put the people in the cages, and not the animals. Male Narrator: Many people share responsibility for the destruction or survival of the earth's rain forests, even people who live far away from them. For example, we've seen that huge areas of rain forests in Central America have been cut down for pasture to raise cattle. However, most of the beef is shipped to the United States to meet America's appetite for fast food hamburgers. Without the demand for this meat, thousands of square miles of rain forest would have been spared. 34

35 Similarly, most of the timber from rain forests is shipped to other countries, particularly Japan and the United States. Female Narrator: One way every person can help save the rain forests is by not buying products that promote their destruction. For example, we can avoid buying furniture and other products made from tropical woods. It is difficult to know where the beef in a hamburger comes from, but we can write to fast food companies to try to find out. We can also write to Congress to encourage our elected representatives to pass laws requiring companies to identify on labels where their beef conies from. Another thing we can do is recycle used paper. Recycling reduces the demand for timber from rain forests and other kinds of forests. Finally, we can donate money to organizations that are trying to preserve rain forests. Costa Rica, for example, has a children's rain forest preserve that has been purchased with donations from students from many different countries. What is the risk of doing nothing? Listen to naturalist Werner Andre. 35

36 Werner Andre: Well, right now we're losing about an acre a second. At that rate in the next twenty years there's not going to be any of this left. And we haven't even learned what is in here what kind of medicines all kinds of marvelous things that are hiding in here just waiting for somebody to discover them, if we let it survive. Male Narrator: Since this video began, probably over 3,500 acres of rain forest have been cut down or burned. This is equal to the area of about 3,000 football fields. Destroyed along with these forests, are plants that range from emergent trees that are over 160 feet tall to orchids and other epiphytes. Female Narrator: As the rain forests are destroyed, more and more species of animals are threatened with extinction, and more might be lost. Perhaps a rain forest plant or animal holds the chemical secret to a cure for cancer or AIDS. Male Narrator: By destroying these forests, we may be permanently damaging the land. We may even be changing the earth's weather patterns. 36

37 Female Narrator: But there is still time to save many of the rain forests that remain. There is still time to save these treasuries of the earth's greatest asset, the diversity of its life. 37

38 CLOZE EVALUATION QUESTIONS STRUGGLING TO SURVIVE: TROPICAL RAIN FORESTS NAME DIRECTIONS: Select the answer, from the four choices given, by circling the correct letter. 1. Providing a unique environment for a diversity of animal and plant life, are now being threatened with extinction. One such environment in Costa Rica is home for over 500 species of birds, more than in all of Canada and the United States. 2. Tropical rain forests have a special combination of characteristics that make them ideal for producing abundant life forms. Although rain forests occupy only 2% of the earth's surface, they contain over of all of the earth's plant and animal life. Since many of these life forms do not exist anywhere else; it is vitally important to protect the rain forests from extinction. 3. Like any land or ocean environment, rain forests have distinctive parts or areas. The area in which there is little vegetation is called the. This part of the rain forest receives the least amount of sunlight and is covered by a thin layer of soil. As plants and animals decompose, they provide nutrients for other plants to begin their growth. 4. The next layer of the rain forest is located above the forest floor. In this region you would see the trunks of some of the forest's tallest trees. You would also see a variety of vines growing in this part of the rain forest known as the region. One type of vine, the liana, starts as a seed and grows upward, spreading from tree to tree. 5. The third layer of the rain forest is characterized by what might be called an "umbrella" look. This region is called the of the rain forest. As seen from above, this area looks like a lush green carpet. There are a variety of animal life forms that occupy this region of the rain forest. 6. The top area of the rain forest is as unique as the other three layers. In this region known as the, we find trees that have won the race for sunlight. They poke their tops out of the third layer and receive the most sunlight. For this reason, some of the rain forest trees may reach a height of 160 feet or more. This is quite an accomplishment as they have struggled for survival. 7. In a typical forest region there may be six or seven different species of trees. However, in the rain forest there are hundreds of species living next to one another. Often a rain forest plant called attaches itself to a tree without harming it. This plant does not have roots that go to the ground; instead it receives nourishment from the air and rain. 8. Although we do not have any tropical rain forests in the United States, we benefit from them. We get such products as grapefruits, bananas, pineapples, coffee beans and cashew nuts. In addition, a very important product, called, is obtained from the rubber tree. There are also useful drugs that are taken from rain forest trees. 9. The rain forest is endangered because of extensive logging operations and the clearing of tree and plant life for farming and ranching. This not only disrupts the delicate ecosystems, but natural cycles of nature. Trees and plants add moisture to the air through the process of. This moisture rises, collects in clouds, and provides water for all life in the forest. This cycle is drastically reduced when trees and plants are destroyed. 1. A. jungles B. rain forests C. woods D. meadows 2. A. 2/3 B. 1/2 C. 3/4 D. 2/5 3. A. canopy B. understory C. floor D. emergent layer 4. A. mid level B. emergent layer C. canopy D. understory 5. A. canopy B. understory C. light zone D. emergent layer 6. A. upper level B. canopy C. light zone D. emergent layer 7. A. ivy B. epiphyte C. creeper D. snake vine 8. A. rubber oil B. syrup C. latex D. cellulose 9. A. transpiration B. evaporation C. condensation D. melting 10. A. global cooling B. deforestation C. carbon reduction D. global warming 10. When areas of the rain forest are burned to speed up the process of clearing the land, there are other negative consequences. Some scientists believe that the burning of the rain forests produces. This is an increase in the temperature of the earth's atmosphere which results in greater levels of carbon dioxide and other gases. As a result, the heat from the sun is trapped and the long range consequences are detrimental. This form may be reproduced without permission from Rainbow Educational Media.