RainforestsRainforests

Rainforests have been called the womb of life Rainforests have been called the womb of life because they are home to 50-90% of the species on because they are home to 50-90% of the species on Earth. It’s vegetation helps clean the earth’s Earth. It’s vegetation helps clean the earth’s atmosphere and regulate the climate.atmosphere and regulate the climate.

Several hundred million people live in or depend on Several hundred million people live in or depend on rainforests. Many of the world’s important food crops and rainforests. Many of the world’s important food crops and domestic animals have been developed from rainforest domestic animals have been developed from rainforest species. species.

Tropical rainforests are the result of the unique climatic conditions found between the Tropics of Cancer and Capricorn. Constant heat and humidity allow trees and plants to grow year round. Columns of hot air rise and condense out as rain, resulting in annual rainfall of 80 to 400 inches: temperatures average over 80 degrees Fahrenheit.

Structure Structure of the of the

RainforesRainforestt

Emergent treesEmergent trees

Above the upper canopy, Above the upper canopy, tower a few emergent trees, tower a few emergent trees, sometimes as tall as 130 feet. sometimes as tall as 130 feet. In all the forest, they alone In all the forest, they alone enjoy unobstructed access to enjoy unobstructed access to the sun and sky. the sun and sky.

The CanopyThe Canopy

The vast carpet of green The vast carpet of green comprises the canopy that comprises the canopy that hovers over the forest below. hovers over the forest below. It absorbs as much as 90% of It absorbs as much as 90% of the sunlight falling on the the sunlight falling on the forest, darkening the lower forest, darkening the lower regions. Here 65-100 feet up regions. Here 65-100 feet up live butterflies and mammals. live butterflies and mammals. Temperatures here reach 96 F Temperatures here reach 96 F but the humidity is only 60%, but the humidity is only 60%, compared to 90% down below.compared to 90% down below.

The UnderstoryThe Understory

In the undeveloped In the undeveloped forest, the understory is forest, the understory is not the jungle of tangled not the jungle of tangled vines seen in old movies. vines seen in old movies. Undisturbed rainforest is Undisturbed rainforest is clear of vegetation close clear of vegetation close to the ground because so to the ground because so little light filters down little light filters down through the canopy, through the canopy, sometimes only 1 to 2 sometimes only 1 to 2 per cent. Temperatures per cent. Temperatures are cooler, averaging are cooler, averaging about 82 F with humidity about 82 F with humidity at about 90%. at about 90%.

By most estimates, the world’s forests are By most estimates, the world’s forests are disappearing at an alarming rate. Logging, disappearing at an alarming rate. Logging, fires, and land-clearing for agriculture and fires, and land-clearing for agriculture and grazing account for most of the loss. More grazing account for most of the loss. More than 80 percent of the Earth’s natural than 80 percent of the Earth’s natural forests already have been destroyed. forests already have been destroyed.

Among the obvious Among the obvious consequences of consequences of deforestation is the loss of deforestation is the loss of living space. Seventy living space. Seventy percent of the Earth’s land percent of the Earth’s land animals and plants reside animals and plants reside in forests. in forests.

It has been estimated that at It has been estimated that at least 40 species are least 40 species are perishing every day. This is perishing every day. This is a rate hundreds of times a rate hundreds of times faster than at any period in faster than at any period in recent geological time.recent geological time.

Rainforests are also a vital source of medicines. Today, less Rainforests are also a vital source of medicines. Today, less than 1% of the world's tropical forest plants have been than 1% of the world's tropical forest plants have been tested for pharmaceutical properties, yet at least 25% of all tested for pharmaceutical properties, yet at least 25% of all modern drugs came originally from rainforests. modern drugs came originally from rainforests.

70% of all plants known to have anti-tumor properties come 70% of all plants known to have anti-tumor properties come from tropical rainforests. Any one of these could lead to from tropical rainforests. Any one of these could lead to breakthroughs in the treatment of cancer. The potential of breakthroughs in the treatment of cancer. The potential of this living pharmaceutical factory remains almost this living pharmaceutical factory remains almost completely untapped.completely untapped.

The potential and fragility of the rainforests as an invaluable The potential and fragility of the rainforests as an invaluable source of medicine is illustrated in the following account from source of medicine is illustrated in the following account from the the World Rainforest Report no.26:World Rainforest Report no.26:

"Starting with twigs from a Malaysian gum tree, researchers in "Starting with twigs from a Malaysian gum tree, researchers in 1991 isolated a compound that blocked the spread of the AIDS 1991 isolated a compound that blocked the spread of the AIDS virus in human cells. The team sent biologists racing back to virus in human cells. The team sent biologists racing back to Malaysia for more samples from the tree. But when they got to Malaysia for more samples from the tree. But when they got to the swamp, the tree was gone, it had been cut down. And no tree the swamp, the tree was gone, it had been cut down. And no tree found since has produced the same compound. "found since has produced the same compound. "

But the harm doesn’t stop there. Rain forests help But the harm doesn’t stop there. Rain forests help generate rainfall in drought-prone countries elsewhere. generate rainfall in drought-prone countries elsewhere.

Deforestation may have catastrophic global effects as Deforestation may have catastrophic global effects as well. Trees are natural consumers of carbon dioxide—well. Trees are natural consumers of carbon dioxide—one of the greenhouse gases whose buildup in the one of the greenhouse gases whose buildup in the atmosphere contributes to global warming. atmosphere contributes to global warming.

No one knows just how the rest of the No one knows just how the rest of the global ecosystem depends on global ecosystem depends on rainforests, but we may find out in the rainforests, but we may find out in the next 30 to 50 years. That is how long it next 30 to 50 years. That is how long it is estimated that it will take for is estimated that it will take for tropical forests to disappear tropical forests to disappear altogether if current trends continue.altogether if current trends continue.

The AmazonThe Amazon

The Amazon is the world's largest tropical rainforest, spanning Brazil, Colombia, Ecuador, Peru, Bolivia, and Venezuela . Within the 2.5 million square miles of the Amazon Basin resides a wealth of life richer than anyplace else on earth, including 500 mammals, 175 different lizards, 300 other reptile species, tree climbers of every kind, and a third of the world's birds. Millions of species still remain undiscovered.

    The basin also has huge reserves of bauxite, nickel, copper, tin The basin also has huge reserves of bauxite, nickel, copper, tin and timber.  Trees and vegetation in the basin help to balance and timber.  Trees and vegetation in the basin help to balance carbon dioxide and oxygen. carbon dioxide and oxygen. 

The basin holds 20% of the earth’s fresh water, more than the The basin holds 20% of the earth’s fresh water, more than the next six largest rivers combined.  The flow of the Amazon is so next six largest rivers combined.  The flow of the Amazon is so powerful that it dilutes the saltwater more than one hundred powerful that it dilutes the saltwater more than one hundred miles beyond the coastline. miles beyond the coastline. 

Most of the people living in South Most of the people living in South America today have both America today have both European and indigenous European and indigenous ancestors. Until recently, ancestors. Until recently, however, few of them lived in however, few of them lived in the Amazon. They preferred to the Amazon. They preferred to live in established cities along live in established cities along the coasts and in the Andes the coasts and in the Andes mountains.mountains.

But in the past few decades, more But in the past few decades, more and more mestizos have moved and more mestizos have moved to the Amazon. They were to the Amazon. They were having trouble finding work in having trouble finding work in their hometowns and saw their hometowns and saw opportunity in the Amazon. opportunity in the Amazon. Many went looking for Many went looking for agricultural land. Others took agricultural land. Others took jobs in oil fields or other jobs in oil fields or other industries.industries.

About a third of Ecuador About a third of Ecuador lies within the Amazon. lies within the Amazon. Since the 1950s, Since the 1950s, Ecuadorians (mostly Ecuadorians (mostly mestizos) from the mestizos) from the Andean highlands and Andean highlands and the western coastal the western coastal plain have been plain have been migrating to the migrating to the Amazon. Amazon.

The population of the The population of the Ecuadorian Amazon Ecuadorian Amazon has increased from has increased from about 60,000 people in about 60,000 people in the 1950s to 350,000 the 1950s to 350,000 people now. By clearing people now. By clearing forest to build homes, forest to build homes, plant crops, and extract plant crops, and extract petroleum, these petroleum, these people have had a people have had a dramatic impact on the dramatic impact on the rainforest. rainforest.

Settlement in the Ecuadorian Amazon 1960 to 1990

The deforestation of the Amazon basin may have long The deforestation of the Amazon basin may have long reaching effects.  When the trees are removed, we reaching effects.  When the trees are removed, we reduce the amount of carbon dioxide taken from the reduce the amount of carbon dioxide taken from the air.  Some scientists predict that the buildup of carbon air.  Some scientists predict that the buildup of carbon dioxide will cause global warming.  If the temperature dioxide will cause global warming.  If the temperature of the earth rises, polar ice will melt, raising the level of of the earth rises, polar ice will melt, raising the level of the ocean. the ocean.

Plants and animals are also in danger of extinction and Plants and animals are also in danger of extinction and medical advances may be delayed or negated as a medical advances may be delayed or negated as a result of deforestation. result of deforestation.

What is lost as the rain forests disappear is more than What is lost as the rain forests disappear is more than biodiversity and a stable environment. The rain forests biodiversity and a stable environment. The rain forests also hold secrets of nature that might improve and also hold secrets of nature that might improve and extend the quality of people’s lives. extend the quality of people’s lives.

Endangered Species of Endangered Species of South AmericaSouth America

http://www.eduweb.com/amazon.htmlhttp://www.eduweb.com/amazon.html http://www.rainforestinfo.org.au/http://www.rainforestinfo.org.au/ http://passporttoknowledge.com/rainforest/main.htmlhttp://passporttoknowledge.com/rainforest/main.html http://www.nationalgeographic.com/eye/deforestation/http://www.nationalgeographic.com/eye/deforestation/

deforestation.htmldeforestation.html http://www.junglephotos.com/http://www.junglephotos.com/ http://www.mrdowling.com/712-amazon.htmlhttp://www.mrdowling.com/712-amazon.html

Rainforest Quiz!Rainforest Quiz! 1. Where are rainforests found around the 1. Where are rainforests found around the

world?world? 2. What is the world’s largest tropical 2. What is the world’s largest tropical

rainforest?rainforest? 3. What country’s population in the 3. What country’s population in the

rainforest increase from 60,000 to 350,000?rainforest increase from 60,000 to 350,000? 4. Name two causes of deforestation. 4. Name two causes of deforestation. 5. Name two effects of deforestation. 5. Name two effects of deforestation. BONUS: Name the three layers of the BONUS: Name the three layers of the

rainforest. rainforest.

1. What are Costa Rica’s major exports, 1. What are Costa Rica’s major exports, and what do they mean to its economy?and what do they mean to its economy?

2. What is ecotourism, and why is it 2. What is ecotourism, and why is it important to Costa Rica?important to Costa Rica?

3. What is the real condition of the tropical 3. What is the real condition of the tropical rainforests in Costa Rica and throughout rainforests in Costa Rica and throughout the world?the world?

4. What is being done to preserve rain 4. What is being done to preserve rain forest ecosystems?forest ecosystems?

5. Can people and natural ecosystems 5. Can people and natural ecosystems coexist? Explain.coexist? Explain.