Rainforest Concern Module 2 Why do we need rainforests?

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1 Rainforest Concern Module 2 Why do we need rainforests?

2 Rainforest Concern Module 2: Why do we need Rainforest? Before we go any further, there are some words you may not understand, and these words and terms are important to understanding rainforests: Atmosphere is made up of the gases surrounding the earth Carbon Dioxide is a gas in the air, used by plants and trees Decay is when something rots, like old vegetables forgotten in the bottom of the fridge! Drought is when there is no rain so there is a lack of water for farming and drinking Erosion is when soil or rock wears away over time. Wind and water can cause erosion. Global Warming an increase in the earth s normal temperatures, partly due to human pollution Hectare a measurement to explain how big a section of land is (about one and half football pitches) Indigenous means local or originally coming from a certain or specific place, used to describe people, plants, or animals. Irrigation providing farm crops with water, usually from a river, using pipes, drains, or ditches to channel the water Nutrients substances that provide what living things need to grow (we get nutrients from the healthy food that we eat) Oxygen the main gas we need to breathe, which is released by plants and trees Species a type of animal, plant, or other living being They provide a place to live for plants and animals It is said that tropical rainforests contain over 30 million species of plants and animals. That's half of the Earth's wildlife and at least two-thirds of its plant species! In fact, there can be more different kinds of ants on one tree than in the whole of the UK put together! Because most tropical rainforests grow in warm and steamy climates, they contain lots of different varieties of plants. One hectare of lowland rainforest may contain 1000 trees and up to 300 different types of tree! That s not counting all the other kinds of plants that are growing there. That is 30 to 60 times more species of tree than our UK forests which are only likely to have 5-10 different types per hectare. These rainforest plants in turn provide food and shelter for many rare animals that need the rainforest for their survival. It is estimated that the planet loses thousands of species to extinction every year, most of which we don t even know about. If we have only found and described about 1 in 6 of the species on the planet, imagine how many different kinds of plants and animals are becoming extinct that no one has even seen! They help stabilise the world s climate Rainforests store water like a huge sponge. In fact, it is believed that the Amazonian forests alone store over half of the Earth's rainwater! Rainforest trees take water from the forest floor and release it back into the atmosphere as swirling mists and clouds.

3 Without rainforests continually reusing huge quantities of water, feeding the rivers, lakes and irrigation systems, droughts would become more common, potentially leading to widespread starvation and disease. Trees also clean our atmosphere. They absorb the carbon dioxide that we breathe out, and provide the oxygen we breathe in. When rainforest trees are burnt they release carbon dioxide, which pollutes the atmosphere and is believed to contribute to global warming. Even though we depend on trees in this way, we are still removing forests from the planet at a faster rate than they can grow back. Lots of people these days are talking about their carbon footprint. Did you know that according to some scientists, deforestation and burning tropical forest releases the same amount of carbon dioxide into the atmosphere in one day, as 8 million people flying from London to New York! They help to prevent soil erosion It might be surprising to discover that, unlike other kinds of forests, soil in the rainforest doesn t have many nutrients. This is because there are so many trees and plants, they use and store all the nutrients leaving very few in the soil. Tree roots bind the soil together, while the canopy protects the soil from heavy rains. When a tree dies and its trunk falls to the forest floor, it decays and the nutrients it contains go back into the soil. Other trees and plants use their roots to take in these nutrients which will help them grow. However, if trees are removed from the forest, the nutrients are removed with it, which means there are less nutrients for the trees and plants that are left. Also lost is the protection that the trees provided with their roots and the shelter from the forest canopy. When rainforests are removed, their roots can no longer protect the soil, and erosion takes place when the unprotected soil is then simply washed away in heavy rains. This means the soil can be carried away to lowland areas causing mudslides and floods. At the same time because the trees are no longer holding and releasing water into to upland rivers, the water just runs into these lowland areas leaving upland rivers dry. They provide a home for indigenous people Many indigenous people have been living in harmony with the rainforest for thousands of years, depending on it for their food, shelter and medicines. When oil and logging companies come to remove vast areas of forest, they can bring diseases which these people have no resistance to, threatening their survival. Today many indigenous tribes have been forced to move out of their forest homes by outside settlers or governments, or they have had to give up their traditional way of life. Rainforest pharmacy It may surprise you to know that more than 25% of our modern medicines originate from tropical forest plants. Even so, we have only learned how to use 1% of these amazing plants, so imagine the possibilities if we could experiment with the other 99%!

4 Some of the illnesses we can help or cure are leukemia, malaria and high blood pressure. 70% of plants that have anti-cancer properties are only found in rainforests. By destroying rainforests we might be destroying a cure for cancer! Rainforests and the native populations who discovered these medicines could hold the cure to many more diseases if we would only take care of the forests and allow their people to show us it s secrets. The Shaman of a village is the person who treats the sick and who knows the healing secrets of rainforest plants. This knowledge is not written down, but passed on from a shaman to his apprentice. Did you know: Tropical rainforests took between 60 and 100 million years to evolve Tropical rainforests are believed to be the oldest and most complicated land-based ecosystem on earth, as well as one of the most threatened. There are thousands of rainforest plants and animals species still waiting to be discovered. Questions Exercises Q. Explain what a hectare is, and if a hectare of rainforest has different species living in it, what does that mean? A. A hectare is a type of measurement for land or area. Different species means there are different types of animals, plants, or other living beings that would live within that hectare of rainforest.s Q. Name two ways trees in a rainforest help control our weather conditions? A. Three examples were given: Trees take water from the forest floor and release it back in to the atmosphere as swirling mists and clouds, absorb the carbon dioxide that we exhale, and also release oxygen for us to breathe. Q. Why are there very few nutrients in rainforest soil? A. The trees absorb most of the nutrients, so they are stored in the trees. Q. What challenges do indigenous people within the rainforest face when oil and forestry companies enter the rainforest? A. New diseases from the oil and forestry workers, losing their homes, and various dangers associated with new unfamiliar areas. 1. Make a rainforest tree on your own, or as a pair! You will need a little bit of sponge, the lid to an old jam jar (or something similar like the bottom of a plastic milk jug), and some materials supplied by your teacher to build your tree. Step 1 You will need: Scissors, tape, sponge, toilet roll tube, cardboard, leaves and a small milk container. Step 2 Cut the sponge in half, cut the bottom off the milk container, and cut the cardboard down a bit.

5 Step 3 Put the half sponge into the milk container. Step 4 Tape the toilet roll to the sponge, and tape the container onto the cardboard. Step 5 Add leaves to the trunk of the tree, the other half of the tree can be used to create a canopy on top of the tree. Step 6 Put all the trees together and look at all the different trees. Remember there are over 300 types of tree in just one hectare of lowland rainforest. Step 7 Pour some diluting juice and water in and watch the roots soak up the water.

6 2. Answer the following questions in your own words: a) What happens to a tree, and the nutrients within it when a tree dies the rainforest. b) What effect might burning trees have on Global Warming? c If a rainforest is removed what could happen? Why are the tree roots important? 3. In small groups discuss the challenges that indigenous people may face if they were forced to move from the area of the rainforest they call home. While discussing this, create a list of challenges. Are there any advantages? 4. Malaria is something that medicine from tropical rainforest plants has helped cure. What is malaria, and how is it caused? Is Malaria particularly common in certain places?