Deforestation/Causes

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Objectives

Module Three Objectives


After completion of this module, you should be able to:

  • Identify the causes of deforestation.
  • Appreciate that others may see deforestation as necessary.
  • Develop an understanding of the causes of deforestation.
  • Synthesise information from different texts.
  • Use an atlas to locate information.
  • Identify continents where the majority of deforestation occurs.


Introductory Activity



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Reflection

Wonderings

Reflect on (think about) the photo below and discuss in a group what you see in the picture. Can you answer all the "I wonder ..." questions below?

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Source

  • I wonder what happened here?
  • I wonder why this happened?
  • I wonder who or what did this?
  • I wonder what effect this will have on the people?
  • I wonder what effect this will have on the animals?




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Activity

Activity One: Venn Diagram
  • Your teacher will assign you to groups. Each group will be given an article to read. Summarise the article in point form with each point being on a separate piece of paper. Each group member should choose a point and be sure to be able to explain it when required.
  • Your teacher will explain to you what a "Venn diagram" is. Once the class has regrouped and everyone has had a chance to report his/her point to the class, your teacher will show you how to draw or make a Venn diagram and explain how to use this diagram to determine causes for deforestation common to all articles. You will then be required to rank these causes in the order depicting the highest level of deforestation to the lowest level of deforestation.



The Main Causes of Deforestation

1. Agriculture: People living near the rainforests sometimes cut down the trees in order to create farms for the cultivation of crops. On a larger scale, in some countries whole groups of people move from place to place around the forest, clearing the trees in order to use the land for agriculture. The process of cutting down trees and burning bush in order to clear the land for farming, is known as "slash and burn".

The farmers find that the rainforest's soil is very fertile at first, but as time progresses, these farmers encounter the same problems as the cash crop growers, i.e. the soil loses its fertility and health due to poor farming methods. This causes the farmers to move on, going deeper into the rainforest and destroying more and more of it.

These migrant farmers have become the agents for destruction, but not the cause.

2. Fuelwood collection: People cut down trees in the forest areas to use as firewood. This is their main fuel supply, both for cooking food and for heat. In the Amazon, and potentially other rainforests, the indigenous tribes (who are becoming more westernised) cut down the trees, building stacks of them to burn to make charcoal. They then transport this charcoal to the nearest town to sell, in order to buy food and other goods.

3. Mining and Industrial Development This leads to the direct forest loss of the forest due to the clearing of land to the establish projects. Roads are constructed through previously inaccessible land, further clearing the rainforest. Severe water, air and land pollution occurs from mining and industry.

4. Large Dams: In India and South America, hundreds of thousands of hectares of forests have been destroyed by the building of hydro-electric dams. This happened because a number of people thought that new dams had to be built, otherwise these countries would suffer an energy crisis, i.e. they would not have enough power. These dams are used both to store water and to create electricity. The construction of dams not only destroys the forest, but also displaces (chases away) wildlife, e.g. wild animals, birds and reptiles, as well as indigenous people. These people are then forced to find other land to cultivate.

5. Commercial Logging: Logging simply means cutting down forest trees for wood. Commercial logging companies cut down mature trees that have been selected for their timber. Wood is used for many things, including building, making furniture, and as firewood.

Selective logging is a process of cutting down large trees that are old enough to die and good enough to use for building and furniture. The logging companies justify their action by saying that this method of "selective" logging ensures that the forest regrows naturally, and in time is once again ready for their "safe" logging practices. However, the felling of one "selected" tree tears down with it climbers, vines, epiphytes and lianas. A large hole is left in the canopy and complete regeneration of the forest in this area can take hundreds of years. Also, the tracks made by heavy machinery and the clearings left behind by loggers (where the trees used to be), are sites of extreme soil disturbance which begin to erode in heavy rain. This causes silt (fine sand) and topsoil which is rich in nutrients, to wash away into rivers and streams, which in turn can suffocate the fish and other organisms in the water.

In most cases, the argument for "Selective logging" does not hold true due to the slow-growing nature of rainforests and the destructive logging practices in use: typically, large areas of rainforest are destroyed in order to remove only a few trees.

6. Oil Exploitation: As petrol prices increase, car manufacturers are changing to making cars that run on biofuels instead of petrol and diesel. Biofuels are fuels made from plants, rather than fossil fuels (e.g. petrol). As more people buy these "hybrid cars" the demand for biofuels is increased.

The expansion of palm oil plantations in Indonesia and Malaysia is a response to high petroleum prices, and this means an increase in global demand for biofuels that many people think are “green”. These days even cooking oil is used to convert to a form of diesel.

In addition to local factors, international trends drive deforestation.



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Activity

Activity Two: Bar graph

Every learner is to pair up with one other person. Number yourselves "one" and "two".

Information for person "one"

  • You will be provided with a copy of a bar graph and an atlas.
  • Your task is to describe the bar graph so that your partner is able to draw it without having seen it. You can describe the bar graph in any manner, except by using the names of the countries. These countries can be described by any information that you may find in your atlas, for instance, by naming the capital cities of these countries or that of adjacent countries or by providing geographical landmarks. You are only allowed to reply "yes" or "no" to any of your partner's questions.

Information for person "two"

  • You will be provided with a piece of paper, a colouring implement, a pencil and a ruler.
  • Your task is to re-create the bar graph supplied to person "one", by using the information provided by your partner. You are not allowed to look at your partner's graph or ask any questions that will elicit "yes" or "no" answers. You may only use the clues and the atlas from your partner, to complete the task.


Exchange your graphs only when you think that they are the same. How close are the two graphs?
Now answer the following questions:

  1. Looking at the bar graph, which five countries have destroyed the most forests?
  2. Which continent(s) are these five countries situated in?
  3. Which five countries have destroyed the least forests?
  4. Which continent(s) are the five countries which destroyed the least forests, situated in?
  5. What is the name of the country at the very bottom?
  6. By what name was this country previously known?
  7. What is the capital of Indonesia?





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Activity

Activity Three: Word Bank

Add new vocabulary to your Word Bank and make sure that you have spelt them correctly. These words and their definitions will help you to write a report at the end of the unit.



Summary



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Assessment

Assessment One: KWL Chart

Return to the KWL chart. As you have now reached the end of Module Three, read through all your additions to your KWL chart - can you add anything more? Have you gained any additional knowledge that will help you answer your big question?




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Assessment

Assessment Two: Causes

Use the Venn diagram completed by the class as a visual aid to remind you of what you have already learned, and read the content provided in this module, above. Work with a partner to complete the activities below:

  • Knowledge
    • Compile a complete list of all the causes of deforestation.
  • Comprehension
    • Explain in detail how mining contributes to deforestation.
  • Application
    • In pairs, role-play a situation where one person is a reporter for a local newspaper, radio station or television station, and the other person is a miner, logger or cash crop grower. The reporter asks questions relating to the other person's job. The interviewee (the person being interviewed) answers either positively or negatively, but in the character of his role. Your teacher will provide additional resources to help with the role-play, if needed.
  • Analysis
    • Research one answer or statement from your KWL chart, using the above content.
  • Synthesis
    • Re-write the content in your own words.
  • Evaluation
    • Rank the list of causes you created in the Knowledge section (above) in order of devastation to global forests, "one" being most devastating and "ten" having the least impact on the world. Be prepared to justify your answer based on the information you have already read.






Teacher Notes