Deforestation why it happens What is deforestation Deforestation

Deforestation & why it happens

What is deforestation? Deforestation It is the cutting down and removal of all or most of the trees in a forested area. If it is not managed properly, it can lead to the permanent destruction and eventual disappearance of a once renewable resource Tropical Rainforest 1980 1990 19. 1 mil km 2 17. 9 mil km 2

Question: Why are trees considered as a renewable resource? A) The will automatically regenerate by themselves B) They can be replanted C) They do not disappear Visit: www. govote. at Code:

Question: Why are trees considered as a renewable resource? However, if the rate A) The will automatically regenerate of deforestation is by themselves faster than the rate of reforestation, then it B) They can be replanted is possible to lose the C) They do not disappear trees forever. Visit: www. govote. at Code:

Deforestation and why it happens? In this section, you will explore these Guiding Questions: 1. What are tropical rainforests? 2. What is deforestation? 3. Where are tropical rainforests found and which areas have been deforested? 4. Why does deforestation occur? 5. How does deforestation impact people and the environment? 6. How should we manage deforestation?

Where are tropical rainforests found? Global distribution of tropical rainforests Less than 5% of the earth’s land surface Equatorial climate (between latitudes 20° N and 20° S) where there is abundant sunlight, high temperatures and heavy rainfall throughout the year High temperatures (of more than 26 o. C, with a range of 2– 3 o. C) and high rainfall (1, 500– 2, 500 mm) annually

Where are tropical rainforests found? Amazon Basin in South America Congo Basin in Africa Refer to textbox pg 88 Southeast Asia World distribution of tropical rainforests

Distribution of tropical rainforests in Singapore Many parts of Singapore were originally covered with rainforests After 1819: Rainforests were rapidly cleared to grow crops and build infrastructure 1882: Only 7 per cent of the original rainforests remained Today: Rainforests occupy an area of about 20 km 2 (3% of total land area) and are mainly found at the Central Catchment Nature Reserve and Bukit Timah Nature Reserve

Question: What is the main purpose of nature reserves? A) To beautify the place B) For recreational activities C) To act as water catchment for the reservoirs for storage of water Visit: www. govote. at Code:

Answer: What is the main purpose of nature reserves? A) To beautify the place B) To act as shed C) To act as water catchment for the reservoirs for storage of water Visit: www. govote. at Code:

Distribution of tropical rainforests in Singapore 1819

Distribution of tropical rainforests in Singapore 2006

Global distribution of deforested areas of tropical rainforest Rainforests are disappearing at alarming rates because of human activities: Agriculture Mining Logging Land clearance (for housing and industries) Remaining rainforests are smaller and broken up into fragments At least 320 km 2 of tropical rainforest disappear each day

Question: What happens when rainforests disappear? Visit: www. govote. at Code:

Answer: There will be less biodiversity in the rainforest, trees are more exposed to winds and may fall Visit: www. govote. at Code:

Global distribution of deforested areas of tropical rainforest Areas of tropical rainforest that have been deforested Refer to pg 92

Global distribution of deforested areas of tropical rainforest Tropical rainforest loss in some countries Refer to pg 92

Global distribution of deforested areas of tropical rainforest Refer to pg 93 In Borneo, logging is one of the main reasons that caused rapid deforestation. If the present rates of deforestation in the world continue, our world’s remaining rainforests could be gone in one hundred years. Deforestation estimates of tropical rainforests in Borneo

Deforestation and why it happens? In this section, you will explore these Guiding Questions: 1. What are tropical rainforests? 2. What is deforestation? 3. Where are tropical rainforests found and which areas have been deforested? 4. Why does deforestation occur? 5. How does deforestation impact people and the environment? 6. How should we manage deforestation?

Why does deforestation occur?

Why does deforestation occur? Agricultural activities Cattle ranching Logging Refer to pg 94 Mining

Why does deforestation occur? Agricultural activities Agriculture is the growing of crops and raising of animals to provide food Shifting cultivation (a form of subsistence farming activity) Have been the traditional cause of deforestation Shifting cultivators grow crops for their own use and consumption They allow land to regain its fertility and for vegetation to regrow when they move to the next plot of land As such, does not pose a major threat to the forest

Question: Do you think this activity would be a major or minor threat to the forest? A) Major B) Minor Visit: www. govote. at Code:

Answer: Do you think this activity would be a major or minor threat to the forest? A) Major B) Minor Visit: www. govote. at Code:

Why does deforestation occur? Large-scale commercial agricultural activities on plantations Burn and clear large areas of the rainforest Crops are grown for cash and are sold to meet both local and global needs As a result, the rate of deforestation has increased greatly!

Why does deforestation occur? Agricultural activities Example: By 2010, about 242, 000 km 2 of the Amazon rainforest have been converted into soya bean farms Major ingredient in food for cattle Also, processed into products such as soya milk and tofu Large areas of rainforest are being cleared for soya bean farms in the Amazon Basin

Why does deforestation occur? Agricultural activities Example: Large areas of rainforest are converted into commercial oil palm plantations in Borneo and Sumatra An oil palm plantation in Malaysia Many everyday products contain palm oil e. g. ice cream, chocolate, chips, soap, toothpaste, pet food An oil palm plantation in Indonesia

Why does deforestation occur? Cattle ranching Involves operating large farms to raise cattle Large areas of rainforest are cleared to create land for cattle to graze For example: Large tracts of the Amazon rainforest are being lost to cattle ranching 80% of deforestation in the Amazon rainforest is caused by land cleared for cattle ranching 1986: Less than 10 million head of cattle 2011: 79 million head of cattle

Why does deforestation occur? Cattle ranching A large amount of beef from cattle in the Amazon is exported to other countries (e. g. USA, Britain)

Why does deforestation occur? Logging The cutting down of trees for timber Commercial logging of tropical hardwoods (teak, mahogany, rosewood) to make furniture, building materials and charcoal Growing demand for timber products Increases logging activities Commercial logging is responsible for destroying 50, 000 km 2 of tropical rainforest every year!

Why does deforestation occur? Logging reduces the number of trees and damages the rainforest as a whole Why? For every tree extracted, five are badly damaged (falling tree will destroy the surrounding trees or smaller-sized plants) Also, the soil is exposed to erosion

Why does deforestation occur? Logging Example: Japan Is one of the world’s biggest consumers of timber A lot of wood is used for their buildings and furniture Much of this supply comes from the rainforest in Borneo

Why does deforestation occur? Logging Example: China Huge demand for timber for making disposable chopsticks and paper Caused heavy logging in the rainforests of Congo and Cameroon in Central Africa, Brazil and Indonesia

Why does deforestation occur? Mining Precious metals and gemstones (gold, copper and diamonds) are found beneath many tropical rainforests Forests are cleared to establish the mines and construct roads to transport the mined materials NASA satellite image showing the extent of deforestation caused by the Carajás Mine, Brazil

Why does deforestation occur? Mining Example: Carajás Mine in Brazil has a rich variety of mineral reserves In 2007: 296 million tonnes of iron ore were extracted (18 billion tonnes of minerals including gold and copper) These minerals are needed to produce electronic products such as computers and telephones as well as electrical wires

Question: What are the main uses of copper and gold minerals? A) For making electronic components B) For making fabric C) For cooking Visit: www. govote. at Code:

Answer: What are the main uses of copper and gold minerals? A) For making electronic components B) For making fabric C) For cooking Visit: www. govote. at Code:

Why does deforestation occur? Although human activities have led to deforestation, some may view these activities as key to development: The clearing of forests provides land for communities to build houses, factories, offices Roads can be built and this makes trade and transport easier Also, the land can be converted to agricultural land to allow the production of more food

Refer to pg 96

Question: 1) From the news article, what are the causes of deforestation? 2) What is the relationship between deforestation and ‘people moving into cities’?

Answer: 1) Farming, large-scale plantations, charcoal production etc. to meet human demands 2) People shift to cities to look for better jobs. With better jobs, they would be able to afford more and better things e. g. food. So to meet with their demands, forests have to be cleared and the land is turned into a cattle pasture (for example) which will supply the beef that they can now afford etc.