1. DEFORESTATION

2. Definition Loss of a renewable resource: trees
Cutting down and removal of trees in a forested area
Lead to permanent destruction and eventual disappearance of rainforest
Loss of a renewable resource: trees

3. Causes of deforestation
Agricultural
Subsistence / commercial farming
b)Cattle ranching
2. Logging
3. Mining
4. Others

4. 1. Agricultural activities
Large scale commercial agricultural activities on plantations
Obtained by burning and clearing large areas of rainforest
Eg. By 2020, about 242,000 sq km of the Amazon rainforest has been converted into soya beans farm. Besides being a main ingredient in food for cattle, soya beans are also processed into products such as soya milk and tofu.

5. 2. Cattle Ranching Refers to operating farms to raise cattle
Cleared to allow cattle to graze
Eg. Eighty percent of deforestation in the Amazon rainforest is caused by land cleared for cattle ranching. In 1986, the Amazon had less than 10 million head of cattle; in 2011, this number increased to 79 million

6. 3. Logging Refers to the cutting down of trees for timber
Used to make furniture, building materials and charcoal
Commercial logging destroyed 50,000 sq km of tropical rainforest yearly
For every tree removed, 5 are damaged as well
Eg. China’s huge demand for timber in the making of disposable chopsticks had resulted in heavy logging in the Amazon rainforest.

7. 4. Mining Precious metals are found beneath the tropical rainforest
Cleared to establish mines and roads for transport
Eg. The Carajas Mine in Brazil has a rich variety of mineral reserves. In 2007, 296 million tonnes of iron ore were extracted from the mine, estimating to contain 18 billion tonnes of minerals, including gold and copper.

8. 5. Other reasons
Meet housing and industrial needs of growing populations
Develop infrastructure, eg roads, rail to improve accessibility
Build dams to increase power supply

9. Impacts of deforestation

10. Impacts Environmental impacts Loss of biodiversity
Loss of water catchment area
Enhanced greenhouse effect
2. Economic impacts
Depletion of natural resource
3. Social impacts
Effects on indigenous people

11. Environmental impacts
Destroys the habitats of plants and animals
Resulting in loss of biodiversity
Causing some plant and animal species to become extinct.
This would reduce the variety of resources we can obtain from the forest, eg food, medicine, timber wood, etc
Increase the occurrence of insect-borne diseases
- reduce predators for mosquito
-mosquito population increase
-malaria and dengue fever cases increase
Lack of nutrients will not allow biodiversity to grow again
LOSS OF BIODIVERSITY

12. Environmental impacts
Disrupts water cycle
Absorbs water via roots, release via evaporation and transpiration
Eg. Deforestation in the Amazon rainforest caused by charcoal production is predicted to reduce half of the water catchments by 2020, causing the cost of water to rise by 4 times.
LOSS OF WATER CATCHMENT AREAS

13. Environmental impacts
Greenhouse gases traps heat
Without greenhouse gases, the earth’s average temp would by -18 °C instead of 15 °C
Deforestation increases CO2 in the atmosphere, as trees are carbon storages
ENHANCED GREENHOUSE EFFECT

14. Environmental impacts
Increase surface runoff
Exceeds the carrying capacity of river
Hence floods occur
Topsoil is washed away
Decreases the pH level
Plants and animals
are unable to
adapt
FLOODS AND WATER QUALITY

15. Environmental impacts
Haze will be produced during burning
Causes airport closures and affects the health of people
Eg. In 1997, cases of forest fires with large smoke clouds were detected in the Amazon Rainforest.
AIR POLLUTION

16. Economic impacts Timber, food and water Essential for many industries
Amount of tropical rainforest
destoyed yearly
= Forest resource
valued at US$ 45
billion
DEPLETION OF NATURAL RESOURCES

17. Social impacts Lose their homes Find other ways of survival
Loss of livelihood
Food for thought
-Malaysia’s oil palm
currently provides
600,000 jobs
EFFECTS ON INDIGENOUS PEOPLE

18. SUSTAINABLE MANAGEMENT
CASE STUDY OF AMAZON RAINFOREST, BRAZIL

19. What is sustainable management?
Ensures the use of forest and its resources in a way
At a rate that maintains its biodiversity, vitality and regenerative capacity
That allows present consumers to meet their current needs of the forest without compromising on the needs of the future generation.

20. Measures
Selective logging
Laws and regulations
Afforestation
Conservation
Ecotourism

21. 1. Selective logging
Allows the cutting of only selected trees that meet a certain criteria
Heavy penalties and fines,
including imprisonment
Eg. Brazilian institute of environment and renewable natural resources started a programme in which every tree that is logged must be accounted for
Meets a certain circumference
Only a certain number of trees per hectare

22. 2. Establishment of Laws and Policies
Withdraw the financial help given to land clearance projects
Eg.
In 1988, the Brazilian Govt withdrew the financial support and tax incentives given to cattle ranches in order to limit forest clearance
Cancelled 70% of the logging permits and established measures against illegal logging
Enforcement agents were employed to patrol forests
SUCCESSFUL?
Illegal logging remains a problem, accounting for 80% of logging activities due to weak enforcement and corrupt govt

23. 3. Afforestation
Refers to the planting of trees in areas which were previously bare or were used for other land uses
Eg.
In 2005, a project to grow popular trees like Brazilian Cedar and mahagony was
implemented by the Amazon Ecological Research Centre on a deforested area near Manaus.
This project involved ha of land which turned into a massive tree farm

24. 4. Conservation
Set aside portions of the rainforest as conservation areas
Ensures that plant species are left undisturbed and protected
Eg.
In 2011, only 4% of Amazon Rainforest is protected as environmental reserves. In 2012, the government increased the amount protected by three times.
20% of the Amazon has been set aside as tribal reserves, protecting the Amazonian indians culture and habitat

25. 5. Ecotourism
Provides activities for visitors to explore and learn more about the forest
Activities include natural history study, bird watching and kayaking etc
Funds raised will go back into research and conservation of the rainforest
Eg.
A company called MT Amazon Expeditions organises trips to parts of the Amazon rainforest in Peru organising various activities to raise funds for the conservation of the Brazil Amazon Rainforest.

26. END
Credits to Pearson “All About Geography” Secondary one by Alicia Brown, Audrey Tan, M C Clarke, Shirley Melissa and Dr Wong Poh Poh