7. Causes of large scale
deforestation
1. Population increase, building of settlements, rapid
urbanisation and land transport system
2. Agriculture: shifting cultivation, subsistence
farming, commercial farming
3. Economic development : commercial logging,
mining, hydroelectricity
8. Amazon rainforest conference
In your groups, prepare an argument to
convince the jury that the forest should be
cleared for your interest.
Presentation:
Appoint a spokesperson to speak for 2 minutes
9. Group members
We represent the ______________
______________
Purpose of
clearance
Short term
benefits
Long term
benefits
10. Rapid
Population
urbanisatio
increase
n
High population growth • Build new housing
rate: standard of living estates, town
and provide jobs centres, hospitals,
schools,
Brazil: 184 million in 2005
transportation and
World: 7 billion in 2011 other facilities
11. Land
Settlements transport
systems
Overcrowded cities
in Rio De Janeiro • Transamazonian highway
and Sao Paulo in Brazil cuts across
Anazon forest
Land for housing
and farmland • Fragmentations of forest
12. Agriculture: shifting cultivation
Yanomamo(tribal farmers) cut down
sections of the forest and burn the
trees
When the soil has no more nutrients,
the farmers shift to another location
and repeats the process
14. Agriculture: Commercial
Extensive cattle
farming
ranching by MNC
Clear and burn forest to
replace with grass for
cattle grazing
Commercial crops eg
sugar cane, coffee, soy
beans
15. Eco dvpt: Commercial
logging
Demand for tropical hardwoods
eg timber
Strict licensing by Brazilian
government
Illegal logging
16. Eco development:
Mining
Amazon forest rich in minerals like iron,
ore, gold and fossil fuels
MNC extracts minerals eg tin mining
Demand of oil in the world
17. Eco dvpt:
Hydroelectricity large
Construction of
dams and reservoirs
causes huge areas of
the Amazon rainforest
to be flooded and
destroyed
Eg Itaipu Dam on
Parana river destroyed
700 sq km of
rainforest
19. Spot the causes and
effects of deforestation
Amazon rainforest deforestation
20. After the conference, all of you have a sudden
realisation of the importance of the Amazon rainforest.
In your groups, you will now representing new
identities to save the rainforest!!!
Right of speech
Prepare a 1 minute speech to convince the class that we
should stop deforestation. In your speech, you are to
mention:
- Who do you represent?
- How would you benefit if we conserve the rainforest?
21. Effects of deforestation
Global warming
Deforestation causes increase in carbon
dioxide as less is absorbed by plants
Results in more trapped heat in atmosphere
Leads to global warming
22. Effects of deforestation
Changes to nutrient cycle and soil
deterioration
Trees help to absorb
nutrients in the soil before
it is washed away
When trees decomposed
they release nutrients back
into the soil= nutrient cycle
Deforestation : reduces soil
fertility
Deforestation increases soil
erosion because no topsoil
23. Effects of deforestation
Floods and water quality
Floods are more frequent due to increased
surface run off
Prone to low lying areas and rivers that has
exceeded its capacity
Topsoil washed into the river raises height of
river bed: more flooding
Deposition of organic debris into river affects
pH level : increase acidity
24. Effects of deforestation
Air pollution
Smoke from forest fires
Creates haze: airport closure, affects health of the
people
Caused by natural or human factors eg dry
weather/ agriculture
25. Effects of deforestation
Loss of biodiversity
Extinction of flora and fauna(plants)
Reduction in biodiversity
Eg medicinal drugs like quinine
Eg mico leao dourado in brazil
26. Effects of deforestation
Impact on inhabitants
of the rainforest
Native brazilians or the amazonian Indians have been
reduced from one million to 700,000 presently
Kayapo ( tribal group) can no longer stay in the forest
Tribal members migrate to the cities
Loss of culture, knowledge and way of life
