Rainforests 3.0 Flashcards
6 uses of tropical rainforests
Environment:
- Water catchment
- Green lungs of the world (provide oxygen)
- Flora and Fauna
Social:
- Indigenous ppl
- Medical application
Econ:
- Source of timber
- (also) Medical application
Uses of tropical rainforests (water catchment)
[elab + evid + link]
Elab:
- Stop rain from reaching ground directly
- Water slowly drips from trees and seeps into ground (infiltration)
- Help maintain water supply by collecting and storing it within a catchment area
- Soil traps impurities in rainwater before flowing into reservoirs, providing a clean water supply. (filtration)
Evid:
- The Central Catchment Nature Reserve lies within one of the biggest water catchments in Singapore
Link:
- Thus, rainforests surrounding these reservoirs are protected in order to maintain the quality of water
Uses of tropical rainforests (green lungs of the earth)
[elab + evid + link]
Elab:
- Absorbs carbon dioxide and gives out oxygen for us through the process of photosynthesis
Evid:
- Over 20% of earth’s oxygen is generated by the Amazon rainforest only
Link:
- Shows that tropical rainforests not only help maintain quality of water but also helps to purify the air by providing oxygen
Uses of tropical rainforests (habitat for flora and fauna)
[elab + evid]
Elab:
- Houses over 2 mil species
- Sufficient sunlight and water throughout the year that allows plants to thrive, and in turn provide food for animals
- Continuous canopy is a suitable habitat for plants and animals
Evid:
- Peace Lily, Flying Lemur
Uses of tropical rainforests (indigenous ppl)
[elab + evid + link]
Elab:
- About 60 million indigenous people are currently wholly dependent on the forest.
- They rely on the rainforest for basic necessities such as food, clothing and medicine.
Evid:
The Penan Tribe from Sarawak, The Yanomami Tribe from the Amazon rainforests.
Link:
- Shows that tropical rainforests are important to both the environment and people
Uses of tropical rainforests (medical applications)
[elab + evid]
Elab:
- TRF aka ‘world’s largest pharmacy’ has been a huge source of medicine
- Many foods like Brazil nuts have cancer-fighting abilities
Evid:
- Amazon rainforest, nearly 3000 plant species have been identified to have such properties.
Uses of tropical rainforests (source of timber)
[elab + evid]
Elab:
- TRF supplies about ⅕ of the world’s industrial timber [aka wood used to build things]
- Furniture can last a long time, thus people are willing to pay a high price for these furniture.
Evid:
- Birch, redwood, teak, sandalwood (pick >2 )
Define deforestation
The cutting down and removal of all or most of the trees in a forested area
Causes of deforestation
[Hint: CALM]
- Cattle ranching
- Agriculture
- Logging
- Mining
Cattle ranching
[ elab]
Elab:
- Large areas of rainforests are cleared to create land for cattle to graze
- Meet the increasing demand for red meat
Agricultural activities
[ elab]
Elab:
- Refers to large scale commercial agricultural activities on plantations
Logging
[ elab ]
Elab:
- Commercial logging of tropical hardwoods in Southeast Asia and Africa
- It not only removes trees but other trees also get damaged due to falling trees and the area suffer from erosion as the soil is exposed
Mining
[ elab + evid]
Elab:
- Precious metals and gemstones such as gold, copper and diamonds are found beneath many tropical rainforests
- Thus, they need to clear the RFs to get access to it
- Forests are also cleared to access roads for transport
6 impacts of deforestation
Environmental:
- loss of biodiversity
- Loss of water catchment
- Increased risk of flooding, soil erosion and sedimentation
- Enhanced green house effect
Econ:
- Depletion of natural resources
Social:
- Effects on indigenous ppl
How does deforestation lead to loss of biodiversity
[elab ]
Elab:
- Due to deforestation, it is estimated that millions of plants and animal species have become extinct.
- Furthermore, a variety of resources from the rainforest like food, medicine and water will also be gone
How does deforestation lead to loss of water catchment
(flow chart so it’s a sequence of events not separate points)
[elab + evid]
Elab: 1. When trees are removed/ forests are cleaned, it disrupts the water cycle 2. Less evaporation and transpiration from trees and vegetation 3. Less condensation 4. Less rainfall THUS 5. Decreased water supply 6. Higher water prices
Evid:
- Tanzania, deforestation caused by charcoal production is predicted to reduce half of the water catchment area by 2020
- Cost of water is expected to rise 4 times
How does deforestation lead to increased risk of flooding
[elab pt.1 ]
Elab: Increased risk of flooding
- When the ground is bare due to deforestation, rainwater falls directly on the ground
- Rainwater would flow over the surface more rapidly as surface run off instead of seeping into the ground (infiltration)
- This causes flooding in the surroundings areas
How does deforestation lead to soil erosion and sedimentation, thus the increased risk of flooding
(Flow chart?)
[elab pt.2 ]
Elab: Soil erosion
- When trees are removed and land is exposed
- The impact of the rain will compact the soil
- less infiltration
- More surface run off
- Wash away soil particles on the top soil (soil erosion)
- The soil particles will be washed/ carries into the river (sedimentation), which would affect the quality of water
- This reduces the river’s capacity to hold more water
- Thus, increasing risk of flooding
How does deforestation lead to soil erosion
[elab + evid]
Elab:
- Removal of the top layers of soil by rainwater, wind and destructive human activities like logging
- Washes away soil from exposed land when it rains
Evid:
- Betsiboka river in Madagascar had bright red soil flowing in it after heavy rainfall due to deforestation of the TRFs around it
How does deforestation affect water quality and the effects of sedimentation and the consequences of it
[elab]
- Water quality also affected when eroded soils is washed into the rivers
Several consequences of increased sedimentation:
- Fish eggs are smothered, resulting in lower hatch rates
- Water turns cloudy, preventing sunlight to reach aquatic plants
- Coral reefs end up being suffocated by sediments due to the lack of sunlight
How does deforestation enhance the greenhouse effect
[elab]
Elab:
- Deforestation is one of the main causes of this
- The forests act as a carbon sink to absorb the CO2 and store it as carbon
- W/o trees, the amount of CO2 would increase, trapping more heat
- When trees are cut down, the stored carbon is released into the atmosphere
- Burning of rainforests also release CO2 into the atmosphere
- This excess of GHGs like CO2 being trapped, warming the earth’s atmosphere would lead to the greenhouse effect
How does deforestation deplete natural resources
[Elab + link]
Elab:
- Many developing countries like Brazil and Indonesia rely on TRFs to provide resources for econ growth
- Rapid deforestation destroys the rainforests faster than it can replenish itself
- Forests not sustainable
Link:
- hence, many natural resources provided by rainforests like timber are being depleted
- Industries who rely on these resources will be greatly affected
How does deforestation affect indigenous ppl
[elab ]
Elab:
- The rainforest is home to many indigenous people who rely on the forest for daily necessities and for shelter.
- When the rainforest is removed, this will affect their daily lives and they will be ~displaced~
Cattle ranching
[evid 1 & 2]
Evid 1:
- 80% of deforestation in the Amazon rainforest is caused by land cleared for cattle ranching
- From 1986 to 2011, the no. of cattle heads increased from 6mil to 29mil
Evid 2 (can probably link to evid 1?): - USA and Britain are the 2 largest importers of Brazilian beef raised in amazon
Agricultural activities
[evid 1 & 2]
evid 1 (better evid i think):
- By 2010, approx. 242,000 km square of the Amazon RF was converted into soy farms
- Soy bean is used in cattle food and products such as soya milk and tofu
Evid 2:
- Borneo and Sumatra, large areas of RFs converted into commercial oil palm plantations
Logging
[evid 1 & 2]
Evid 1:
- Japan is one of the biggest consumers as their buildings and furniture are made of wood
- Most of this wood comes from TRFs in Borneo
Evid 2:
- China’s large population of disposable chopsticks and paper has resulted in heavy logging in the rainforests of Congo and Cameroon in Central Africa, Brazil and Indonesia
Mining
[evid]
Evid:
- The Carjás Mine in Brazil has a rich variety of mineral reserves
- In 2007, 296 mil tonnes of iron ore was extracted from the mine which is estimated to contain 18 billion tonnes of minerals including gold and copper
- Many electronic products such as computers and telephones have gold components and copper is used to make electrical wires
How does deforestation lead to loss of biodiversity
[evid, gum tree story]
Evid:
- Starting with twigs from a Malaysian gum tree, researchers in 1991 isolated a compound that blocked the spread of AIDS virus in human cells
- A team of biologists were sent racing back to Malaysia for more samples produced from the tree
- However, the tree was gone and no other tree has since been found to produce the same compound
How to prevent soil erosion caused by deforestation
[prevention]
Prevention:
1. More trees as their roots hold the soil to the ground and keep the ground stable
2. Moss and leaves covering the forest floor serves as a soil cover
THUS
3. Rain is intercepted by the different forest layers before hitting the ground
How does deforestation enhance the greenhouse effect
[evid]
Evid:
- The increase in the earth’s temp. went from 0.54C in 2010 to 0.74C in 2019
- In 2010, the world had 3.92 global hectare of tree cover, extending over 30% of its land area. In 2020, it lost 25.8 million hectares of tree cover.
How does deforestation affect indigenous ppl
[evid]
Evid:
- Guarani community from the Amazon rainforest are living in makeshift camps
- Guarani and Yanomami tribes protesting against deforestation
