W&C: Amazon Rainforest

Question 1

Give an overview of the Amazon Rainforest:

Answer 1

Largest tropical rainforest

Covers 40% of South American landmass

Home to over 1 millon plant species, 500 mammal species, 2000 fish species

Question 2

What contributes to the Amazon’s wet climate?

Answer 2

• High evaporation over Atlantic Ocean
• Wet air blown towards Amazon
• Results in high rainfall

Question 3

What are the characterisics of the water cycle in the Amazon?

Answer 3

• High precipitation - due to evaporation from Atlantic Ocean + warm temps
• High interception - dense canopy

Question 4

Describe the role of the Amazon in the carbon cycle:

Answer 4

Carbon sink

• Increasing CO₂ in atmosphere
• Increasing productivity as vegetation is able to access more CO₂ for photosynthesis

Question 5

Why might we not be able to rely on the Amazon rainforest as an effect carbon sink in the future?

Answer 5

Although the trees are growing more quickly, they are dying younger.

Question 6

How does deforestation affect the water cycle in the Amazon?

Answer 6

• Less interception
• Increased surface runoff = increased flood risk
• Reduced rate of evapotranspiration
• Less water vapour reaches atmosphere
• Fewer clouds = increased risk of drought

Question 7

How does deforestation affect the carbon cycle?

Answer 7

• No roots to hold soil together = heavy rain washes away the nutrient-rich soil = transfers carbon to hydrosphere
• Less leaf litter = no humus = soil cannot support growth = limits carbon absorbed
• Fewer trees = more atmospheric CO₂

Question 8

How does climate change affect the Amazon rainforest?

Answer 8

• Severe droughts - in 2005 and 2010
• Plants + animals adapted to moist conditions and so die in dry climates.
• Droughts = wildfires = CO₂ released

Question 9

What will a 4^oC temperature rise do to the Amazon according to scientist predictions?

Answer 9

Kill 85% of the rainforest.

Question 10

What attempts have been made to limit human impacts in the Amazon rainforest?

Answer 10

Selective logging

Replanting

Environmental law

Protection

Question 11

How has selective logging reduced human impacts in the Amazon?

Answer 11

• Only some trees are felled
• Forest structure is kept - canopy in tact and soil is protected
• Forest can regenerate with limited impact on carbon + water cycles

Question 12

How has replanting reduced human impacts on the Amazon?

Answer 12

• New trees are planted to replace old trees, eg. Peru restoring 3.2 million hectares of forest by 2020.
• Important to plant trees of the same type as those cut down, so variety is kept.

Question 13

How environmental law reduced human impacts in the Amazon?

Answer 13

• Ban the use of wood from unsustainable forests
• Ban excessive logging
• Control land use, eg. Brazilian Forest Code (50-80% of land must be kept forest)

Question 14

How has protection reduced human impacts on the Amazon?

Answer 14

• Central Amazon Conservation Complex (Brazil) protects biodiversity while allowing locals to use the forest sustainably.
• National parks can monitor and prevent damaging activites like logging.