Carbon And Water: Amazon Rainforest

Question 1

Rainforest

Answer 1

• largest tropical rainforest and covers 40% of South Americans land mass
• hot and wet climate: dense vegetation
• diverse biosphere

Question 2

Water cycle

Answer 2

• lots of evaporation over Atlantic Ocean
• blow towards Amazon: high rainfall
• Warm temperatures mean that evaporation is high in the rainforest, increasing precipitation.
• Dense canopy, meaning interception is high, meaning less water flows into rivers and does so more slowly than expected.

Question 3

Carbon cycle

Answer 3

• Stores a lot of its carbon in it’s vegetation and soil, making it a carbon sink.
• Increasing concentration of CO2 in atmosphere has led to increased productivity, as vegetation is able to access more CO2 for photosynthesis, increasing the biomass.
• Due to this, amount of CO2 sequestered has increased, making it an even more important carbon store.
• However, it has been suggested that although trees are growing more quickly, they’re also dying younger.
• As a result, we may not be able to rely on the Amazon rainforest to continye to be such an effective carbon sink for the future.

Question 4

Deforestation on WC

Answer 4

In deforested areas, theres no tree canopy to intercept rainfall, so more water raches the ground surface.
There’s too much water to soak into the soil.
Instead the water moves to the rivers as surface runoff, increasing risk of flooding.

Deforestation reduces the rate of evapotranspiration, meaning less water vapour reaches the atmosphere. Fewer clouds form and rainfall is reduced.
This increases risk of drought.

Question 5

Deforestation CC

Answer 5

Without roots to hold the soil together, heavy rain washes away the nutrient-rich top layer of soil, transferring carbon stored into the soil to the hydrosphere.
Less leaf litter, means humus isn’t formed. The soil can’t support much new growth, limiting the amount of carbon stored.
Trees remove CO2 from the atmosphere and store it, so fewer trees means more atmospheric CO2, which enhances the greenhouse effect and global warming.

Question 6

Climate change

Answer 6

Some areas, tempertature is increasing and rainfall is decreasing, leading to drought, like in 2005 and 2010.
Plants and animals living in tropical rainforests adapted to moist conditions, may die in dry weather. Frequent or long periods of drought could lead to extinction of some species, and forest fires which can destroy large areas, releasing lots of CO2 and causing positive feedback.
Scientists predict a 4’ rise could kill 85% of the Amazon rainforest, resulting in a lot of carbon released as the dead material decomposes, and less CO2 taken in through photosynthesis.

Question 7

Selective logging

Answer 7

Only some trees (oldest) are felled, less damaging than felling all. If only a few trees are taken, the forest strucure is kept, as the canopy is still there and the soil isn’t exposed. Allows forest to regenerate.

Question 8

Replanting

Answer 8

New trees planted to replace ones that were cut down. Pery plans to restore 3.2 million hectares by 2020.
It’s important to use the same types of tree as those cut down to keep the variety for the cycles to return to normal state.

Question 9

Environmental law

Answer 9

Laws to help protect rainforest, like:
Laws banning used of wood from forests not managed sustainably.
Laws banning excessive logging
Laws controlling land use e.g. Brazilian forest Code says landowners must keep 50-80% land as forest.

Question 10

Protection

Answer 10

National Parks and Nature Preserves to protect rainforests, e.g. Central Amazon Conservation Complex in Brazil, protecting biodiversity in an area of 49,000km’’ while allowing locals to use it sustainably.
Within these areas damaging activities like logging can be monitored and prevented.