Amazon Rainforest

Question 1

Area of South American landmass?

Answer 1

40% / 6.7 million km²

Question 2

Climate?

Answer 2

Hot, wet, dense and humid.

Question 3

Inhabitants?

Answer 3

Many indigenous tribes, 1 million plant species, 500 mammal species and over 2000 fish species.

Question 4

Water Cycle - Reasons for high rainfall?

Answer 4

High evaporation over Atlantic Ocean and warm temperatures causing evapotranspiration in the Amazon.

Question 5

Water Cycle - Reasons and impacts of high interception?

Answer 5

Dense canopy intercepts water and reduces rate it reaches the ground.
This means that water flows into the rivers slower and more steadily.

Question 6

Carbon Cycle - Why is the amazon a carbon sink?

Answer 6

Large amount of vegetation and soil means that the Amazon sequesters more CO2 from the atmosphere than it releases via decomposition.

Question 7

Carbon Cycle - What are the effects of higher atmospheric CO2 levels?

Answer 7

Has led to increased productivity as the vegetation can absorb more CO2 for photosynthesis.
This has caused an increase in biomass stored and a rise in the amount of CO2 sequestered. This is an example of a negative feedback mechanism.

Question 8

Carbon Cycle - Why does relying on the Amazon make us vulnerable?

Answer 8

Although there has been an increase in CO2 sequestration and plant growth, plants are also dying younger so may not be reliable as a carbon sink in the future.

Question 9

Where is deforestation taking place?

Answer 9

South West Brazil, as the main urban areas are expanding.
North East Columbia.

Question 10

What are the effects of deforestation on the water cycle?

Answer 10

Lack of tree canopy in deforested areas reduces interception so water reaches the ground faster. Therefore, surface runoff rises and increases the risk of flooding.

Fewer trees means less evapotranspiration and so lower cloud coverage and rainfall, increasing the risk of droughts.

Question 11

What are the effects of deforestation on the carbon cycle?

Answer 11

Lack of roots and tree canopy leaves the soil vulnerable to soil erosion where heavy rainfall washes away nutrients and carbon into the hydrosphere.

Less leaf litter means humus isn’t formed, limiting new growth and future carbon sequestration.

Question 12

What are the impacts of climate change?

Answer 12

Increased temperature and lower rainfall has led to increased droughts (mainly in 2005 and 2010).

Higher temperatures also increases the risk of forest fires.

Species are adapted to wet and humid conditions so droughts can cause the extinction of some species.

Question 13

Human Causes - Cattle Ranching

Answer 13

This accounts for 80% of deforestation and has been expanded due to improved infrastructure and devaluation of Brazilian Currency.

Question 14

Human Causes - Colonisation

Answer 14

Overcrowding in urban areas due to govt incentives has led to growth into the Amazon.

Question 15

Human Causes - Hydroelectric power generation

Answer 15

In 2010 the construction of the Belo Monte Dam was approved on the Xingu River.
This would flood 400km^2 and displace 12,000 locals and become the 3rd largest dam worldwide.

Question 16

Human Causes - Logging

Answer 16

They often work with cattle ranchers, taking the best trees and burning the rest. Illegal logging is widespread due to valuable trees such as Kapok

Question 17

Human Causes - Mining

Answer 17

Oil and gas are extracted in western Amazonia in Colombia, Ecuador and Peru.
Gold mining occurs in the Brazilian state of Para.
Other minerals mined include manganese, iron and tin.

For this large open cast mines are dug destroying large areas of wildlife.

Question 18

Management - Selective logging

Answer 18

Only some trees are chopped down, typically the oldest ones, whilst most are left standing.
This is less damaging as the forest structure and tree canopy are kept.

Question 19

Management - Replanting

Answer 19

New trees are replanted to replace the old ones that were chopped down or died. Peru planed to replant 3.2 million hectares of forest by 2020.

Its important to replant the same type of trees that were chopped down to keep the initial state of the carbon and water cycle.

Question 20

Management - Environmental laws

Answer 20

These can help protect rainforests by banning the use of woods from forests that aren’t managed sustainably.
This can be done by banning excessive logging and controlling land use.

Question 21

Management - Protection

Answer 21

The Central Amazon Conservation Complex was set up in 2003 and protects the biodiversity of 49,000km^2 whilst allowing locals to use it sustainably.

Within natural parks, logging and other harmful activities can be monitored and prevented.