Deforestation

Question 1

Define deforestation

Answer 1

Removal / clearance of a forest or stand of trees subsequently leading to uses which may or may not be associated with the forest.

Eg conversion of forest land into farms

Deforestation is occurring in Amazon rainforest

Question 2

Why do humans deforest areas?

Answer 2

Extra agricultural land.

Grow crops/food / plants - income (subsistence) positive reasons.

Loggers (illegally) and also create roads.

Question 3

Natural deforestation

Answer 3

Wildfires

Over Grazing

Question 4

Name 4 main methods which humans use to remove trees

Answer 4

1. slash and burn
2. Clear cutting
3. selective logging
4. Perennial shade agriculture

Question 5

Slash and burn

Answer 5

Main methods

Burning trees

Removes parasites and pests in desired land

Releases co2

Question 6

Clear cutting

Answer 6

Removal of trees / negation despite habitat / species living there

Leaves land bare

Question 7

Selecting logging

Answer 7

Only selected trees cut down

Question 8

Perennial shade agriculture

Answer 8

Similar to selective logging

Leaves large areas of land intact meaning shorter regrowth period

Question 9

Advantages of deforestation on carbon cycle

Answer 9

Wood used for renewable source of energy instead of burning fossil fuels.

Removal of trees can make way for plants which do still absorb co2 (not as much)

Generates income ( not associated with carbon cycle )

Question 10

Disadvantages of deforestation on carbon cycle

1

Answer 10

Trees covert co2 in atmosphere into breathable o2. As forests cleared this slows down the conversion allowing co2 to build up into atmosphere.
Layer of co2 traps gases in atmosphere and radiation causing temp rise.

Question 11

Disadvantages of deforestation on carbon cycle

2

Answer 11

Impacts greenhouse gas effect.

Trees balance amount of co2 into atmosphere through photosynthesis in which plants make their own food with carbon dioxide.

If plants dont photosynthesise then co2 will be suspended in atmosphere instead of being stored in biosphere and in turn less o2 will be released into atmosphere.

Question 12

Disadvantages of deforestation on carbon cycle

3

Answer 12

Trees burnt to clean space it releases carbon dioxide into atmosphere. ( accounts for 30% of carbon released by humans )

Remaining parts (roots) are decomposed by microorganism.

This adds further carbon dioxide to atmosphere contributing to global warming.

Question 13

Overall how does Deforestation change carbon cycle

Answer 13

Positive feedback effect 
Releases co2 directly when burnt.
Biosphere store destroyed.
Equilibrium destroyed / not balanced.
Leads to warming / cc

Question 14

Deforestation in Amazon

Answer 14

WWF estimates that 27% will be without trees by 2030.

Amazon governments are to design “zero net deforestation” to create awareness of issues.

90-140 billion metric tonnes of carbon stored in Amazon forest.

Could double to 48 million ha between 2010 -2030

Question 15

Fast carbon cycling

Answer 15

Xxx

Question 16

Deforestation positive feedback

Answer 16

In normal years, the Amazon alone absorbs three billion tons of carbon
During 2005 drought and deforestation increased.
Amazon gave off 2 billion tons of carbon creating 5 billion tons of heat trapping gases in the atmosphere - causing warming.

In turn reducing the store of carbon in biosphere and increasing store in atmosphere

Question 17

Selective logging and the impact on carbon cycle

Answer 17

It has less of negative impact.

Ghana selective logging occurs frequently.
Residents understand recovery rate and carbon cycle so try to control and maintain carbon in natural rainforests so they increase store of carbon within biosphere.

Question 18

Slash and burn impact on carbon cycle

Answer 18

Increases air pollution
Directly releases carbon
Contribute to global warming.
Causes further decomposition of roots which give off co2

Question 19

Clear cutting and impact on carbon cycle

Answer 19

Clear cutting is main example of why carbon is being released from soilsZ

Soils are one of largest terrestrial carbon store

Question 20

Forests carbon source

Answer 20

A lot of forest eg amazon emit a lot more co2 then previously which mean they absorb much less - due to deforestation / slash and burn.

Plants respire giving off co2

Natural wildfires

Question 21

Forests carbon store

Answer 21

Store a great amount
Trees absorb co2 in photosynthesis and use it to built new leaves / roots
Gives off o2

Creates equilibrium