Deforestation process (AOS_2)

Question 1

spatial distribution of global land cover (define deforestation)

Answer 1

deforestation is the long-term reduction of tree canopy cover to below 10-30%

Question 2

spatial distribution of deforestation during the LGM

Answer 2

• 20,000 years ago
  
  • Global mean temperature cooled by ~8◦C, resulting in less forest
  • Forests were mainly limited to wetter areas near the Equator
  • They did not rise up in altitude
  • Tropical land temperature cooled by ~2.6◦C
• Sea level was 125 metres lower than present

Question 3

spatial distribution of deforestation during the HCO

Answer 3

• 8,000 years ago
  
  • Increases of up to 4◦C near the North Pole, resulting in forests expanding and moving pol-wards
  • Extended to in to higher altitudes
  • Forests covered about 47% of the Earth
  • Current desert regions of Central Asia were extensively forested due to higher rainfall
• This coincided with the first agricultural societies, which led to its own impact on forest cover

Question 4

the distribution of deforestation on a global scale

Answer 4

• 4 billion hectares of forest worldwide
  
  • Forests cover about 31% of the global land cover
  • Climate determines their location
  • Total net loss of 129 million hectares over 1990-2015
  • Prior to the 20th century, deforestation was mainly occurring in the temperate regions of the world
• Mid-20th century, this reversed as the temperate regions slowed while the tropical regions were experiencing a rate of accelerating loss

Question 5

deforestation good statistics

Answer 5

• Deforestation impacts more than 2 billion people who rely on the forests as sources of food and shelter
  
  • Around 18 million hectares of forest is destroyed each year around the world

Question 6

the nature of deforestation as processes

Answer 6

• 80% of deforestation for agriculture including subsistence agriculture, commercial agriculture, logging, and fuel wood
  
  • Deforestation is also caused by fires, pine-beetles, tsunamis
• Forestry and agriculture are responsible for 24% of greenhouse gas emissions

Question 7

natural processes (deforestation)

Answer 7

• Climate change and El Nino will cause a change in the type, the range, the location, and the overall cover of forest
  
  • Wildfires cause a loss of 1% of all forests world-wide. Some forests rely on fire to regenerate, however many do not and are adversely affected. Large tracts of forest are replaced by other species, such as weeds and grasslands
• Pests and invasive species have limited impact, though there are expectations of large impact in certain areas. This is enhanced by climate change

Question 8

human processes (deforestation)

Answer 8

• Social:
  ○ Projects to improve infrastructure, such as mines, dams, and transport leads to forest loss through fragmentation and opening up access to forests
  
  • Economic:
    ○ Supporting of agriculture sector (through govt. subsidies) can enhance value of farming over value of intact forests
    ○ More than 15% of the Amazon’s forest cover had already been lost to cattle ranching and logging by the 1970s
    ○ Economic growth (increase in demand for forest products
  • Political:
    ○ Enforcement of laws to protect forests is difficult due to their remote location
    ○ Countries, particularly poor countries, are susceptible to corruption as forest revenue is very high relative to average incomes
    ○ Wars and civil disturbance can lead to habitat destruction and fragmentation