Global And Local Threats

Question 0

Deforestation (global)

Answer 0

Clearance of forest cover results in loss of biodiversity and resources for indigenous people. Also knock on effects on the good web and nutrient cycle.

Question 1

Climate change (global)

Answer 1

Climate change will occur too rapidly for many species to adapt.
Won’t just lead to increased temperature and changes in rainfall but also more extreme weather events such as floods and storms.
Indirect threats from pests and disease.
Human pressure such as deforestation and pollution worsening the threat.

Question 2

Pollution (global)

Answer 2

Acidification of oceans and acid precipitation on land.
Nitrate and phosphate pollution in lakes and coastal waters.
Airborne pollution eg DDT
Ozone depletion by CFCs

Question 3

Case study: Arctic and GW

Answer 3

Localised shifting of ecosystems poleward. Coniferous forests will expand into the tundra.
The tundra will shrink due to rising sea levels drowning coastal areas.
Increased forest fires and insect infestations are expected to range forests and reduce biodiversity and biomass.
Improved food supply will mean bigger fish sticks - more marine life to catch due to less ice cover.

Question 4

Habitat change (local)

Answer 4

Eg developing land for agriculture or urbanisation inevitably leads to loss of biodiversity. Modern large scale agriculture can lead to drastic habitat change but it can dealt with by creating features such as hedgerows and ponds.
Over exploitation such as over fishing can easily unbalance food webs and lead to species extinction.