Q.1
Which of the following is a disadvantage of afforestation?
  • Trees lock up carbon dioxide
  • Newly planted trees prevent other plants from getting water
  • Trees prevent windblown sand moving to form sand dunes
  • Trees become a source of firewood that will be used in stoves by local people
Q.2
Which of the following is a human cause of desertification?
  • Increased flock and herd size
  • Seasonal rainfall being unreliable
  • Climate change
  • Certain crops going extinct
Q.3
Magic stones are a project in which piles of stones are placed across slopes. How do these help reduce desertification?
  • The stones prevent soil blowing away by holding it down
  • The stones slow surface water run-off and soil erosion
  • The stones stop goats and other grazing animals destroying the vegetation
  • The stones remind people that the soil needs to be protected
Q.4
How can rainfall be made more reliable in areas under threat from desertification?
  • Better weather forecasting
  • Damming of rivers
  • Better crop selection
  • Cloud Seeding
Q.5
Which of the following is a possible strategy to reduce desertification?
  • Havesting branches rather than complete trees for fire wood
  • Controlled burning of grasslands to reduce the spread of wildfires
  • Reducing the number of livestock animals
  • Developing national parks and reserves where local people aren't permitted
Q.6
In areas under threat from desertification, people are forced to use marginal lands. How are these marginal lands defined?
  • Lands along the edges of a desert or a lake
  • Lands that form the boundary between two tribal areas. Grazing here can lead to tribal conflict
  • Lands that have little or no potential for profit. They often have poor soils or other undesirable characteristics
  • Lands that are at the edges of cities and may be heavily contaminated
Q.7
Dams have been built on a number of major rivers to increase the amount of water available for drinking and agriculture. How can artificial irrigation increase desertification?
  • It causes rapid soil erosion
  • It causes salinisation of the soil
  • It causes soil contamination
  • It causes sheet erosion
Q.8
Which of the following is a physical cause of desertification?
  • Overgrazing
  • Irrigation
  • Changing farming practices
  • Climate change
Q.9
Which of the following is a way that planting trees will help reduce desertification?
  • By acting as a wind-break to reduce the amount of sand being blown away
  • By producing water as rainfall in the immediate area
  • By providing a source of sustainable fuel
  • By protecting the remaining soil and allowing a leaf litter layer to develop
Q.10
How can plant science help increase the amount of vegetation in areas and so slow, or even reverse desertification?
  • By developing or discovering more drought resistant versions of crops such as millet and cotton
  • By creating new crops from varieties such as algaes and cactus
  • By changing the ground in specific ways to suit the water-intensive crops that are required
  • By developing treatments and medicines to help the crops survive times when there is little water
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