Deserts

• Camel

  • Large feet to spread their weight on sand
  • Thick fur on top of body for shade, thin fur to allow heat loss
  • Large surface area to volume ratio to maximise heat loss
  • Ability to tolerate body temps up to 42C
  • Slit-like nostrils and two rows of eyelashes to help keep the sand out
• Thorny Devil


  • Collects water within its many layers of scales and drains it back to mouth
  • Camouflage exterior blends into surrounding environment
  • False head when feeling threatened, bucks its real head between its front legs, the head is larger and thornier
• Fennec Fox


  • Large ears (15cm) help excess body heat to disappear on hot days
  • Only carnivore living in the Sahara desert able to survive without free water
  • Thick fur helps insulate them at nights
  • Sandy fur reflects heat, camouflage and nocturnal lifestyle helps
  • Burrowing slows water loss
• Special physical characteristics of xerophytes

  • Cacti are the best xerophytes
• Characteristics of ephemerals

  • Plants that change their behaviour e.g. grow after raining or produce seeds once a year after it rains
• Desertification


  The process by which fertile land turns into desert, typically as a result of drought, deforestation or inappropriate agriculture
• Over-cultivation


  The excessive use of farmland to the point where productivity falls off due to soil exhaustion
• The Sahel Region is located in Northern Africa in the country of Mali
• Increase in population

  Deforestation for firewood, leaves no longer protect soil from weather
• Increase in cattle


  Roots may be eaten as well as grass, grasslands grazed more intensely, less vegetation means less protection for soil, loose top soil blown away by wind (soil erosion)
• Drought resistant crop strategies

  • Using drought-tolerant crops grown from improved seed varieties supplied by farm Africa
  • Aim to stop desertification with an increase of average yield from 119kg to 275kg
• Water and soil management strategies

  • Cutting terraces on steep mountainsides so heavy rainfall cannot wash the topsoil away
  • On more gentle slopes, building up soil and water behind to filter in and maintain moisture
  • Building up stones in gullies/steel cages with rocks (gabion traps) to reduce rainfall runoff
• Afforestation


  The establishment of a forest or a stand of trees in an area where there was no previous tree cover