Deserts

Question 1

Plant adaptations to deserts

Answer 1

– Shallow roots to soak up surface water
– No leaves
– Deep roots for water underground
– Small surface area to reduce transpiration
– Spikes are protection
– Holds water in main stem
E.g. Cactus: wide roots, succulent, seads can stay dormant

Question 2

Adaptations of animals in Desert

Answer 2

– Large ears to give off heat e.g hares
– Little urine to save water
– Active at night because it’s cooler
– Burrow to avoid heat
– Few species of plant so high competition
E.g. Camel: two rows of eyelashes, long legs, fat stored in hump

Question 3

Facts about deserts

Answer 3

Distribution – occur along tropics, data: Sahara, anomaly: South East Asia, dry air descending from equator where the rain has already fallen
Climate – less than 250 mm of rainfall, over 50° C in the day, 0°C at night. Arid conditions.

Question 4

Causes of Desertification

Answer 4

Commonly on fringe of deserts
– climate change
– Population growth
– Deforestation
– Overgrazing
– Over cultivation (nutrients)
– Soil erosion

Question 5

How to reduce risks of desertification

Answer 5

– Water and soil management
– Tree planting: providing shade, reduces evaporation, reduces soil erosion.
– Appropriate technology, low cost, low tech.
– Tal Rimah Range in Badia, building stone walls on steep slopes: reduces surface run-off and stores water.

Question 6

Badia, Jordan

Answer 6

• annual rainfall <150 mm, exceeds 40 decrees Celsius
• The Tal Rimah Rangeland Rehabilitation Project aims to reverse the desertification caused by overgrazing in the 1990s
• low stone walls to stop water running down slopes after heavy rainfall
• atriplex (well adapted to semi-desert environments) holds the soils together and provides grazing for sheep and goats
• as soil conditions improve, plants have started to grow, attracting birds and butterflies to the area