Hot Deserts Flashcards
(29 cards)
Where are hot deserts located?
15-45 degrees north and south of the equator where the air descends along the tropics. (Tri-cellular model)
What is a desert defined by?
Its lack of rainfall and aridity (less than 250mmpa)
Examples of hot deserts?
Sahara, Arabian, Atacama
What is the diurnal temperature range
The diurnal (day to night) temperature range is high because of the clear skies - this leads to high levels of sunshine/heat during the day, and cold nights.
Adaptations of plants in the hot deserts?
- Some plants (succulents) store water in their roots, stems, leaves or fruit.
- Small leaves, spines, glossy and waxy leaves
- Horizontal or long roots
- Dormant seeds
Adaptations of animals in hot deserts?
- Big ears
- 2 rows of long eyelashes
- Closed nostrils
- Broad flat feet
- Fat stores
- A tough, leathery mouth
- Light, thick woolly fur
Why do some plants store water?
To survive through extreme droughts, etc
Why do some plants have small leaves, spines, glossy and waxy leaves?
To help reduce water loss
Why do some plants have horizontal or long roots?
Horizontal for stability, long taproots to reach groundwater
Why do some plant’s seeds stay dormant?
To germinate very quickly when it rains
Why do some animals have long, double eyelashes?
To protect eyes from sand and sun.
Why can some animals close their nostrils?
To protect from sand
Why do some animals have thick, light, woolly fur?
To protect from sun during day by reflecting heat, and retain warmth at night
Why do some animals have a tough leathery mouth?
To allow them to eat thorny bushes (cacti)
Why do some animals have fat stores?
To provide food for several weeks
Why do some animals have broad flat feet?
To enable them to walk on sand
Challenges of deserts?
- Hot temps make it difficult to work outside
- Extreme aridity makes farming difficult, combined with high rates of evaporation and little rainfall
- Plants and animals have to adapt to survive
- Most communication is very challenging
What is desertification?
The degradation of land to an infertile, unusable state
Where does desertification take place?
In arid areas next to existing deserts, but affects both HIC and LIC countries:
- Spain
- Greece
- SW USA (california)
- The SAHEL area just to the south of the Sahara
What causes desertification?
- Natural events like droughts
- Climate change
- Population growth putting pressure on resources
- Removal of wood for building, or firewood - when trees are removed the roots holding the land together are gone, making soil erosion more common
What is overgrazing?
Sheep, cattle and goats are overgrazing the vegetation. This leaves the soil exposed to erosion
What is over cultivation?
On weak infertile soil, growing crops without adding back enough nutrients or giving the land breaks
What is geopolitics?
Politically unstable areas across the Sahel means that resources are not being used to look after the environment
List 3 ways to reduce desertification
- Zai pits
- Stone bunds
- Create national parks
