Section 2 - Deserts Flashcards
What is a desert defined as
An area with less than 250mm of precipitation per year
What temperature can the desert reach in the day
50 celsius
What temperature can the desert reach at night
0 celsius
Describe 3 desert animal adaptations for camels
- 2 sets of eyelashes
- Hump stores fat
- Leathery thick feet
- Closing nostrils
What is the purpose of camels nostrils and eyelashes
It keeps sand out of their eyes
What is the purpose of the camel hump
It stores energy
What is the purpose of desert animals having thick feet
Get a good stance in the stand and so they don’t burn them
Describe 3 plant adaptations for plants
- Bright seeds/ fruit
- Saguaro cactus has spikes
- Plants have long and narrow roots
What is the purpose of bright seeds and fruit
Animals take them and naturally disperse the seeds
What is the purpose of spikes
To ensure animals don’t enter and steal the water
What is the purpose of long and narrow roots
To ensure as much water is taken in as possible
How much water can the saguaro cactus store
8,000 litres
What is desertification
when fertile land becomes dry, cracked and infertile due to excess heat and over farming
Name 3 causes of desertification
- Deforestation
- Overgrazing
- Poor farming practises
How does deforestation cause desertification
The broken nutrients cycle means all nutrients becomes washed away so the soil eventually starts to erode. Also makes the earth get hotter, so more intense heat on land
How does overgrazing cause desertification
The ground is constantly trampled on, causing it to become infertile, when the ground is abandoned it begins to crack
How does poor farming cause desertification
As population increases, more food is needed so they over graze and over farm. Eventually this causes the ground around them to erode, so instead of fixing the problem they move somewhere else and leave the old land to die
How can we prevent desertification
- Plant more trees
- Stone lines
- Plant grass
How much rainfall does the Sahel get
100-300mm
How does planting trees prevent desertification
Acacia trees holds the soil together to prevent erosion. They also shade crops to make sure they have a good yield
How do stone lines prevent desertification
It reduces leeching because it stops the water from slipping away and makes it soak into the ground, fertilising it
How does planting grass prevent desertification
Roots hold the soil together. Also it is cheap and easy to grow
How many people live in the Sahel
50million
How does climate change cause desertification
climate change causes extreme weather, meaning extreme droughts so less vegetation and crops will grow. This means the soil isn’t held together and migrate to other places, so no one looks after the old land
How does population increase cause desertification
It creates more need for energy, farming etc. More energy needed means more desertification for energy and more agriculture for food.
