Show:
Causes
Areas effected
Effectes
100
The growth of this population has started desertification
What are humans
100
The biggest desert in the world.
What is the Sahara
100
When desertification occurs ____ becomes almost impossible to use
What is soil
200
When _______ are cut down soil degradation can take place.
What are Forests/ Trees
200
It is estimated that __-__% of dry-lands are already degraded
What is 10-20%
300
When livestock __________, nutrients in the soil eventually are lost leading to a bigger layer of topsoil
What is overgrazes
300
The Sahara is currently expanding at a rate of __ kilometers per year
What is 48
300
____ can build up in the soil making it extremely hard to grow plants
What is salt :D
400
With overgrazing removing vegetation soil ________ can take place
What is Erosion
400
It is estimated that desertification has effected between _ and _ million square kilometers
What is 6 and 10 million square kilometers
400
With topsoil blown away by wind the ___ of plants will be exposed, killing the plant
What are roots
500
If _______ is used poorly salt will build up in the soil
What is Irragation
500
Desertification has contributed to the falling of which empires?
What are Carthage, Greece and the Roman empire