دانلود رایگان پاورپوینت بیابان زایی تهدید جدی به محیط زیست آفریقا (انگلیسی)

DESERTIFICATION IS A SERIOUS THREAT TO THE AFRICAN ENVIRONMENT
The sahel is shrinking and the desert is growing!
What Are Humans Doing To Cause Desertification?
When Was Desertification Recognized?
How Can Desertification Be Stopped?
What Else Can They Do?
Anything Else?…Yes!
So What’s the Problem?

How Can Desertification Be Stopped?(Draw a picture for each answer with a caption)
Plant trees in the sahel. Trees help to put nutrients back into the soil, add moisture to the air, and cool the ground. (C.A.R.E. group)
Dig water basins to catch run off rain water and keep it near plants (sculpting the land).
Build stone walls along the desert to hold back blowing sand.
They found out certain types of rocks could be used as fertilizer to help vegetation grow.