Why is the Sahara Desert, the World's largest desert, has so little plant growth (as you can see on this picture taken in Tunisia)? The Sahara Desert is far from the ocean and air is therefore very dry. O The Sahara Desert lies about 30 degrees North, a region that receives little rainfall due to the effects of global air circulation system. The Sahara Desert lies in the rain-shadow of a large mountain range Human have lived in the Sahara for many thousands of years and have destroyed most of the natural vegetation.