Why does wind erosion occurs at a faster rate in deserts than in places with a thicker layer of vegetaion covering the ground

The vegetation protect the soil from being picked up and carried by the wind.

Explanation:  when the soil is bare of vegetation the wind can pick up and carry sand, small rocks and soil. The sand being carried by the wind can act as an abrasive cutting into rocks, causing further erosion. This is nature's form of sand blasting.

Vegetation protects the soil, preventing the wind from picking up and carrying abrasives like sand and small pebbles. The wind by itself has little erosive power. Without the bare soil where wind can pick up sand there is little wind erosion.