Natural Sand Fence

While spending time on sand dunes on the Outer Banks of North Carolina I noticed an obvious example of a wind break or a natural sand fence. 

The grass slows the wind allowing the finer grains of sand to settle on the leeward side of the plant. 
You can think of it as nature's own sand fence. Sand fences are used to manage where sand is deposited, keeping it out of areas like roads or keeping it in areas like beaches to help control erosion.