Cape Henelopen State Park Tour By 360° Visions

Though sand dunes may look simply likes piles of sand strewn with weeds, they are, in fact, much more.

Beach dunes are part of a delicate system to protect marshes, bays and land behind the beach from high water and stormy seas.

Don't be fooled by dunes that appear to be shallow or have breaks in them. The height of a dune is determined by several factors, including the direction the dune is facing, wind velocity and direction, and rainfall.

Those breaks in the dune are important, too. During storms, when waves repeatedly batter the dunes, the dune line can be breached. That is, water can funnel through these breaks without sacrificing the entire dune line.

A dune system left in its natural state will eventually travel landward at a slow pace due to the continuing rise of sea level. The reason it's important for people to stay off the dunes is to prevent damage to the plants growing there.

The large barrier dunes would be highly unstable and would move landward even faster if it weren't for the beach grasses and other delicate plants that can grow under the incredibly harsh conditions confronting the upper beach.

Unless these grasses can develop a root long enough to reach the water table, they won't survive long. Because they are so delicate, walking over them can often kill them, leaving the dune that much closer to collapse.

Dunes extend beyond the initial beach berm. Those closest to it are the barrier dunes. Vegetation on these is limited.

Smaller, more stable dunes are behind these barrier dunes and feature different vegetation, such as beach heather and goldenrod. Still further away, woody plants such as bayberry and huckleberry begin to grow in lower dunes.

All of this is important to the ongoing health of the dune, and why it's important to keep off the dune.