Sand dunes play an important role in protecting our coastlines from erosion and flooding.
The presence of these mounds creates a barrier that helps dissipate waves, preventing damage to the beaches. Whether it be storms or very high tides, sand dunes are defenders and protectors of out beloved Daufuskie Island.
Picture this. The wind blows some sand onto a surface of land, and voila – a beautiful pile appears. You guessed it. It’s a sand dune. They’re an important part because without them beach erosion would happen much quicker, if not entirely too quickly. All coastal communities are flooded out due to constant high-powered waves, at least once. This is why keeping a healthy amount of these dunes is so important, among other reasons.
Coastal sand dunes can provide privacy and/or habitats to support local flora and fauna.
Animals such as snakes, lizards, and rodents can live in coastal sand dunes, along with insects of all types. The vegetation of sand dunes is vital for these animals. Further, some animals, such as foxes and feral pigs can use coastal dunes as hunting grounds to find food. Birds are also known to utilize coastal dunes as nesting grounds. All these species rely on the sand dunes for survival.
As a dune forms, plant succession occurs.
The conditions on an embryo dune are harsh, with salt spray from the sea carried on strong winds. The dune is well drained and often dry, and composed of calcium carbonate from seashells. Rotting seaweed, brought in by storm waves adds nutrients to allow pioneer species to colonize the dune.
Also, the deep roots bind the sand together, and the dune grows into a foredune as more sand is blown over the grasses. The grasses add nitrogen to the soil, meaning other, less hardy plants can then colonize the dunes.
Young dunes are called yellow dunes and dunes which have high humus content are called grey dunes.
Humus is well-aged compost. Leaching occurs on the dunes, washing humus into the slacks. Dune slacks are depressions in the dune system. Slacks develop well on the exposed tops dunes. It is usually in the slacks that rarer species thrive. Dune slacks’ soil water logs, where only marsh plants can survive.
Human activities can have a negative impact on sand dunes.
When people drive vehicles on dunes, or remove vegetation for firewood or other uses, it can damage or destroy the dunes.
When visiting a coastline, always stay on designated paths and trails. Do not drive vehicles on dunes, and do not remove any plants. By taking these simple steps, you can help to protect these delicate ecosystems.