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Sand dunes are common features of shoreline and desert environments. Dunes provide habitat for highly specialized plants and animals, including rare and endangered species. They can protect beaches from erosion and recruit sand to eroded beaches. Dunes are threatened by human activity, both intentional and unintentional. Countries such as the United States, Australia, Canada, New Zealand, the United Kingdom, and Netherlands, operate significant dune protection programs.

Stabilizing dunes involves multiple actions. Planting vegetation reduces the impact of wind and water. Fences catch sand and other material. Footpaths protect dunes from damage from foot traffic.

Vegetation

Sand dunes which already exist on the upper beach but vegetation can be stabilized by transplanting plants onto the dune. What type of plants are used is generally dictated by where on the dune the plants are going to be placed. A coastal dune is composed of the foredune, which is the angled side of the linear dune which faces the ocean, the broad sand plain which may or may not be present on some coastal dunes, but is the flat expanse on the top of the dune, and the backdune which is the other angled side of the dune which faces away from the ocean.

Foredune flora

Plants that thrive on the foredune must be tolerant to salt spray, strong winds, and sand burial. Vegetation typically found on the foredune are Ammophila arenaria, Honckenya peploides, Cakile maritima, and Spartina coarctata.

Backdune flora

Plants which thrive on the broad dune plain and backdune have characteristics which cause the grasses to grow together into dense vegetation termed a "Dune Mat" that firmly holds the sand dune together. Vegetation typical of the broad sand plain and backdune are Hudsonia tomentosa, Spartina patens, Iva imbricata, and Eregeron glaucus. Sometimes these species can be invasive to native plant and animal life, however in dunes where no habitat currently exists, they pose no great threat.

After the herbaceous plant species mentioned above have taken root and developed fully on the dune, the next stage of stabilization, or "shrub stage" can begin. During this phase, larger shrubs with deeper extending root systems are introduced to the habitat. Some examples are Empetrum nigrum, Ilex vomitoria, and Vaccinium ovatum. The shrub stage is usually the final phase of stabilization and may last for short or long periods of time depending on microclimatic conditions such as distance from the shoreline, availability of groundwater, or salt spray effects.

Public and private coastal management

Often, long stretches of shoreline are not owned by a single owner, but are instead divided into segments usually owned by many separate owners. Because of this, it is sometimes difficult to stabilize an entire linear dune which may run the length of the beach due to private unwillingness to cooperate or from extended deliberation when deciding if and how to best stabilize the dune. Vegetation on private lots is chosen at the discretion of the lot owner and thus can be decided based on aesthetic appearance and personal taste rather than on traits that would best characterize the plant for that position. Because of this, dune integrity can be segmented, known as a fragmented or decoupled gradient which creates weak points in the dune that are ineffective against mitigating floods. Fragmented dune gradients are in an environmentally degraded state, however they can provide unique opportunities for nature to grow where it otherwise may not have.

References

1. "A guide to managing coastal erosion in beach/dune systems". Scottish Natural Heritage. Retrieved December 12 2009. {{cite web}}: Check date values in: |accessdate= (help)
2. Martinez, M. L. (2004). Coastal Dunes: Ecology and Conservation. Springer-Verlag Berlin Heidelberg. ISBN 3-540-40829-0. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
3. Nordstrom, Karl F. (2008). Beach and Dune Restoration. Cambridge University Press. ISBN 978-0-521-85346-0.

See also

• Coastal management
• Sand dune ecology
• Coastal erosion
• Coastal geography
• Integrated coastal zone management
• Beach evolution
• Longshore transport

External links

• Sand Dune Stabilization And Reclamation In Southeastern Colorado
• Monitoring sand dune stabilization along the coastal dunes of Ashdod-Nizanim Israel
• Vetiver System for Sand Dune Stabilization A Vietnamese Experience

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v t e Coastal management
Management	Accretion Coastal engineering Coastal management Integrated coastal zone management Managed retreat Submersion
Hard engineering	A-Jacks Accropode Akmon Artificial reef Breachway Breakwater Cliff stabilization Dolos Flood wall Floodgate Gabion Groyne Jetty Levee Hard engineering Honeycomb sea wall Hudson's equation KOLOS Mole Pier Revetment Riprap Seawall Tetrapod Training wall Van der Meer formula Wharf Xbloc
Soft engineering	Beach nourishment Beach drainage Dynamic revetment Living shorelines Sand dune stabilization Soft engineering
Related topics	Beach evolution Coastal erosion Geotechnical engineering Land reclamation Longshore transport Modern recession of beaches Stream restoration

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