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			{{Short description\|Coastal management practice}}
	'''Sand Dune Stabilization''' is a ] technique for preventing ]. ]s may be stabilized through the planting of ]. Sand dunes trap sand and beach material washed and blown up, thereby slowing the rate of erosion and creating an effective ]. ]s will also have to be introduced to stop trampling. Sand dune stabilization does not disrupt the coastline, creates natural habitats for animals and plants and is not regarded as unattractive. However, for successful dunes to be placed it must be thoroughly researched beforehand and can generally take long periods of time until established<ref>{{cite web \|url=http://www.snh.org.uk/publications/on-line/heritagemanagement/erosion/appendix_1.2.shtml \|title=A guide to managing coastal erosion in beach/dune systems \|publisher=] \|accessdate=December 12 2009}}</ref>.
			'''Sand dune stabilization''' is a ] practice designed to prevent erosion of sand dunes. ] ]s are common features of shoreline and desert environments. Dunes provide habitat for highly specialized plants and animals, including ] and ]. They can protect beaches from erosion and recruit sand to eroded beaches. Dunes are threatened by human activity, both intentional and unintentional (see ] and ]). 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 ] reduces the impact of wind and water. Wooden sand fences can help retain sand and other material needed for a healthy sand dune ecosystem.<ref>{{
	==Vegetation==
			cite web \|url=http://woodensandfence.com/benefits-of-sand-fencing.html#sand-dune-stabilization \|title=How to use wooden fence for sand dune stabilization \|publisher=] \|accessdate=December 10, 2013}}</ref> ]s protect dunes from damage from foot traffic.<ref>{{
	]
			cite web \|url=http://www.snh.org.uk/publications/on-line/heritagemanagement/erosion/appendix_1.2.shtml \|title=A guide to managing coastal erosion in beach/dune systems \|publisher=] \|accessdate=December 12, 2009}}</ref>
	Sand dunes which already exist on the upper beach but ] can be stabilized by ] 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===
			The location of the dune limits the types of plant that can thrive there. Beach dunes consist of the ''foredune'', the angled side which faces the ocean, the ''sand plain'' at the top of the dune, which may or may not be present, and the ''backdune'', the angled side that faces away from the ocean.
	Plants that thrive on the foredune must be tolerant to ], strong winds, and sand burial. Vegetation typically found on the foredune are ], ], ], and ].
	===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 ], ], ], and ]. 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.

			== Foredune flora ==
	After the ] 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 ], ], and ]. 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 ], availability of ], or salt spray effects<ref>{{cite book\|last=Martinez\|first=M. L. \|coauthors=Psuty, N. P. \|year=2004 \|title=Coastal Dunes: Ecology and Conservation \|publisher=Springer-Verlag Berlin Heidelberg \|isbn=3-540-40829-0}}</ref>.
			Plants that thrive on the foredune must be tolerant to ], strong winds, and burial by blowing/accumulating sand. Examples of beach and foredune vegetation of temperate zones include '']'' (an invasive species on the west coast of North America<ref name=martinez/>{{rp\|56}}), '']'', '']'', and ''] coarctata''.<ref name=martinez/>{{rp\|55}}

			== Backdune flora ==
	==Public and private coastal management==
			Plants which thrive on the broad dune plain and backdune grow together into dense patches termed "dune mats" that hold the dune together. Examples of temperate zone flora of the plain and backdune include '']'', '']'', '']'', and '']''. Introduced ] can out compete native plants and disrupt animal life, making them formally "invasive species".<ref name=martinez/>{{rp\|55-56}}
	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<ref>{{cite book\|last=Nordstrom\|first= Karl F. \|year=2008 \|title=Beach and Dune Restoration \|publisher=Cambridge University Press \|isbn=978-0-521-85346-0}}</ref>.

	==~~References~~==		== Shrub stage ==
			The above species are ]s. After they have rooted and developed fully, a second stage, the "] stage", can begin. During this phase, larger plants with deeper root systems can be planted. Examples are '']'', '']'', and '']''. The shrub stage is variable depending on ], and may be influenced the height of the ], wind and ]. The shrub stage may eventually give way to forest or chapparal.<!--why would it not continue?--><ref name=martinez>{{
	{{reflist}}
			cite book\|editor-last1=Martinez\|editor-first1=M.L.\|editor-last2=Psuty\|editor-first2=N.P. \|year=2004 \|title=Coastal Dunes: Ecology and Conservation \|publisher=Springer-Verlag Berlin Heidelberg \|isbn=3-540-40829-0\|chapter=Chapter 4: Temperate Zone Sanddunes\|last1=Wiedemann\|first1=A.M.\|last2=Pickart\|first2=A.J.\|pages=53-66}}</ref>{{rp\|54-55}}

			==Coastal management==
			A single beach may be divided into segments with different owners. Gaining agreement among all owners complicates the process of stabilizing the dunes. Without agreement, some parts of the dune may go unplanted, while others host visually appealing plants that do little to stabilize the dune. Inconsistent vegetation, known as a fragmented or decoupled gradient, can create weak points in the dune that limit its effectiveness against floods and even its continued existence.<ref name=nordstrom>{{
			cite book\|last=Nordstrom\|first= Karl F. \|year=2008 \|title=Beach and Dune Restoration \|publisher=Cambridge University Press \|isbn=978-0-521-85346-0}}</ref>

			Publicly owned beaches, found in U.S. states such as California and Hawaii and in other jurisdictions, present the opportunity to systematically manage—or mismanage—beaches and their accompanying dunes.<ref name=nordstrom/>

			==Coastal sand dune management==
			]
			]
			]
			]

			Coastal sand dunes fringe thousands of kilometres of coastline around the world. They are made up of continuous, hummocky hills of sand that are held together by specially adapted sand dune vegetation.<ref name=Gomez-Pina /> See Figure 1. These plants have ] that allow them to survive in sand dune ], these include adaptations to a moving substrate which covers and uncovers its roots, adaptation to ], to strong winds carrying salt and sand and to wildly changing temperatures.<ref name=Esler /> Coastal sand dunes formed during a time of low ] where sand and sediments on the foreshore became exposed and in conjunction with sufficient winds, this sand was transported up the beach face via a process known as ].<ref>Aargard et.al, 2007</ref> Once sufficient wind (>15 km/h) mobilises sand particles they become trapped in vegetation or drift wood at the back of the beach, sand then continues to accumulate among the vegetation and over time slowly builds up the dunes we see today. Sand dunes serve an important purpose by protecting inland areas from coastal water intrusion. They are able to absorb the impact and protect inland areas from high energy ] and act as a resilient barrier to the destructive forces of wind and ].<ref name=Gomez-Pina />

			===Human impacts===
			{{see\|sand mining\|sand theft}}
			It is generally observed that ] are highly sensitive to any number of human activities. It is also understood that coastal dunes need to have limited interaction with humans in order for their protection and survival.<ref name=Rust /> Around the world coastal dunes are eroding and under pressure due to increased ] loss because of increased coastal human activities.<ref name=Rust /> For example, in the last 30 years, mainly because of tourism, nearly 75% of the Mediterranean's coastal dunes have been damaged or destroyed.<ref name="Van Der Meulen" /> Human impacts can expand from minor to highly significant adverse effects. Minor effects include pedestrian trampling, constructing footpaths, and off-road vehicle tracks, to the more significant which includes the construction of roads, car parks, houses, the use of sand dunes for ground water extraction, the conversion of sand dunes to land for ], ] or waste disposal and ].<ref name=Williams />

			] is a country with a very long ] line that consists of around 1090 km of sand dunes. From the early 1900s to the early 2000s the area of sand dunes has declined by about 70% from 129,000 ha to 39,000 ha.<ref name=Hilton /> This decline has been mainly due to erosion caused by the depletion of vegetation cover in order to convert sand dunes to land for forestry, farming and urban areas. Loss in vegetation cover exposes sand to the action of wind and leaves sand dunes vulnerable to increased erosion as it is vegetation that binds sand together.<ref name=Gadgil />
			The loss of vegetation causes sand to move inland which is a process known as sand ], this process can having damaging effects on inland properties and leaves properties vulnerable to future ] for example ].

			As well as human activities, natural processes operate within coastal dune environments, these processes include events such as ], ], ], and sediment supply changes. Coastal dune systems are mainly controlled by a principal natural process called the sediment supply and transport system. This system consists of an offshore zone (sediment bank), transit zone (beach and active foredune) and a resting zone (stable sand dunes). The sediment in this system is supplied by ] predominantly from ]s and from the erosion of cliffs, headlands, other dune systems and when sediment supply is low sand dunes are subject to erosion.<ref name="Van Der Meulen" /> Humans affect sediment supply in a number of ways including the ] of rivers, ] in coastal water and the construction of ], all of which depletes sediment supply. They also disrupt the long shore transport of sediment through the construction of ], ] or ], ] and other hard structures. Excavating, building roads, houses and walkways on coastal dunes or beaches also causes sand dune erosion by disrupting natural sediment processes.<ref name="Van Der Meulen" /> Effective management of coastal dune systems must consider natural processes as a normal part of the natural environment as well as controlling human activities and seeking to alter natural processes should be kept at a minimum in order for restoration to be successful.<ref name=Rust />

			===Integrated management===
			Sand dunes are an important part of the coast as they are land's first defence against the forces of the ]. Because of this, ] of sand dunes will focus on the natural authenticity and values of the dunes themselves including ], ], and the ] as a whole. The concept of integrated management can be incorporated into management of coastal sand dunes. This concept is made up of three main aspects:<ref name="Van Der Meulen" />
			* Restore and conserve natural processes
			* Create conditions for future natural processes
			* Develop types of land use that agree with the above
			These concepts seek to incorporate natural processes and human activities within coastal dunes systems. Sand dune management issues are related to the nature of sediment, which has no cohesiveness so the influence of wind and sediment supply is an important factor in determining erosion and ] of dry sand grains .<ref name=Gadgil />

			Sand dune management consists of restoring natural dune systems and processes with the implementation of “soft” technique which includes the cessation of any activity that adversely effects the sediment supply of the dunes, planting vegetation, fencing off sensitive areas, creating dune ], and providing information to the public regarding the importance of maintaining stable sand dunes.<ref name=Gomez-Pina /> The concept of “soft” techniques is in contrast to the widely used “hard” techniques which consist of protecting the coast through the construction of concrete ], ], ], ] and offshore break waters. The problem with using these “hard” engineering methods is that they only provide temporary protection against ocean hazards and each "hard" method produces an “end effect” that causes erosion problems to adjacent coastal areas. This is why the implementation of “soft” techniques in dune restoration should be used more widely in coastal protection as they provide natural, long term protection with no adverse effect to adjacent coastal areas. The use of soft techniques can be seen in many coastal protection projects around the world including many in New Zealand.<ref name=Gomez-Pina />

			===Restoration and protection===
			] dunes]]
			One of the first things a coastal manager must look for when establishing sand dune ] is to ascertain the main cause of sediment loss and from there, make decisions on how to minimise the cause and how to restore sand dunes appropriately. In New Zealand the main cause of dune erosion has been the loss of sand vegetation and this means that sand dune management consists primarily of stabilizing dune systems through the “soft” technique of replanting and protecting native dune vegetation. It is advised that dunes should not be restored with the planting of ] and managers should aim to only use species ] to an area,<ref name="Van Der Meulen" /> originally New Zealand used exotic, fast growing dune vegetation called ] to stabilize eroding sand dunes. It was later discovered that this exotic species created very high, steep sand dunes that were increasingly susceptible to New Zealand's high storm energy climate. It also became apparent that the native New Zealand dune vegetation was out-competed by this introduced species which caused issues biologically. At present, there is a large push to eradicate marram grass as it is now classed as a pest species in New Zealand, and coastal managers encourage the ] of the two indigenous species, ] ('']'') and '']'' as these two species create low angle, strong, stable dunes.<ref name=Hilton />

			The management of dune restoration projects includes planting vegetation successfully. Merely scattering and leaving ] over sandy areas is perceived as a potential waste as strong winds can blow seeds away. Planting of nurseries should be conducted in the hollows of any present sand hills or in depressions of sandy areas. Seeds should be planted in moist conditions and should be lightly covered by a layer of sand and large mature grass individuals should be planted in deep holes with the tops of the plants cut short so as to reduce wind resistance.<ref name=Gadgil />

			Planting of sand dune vegetation alone does not entirely restore or protect sand dunes from human impacts. ] need to be protected from human trampling, which is done mainly by fencing off newly planted areas. Fencing also acts as another way of trapping and accumulating sand among the dunes and can also act as protection against strong winds.<ref name=Gadgil /> Figure two shows an area of newly planted vegetation at Spencer Park Beach, New Zealand. It shows that fencing protects plants from trampling and figure three shows how small fencing using ] can encourage plants to grow. In addition to erecting fences to protect sand dune vegetation, the establishment of walkways will protect developed sand dunes from degrading again over time. These walkways provide access to beaches for the public that does not require pedestrians to cross the dunes themselves thus preventing damage. Figure four shows a typical walkway at New Brighton Beach, New Zealand. The walkway itself is built to go over the sand dunes as opposed to straight through them, in order to maintain the continuity and strength of the dunes.<ref name=Gomez-Pina />

			===The public===
			Because sand dunes and beaches are extremely popular for ], the success of restoration and dune management depends a great deal on the information available and understanding of the public. This is important because not all aspects of sand dune management are obvious or important to the public if they do not understand why management is necessary e.g. stabilization. There are many ways in which information can be provided to the public including the erection of panels at entrances to dune walkways, leaflets, brochures, maps and council workers who can talk to the public about the importance of protecting sand dunes.<ref name="Van Der Meulen" /> Figure five shows a photo of a panel put up at Spencer Park by the Christchurch City Council indicating that people should not walk on the area, as it is an area for sand dune restoration. It needs to be re-iterated that sand dune restoration and protection is in the public's best interest as the loss of sediment on any coast line leads to the erosion of beaches, which in turn leads to a loss of recreational value of many coastlines. The public needs to be aware of the role that sand dunes play in coastal protection, because without public support, coastal sand dune management is virtually impossible.

	==See also==		==See also==
			{{div col}}
	*]
	*]		*]
			*]
			*]
			*]
	*]		*]
	*]		*]
			*]
	*]		*]
	*]		*]
	*]		*]
			*]
			*]
			{{div col end}}

			==Notes==
			{{reflist\|colwidth=30em\|refs=

			<ref name=Esler>Esler AE (Williams) "Manawatu sand dune vegetation", ''Proceedings of the New Zealand Ecological Society'', '''17''': 41–46</ref>

			<ref name=Gadgil>Gadgil RL and Ede FJ (1998) "Application of scientific principles to sand dune stabilisation in New Zealand: Past progress and future needs", ''Land Degradation and Development'', '''9''': 131–142.</ref>

			<ref name=Gomez-Pina>Gomez-Pina G (2002) "Sand dune management problems and techniques, Spain", ''Journal of Coastal Research'', Iss '''36''': 325–332.</ref>

			<ref name=Hilton >Hilton MJ (2006) "The loss of New Zealand’s active dunes and the spread of Marram Grass ''(Ammophila arenaria)''", ''New Zealand Geographer'', '''62''': 105–120.</ref>

			<ref name=Rust >Rust I.C, Illenberger WK (1996) "Coastal dunes, Sensitive or not?", ''Landscape and Urban Planning'', '''34''': 165–169.</ref>

			<ref name="Van Der Meulen">Van Der Meulen F and Salman AHPM (1996) "Management of Mediterranean coastal dunes", ''Ocean and Coastal Management'', '''30'''(2–3): 177–195.</ref>

			<ref name=Williams>Williams AT, Alveirinho-Dias J, Garcia Novo F, Garcia Mora MR, Curr R and Pereira A (2001) "Integrated coastal dune management: checklist", ''Continental Shelf Research'', '''21''': 1937–1960.</ref>
			}}

			==References==
			* Aagaard T, Orford J and Murray AS (2007) "Environmental controls on coastal dune formation: Skallingen Spit, Denmark", ''Geomorphology'', '''86''': 29–47.

	==External links==		==External links==
	*		*
	*		*
	*		*
			*{{URL\|https://data.mendeley.com/datasets/675gwk5jp7/1\|The Bibliography of Aeolian Research}}


	{{environment-stub}}
	{{coastal management}}		{{coastal management}}
			{{Deserts}}

			]
			]
	]		]

	]

Revision as of 05:51, 14 April 2024

Coastal management practice

Sand dune stabilization is a coastal management practice designed to prevent erosion of sand dunes. 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 (see sand theft and sand mining). 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. Wooden sand fences can help retain sand and other material needed for a healthy sand dune ecosystem. Footpaths protect dunes from damage from foot traffic.

The location of the dune limits the types of plant that can thrive there. Beach dunes consist of the foredune, the angled side which faces the ocean, the sand plain at the top of the dune, which may or may not be present, and the backdune, the angled side that faces away from the ocean.

Foredune flora

Plants that thrive on the foredune must be tolerant to salt spray, strong winds, and burial by blowing/accumulating sand. Examples of beach and foredune vegetation of temperate zones include Ammophila arenaria (an invasive species on the west coast of North America), Honckenya peploides, Cakile maritima, and Spartina coarctata.

Backdune flora

Plants which thrive on the broad dune plain and backdune grow together into dense patches termed "dune mats" that hold the dune together. Examples of temperate zone flora of the plain and backdune include Hudsonia tomentosa, Spartina patens, Iva imbricata, and Erigeron glaucus. Introduced species can out compete native plants and disrupt animal life, making them formally "invasive species".

Shrub stage

The above species are herbaceous plants. After they have rooted and developed fully, a second stage, the "shrub stage", can begin. During this phase, larger plants with deeper root systems can be planted. Examples are Empetrum nigrum, Ilex vomitoria, and Vaccinium ovatum. The shrub stage is variable depending on microclimate, and may be influenced the height of the water table, wind and salt spray. The shrub stage may eventually give way to forest or chapparal.

Coastal management

A single beach may be divided into segments with different owners. Gaining agreement among all owners complicates the process of stabilizing the dunes. Without agreement, some parts of the dune may go unplanted, while others host visually appealing plants that do little to stabilize the dune. Inconsistent vegetation, known as a fragmented or decoupled gradient, can create weak points in the dune that limit its effectiveness against floods and even its continued existence.

Publicly owned beaches, found in U.S. states such as California and Hawaii and in other jurisdictions, present the opportunity to systematically manage—or mismanage—beaches and their accompanying dunes.

Coastal sand dune management

Coastal sand dunes fringe thousands of kilometres of coastline around the world. They are made up of continuous, hummocky hills of sand that are held together by specially adapted sand dune vegetation. See Figure 1. These plants have adaptations that allow them to survive in sand dune habitats, these include adaptations to a moving substrate which covers and uncovers its roots, adaptation to desiccation, to strong winds carrying salt and sand and to wildly changing temperatures. Coastal sand dunes formed during a time of low sea level where sand and sediments on the foreshore became exposed and in conjunction with sufficient winds, this sand was transported up the beach face via a process known as saltation. Once sufficient wind (>15 km/h) mobilises sand particles they become trapped in vegetation or drift wood at the back of the beach, sand then continues to accumulate among the vegetation and over time slowly builds up the dunes we see today. Sand dunes serve an important purpose by protecting inland areas from coastal water intrusion. They are able to absorb the impact and protect inland areas from high energy storms and act as a resilient barrier to the destructive forces of wind and waves.

Human impacts

Further information: sand mining and sand theft

It is generally observed that coastal dunes are highly sensitive to any number of human activities. It is also understood that coastal dunes need to have limited interaction with humans in order for their protection and survival. Around the world coastal dunes are eroding and under pressure due to increased sediment loss because of increased coastal human activities. For example, in the last 30 years, mainly because of tourism, nearly 75% of the Mediterranean's coastal dunes have been damaged or destroyed. Human impacts can expand from minor to highly significant adverse effects. Minor effects include pedestrian trampling, constructing footpaths, and off-road vehicle tracks, to the more significant which includes the construction of roads, car parks, houses, the use of sand dunes for ground water extraction, the conversion of sand dunes to land for farming, forestry or waste disposal and sand dune mining.

New Zealand is a country with a very long coast line that consists of around 1090 km of sand dunes. From the early 1900s to the early 2000s the area of sand dunes has declined by about 70% from 129,000 ha to 39,000 ha. This decline has been mainly due to erosion caused by the depletion of vegetation cover in order to convert sand dunes to land for forestry, farming and urban areas. Loss in vegetation cover exposes sand to the action of wind and leaves sand dunes vulnerable to increased erosion as it is vegetation that binds sand together. The loss of vegetation causes sand to move inland which is a process known as sand encroachment, this process can having damaging effects on inland properties and leaves properties vulnerable to future coastal hazards for example storm surge.

As well as human activities, natural processes operate within coastal dune environments, these processes include events such as storms, floods, sea level change, and sediment supply changes. Coastal dune systems are mainly controlled by a principal natural process called the sediment supply and transport system. This system consists of an offshore zone (sediment bank), transit zone (beach and active foredune) and a resting zone (stable sand dunes). The sediment in this system is supplied by long shore drift predominantly from rivers and from the erosion of cliffs, headlands, other dune systems and when sediment supply is low sand dunes are subject to erosion. Humans affect sediment supply in a number of ways including the damming of rivers, dredging in coastal water and the construction of harbours, all of which depletes sediment supply. They also disrupt the long shore transport of sediment through the construction of piers, marinas or groynes, breakwaters and other hard structures. Excavating, building roads, houses and walkways on coastal dunes or beaches also causes sand dune erosion by disrupting natural sediment processes. Effective management of coastal dune systems must consider natural processes as a normal part of the natural environment as well as controlling human activities and seeking to alter natural processes should be kept at a minimum in order for restoration to be successful.

Integrated management

Sand dunes are an important part of the coast as they are land's first defence against the forces of the ocean. Because of this, management of sand dunes will focus on the natural authenticity and values of the dunes themselves including flora, fauna, and the ecosystem as a whole. The concept of integrated management can be incorporated into management of coastal sand dunes. This concept is made up of three main aspects:

Restore and conserve natural processes
Create conditions for future natural processes
Develop types of land use that agree with the above

These concepts seek to incorporate natural processes and human activities within coastal dunes systems. Sand dune management issues are related to the nature of sediment, which has no cohesiveness so the influence of wind and sediment supply is an important factor in determining erosion and deposition of dry sand grains .

Sand dune management consists of restoring natural dune systems and processes with the implementation of “soft” technique which includes the cessation of any activity that adversely effects the sediment supply of the dunes, planting vegetation, fencing off sensitive areas, creating dune walkways, and providing information to the public regarding the importance of maintaining stable sand dunes. The concept of “soft” techniques is in contrast to the widely used “hard” techniques which consist of protecting the coast through the construction of concrete sea walls, revetments, gabions, groynes and offshore break waters. The problem with using these “hard” engineering methods is that they only provide temporary protection against ocean hazards and each "hard" method produces an “end effect” that causes erosion problems to adjacent coastal areas. This is why the implementation of “soft” techniques in dune restoration should be used more widely in coastal protection as they provide natural, long term protection with no adverse effect to adjacent coastal areas. The use of soft techniques can be seen in many coastal protection projects around the world including many in New Zealand.

Restoration and protection

One of the first things a coastal manager must look for when establishing sand dune management is to ascertain the main cause of sediment loss and from there, make decisions on how to minimise the cause and how to restore sand dunes appropriately. In New Zealand the main cause of dune erosion has been the loss of sand vegetation and this means that sand dune management consists primarily of stabilizing dune systems through the “soft” technique of replanting and protecting native dune vegetation. It is advised that dunes should not be restored with the planting of exotic species and managers should aim to only use species indigenous to an area, originally New Zealand used exotic, fast growing dune vegetation called marram grass to stabilize eroding sand dunes. It was later discovered that this exotic species created very high, steep sand dunes that were increasingly susceptible to New Zealand's high storm energy climate. It also became apparent that the native New Zealand dune vegetation was out-competed by this introduced species which caused issues biologically. At present, there is a large push to eradicate marram grass as it is now classed as a pest species in New Zealand, and coastal managers encourage the planting of the two indigenous species, pingao (Desmoschoenus spiralis) and Spinifex sericeus as these two species create low angle, strong, stable dunes.

The management of dune restoration projects includes planting vegetation successfully. Merely scattering and leaving seeds over sandy areas is perceived as a potential waste as strong winds can blow seeds away. Planting of nurseries should be conducted in the hollows of any present sand hills or in depressions of sandy areas. Seeds should be planted in moist conditions and should be lightly covered by a layer of sand and large mature grass individuals should be planted in deep holes with the tops of the plants cut short so as to reduce wind resistance.

Planting of sand dune vegetation alone does not entirely restore or protect sand dunes from human impacts. Seedlings need to be protected from human trampling, which is done mainly by fencing off newly planted areas. Fencing also acts as another way of trapping and accumulating sand among the dunes and can also act as protection against strong winds. Figure two shows an area of newly planted vegetation at Spencer Park Beach, New Zealand. It shows that fencing protects plants from trampling and figure three shows how small fencing using chicken wire can encourage plants to grow. In addition to erecting fences to protect sand dune vegetation, the establishment of walkways will protect developed sand dunes from degrading again over time. These walkways provide access to beaches for the public that does not require pedestrians to cross the dunes themselves thus preventing damage. Figure four shows a typical walkway at New Brighton Beach, New Zealand. The walkway itself is built to go over the sand dunes as opposed to straight through them, in order to maintain the continuity and strength of the dunes.

The public

Because sand dunes and beaches are extremely popular for outdoor recreation, the success of restoration and dune management depends a great deal on the information available and understanding of the public. This is important because not all aspects of sand dune management are obvious or important to the public if they do not understand why management is necessary e.g. stabilization. There are many ways in which information can be provided to the public including the erection of panels at entrances to dune walkways, leaflets, brochures, maps and council workers who can talk to the public about the importance of protecting sand dunes. Figure five shows a photo of a panel put up at Spencer Park by the Christchurch City Council indicating that people should not walk on the area, as it is an area for sand dune restoration. It needs to be re-iterated that sand dune restoration and protection is in the public's best interest as the loss of sediment on any coast line leads to the erosion of beaches, which in turn leads to a loss of recreational value of many coastlines. The public needs to be aware of the role that sand dunes play in coastal protection, because without public support, coastal sand dune management is virtually impossible.

Notes

"How to use wooden fence for sand dune stabilization". Wooden Sand Fence. Retrieved December 10, 2013.
"A guide to managing coastal erosion in beach/dune systems". Scottish Natural Heritage. Retrieved December 12, 2009.
^ Wiedemann, A.M.; Pickart, A.J. (2004). "Chapter 4: Temperate Zone Sanddunes". In Martinez, M.L.; Psuty, N.P. (eds.). Coastal Dunes: Ecology and Conservation. Springer-Verlag Berlin Heidelberg. pp. 53–66. ISBN 3-540-40829-0.
^ Nordstrom, Karl F. (2008). Beach and Dune Restoration. Cambridge University Press. ISBN 978-0-521-85346-0.
^ Gomez-Pina G (2002) "Sand dune management problems and techniques, Spain", Journal of Coastal Research, Iss 36: 325–332.
Esler AE (Williams) "Manawatu sand dune vegetation", Proceedings of the New Zealand Ecological Society, 17: 41–46
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References

Aagaard T, Orford J and Murray AS (2007) "Environmental controls on coastal dune formation: Skallingen Spit, Denmark", Geomorphology, 86: 29–47.

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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
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