Sand dune stabilization
Encyclopedia
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. Footpath
s protect dunes from damage from foot traffic.
The location on 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.
, Honckenya peploides
, Cakile maritima
, and Spartina coarctata.
tomentosa, Spartina patens
, Iva imbricata, and Eregeron glaucus. Introduced species
can outcompete native plants and disrupt animal life, making them formally "invasive species".
are herbaceous plant
s. 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 usually the final phase 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..
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 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/hr) 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
.
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 highly more significant which includes the construction of roads, car parks, houses, and the use of sand dunes for ground water extraction, the conversion of sand dunes to land for farming, forestry
, 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 principle 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.
. 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:
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.
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 re planting 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 (Ammophila arenaria
) to stabilize eroding sand dunes. It was later discovered that this exotic species created very high, steep sand dunes that were increasing susceptible to New Zealand’s high storm energy climate, it also became apparent that the native New Zealand dune vegetation were 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 at present coastal managers encourage the planting of the two indigenous species, Pingao
(Desmoschoenus spiralis) and Spinifex
(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 overtime. 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 walk way 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 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 coast lines. The public needs to be aware of the role that sand dunes play in coastal protection because without public support coastal sand dune management will be virtually impossible.
Rare species
A rare species is a group of organisms that are very uncommon or scarce. This designation may be applied to either a plant or animal taxon, and may be distinct from the term "endangered" or "threatened species" but not "extinct"....
and endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
. 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
Vegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...
reduces the impact of wind and water. Fences catch sand and other material. Footpath
Trail
A trail is a path with a rough beaten or dirt/stone surface used for travel. Trails may be for use only by walkers and in some places are the main access route to remote settlements...
s protect dunes from damage from foot traffic.
Vegetation
Foredune flora
Plants that thrive on the foredune must be tolerant to salt spray, strong winds, and burial by blowing/accumulating sand. Typical vegetation includes Ammophila arenariaAmmophila arenaria
Ammophila arenaria is a species of grass known by the common names European Marram Grass and European Beachgrass. It is one of two species of the genus Ammophila . It is native to the coastlines of Europe and North Africa where it grows in the sands of beach dunes. It is a perennial grass forming...
, Honckenya peploides
Honckenya peploides
Honckenya peploides or Sea sandwort or Seaside Sandplant is the only species in the genus Honckenya of the flowering plant family Caryophyllaceae. It is often spelled "Honkenya". It has a circumboreal distribution....
, Cakile maritima
Cakile maritima
Cakile maritima, the European searocket, is a common plant in the mustard family. It is widespread in Europe, especially on coastlines, and it can now be found in other areas of the world where it has been introduced. It is an inhabitant of the west and east coasts of North America, where it has...
, 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. Vegetation typical of the plain and backdune include HudsoniaHudsonia
Hudsonia is a small genus of three species of flowering plants in the family Cistaceae, native to North America.They are evergreen subshrubs growing to 20 cm tall....
tomentosa, Spartina patens
Spartina patens
Spartina patens , also known as salt marsh hay, is a species of cordgrass native to the Atlantic coast of the Americas, from Newfoundland south along the eastern United States to the Caribbean and northeast Mexico...
, Iva imbricata, and Eregeron glaucus. Introduced species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
can outcompete native plants and disrupt animal life, making them formally "invasive species".
Shrub stage
The above speciesSpecies
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
are herbaceous plant
Herbaceous plant
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
s. After they have rooted and developed fully, a second stage, the "shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
stage", can begin. During this phase, larger plants with deeper root systems can be planted. Examples are Empetrum nigrum
Empetrum nigrum
Empetrum nigrum is a species of crowberry known as black crowberry which is native to most northern areas of the northern hemisphere, as well as the Falkland Islands in the southern hemisphere....
, Ilex vomitoria, and Vaccinium ovatum. The shrub stage is usually the final phase and may last for short or long periods of time depending on microclimatic conditions such as distance from the shoreline, availability of groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
, or salt spray effects..
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
Desiccation
Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container.-Science:...
, to strong winds carrying salt and sand and to wildly changing temperatures. Coastal sand dunes formed during a time of low sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
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
Saltation
Saltation may refer to:* Saltation , an evolutionary hypothesis emphasizing sudden and drastic change* Saltation , a process of particle transport by fluids* Saltation , the antithesis of Continuous Integration...
. Once sufficient wind (>15 km/hr) mobilises sand particles they become trapped in vegetation
Vegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...
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
WAVES
The WAVES were a World War II-era division of the U.S. Navy that consisted entirely of women. The name of this group is an acronym for "Women Accepted for Volunteer Emergency Service" ; the word "emergency" implied that the acceptance of women was due to the unusual circumstances of the war and...
.
Human impacts
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 sedimentSediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
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 highly more significant which includes the construction of roads, car parks, houses, and the use of sand dunes for ground water extraction, the conversion of sand dunes to land for farming, forestry
Forestry
Forestry is the interdisciplinary profession embracing the science, art, and craft of creating, managing, using, and conserving forests and associated resources in a sustainable manner to meet desired goals, needs, and values for human benefit. Forestry is practiced in plantations and natural stands...
, waste disposal and sand dune mining
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
.
New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
is a country with a very long coast
Coast
A coastline or seashore is the area where land meets the sea or ocean. A precise line that can be called a coastline cannot be determined due to the dynamic nature of tides. The term "coastal zone" can be used instead, which is a spatial zone where interaction of the sea and land processes occurs...
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
Encroachment
Encroachment is a term which implies "advance beyond proper limits," and may have different interpretations depending on the context. Encroachment may refer to one of the following:* Temporal encroachment* Structural encroachment...
, this process can having damaging effects on inland properties and leaves properties vulnerable to future coastal hazards
Hazards
Hazards is the only independent, union-friendly magazine to win major international awards. A recurring theme in the magazine is that workplace unions are the best hope for better, safer work - and Hazards says it provides the information and resources to make the union job easier. Hazards looks...
for example storm surge
Storm surge
A storm surge is an offshore rise of water associated with a low pressure weather system, typically tropical cyclones and strong extratropical cyclones. Storm surges are caused primarily by high winds pushing on the ocean's surface. The wind causes the water to pile up higher than the ordinary sea...
.
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 principle 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 oceanOcean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
. Because of this, management
Management
Management in all business and organizational activities is the act of getting people together to accomplish desired goals and objectives using available resources efficiently and effectively...
of sand dunes will focus on the natural authenticity and values of the dunes themselves including flora
Flora
Flora is the plant life occurring in a particular region or time, generally the naturally occurring or indigenous—native plant life. The corresponding term for animals is fauna.-Etymology:...
, fauna
Fauna
Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...
, and the ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
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
Deposition
Deposition or Depose may refer to:* Deposition , taking testimony outside of court* Deposition , molecules settling out of a solution...
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 managementManagement
Management in all business and organizational activities is the act of getting people together to accomplish desired goals and objectives using available resources efficiently and effectively...
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
Vegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...
and this means that sand dune management consists primarily of stabilizing dune systems through the “soft” technique of re planting 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
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
indigenous to an area, originally New Zealand used exotic, fast growing dune vegetation called Marram Grass (Ammophila arenaria
Ammophila arenaria
Ammophila arenaria is a species of grass known by the common names European Marram Grass and European Beachgrass. It is one of two species of the genus Ammophila . It is native to the coastlines of Europe and North Africa where it grows in the sands of beach dunes. It is a perennial grass forming...
) to stabilize eroding sand dunes. It was later discovered that this exotic species created very high, steep sand dunes that were increasing susceptible to New Zealand’s high storm energy climate, it also became apparent that the native New Zealand dune vegetation were 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 at present coastal managers encourage the planting of the two indigenous species, Pingao
Pingao
Pingao, Ficinia spiralis, also known as golden sand sedge is a coastal sedge endemic to New Zealand . Originally widespread, it has suffered severely from competition with introduced marram grass and animal grazing and now has only a patchy distribution.Leaves from this plant are used by Maori in...
(Desmoschoenus spiralis) and Spinifex
Spinifex
Spinifex may refer to:* Spinifex , a genus of grass which is indigenous to the coastal areas of Australasia and Indonesia* Triodia , a hummock grass of arid Australia, covering twenty percent of the Australian continent ** Spinifex resin* Spinifex people, or Pila Nguru, an Australian...
(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
SEEDS
SEEDS is a voluntary organisation registered under the Societies Act of India....
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
Chicken wire
Chicken wire, or poultry netting, is a mesh of wire commonly used to fence poultry livestock. It is made of thin, flexible galvanized wire, with hexagonal gaps...
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 overtime. 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 walk way 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 recreationOutdoor recreation
Outdoor recreation or outdoor activity is leisure pursuits engaged in outside, especially in natural or semi-natural settings out of town...
, the success of restoration and dune management depends a great deal on the information available and understanding of the public
Public
In public relations and communication science, publics are groups of individuals, and the public is the totality of such groupings. This is a different concept to the sociological concept of the Öffentlichkeit or public sphere. The concept of a public has also been defined in political science,...
. 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 coast lines. The public needs to be aware of the role that sand dunes play in coastal protection because without public support coastal sand dune management will be virtually impossible.
See also
- Aeolian processes
- Beach evolutionBeach evolutionThe shoreline is where the land meets the sea and it is continually changing. Over the long term, the water is eroding the land. Beaches represent a special case, in that they exist where sand accumulated from the same processes that strip away rocky and sedmientary material. I.e., they can grow as...
- BlowoutBlowout (geology)Blowouts are sandy depressions in a sand dune ecosystem caused by the removal of sediments by wind.Blowouts occur in partially vegetated dunefields or sandhills. A blowout forms when a patch of protective vegetation is lost, allowing strong winds to "blow out" sand and form a depression...
- Coastal erosionCoastal erosionCoastal erosion is the wearing away of land and the removal of beach or dune sediments by wave action, tidal currents, wave currents, or drainage...
- Coastal geographyCoastal geographyCoastal geography is the study of the dynamic interface between the ocean and the land, incorporating both the physical geography and the human geography of the coast...
- Coastal managementCoastal managementIn some jurisdictions the terms sea defense and coastal protection are used to mean, respectively, defense against flooding and erosion...
- DuneDuneIn physical geography, a dune is a hill of sand built by wind. Dunes occur in different forms and sizes, formed by interaction with the wind. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind...
- Integrated coastal zone managementIntegrated coastal zone managementIntegrated coastal zone management or Integrated coastal management is a process for the management of the coast using an integrated approach, regarding all aspects of the coastal zone, including geographical and political boundaries, in an attempt to achieve sustainability.This concept was born...
- Longshore transport
- Sand dune ecologySand dune ecologySand dune ecology describes the biological and physico-chemical interactions that are a characteristic of sand dunes.Sand dunes provide a range of habitats for a range of unusual, interesting and characteristic plants that can cope with disturbed habitats...
- SandhillSandhillA sandhill is a type of ecological community or xeric wildfire-maintained ecosystem. It is not the same as a sand dune. It features very short fire return intervals, one to five years. Without fire, sandhills undergo ecological succession and become more oak dominated.Entisols are the typical...