People and the Dunes

The major sand dunes on the north coast of Cornwall are thought to have originated more than 5000 years ago and have been used by people ever since. The sands of time hide evidence of lost settlements, places of religious worship and industrial activity, deep within the buried landscape.

Sand dunes can be of outstanding archaeological importance. Successional episodes of sand inundation can preserve a series of old land surfaces, which can range in date from pre-history to recent centuries. The alkali nature of the dunes permits the survival of bone, which is unusual in a county dominated by acidic soil. The Cornish dunes provide opportunities for the study of animal remains from different periods. By far the greatest changes to the dunes by people have occurred during the last two hundred years throughout the Industrial Revolution, two World Wars and more recently due to tourism and recreation, sand extraction and agriculture.

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With the decline of traditional industries such as tin mining, fishing and agriculture, tourism has become the mainstay of the Cornish economy. Due to the lack of planning restrictions and foresight during the 1950s a number of caravan and chalet parks were developed on/or near Cornwall's sand dunes. The sand dunes also tend to be very popular with people for recreation.

Impacts of Tourism and Recreation

People visiting the sand dunes for recreation can have a severe impact on the environment if they do not act responsibly. Things to look out for include:

  • Litter - looks ugly and can be mistaken for food by animals causing them harm or even death.
  • Dog fouling - on the dune habitats acts as an unwanted fertiliser, harming rare plants and habitats. Dogs can also disturb ground nesting bird species.
  • Illegal motorbike riding, cars, horses and bikes - tear up the dune grassland, which can takes years to recover. The unusual noises produced by these activities can also disturb ground nesting birds.
  • Fires- Can damage swathes of dune habitat.
  • Footfall - The shear numbers of people visiting the dunes, or using them to access the beach, can have a huge impact on the quality of the habitat.

The vegetation that covers sand dunes cannot withstand trampling by thousands of feet during the summer. The grasses die off, leaving bare sand, which is easily blown by the wind. Ideally a dune system should have between 10-25% bare sand by area but on some systems the amount of bare sand exceeds this.

Where there is a demand for public access to the dunes and beaches, there is also a need for adequate car parking and roads. Historically, large areas of dune were driven over, or parked on with little, or no control. This led to the creation of a succession of deep, eroded tracks and a reduction in plant species diversity on large areas. To combat this road and car park surfacing was introduced. Although this caused the direct loss of some dune habitat, it has clearly defined the area which should be driven on.

There has been small scale sand removal from some of Cornwall's dunes and beaches for centuries. Until recently, a Seventeenth Century Act of parliament allowed local farmers to remove sand from below the high water mark on any beach to improve the soils in their fields. With mechanisation, quantities of sand removal from some beaches increased at an alarming rate, leading to stony beaches and dunes vulnerable to erosion from the sea.  Shortly after the Second World War, planning permission was granted for larger scale sand quarrying at Gwithian and Phillack. The sand was used to rebuild Plymouth and as an agricultural soil improver. Extraction has now ceased but at Gwithian over 60 hectares of sand dunes have been dug.

Impacts of Sand Extraction

  • Sand extraction on the dunes can result in direct loss of sand dune habitat and associated species. In some instances, valuable new habitats are created in their place, including dune slacks and areas of open water and;
  • Sand extraction from beaches and estuaries can result in a negative loss of sand from the system. This can lead to increased vulnerability to erosion from the sea, reducing the beach and dunes effectiveness as natural sea defences as the sand supplying most dune systems is finite.

Archaeological investigations at Gwithian have revealed evidence of ploughing in the soil layers buried under the dunes, dating from as long ago as the Bronze Age, when small fields were used to grow crops. The inhabitants were at the mercy of the moving sands and trenches were constructed to try and trap the sand.  In medieval times, expansive areas of sand dunes were used for sheep grazing. Nowadays, livestock are mostly absent from Cornwall's sand dunes as the land has increasingly become used for tourism and recreation. However, there are some sites where livestock have been reintroduced for nature conservation grazing.

Impacts of Agriculture

  • The sand of the dunes is used as an agricultural soil improver, the extraction leads to direct loss of habitat.
  • Seeds used as animal feed have led to the introduction of some alien plant species to the dunes.
  • Over-grazing of dunes would reduce nature conservation interest through erosion and by preventing plants from flowering.
  • Use of agricultural chemical sprays or fertilisers on land close to the dunes can lead to localised impacts through nutrient enrichment encouraging a few aggressive plants to dominate, or pesticides killing insects or plants.

As with much of Cornwall, areas of the dunes are dotted with deep depressions where mine shafts were dug in search of metal ores. At Gwithian and Upton Towans, remains of Wheal Emily and Boiling Well mine engine houses are still evident.  Upton Towans was the site of the National Explosives Factory which employed nearly 2000 people when production was at its peak during the First World War. The Factory closed in 1919 and many of the buildings and chimneys were destroyed.  Impacts of industry included:

  • Mining and other industrial activity, historically caused major disruption on the dunes, which have since recovered.
  • Mine shafts still pose a risk to the public on some sites.
  • These activities have altered the landscape creating sheltered hollows, favoured by some plants and animals.
  • The water in the dunes tends to flow through the adits that were dug on the Towans, reducing the range of aquatic habitats.

There are pill boxes, dating from the Second World War along the seaward edge of the Towans and other sites. It is thought that these were decoys to encourage German bombers to drop their bombs onto the uninhabited sand dunes.  At other sites there is evidence of anti-tank defences in the form of walls at the back of the beach and structures in the sand to prevent tank invasions from the sea.  A significant section of Penhale Sands is owned by the Ministry of Defence as used as a military training camp for young cadets.  The exclusion of the public by the MOD at Penhale has protected the nature conservation interest of this area.

Historically, a number of very significant buildings for religious worship were built amongst the sand dunes, from as early as 600AD. For example, St Pirans oratory and Perranzabuloe parish church at Penhale Sands, St Gothians chapel at Godrevy, St Enodoc church at Rock; and churches at Lelant, Phillack and Holywell.

Over the centuries, some of these buildings have been successively buried and exposed by the changing sand cycles.  The remains of places of religious worship attract thousands of visitors per year, which can lead to localised erosion of the dunes and make the structures vulnerable to damage.  Often, the churches are surrounded by cemeteries and skeletons are well-preserved in the alkaline sand.

Sand dunes and wide sandy beaches act as very effective natural coastal defences, protecting the land behind the dunes from the power of the sea.  Some of the sand supply to dune systems may be through on and off shore movement of sediment. This is when sand and other sediments move around the coastline due to the action of the sea. Some of this sand ends up helping to form the beaches and dunes.  Coastal defence walls, groynes, harbours and other structures built out into the sea or on the cliffs can interrupt sediment movement, starving the dunes and beaches of their sediment supply. This can make the sand dunes and beaches more vulnerable to the destructive effects of the waves.

Natural succession on the dunes eventually leads to scrub growth which can take over the flower-rich dune grassland, unless it is kept in check by grazing. Unlike sand dunes, scrub is a very common habitat in Cornwall and has limited nature conservation value. Grazing also removes nutrients from the dune system, preventing habitats from becoming over-enriched with nutrients. Nutrient enrichment reduces the plant species diversity as a few species of common grasses tend to take over and dominate.

Climate change and sea level rise could drastically alter the Cornish dunes. Increased storminess could lead to losses of strandline and mobile foredune habitats and erosion due to the wind. Changes to the direction of the prevailing wind direction from current could increase coastal erosion while the sea level rise could lead to direct loss of habitat.

A variety of invasive, alien species have been either accidentally or purposefully introduced to some of Cornwall's sand dunes.  Japanese Knotweed and Montbretia have been dumped as fly-tipped garden waste. Sea buckthorn has historically been planted on some dunes in order to stabilise areas of exposed sand. It achieved this very successfully but has since dominated large areas of dune, to the exclusion of the native dune plants.

Follow the links below for more information:

Introduction to Cornwall's Sand Dunes: Provides information on how dunes form and where they have developed in Cornwall.

Plants of the Dunes: Provides information on dune succession and plant adaptation to survive in dune habitat.

Animals on the Dunes: Provides information on animals that can be found on dunes.

The Management of Cornwall's Sand Dunes: Provides information on factors that must be considered when managing sand dunes.