Dune succession in a natural ecosystem

Aberlady dunes

Aberlady links

Aberlady processes

Aberlady salt marsh

Aberlady Sands

Aberlady slacks

Plagiosere

Definition: a plant succession or a stable environment where human activities have a significant impact on vegetation

The dune systems at Aberlady Bay provide a good example of a plagiosere. The dunes have been used and managed by humans over many centuries produce a complex vegetation mosaic.

The natural vegetation has been modified in many ways:

  • The Aberlady Bay dune system has been part of a Local Nature Reserve since 1952. It is managed for the conservation of its plants, animals and birds.
  • The Reserve receives many visitors and uncontrolled access led to erosion of paths and the development of blow-outs. Today, a system of managed paths reduces the visitor impact.
  • In the 1930s blow outs occurred as a result of taking too much marram grass to use as thatch.
  • Due to the lack of hunting and wild-fowling over the last 50 years, there has been a great increase in grazing pressure due to numbers of herbivores, including rabbits, roe deer and geese. This has created large areas behind the dunes that are dominated by grasses and flowers that can withstand heavy grazing. Many of these plants are calcium-loving, reflecting the high calcium contents in the shell-rich raised beach sands that form the ground surface here.
  • An area of links grassland is managed by mowing this is to encourage the growth of new grass for geese and to provide suitable nest sites for peewits.
  • A larget area of links is now part of Gullane golf course. Here the climax vegetation has been suppressed by planting and mowing.
  • During WW2 the dunes were used heavily for military training but, although the remains of tank traps and fortifications can still be seen, the vegetation has largely recovered.
  • The vegetation becomes very dry after drought, with danger of fire.
  • The sewage outfall pipe for Aberlady and Gullane passes through the dunes. Its laying in 1968 required the digging of a trench and the replanting of dune vegetation and its path is still clearly visible on the ground and from the air.

At neighbouring Gullane Bents the management has been more intensive. After extensive damage due to WW2 military manoeuvres and consequent blow-outs there was concern over the loss of habitat and the drop in tourist numbers. Parts of the eroded dune system were remodelled by earth movers and then planted with marram and sea buckthorn.