Main question

Are sand dunes sub-climax or plagioclimax communities?

• Resource A

  
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  Source: http://www.geograph.org.uk/photo/205069
  Created by Gary Rogers and licensed for reuse under the Creative Commons 2.0 License.

  
  
  2.
  
  

  Source: http://www.soil-net.com/album/soils_rocks/slides/Gower%20Three%20Cliffs%20Bay%20Sandy%20Soil%20Profile.html
  This work is licensed for reuse under the Creative Commons 2.0 License.

  
  
  3.
  
  

  Source: http://www.geograph.org.uk/photo/71546
  Created by David Crocke and licensed for reuse under the Creative Commons 2.0 License.

  
  
  The natural environment of Ainsdale dunes.
  

  • Xerophytic conditions on the dunes - water infiltrates rapidly into the sand.
  • Halophytic conditions – onshore wind blows salt inland.
  • Water table close to the surface in the slacks. In winter the ground becomes marshy and ponds may develop.
  • Sandy soil – few nutrients.
  • Windy – prevailing Westerly winds.
  
  

• Resource B

  
  
  
  
  
  Ainsdale Sand Dunes National Nature Reserve.
  
  

  One of England's most important wildlife sites. Established in 1965. 508 hectares, with over 450 different species of plants.
  
  During the eighteenth century it was a rabbit warren and later an attempt was made to improve the poor sandy soils for farming. At the beginning of the twentieth century pine trees were planted on the inland parts of the dunes in an attempt to reduce erosion - the plantations remain to this day.
  
  The number of rabbits has declined greatly since the 1950s due to myxomatosis, therefore trees, e.g. birch, creeping willow and thorns began to colonize the dunes.
  
  Pine cones also spread to the dunes. To conserve habitats for rare dune plants and animals some of these trees and shrubs are removed. In addition some of the pine trees were cleared to restore the original dune habitat and sheep and cattle graze the dunes in winter.
  
  Marram grass has been planted to stabilize the dunes (a practice that has been maintained for over 300 years).
  
  Grass is mown on the older dunes to create footpaths and turf removed to maintain the natterjack toad’s habitat.
  
  Urban development has occurred on the eastern side of the dunes.

• Resource C

  
  1.
  
  

  Source: http://www.geograph.org.uk/photo/2574719
  Created by Humphrey Bolton and licensed for reuse under the Creative Commons 2.0 License.

  
  
  2.
  
  

  Source: https://www.geograph.org.uk/photo/4744406
  Created by Mike Pennington and licensed for reuse under the Creative Commons 2.0 License.

  
  
  3.
  
  

  Source: https://www.flickr.com/photos/londonmatt/8996126977
  This work is licensed for reuse under the Creative Commons 2.0 License.