2.B3C: Vegetation Stabilisation of Sediment

• Dunes

  • Large amount of sand washed ashore
  • Strandlines of seaweed from storms - sand trapped in seaweed
  • Pioneer species inhabit embryo dunes (e.g. marram grass)
  • Dune becomes stabilised by roots
  • Process repeats as more storms create more strandlines
  • Plants such as heathers move in - lowland heath habitat
  • 3 dunes over 400 years
  • Woodland further in
  • Fixed dunes - rabbits etc. Species rich vegetation
  • Dune slack - water between hills
  • Dune scrub - dry, acid and nutrient-poor substrate
  • Woodland - Trees colonise scrub
  • Blowout - Plants die due to trampling of beach visitors
• Salt marshes

  • Areas of periodically flooded low-lying coastal wetlands
  • Rich in biodiversity
  • Halophytes, birds
  • Accumulation of sediment
  • Usually behind a spit or bar
• Salt marsh diagram

  1. Sediment accumulates - sticks together and builds up to form mudflats
  2. Pioneer plants (e.g. marram grass) colonise area. Long roots trap sediment, encourage deposition and stabilise the mudflats.
  3. Conditions less harsh; mud level rises, rain washed out salt, decomposition of plants increases soil fertility
  4. Characterised by oak trees and shrubs. Takes hundred of years.

  A) sediment