Geography-Biosphere-Sand dune succession

Card Set Information

Geography-Biosphere-Sand dune succession
2011-04-21 11:43:50
Geography Biosphere Sand dune succession

Geography-Biosphere-Sand dune succession
Show Answers:

  1. Plant cover increases –
    • the amount of sand showing through the dune decreases as more of the ground is covered by vegetation.
    • Little cover in the pioneer stage, more in the building stage and complete cover in the climax stage unless disturbed by animals/humans/storms etc.
  2. • Soil moisture increases –
    • rain/fresh water is trapped with added humus/plant cover and longer rooted plants drawing water up from the water table.
    • Xerophytic plants found in the drier strandline and embryo dune
    • On the yellow dune Marram grass has long rhizomes to spread through the sand.
    • Dune slacks at or near the water table
    • have hydrophytic species like reeds, rushes and flag iris.
  3. • Organic matter content increases
    • – decaying pioneer species adding humus to the sand.
    • In the fore-dune more plants stabilise the sand adding humus changing the sand to a sandy loam and from the sandy colour of this and the yellow dune to the grey dune.
  4. • PH decreases –
    • shells (CaCO3) producing alkaline conditions on shore, more neutral pH by the climax stage as plants decay and add acid to the soil.
    • . In the climax stage a range of plants from heathers to birch, pine or oak woodland can grow depending on the final pH value of the soil.
  5. • Salinity decreases –
    Increased distance from the sea and salt water/tides/spray increases the amount and variety of plant species that can cope with the conditions.
  6. Plants on embryo and fore dunes
    • Sallwort
    • Sea ricket
    • Lyme grass
  7. yellow dunes plants
    • Marram grass
    • Thistles
  8. Grey dunes
    • Wavy hair grass
    • Dandelions
    • Sea buckthorn
    • heather
  9. Slacks
    • rushes
    • cotton grass
    • Flag iris