Geography-Biosphere-sand dunes

  1. What difficulties to colonising plants have to face?
    • Strong stormy high tides and the use of the beach by people can destroy plants and dunes
    • Sand is a sterile environment often lacking humus and nutrients
    • Sand can be very dry. Water retention is poor because of rapid drainage and the drying effect of the wind. Even wetting from sea spray is of little use because of it's salty nature.
    • Pioneer species therefore have to be able to withstand consistently dry conditions-such drought resistant plants are classified as Xerophytic
  2. Embryo and fore dune plants
    Sea rocket, sea Lyme and sallwort
  3. Marram grass
    • Ideal for low moisture and high salinity as they have long roots which bind the soil
    • Also have rhizomes which bind are long creeping underground stems which spread rapidly, helping the plant to grow
    • These plants also adapt to their surroundings by curling up when it is dry to reduce transpiration and spreads out when wet to increase transpiration
  4. Yellow dunes
    • Marram grass
    • Thistles(far side)
  5. Grey dunes
    • Increased humus content of the soil and surface growth of lichens
    • Salinity and ph of the soil decreases and the organic matter, plant cover and soil moisture increases
    • This is due to the increased plant cover in the yellow dunes resulting in more humus and plat decays
    • This increase in organic matter helps the plants to grow
    • Increased shelter inland from high winds
  6. Plants on grey dunes
    Heather, bramble and wild rose
  7. Slacks plants
    Hydrophytic plants rushes, willows and alders
Card Set
Geography-Biosphere-sand dunes
Geography-Biosphere-sand dunes