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
Embryo and fore dune plants
Sea rocket, sea Lyme and sallwort
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
Yellow dunes
Marram grass
Thistles(far side)
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