Upward growth of the embryo dunes allows the surface
to be raised so it is out of the reach of all but the highest storm
tides. This, together with the washing by fresh rainwater, results
in a slightly less salty and unstable substrate. Under these conditions
another grass is able to colonise - Marram Ammophila arenaria.
Marram grass is the major dune building grass. It is tall and robust
(but flexible in the wind) and very effective at trapping sand by
reducing the windspeed at the surface. This remarkable grass is
able to grow upwards through accumulating sand at rates of up to
one metre a year. Thus, if there is a plentiful supply of sand from
the beach, Marram will build up the sand to form high mobile dunes.
Marram on mobile dunes
The environment is still extremely
stressful to plants and over large areas of the frontal dune ridge
(formed by the coalescence of the original embryo dunes) Marram is
the dominant and only species present. Bare sand can clearly be seen
between the clumps of Marram (see vegetation and soil data relating
to Quadrat 1).
The dead leaves of the Marram add organic matter
to the soil which increases water-holding capacity and also breaks
down to release plant nutrient. On the landward side of the frontal
dunes the surface is more sheltered from the onshore winds and the
effects of sea spray. More (still highly adapted) plants are able
to colonise and the species diversity starts to increase. Good examples
of these plants are
Sea Holly Eryngium maritimum
Sea Spurge Euphorbia paralias
Sea Spurge and Sea Holly on the
With gradual amelioration of conditions for plant growth and increasing
distance from the sea, the species diversity continues to increase.
A much smaller and very fine-leaved grass starts to fill in the
bare spaces between the clumps of Marram - this is
Red Fescue Festuca rubra
See vegetation and soil data relating to Quadrat
For more information about this project email email@example.com
at Liverpool Hope University.
Liverpool Hope University worked with English
Nature and the Sefton Coast Partnership to implement the Sands of Time project.