Sand dune succession montage
Sand dune in Portugal following the chronological sequence (a-f) from strandline to the arrival of Pinus. The further from the shore, the older the dune ecosystem.
a) Sea holly (Eryngium maritimum) growing on the strandline nearest the sea. Note how the plant is trapping the windblown sand. It is well-adapted to life in the harsh conditions, its taproot can grow up to a metre in length to anchor in the shifting sand and obtain water.
b) The yellow dune above the strandline - marram (Ammophila arenaria) stabilizes the shifting sand. This species has evolved to cope with burial by wind-blown sand (see also Figure 5.23 in the book, which details these).
c) More established yellow dune with established tussocks of Marram and other species, trapping the sand and building a ridge above high water.
d) The grey dune and the establishment of a range of plants which begin to displace the marram.
e) A fully developed garrigue with a wide range of flowering plants growing on a soil with a developing profile of organic matter, and consequently an improved water and nutrient holding capacity.
f) Pinus halepensis indicates a relatively stable and well-developed soil.
