DU1B Ammophila arenaria duneland
Vegetation
Ammophila arenaria forms the vast majority of the vegetation in this duneland community, although cover here is often incomplete with areas of bare sand occurring between the tall tussocks (mean maximum vegetation height = 90.0 cm, n = 78). There are no other constant species. Elytrigia juncea and Festuca rubra are the next most frequent plants, the former lingering from an earlier seral stage whilst the latter colonises more stabilised sands. Occasionally, one will encounter the yellow flowers of Hypochaeris radicata, Taraxacum officinale agg. and Senecio jacobaea, but they are seldom plentiful.
Ecology
This is the classic coastal community of mobile (or white) dunes found between embryonic dunes to the seaward and fixed dunes to the landward, or in blow-outs. Ammophila arenaria traps wind-blown sand leading to the formation of dunes that can be several metres high. Mean altitude = 9.0 m, n = 57; mean extent of bare sand = 57.3%, n = 57.
Sub-communities
No sub-communities are described.
Similar communities
Ammophila arenaria can also be abundant in the DU2A Ammophila arenaria – Festuca rubra duneland, but there it is usually co-dominant with Festuca rubra and accompanied by a number of fixed dune species.
Conservation value
This community corresponds to EU HD Annex I habitat 2120 Marram dunes (white dunes). It is not very diverse (species/4 m2 = 5.6, n = 129).
Management
Mobile dunes are unstable habitats and part of the dynamic duneland system. They may be naturally removed by storms and high tides. Anthropogenic impacts include recreation and modification of the coastline.