SD4: Elymus farctus ssp. boreali-atlanticus foredune community

Summary

Synonymy

Agropyretum juncei Moss 1906, Tansley 1911, 1939; Agropyretum boreo-atlanticum (Warming 1909) Br.-Bl. & De Leeuw 1936; Elymo-Agropyretum junceiforme Tx. 1955; Agropyron junceiforme stands Gimingham 1964a; Elymo-Agropyretum boreo-atlanticum Tx. (1937) 1967; Sociation à Agropyron junceiforme Géhu & Géhu 1969.

Constant species

Elymus farctus ssp. boreali-atlanticus.

Rare species

Euphorbia paralias.

Physiognomy

The Elymus farctus community comprises generally open, though often locally dense, vegetation in stretches of wind-blown sand, in which the dominant is the perennial grass long familiar as Agropyron junceiforme, but now known as Elymus farctus ssp. boreali-atlanticus. It is a rhizomatous plant, growing in the early stages after colonisation as small rosettes of shoots, often appressed to the surface, but then spreading outwards by means of its long and wiry underground stems and putting up vertical sympodial branches which by repeated tillering can keep pace with rapid though quite modest accumulation of sand (Nicholson 1952). Young colonies of the grass often have little more than small, low domes of sand around them but, where accretion progresses, distinct dunes, sometimes 1 m or more high, can develop. The grass shoots grow 20–60 cm tall and may be closely massed where the plants are especially vigorous, the glaucous foliage contrasting sharply with the bright yellow of the mobile sand.