SM7A Elytrigia repens coarse grassland
Vegetation
A sward of the tall, coarse grass Elytrigia repens dominates this low diversity community. Mixed into this is usually some small amount of Agrostis stolonifera and less frequently some Festuca rubra or Holcus lanatus. Occasionally there will be some scattered growth of Atriplex prostrata. Other halophiles, such as Beta vulgaris, Aster tripolium, Triglochin maritimum or Juncus gerardii, may also occur. Bryophytes are usually absent.
Ecology
This sward is to be found on fertile, base-rich soils at the very top of saltmarshes, where it occurs along driftlines and on the lower sections of levees. It also occurs inland in disused gardens, uncut verges and abandoned farmland.
Sub-communities
Two sub-communities are described. The Atriplex prostrata sub-community (SM7Ai) represents coastal swards whilst the Holcus lanatus – Potentilla anserina sub-community (SM7Aii) represents inland swards.
Similar communities
Elytrigia repens also occurs in the SM7B Elytrigia atherica saltmarsh but does not dominate; SM7B may co-occur with SM7A but forms slightly lower in the tidal frame.
Conservation value
Although these swards are off low plant diversity (species/4 m2 = 6.1, n = 39), coastal instances constitute part of the spectrum of communities within the EU HD Annex I habitat 1330 Atlantic salt meadows. In gardens and on agricultural land Elytrigia repens is regarded as a pernicious weed.
Management
In coastal situations, these are ungrazed swards that are likely to be replaced by other saltmarsh communities following the introduction of livestock. Sea-level rises as a result of climate change will have an impact, particularly in areas susceptible to coastal squeeze. As they occur at the very top of the saltmarsh profile, they are also vulnerable to reclamation. In inland situations these swards tend to occur where agricultural practices have lapsed.