SM20: Eleocharis uniglumis salt-marsh community: Eleocharitetum uniglumis Nordhagen 1923

Summary

Constant species

Eleocharis uniglumis, Agrostis stolonifera.

Physiognomy

Although Eleocharis uniglumis is a widespread minor constituent of a variety of damp transitional communities along the upper marsh fringes (Birks 1973, Adam 1976), it is here dominant in a species-poor association, similar in floristics and appearance to the Blysmetum rufi. There is often an extensive undercarpet of Agrostis stolonifera and Juncus gerardii, Glaux maritima, Festuca rubra, Triglochin maritima, Potentilia anserina and Alopecurus geniculatus all occur frequently and may be abundant in particular stands. As in the Blysmetum, cover is variable and algae and bryophytes may form a patchy carpet over the substrate surface.

Habitat

In Britain, the Eleocharitetum occurs most frequently in depressions in the upper marsh. Some of the most extensive stands occur in brackish marshes by the River Gilpin, Cumbria. Rarely, it occurs in what is a widespread habitat in Scandinavia, as a fringe of emergent vegetation, as around the brackish and atidal Loch an Amadain in Skye.

Zonation and succession

The Eleocharitetum occurs patchily within other uppermarsh associations such as the Juncetum gerardi and it does not play a major role in salt-marsh succession.

Distribution

The association is a rare community on British saltmarshes occurring locally along the west coast from the Dovey estuary northwards.

Affinities

British vegetation dominated by E. uniglumis is clearly closely related to that described from Scandinavia (Gillner 1960, Tyler 1969b, Siira 1970) although the emergent stands in Britain lack the aquatic species characteristic of the Eleocharetum of, for example, the Baltic.