S19 - Eleocharis Palustris Swamp Eleocharitetum Palustris Schennikow 1919

Summary

Synonymy

Eleocharis palustris consocies Pearsall 1918.

Constant species

Eleocharis palustris.

Physiognomy

The Eleocharitetum palustris is dominated by an open or closed cover of the slender shoots of Eleocharis palustris. There are no other species frequent throughout.

Sub-communities

Eleocharis palustris sub-community: Eleocharis palustris Community Birse 1980. Here are included pure and species-poor stands in which E. palustris is overwhelmingly the most abundant species. Alismaplantago-aquatica, Mentha aquatica, Myosotis laxa ssp. caespitosa and Ranunculusflammula occur occasionally and a variety of other water-margin species at very low frequency.

Littorella uniflora sub-community: Eleocharis palustris-Littorella sociation Spence 1964. In this sub-community Littorella uniflora forms a diminutive understorey to the E. palustris, sometimes with a little Lobelia dortmanna. There is frequently some emergent Equisetum fluviatile and floating Juncus bulbosus and aquatics such as Potamogeton natans and Myriophyllum alterniflorum occur occasionally.

Agrostis stolonifera sub-community: Eleocharis palustris-Agrostis stolonifera nodum Adam 1981. Here, Agrostis stolonifera and, less frequently, Potentilla anserina, form a sometimes extensive low mat beneath the E. palustris and there are occasional records for species characteristic of the Juncetum gerardi: Festuca rubra, Juncus ger ar di, G faux maritima, Triglochin maritima and Trifolium repens. Eleocharis quinqueflora may be locally prominent.

Habitat

The Eleocharitetum is a swamp of standing or running waters up to 50 cm deep and it occurs round large lakes, small ponds and along stream sides. The sub-communities show some relationships to substrate type and trophic state of the waters. The Eleocharis sub-community occurs over various substrates including silts in mesotrophic conditions; the Littorella sub-community is more characteristic of sandy or stony substrates in more oligotrophic waters and is common around the shores of some Scottish lakes; the Agrostis subcommunity occurs in brackish and saline habitats on upper salt-marshes.

Zonation and succession

The community can occur as the distal component of swamp and fen zonations in open-water transitions. The Littorella sub-community is commonly found in such situations over sand and gravels around exposed shores in some Scottish lakes (Spence 1964). Here, it grades in deeper water to submerged vegetation with combinations of L. uniflora, Lobelia dortmanna and Juncus bulbosus. In other cases there is a front of the Scirpetum lacustris in deeper water. Inshore, this sub-community can give way to the Caricetum rostratae, the Caricetum vesicariae, the Phragmitetum australis or the Phafaridetum arudinaceae (e.g. Pearsall 1918).