S8 - Scirpus Lacustris ssp. lacustris swamp Scirpetum lacustris (Allorge 1922) Chouard 1924

Summary

Synonymy

Scirpus lacustris open reed-swamp auct. angle, Scirpo-Phragmitetum Koch 1926 p.p.. (not sensu Wheeler 1980a); Scirpeto-Phragmitetum medioeuropaeum (Koch 1926) R.Tx. 1941 p.p.

Constant species

Scirpus lacustris ssp. lacustris.

Physiognomy

The Scirpetum lacustris typically has a somewhat open cover of S. lacustris ssp. lacustris, the stout emergent flowering shoots of which may reach more than 2 m above water-level. The robust creeping rhizomes frequently produce tufts of totally submerged leaves. No other species is frequent throughout but the sub-communities are distinguished by preferentially frequent species which may attain local abundance. It should be noted that, in the data available, submerged and floating-leaved aquatics are largely confined to the Equisetum fluviatile sub-community. This is probably, at least in part, a reflection of the fact that in many lowland waters, the sometimes rich aquatic flora which often overlapped in distribution with the Scirpetum lacustris has been lost because of pollution and disturbance.

Sub-communities

Scirpus lacustris ssp. lacustris sub-community: Scirpus lacustris open reed-swamp Pallis 1911; Scirpetum lacustris, Scirpus-Nymphaea mictium and Phragmites-Scirpus associes p.p.. Tansley 1939; Schoenoplectus lacustris society Wheeler 1978; Association of Phragmites australis and Schoenoplectus lacustris Pigott & Wilson 1978. Here are included pure stands of S. lacustris ssp. lacustris and mixed stands with P. australis where the former species remains the more abundant. No other species is frequent or abundant, although it is clear that, in the past, such swamps were sometimes associated with a rich aquatic flora including Nupharlutea, Nymphaea alba, Lemna minor, L. gibba, Wolfia arrhiza, Spirodela polyrhiza, Potamogeton natans, P. lucens, P. perfoliatus and P. crispus (e.g. Pallis 1911, Tansley 1939).

Sparganium erectum sub-community: Scirpus lacustris riparian reedswamp Butcher 1933. In this subcommunity, there is a generally lower emergent canopy of S. lacustris ssp. lacustris intermixed with Sparganium erectum and, sometimes, Alisma plantago-aquatica.

Equisetum fluviatile sub-community: Schoenoplectus lacustris-Juncus fluitans sociation Spence 1964; Schoenoplectus lacustris-Phragmites communis Association, Schoenoplectus lacustris-Equisetum fluviatile subassociation Birks 1973. Here, there is again a generally shorter canopy of S. lacustris ssp. lacustris but, in this sub-community, the shoots are intermixed with emergent Equisetum fluviatile, Carex rostrata and Menyanthes trifoliata, each of which may be locally prominent.