S4 - Phragmites Australis Swamp and Reed-Beds Phragmitetum Australis (Gams 1927) Schmale 1939

Summary

Synonymy

Scirpo-Phragmitetum Koch 1926 p.p.; Scirpeto-Phragmitetum medioeuropaeum (Koch 1926) R.Tx. 1941 p.p.

Constant species

Phragmites australis.

Rare species

Cicuta virosa, Utricularia intermedia.

Physiognomy

All the vegetation types included here are characterised by the generally overwhelming dominance of Phragmites australis. However, this is a very polymorphic species and the gross appearance of the vegetation, even with pure stands, can be very variable. Much of this variation is known to be phenotypic adaptation perpetuated in clonal populations and variously described as ‘kinds’, ecotypes, biotypes or biotopes of reed (e.g. Rudescu et al. 1965; Björk 1967; Haslam 1971a, 1972a, Dykyjová 1978a); some is related to genotypic differences (e.g. Björk 1963, 1967; van der Toorn 1972; Riacu et al. 1972; Pazourková 1973: Dykyjová 1978a). Although variation in Britain is said to be less than elsewhere (Haslam 1972a) and presumed to be phenotypic, there has been no systematic study of its extent in this country or of its relationships to the kind of environmental differences that are reflected in the floristics of the various kinds of Phragmitetum. Here, it is possible only to give a very general indication of the reed morphology in each of the sub-communities.

Phragmites is normally a highly gregarious species and individual stands of the community can be very extensive. The vegetation is generally very species-poor and no other species attains even occasional frequency throughout. The Phragmitetum is, however, very variable and individual stands may show marked peculiarities of composition.

Sub-communities

Phragmites australis sub-community: Phragmites communis reedswamp Tansley 1911; Phragmites-Scirpus associes Pearsall 1918 p.p.; Phragmites communis-Sparganium minimum and Phragmites communis-Littorella open sociations and Phragmites communis society Spence 1964; Phragmites monodominant stands Haslam 1971a; Phragmites nodum Daniels 1978; Association of Phragmites australis and Schoenoplectus lacustris Pigott & Wilson 1978 p.p.; Phragmites communis swamp sociation Wheeler 1978; Phragmites australis reedswamp, species-poor variant Meres Survey 1980; Scirpo-Phragmitetum typicum Wheeler 1980; Phragmites communis nodum Adam 1981 p.p.; this sub-community includes pure and very species-poor swamps and reed-beds in which Phragmites is the sole constant. The reed cover can be open or closed but Phragmites is always the most abundant helophyte forming a canopy from about 1-3 m high. Other species can, however, be locally prominent including other swamp dominants such as Typha latifolia, T. angustifolia, Carex riparia, C. acuta, Glyceria maxima, Cladium mariscus, Scirpus lacustris ssp.