Common Reed

Although the extensive system of rhizomes is perennial, in autumn the leaves of the reeds break away from the sheaths, which hold them in place. The dead reed stem remains in place throughout the winter (3). Reeds are still harvested for use in thatching, especially in the Norfolk Broads. Recently, there has been much interest in the potential of reedbeds as water filters; their spreading, creeping system of roots can remove nitrates and heavy metals from water (5).

Reedbeds are a priority habitat under the UK Biodiversity Action Plan. Many important reedbeds are listed as Sites of Special Scientific Interest (SSSIs), classified as Wetlands of International Importance under the RAMSAR Convention, and Special Protection Areas (SPAs) under the EC Birds Directive (6). Many are managed as reserves by the RSPB, English Nature and the Countryside Council for Wales (6).

This common reed forms large beds in shallow water; it has round, hollow stems, which typically grow to 2m in height, but may reach 4m (2). These stems grow from a system of stout, creeping rhizomes (3). The flat leaves taper into a point, and are attached to the stem by smooth sheaths, which are loose so that the leaves all point in one direction in the wind (2). The flowers are borne on highly branching purple inflorescences, which measure from 20 to 60cm in length (2). The flowers are grouped into 'spikelets', which are 10-15 mm in length and support 1-6 flowers (2).

This wetland species forms large beds on mud or in shallow water (2); it is found in swamps and fens, ditches, at the edges of lakes, ponds, and rivers as well as in coastal lagoons, brackish swamps, estuaries and where freshwater seeps over sea-cliffs (4). This reed is the dominant species in reedbeds, a priority habitat under the UK Biodiversity Action Plan (UK BAP) (2).

Found in appropriate habitats throughout Britain, and is particularly common in the south-east (2). Although the distribution of this species seems to be stable, there have been local losses (4). The common reed has a very broad global range; it is found in all parts of the world except for some tropical areas (3).

Common and widespread (4). Reedbeds are a priority habitat under the UK Biodiversity Action Plan (UK BAP) (6).

In Britain, reedbeds are one of the most important habitats for birds; a number of extremely rare birds are entirely dependent on the habitat, including the bittern (Botaurus stellaris), the marsh harrier (Circus aeruginosus) and the bearded tit (Panurus biarmicus). Unfortunately the total area of reedbeds is small, water abstraction, resulting in a lowering of the water table, as well as conversion to agricultural land have further reduced the area of reedbeds (6). Unsuitable management or neglect can result in a reedbed drying out; if the reeds are not cut regularly, the habitat will be invaded by willow scrub and will eventually become a wet woodland (5). Pollution of freshwater inputs into reedbeds can lead to the death of reeds, and siltation can cause drying out. Furthermore, many of the largest and most important reedbeds in Britain are on the eastern coast, and are threatened by sea-level rise (6).