FW3A Schoenoplectus lacustris – Sparganium erectum swamp
Vegetation
Schoenoplectus lacustris, Sparganium erectum and Apium nodiflorum are constants within this swamp community. Of the other emergents, Phalaris arundinacea is frequently encountered while Berula erecta and Myosotis scorpioides are occasionally found. An accompanying element of floating-leaf and free-floating plants is characterised by Nuphar lutea with Potamogeton natans, Potamogeton crispus and Lemna minor occasional. Sparganium emersum is a frequent plant which may contribute to either or both of these elements. Submerged plants may also occur but are infrequent, the chief species are likely to be the non-native Elodea canadensis, submerged forms of Veronica anagallis-aquatica, the bryophyte Fontinalis antipyretica and Myriophyllum spicatum.
Ecology
This is a community of lowland freshwater river systems with fairly base-rich and eutrophic waters.
Sub-communities
No sub-communities are currently described.
Similar communities
Schoenoplectus lacustris is also a constant in community FW3D Schoenoplectus lacustris swamp. In that less diverse assemblage, Sparganium erectum and Nuphar lutea are much less frequent, however, and S. lacustris tends to dominate.
Conservation value
Elodea canadensis is an invasive non-native species found in this community but it is not considered a major ecological threat and has already colonised much of its suitable niche in Ireland.
Management
This community may be affected by eutrophication, river engineering including dredging and canalisation, clearance works for navigation and trampling from livestock with access to the bankside.