A ring of water surrounding raised bogs, often colonised by intermediate mire or acid fen communities of units D2.2 or D2.3, sometimes accompanied by more basicline species typical of neighbouring fens: Eriophorum angustifolium, Eriophorum vaginatum, Scirpus hudsonianus, Carex rostrata, Carex flava and Parnassia palustris are frequent components.