|Scientific name||Rhynchostegium riparioides – Chiloscyphus polyanthos aquatic community|
|Common name||Long-beaked Water Feather-moss – St Winifred’s Moss aquatic community|
Download full pdf synopsis: FW2B
Bryophytes dominate this aquatic community and vascular plants seldom occur. Rhynchostegium riparioides is the only constant species and patches of this moss, growing on rocks and stones, usually form the main vegetative cover. The liverwort Chiloscyphus polyanthos and the moss Fontinalis antipyretica are also frequent components. The thalli of Conocephalum conicum, Pellia endiviifolia and Marchantia polymorpha are occasionally found on shady rocks close to the water. Nutrient-poor, acidic streams in the uplands favour Scapania undulata and Fontinalis squamosa, the latter of which can grow abundantly in those waters. Conversely, in more base-rich situations, Cratoneuron filicinum can dominate. The most frequent higher plants found here are Oenanthe crocata and Phalaris arundinacea.
This community usually occurs in fairly fast-flowing, shaded, mesotrophic rivers and streams with a rocky substrate and beside waterfalls. Waters are typically mildly base-rich, but, as mentioned above, variants can occur in more acidic or alkaline conditions.
No sub-communities are currently described.
From the other bryophyte-dominated community in this group, FW2A, the present assemblage differs by its greater diversity of species and the lower frequency of Fontinalis antipyretica. It is also more confined to watercourses.
This is a fairly bryophyte-rich community but typically of relatively low conservation value.
This community has no specific management. It may be adversely affected by eutrophication, acidification, river engineering and trampling from livestock with access to the bankside. Removal of bankside tree cover may impact upon shade-loving bryophytes.