SM6C Agrostis stolonifera – Potentilla anserina grassland
Vegetation
This variable community is typically dominated by a combination of Potentilla anserina and Agrostis stolonifera. Juncus gerardii is frequently found. Glaux maritima and Leontodon autumnalis are occasional while Trifolium repens, Rumex crispus and Lotus corniculatus are the most likely of other species to be seen. Less frequently, one will find species indicative of freshwater conditions such as Carex nigra and Mentha aquatica.
Ecology
This community has predominantly been defined based on data from upper saltmarshes and lagoon margins that are infrequently inundated by saline or brackish water. However, it also provides a home for some inland swards dominated by Agrostis stolonifera and Potentilla anserina that may be periodically inundated by freshwater. Conditions are circumneutral.
Sub-communities
Two sub-communities are described. The Juncus gerardii sub-community (SM6Ci) represents coastal saltmarsh swards whilst the Rumex crispus – Galium palustre sub-community (SM6Cii) represents swards occurring more inland
Similar communities
This community differs from other saltmarsh types in the abundance of Potentilla anserina. It has some similarities to FE3B Carex nigra – Potentilla anserina fen, but in that community Carex nigra is abundant.
Conservation value
Examples of this vegetation supporting saltmarsh indicators such as Juncus gerardii and Glaux maritima should qualify as EU HD Annex I habitat 1330 Atlantic salt meadows. Compared with other saltmarsh communities, it is diverse (species/4 m2 = 9.3, n = 40). Centaurium pulchellum is a nationally rare species listed on the Floral Protection Order, 2015.
Management
The main immediate threat to saltmarsh examples of this community is probably grazing by livestock. Sea-level rises as a result of climate change will have an impact, particularly in areas susceptible to coastal squeeze.