FE3D Carex nigra – Calliergonella cuspidata fen
Vegetation
A striking feature of this fen community is the typical presence of a mossy carpet of the pointy shoots of Calliergonella cuspidata. Through this grows a modest sward of Agrostis stolonifera. Other constant species are Hydrocotyle vulgaris, Carex nigra, Juncus articulatus, Galium palustre, Mentha aquatica and Ranunculus flammula. Frequently found are Eleocharis palustris, Caltha palustris, Equisetum fluviatile and Cardamine pratensis. Bryophytes other than Calliergonella are seldom seen.
Ecology
This wetland community occurs in mildly base-rich and mildly nutrient-poor situations, often where there is a fluctuating water table. It has predominantly been recorded from dune-slacks in coastal systems as well as more typical fens, lake margins and wet grasslands.
Sub-communities
No sub-communities are currently described.
Similar communities
The abundance of Calliergonella cuspidata will help separate FE3D from other communities in this group. Two Agrostis stolonifera grassland communities are also similar. The GL1B Agrostis stolonifera – Filipendula ulmaria marsh-grassland differs in that Filipendula ulmaria is a constant there but seldom seen in FE3D, while in the rather species-poor GL2A Agrostis stolonifera – Ranunculus repens marsh-grassland, Carex nigra is only occasional and Ranunculus repens a constant.
Conservation value
This is a community of medium species richness (species/4 m2 = 20.4, n = 119). Examples from coastal dune-systems may correspond with the EU HD Annex I habitat 2190 Dune slack. It has also been recorded adjacent to areas corresponding to priority habitat 1150 Lagoon*
Management
These stands may be subject to livestock grazing. The main threats are groundwater pollution, drainage, inappropriate grazing and reclamation.