GL1B Agrostis stolonifera – Filipendula ulmaria marsh-grassland
Vegetation
Broadleaved herbs are at their most abundant here out of all the wet grassland communities, with grass species being much less prominent. Nevertheless, Agrostis stolonifera is one of the most frequent species, with Festuca rubra, Anthoxanthum odoratum, Juncus effusus and Holcus lanatus also sometimes found. Sedges are a noteworthy component of the assemblage, with Carex nigra being a constant species and often plentiful, while Carex disticha, C. panicea and C. flacca may also occur in the relatively tall sward (mean graminoid height = 43.3 cm, n = 114). Filipendula ulmaria is the mainstay of the forb cover (mean forb height = 30.9 cm, n = 114), typically accompanied by Galium palustre, Ranunculus repens, Cardamine pratensis and Trifolium repens, and less frequently by Mentha aquatica, Ranunculus flammula, Potentilla anserina and Ranunculus acris. Calliergonella cuspidata is also a constant and may be the only bryophyte present but it can be very abundant. On the wettest sites, Equisetum fluviatile and E. palustre may occur.
Ecology
The Agrostis stolonifera – Filipendula ulmaria marsh-grassland occurs on basin peats and gleys in low-lying areas (mean altitude = 49 m, n = 114) on seasonally flooded level ground (mean slope = 0.3°, n = 114) near lakes and rivers. The upper soil horizons are typically rich in organic matter (mean organic content = 40.9%, n = 77). Soils are of average fertility and are mildly base-rich in relation to other grasslands.
Sub-communities
No sub-communities have been described for this community
Similar communities
Community GL2A is similar, but that community is less species-rich and occurs on more mesotrophic soils. Sedges are also less characteristic in that community. Filipendula is also abundant in the FW3F Filipendula ulmaria – Valeriana officinalis tall-herb swamp but there it tends to be accompanied by other tall-growing forbs and grasses.
Conservation value
This is a grassland community of medium species richness (species/4 m2 = 24.3, n = 146), of which some examples correspond to EU HD Annex I habitat 6410 Molinia meadows. Assemblages of river banks and lake margins with plants such as Filipendula ulmaria, Iris pseudacorus and Equisetum fluviatile may be regarded as EU HD Annex I habitat 6430 Hydrophilous tall herb.
Management
These swards are managed as rough grazing land (typically for cattle). The main threats to these marshy grasslands include improvement, abandonment and changes to the flooding regime.