GL1A Juncus acutiflorus – Holcus lanatus grassland
Vegetation
Juncus acutiflorus is the main component of this rather rank community, usually forming a tall sward with the other constants, Holcus lanatus, Anthoxanthum odoratum and Agrostis stolonifera (mean graminoid height = 52.5 cm, n = 234). Frequent forbs include Rumex acetosa, Ranunculus repens, Ranunculus acris, Galium palustre, Filipendula ulmaria and Lotus pedunculatus, and these also display robust growth (mean forb height = 34.1 cm, n = 234); the latter two species in particular can be abundant. The chief bryophyte is Calliergonella cuspidata, which grows alongside Kindbergia praelonga, Rhytidiadelphus squarrosus and Brachythecium rutabulum.
Ecology
This is a wet grassland community of marginal farmland that occurs on mildly acidic, organic gley soils and peats (mean organic content = 31.7%, n = 156). It is typically found on gently sloping ground in the lowlands (mean slope = 2.1°, n = 234; mean altitude = 84 m, n = 234). There are usually few signs of agricultural improvement and the soils are relatively infertile.
Sub-communities
No sub-communities have been described for this community
Similar communities
The most similar community is the GL1E Juncus acutiflorus – Rhytidiadelphus squarrosus grassland but in that community the sward is typically less rank and more diverse. There are also similarities with GL4D Agrostis canina/vinealis – Rhytidiadelphus squarrosus grassland but that community contains indicators of dry-humid, upland swards such as Potentilla erecta, Hylocomium splendens and Luzula multiflora. Juncus effusus is frequent in community GL1A but is typically not as abundant as it is in the more mesotrophic wet grasslands of the GL2 Agrostis stolonifera – Ranunculus repens group.
Conservation value
This is on average a fairly species-poor grassland community (species/4 m2 = 17.9, n = 267), but more diverse examples may qualify as EU HD Annex I habitat 6410 Molinia meadows.
Management
These swards are managed as rough grazing land (typically for cattle). The main threats to these grasslands include improvement, abandonment and afforestation.