DU2D Festuca rubra – Thymus polytrichus duneland
Vegetation
This is a dune grassland community in which the main constituents are Festuca rubra, Thymus polytrichus and Galium verum. Other constant herbaceous species are Trifolium repens, Lotus corniculatus, Plantago lanceolata, Luzula campestris and Bellis perennis. In addition to Thymus, with its delicate pink-purple flowers, several calcicole turf species may be encountered here, including Linum catharticum, Euphrasia officinalis agg., Carex flacca, Ranunculus bulbosus, Koeleria macrantha and Campanula rotundifolia. Tussocks of Ammophila arenaria are frequent. A typically modest moss layer occurs composed of Rhytidiadelphus squarrosus and Homalothecium lutescens. Mean maximum vegetation height = 34.6 cm, n = 19.
Ecology
This community represents a variant of dune grassland found on fixed dunes and machair plains, occurring on sandy soils which have developed some mor-humus (mean altitude = 8.2 m, n = 117; mean extent of bare sand/soil = 2.9%, n = 117). Rarely, instances of this community may be found at inland locations.
Sub-communities
No sub-communities are described.
Similar communities
The suite of calcicole species, particularly Thymus polytrichus, separate this DU2D assemblage from the other dune grassland communities. In the calcareous swards of the GL3A Briza media – Thymus polytrichus grassland, several different grasses are found, notably Briza media, Anthoxanthum odoratum and Sesleria caerulea, but psammophilic species, such as Ammophila arenaria and Carex arenaria, are lacking.
Conservation value
Most examples of this vegetation correspond to EU HD Annex I habitat *2130 Fixed dunes (grey dunes). On the northwest coast, this assemblage can be a component of priority habitat *21A0 Machair. It is quite diverse in terms of plants (species/4 m2 = 24.4, n = 194).
Management
This dune grassland is often grazed by livestock and rabbits, and overgrazing or undergrazing can be a problem, as can disturbance due to recreational activities in popular coastal areas.