|Scientific name||Molinia caerulea – Nardus stricta heath|
|Common name||Purple Moor-grass – Mat-grass heath|
Download full pdf synopsis: HE4B
This is a rather variable community in which the main field layer species are Molinia caerulea, Nardus stricta and Carex panicea. Dwarf shrub cover is provided by Erica tetralix and Calluna vulgaris but is typically low. Other constant vascular plants are Narthecium ossifragum and Trichophorum cespitosum/germanicum. In addition to Carex panicea, there are several frequent species which are indicators of disturbance or flushing: Juncus squarrosus, Juncus bulbosus, Eleocharis multicaulis and Carex viridula. In the bryophyte layer, the main species are Racomitrium lanuginosum, Hypnum jutlandicum and Campylopus atrovirens, but Sphagnum compactum, an indicator of disturbance, is also frequent.
This vegetation occurs mainly on the middle slopes of hills and mountains, on peaty, acidic, infertile soils. It may develop from other wet heath types due to grazing pressure. There is also a distinct element of flushing.
Two sub-communities have been described. The Eriophorum angustifolium – Carex echinata sub-community (HE4Bi) represents the more flushed examples of this assemblage. Eriophorum angustifolium, Carex echinata, Juncus bulbosus, Eleocharis multicaulis and Drosera rotundifolia are all much more frequent there than in the grassier Nardus stricta – Agrostis canina/vinealis sub-community (HE4Bii) in which Juncus squarrosus is often found.
From other HE4 Molinia heath communities, HE4B is differentiated by the high cover of Carex panicea and the presence of other flush-preferring species. It is noteworthy that ‘brown mosses’ associated with alkaline flushes and fens are not typically found in this community. From the grassland communities of the GL4 Nardus stricta – Galium saxatile group, HE4B differs in the abundance of heath species including Molinia caerulea, Narthecium ossifragum and Erica tetralix.
This is on average a moderately species-rich community. Most instances can be referred to the EU HD Annex I habitat 4010 Wet heath but there are also some cases from habitat 7130 Blanket bog (active)*.
This community, which often forms parts of commonages, is usually used as rough grazing land (typically for sheep) and there are signs of overgrazing. Burning may be periodically used across large areas to suppress the dwarf shrubs and encourage grass growth. Another threat is agricultural improvement.