RH2F Festuca vivipara – Oligotrichum hercynicum fellfield
Vegetation
Growth of plants in this montane vegetation type is invariably very short, with cover ranging from very sparse to moderate. Constant vascular plants are Agrostis capillaris, Festuca vivipara and Galium saxatile, while Deschampsia flexuosa is frequent. These species are typically accompanied by some small patches of the hoary Racomitrium lanuginosum and scraps of Diplophyllum albicans are to be found between the stones. A fair number of diminutive acrocarps may be found here, the chief ones being Dicranella heteromalla, Polytrichum alpinum and Oligotrichum hercynicum. Arctic-alpines are not uncommon; frequently one will spot the round, green leaves of Salix herbacea and sometimes Carex bigelowii. Occasional finds of Thymus polytrichus or Armeria maritima may be made.
Ecology
This community is limited to exposed plateaux and upper slopes of the high mountains (mean altitude = 658 m, n = 29; mean slope = 8.3°, n = 29; mean extent of bare rock = 42.9%, n = 29; mean soil depth = 3.0 cm, n = 29) and includes vegetation from scree, stony grasslands and gravelly flats; these latter have potential links with the fellfields of Scotland, Scandinavia, Iceland and the Faeroe Islands. See account in Rodwell (2002).
Sub-communities
No sub-communities are described.
Similar communities
This community is closely related to the HE3E Racomitrium lanuginosum – Festuca vivipara heath and the scree communities RH2B and RH2C, but differs in the lower cover of Racomitrium species and the typical absence of dwarf shrubs and pleurocarpous mosses. The GL4B Nardus stricta – Potentilla erecta grassland has a higher cover of Nardus and pleurocarps and lower frequency of Festuca vivipara. It also occurs at lower altitudes.
Conservation value
Examples of this community from scree slopes correspond with the EU HD Annex I habitat 8110 Siliceous scree. Other examples, particularly those which support arctic-alpine species, are likely to correspond with habitat 6150 Siliceous alpine and boreal grasslands. Species/4 m2 = 13.9, n = 29.
Management
This vegetation, which often form parts of commonages, may be used as rough grazing land (typically for sheep) and overgrazing may be a problem. Climate change threatens arctic-alpine species which are restricted to montane communities such as this.