Calluna Vulgaris-Vaccinium Myrtillus-Sphagnum Capillifolium Heath

Synonymy Vaccineto-Callunetum hepaticosum McVean & Ratcliffe 1962, Birks 1973; Vaccinium-Sphagnum-Hymenophyllum wilsonii nodum Prentice & Prentice 1975; H erber ta adunca-Calluna vulgaris Association Birse 1984. Constant species Blechnum spicant, Calluna vulgaris, Deschampsia flexuosa, Potentilla erecta, Vaccinium myrtillus, Dicranum scoparium, Hylocomium splendens, Hypnum cupressiforme s.l., Plagiothecium undulatum, Pleurozium schreberi, Rhytidiadelphus loreus, Sphagnum capillifolium. Rare species Anas trophy llum donianum, A. joergensenii, Bazzania pearsonii, Campylopus setifolius, Colura calyptrifolia, Mastigophora woodsii, Myurium hochstetteri, Plagiochila carringtonii, Scapania ornithopodioides. Physiognomy The Calluna vulgaris-Vaccinium myrtillus-Sphagnum capillifolium heath has a mixed canopy of sub-shrubs, usually 3-5 dm tall, with a damp layer of luxuriant bryophytes. Calluna vulgaris is usually the dominant ericoid, although Vaccinium myrtillus is also constant and Empetrum nigrum, almost always ssp. hermaphroditum, is present in many stands, and each of these can show modest abundance. Erica cinerea occurs quite frequently, although it becomes distinctly patchy in the most humid situations occupied by this vegetation, and there is occasionally some V. vitis-idaea. In its general composition, then, the canopy is like that of much Calluna-Vaccinium heath, although E. nigrum ssp. nigrum tends to be the predominant crowberry there and, more importantly, regeneration after burning plays a large part in determining the floristics and structure of the sub-shrub element, and the associated flora, at any particular time. With the Calluna-Vaccinium-Sphagnum heath, on the other hand, fire is highly inimical to the distinctive composition of the richest stands and, though this vegetation sometimes experiences light grazing, treatments are not of consequence in maintaining its characteristic features. Other sub-shrubs figure very occasionally, with sometimes a little Arctostaphylos uvaursi, A. alpinus or Juniperus communis ssp. nana, but the general scarcity of these species helps separate the community from the Calluna-Juniperus heath, a vegetation type of rather similar geographical range and particular habitat requirements. As in the Calluna-Vaccinium heath, Deschampsiaflexuosa and Potentilla erecta are both very common among the associates, although they are usually present here as sparse, scattered individuals. More distinctively in this heath, there is constant Blechnum spicant and frequent records for Solidago virgaurea and Listera cordata, the last Northern Montane plant providing one of the floristic links between this community and our native pine and related juniper and birch woods.