RH3A Cephaloziella stellulifera – Dicranella varia mine-spoil community
Vegetation
This is a highly variable community of spoil heaps. It brings together, however, patchy vegetation characterised by the presence of several metallophytes. Much of the cover is provided by diminutive bryophytes with Cephaloziella stellulifera and Dicranella varia both frequent. Other components of the bryophyte layer may include Cephaloziella nicholsonii, Bryum pallescens, Pohlia nutans, Jungermannia gracillima and Ditrichum cornubicum. Agrostis capillaris and Rumex acetosa are the most likely vascular plants to be encountered, the former being a constant presence.
Ecology
Only on metalliferous spoil associated with old mine workings is this community likely to be encountered, where the ground contains high concentrations of zinc, lead or copper. Mean altitude = 124 m, n = 30; mean slope = 12.2°, n = 30; mean extent of bare rock = 24.2%, n = 30.
Sub-communities
No sub-communities are described.
Similar communities
This is a rather difficult community to settle on with confidence as it is characterised by the presence of several diminutive bryophyte species which usually require fertile plants, a microscope and specialist expertise for a positive identification. Community RH3B can also occur on mine spoil, but bryophytes are a less important part of the flora there and Silene uniflora is invariably present.
Conservation value
Most examples of this vegetation correspond to the Irish interpretation of EU HD Annex I habitat 6130 Calaminarian grassland. It supports a range of rare and protected bryophyte species, such as Cepahaloziella nicholsonii and Pohlia andalusica. Species/0.25 m2 = 4.5, n = 29.
Management
This community is usually unmanaged. Disturbance of the substrate can be used to generate new niches for bryophytes. Pressures include recreational activities and gradual succession to other vegetation types as metals are leached from the soil.