A survey of the vegetation of Ben Nevis - Scottish Natural Heritage

Scottish Natural Heritage Commissioned Report No. 090 (ROAME No. F02LD01)
U6R Juncus squarrosus-Festuca ovina grassland, herb-rich form
This is the herb-rich form of Juncus squarrosus rush heath. It is the Juncus-dominated equivalent of the herbrich
Nardus grassland U5c and the Festuca-Agrostis-Galium grassland U4F. Although it was described by
McVean & Ratcliffe (1962), was incorporated into the classification by Birks & Ratcliffe (1980) and is
widespread though not extensive in the uplands, it is unaccountably missing from the NVC scheme. It occurs
where peaty mineral soils are flushed with base-rich water. There are small patches of it on the upper slopes
of Sgurr Chòinnich Beag and on the col between there and Sgurr a’ Bhuic. It also occurs on the eastern
slopes of Stob Coire na Ceannain. The dark, shiny leaves of Juncus squarrosus grow in a dense green turf
with Anthoxanthum odoratum, Deschampsia cespitosa, Nardus stricta, Carex nigra and C. echinata.
This sward conceals an array of base-tolerant species including Ranunculus acris, R. repens, R. flammula,
Alchemilla glabra, A. alpina, Geum rivale, Parnassia palustris, Persicaria vivipara, Valeriana officinalis,
Rhinanthus minor, Thalictrum alpinum, Taraxacum officinale agg. and Crepis paludosa. The less demanding
Potentilla erecta, Galium saxatile and Viola palustris are common too. Among the vascular plants are
patches of bryophytes such as Calliergonella cuspidata, Rhizomnium punctatum, Hylocomium splendens,
Rhytidiadelphus loreus, Chiloscyphos polyanthus, Sphagnum fallax, S. denticulatum and Scapania undulata.
U7a Nardus stricta-Carex bigelowii
Cetraria islandica sub-community
grass heath, Empetrum nigrum hermaphroditum-
The montane Nardus grasslands – pale blond swards on the high slopes and in the corries – show where
snow lies late in spring. U7a is the sub-community of the dampest ground, and it is common to see
almost as much Trichophorum cespitosum as Nardus stricta in the sward. There are grey-green spikes of
Carex bigelowii, C. panicea and C. pilulifera, green clumps of Empetrum nigrum ssp. hermaphroditum and
a sprinkling of small plants such as Huperzia selago, Diphasiastrum alpinum, Potentilla erecta, Galium
saxatile, Viola palustris, Narthecium ossifragum and Succisa pratensis. The bog plant Rubus chamaemorus
is not uncommon in wetter examples in the Grey Corries, and locally there are floristic and ecological
transitions between U7a and montane Calluna-Eriophorum bog M19c. The most common bryophytes are
Racomitrium lanuginosum and Sphagnum capillifolium. There is generally also a little Pleurozium schreberi,
Hylocomium splendens, Hypnum jutlandicum, Polytrichum alpinum, Pleurozia purpurea, Bazzania tricrenata,
Anastrepta orcadensis, Mylia taylorii and Scapania gracilis. This sub-community may be home to scarce
oceanic liverworts such as Scapania ornithopodioides, Plagiochila carringtonii and Bazzania pearsonii.
There is a speckling of lichens such as Cetraria islandica, Coelocaulon aculeatum, Cladonia portentosa
and C. uncialis. U7a occurs in hollows and gullies and on concave slopes where snow accumulates and
where drainage is slow. It is common throughout the higher parts of the study area.
U7b Nardus stricta-Carex bigelowii grass heath, Typical sub-community
This is the typical form of Nardus snow-bed grassland, with neither the species of damp ground which
distinguish the Empetrum-Cetraria sub-community U7a nor the grasses and herbs of the Alchemilla-Festuca
sub-community U7c. It has the characteristic pale sward of Nardus stricta and Carex bigelowii, interleaved
with a little Anthoxanthum odoratum, Deschampsia flexuosa and Carex pilulifera. There are green sprigs of
Vaccinium myrtillus, V. vitis-idaea and V. uliginosum and clumps of Empetrum nigrum ssp. hermaphroditum.
Salix herbacea can grow in this type of vegetation. There is an assemblage of small herbs such
as Potentilla erecta, Galium saxatile, Huperzia selago, Diphasiastrum alpinum, Blechnum spicant and
Campanula rotundifolia. The bryophyte layer is made up of species such as Polytrichum alpinum, Pleurozium
schreberi, Rhytidiadelphus loreus, R. squarrosus, Hypnum jutlandicum and Dicranum scoparium. There is a
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