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

Scottish Natural Heritage Commissioned Report No. 090 (ROAME No. F02LD01)
U5c Nardus stricta-Galium saxatile grassland, Carex panicea-Viola riviniana sub-community
This is the herb-rich form of Nardus grassland. It is quite variable in its species composition and many
examples are more species-rich than the NVC tables suggest. U5c occurs around the exposures of base-rich
rock on the west side of Ben Nevis, on Meall Cumhann, Sgurr a’ Bhuic and Sgurr Chòinnich Beag and in
Coire Giubhsachan. It is extensive on Beinn na Sochaich and Beinn Bhàn. This type of grassland has
a sward of Nardus stricta, Anthoxanthum odoratum, Agrostis capillaris, Festuca vivipara, Carex panicea,
C. viridula ssp. oedocarpa, C. binervis and C. pulicaris. The sward is enriched with Thymus polytrichus
and with base-tolerant herbs such as Plantago lanceolata, Ranunculus acris, Campanula rotundifolia,
Persicaria vivipara, Prunella vulgaris, Lysimachia nemorum, Alchemilla alpina, A. glabra, Linum catharticum,
Filipendula ulmaria, Geum rivale, Selaginella selaginoides and Thalictrum alpinum. There is a deep, damp
carpet of bryophytes made up of species including Hylocomium splendens, Calliergonella cuspidata,
Rhytidiadelphus squarrosus, Scleropodium purum and Thuidium tamariscinum.
U5e Nardus stricta-Galium saxatile grassland, Racomitrium lanuginosum sub-community
This form of Nardus grassland takes the community to its highest altitudes. Although there are a few patches
on shallow, stony soils on the lower slopes, most of the U5e in the study area is on the mid to upper slopes
of the hills. It clothes stony plateaux and shallow slopes where the soils are thin accumulations of peat and
humus over frost-shattered bedrock. On Meall an t-Suidhe, Meall Cumhann, Sgurr a’ Bhuic and Beinn Bhàn
it occupies one of its typical habitats: stony plateaux just below the lower altitudinal limit of
Carex-Racomitrium heath U10. U5e is very distinctive. The open, sparse, pale sward of Nardus stricta,
Carex panicea and C. pilulifera grows through a thin grey-green layer of Racomitrium lanuginosum, dotted
with dwarfed, wind-pruned bushes of Calluna vulgaris and with small plants such as Empetrum nigrum ssp.
hermaphroditum, Huperzia selago, Diphasiastrum alpinum, Succisa pratensis and Potentilla erecta.
Within the carpet of Racomitrium lanuginosum are a few other bryophytes such as Hypnum jutlandicum,
Rhytidiadelphus loreus and Pleurozium schreberi. There is also generally a dusting of lichens such as
Coelocaulon aculeatum, Cladonia portentosa, C. rangiferina and C. uncialis. It is not a species-rich community,
but is interesting because some examples, at least, may be near-natural forms of vegetation of windswept
plateaux and ridges at moderate altitudes. U5e is especially common in the oceanic, windy climate of the
western Highlands and the Hebrides.
U6a Juncus squarrosus-Festuca ovina grassland, Sphagnum sub-community
This is a Juncus squarrosus bog. The thick, dark green, tufted sward of J. squarrosus is spiked through by
Eriophorum angustifolium and with grasses such as Festuca vivipara, Anthoxanthum odoratum, Deschampsia
flexuosa and Agrostis canina. There is a thin speckling of Vaccinium myrtillus and Potentilla erecta, together
with more typical bog species such as Narthecium ossifragum, Trichophorum cespitosum and Eriophorum
vaginatum. Set in the sward are patches and cushions of bryophytes such as Sphagnum capillifolium,
S. papillosum, Polytrichum commune and Aulacomnium palustre. U6a occurs on benches on the south-facing
slope of Glen Nevis, in Coire Rath, and on Beinn na Socaich and Beinn Bhàn. Most examples of this type
of vegetation seem likely to be derived from more heathery blanket-bog where the dwarf shrubs have been
eliminated by burning and grazing in the past. However, it is possible that some patches of U6a at higher
altitudes, such as on the col between Sgurr a’ Bhuic and Sgurr Chòinnich Beag, which are in the montane
zone above the range of Calluna vulgaris, may be near-natural. They have montane species such as
Empetrum nigrum ssp. hermaphroditum and Vaccinium uliginosum, are not especially heavily grazed and are
unlikely to have been burned.
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