Loch Glencoul

Site of Special Scientific Interest · 58.2301, -4.9500

Condition (NatureScot)

Favourable (1) Unfavourable Declining (1)
UnitFeatureConditionArea (ha)Assessed
F1 Moine Favourable 2015-08-26
F2 Upland birch woodland Unfavourable Declining 2009-12-17

Climate exposure

This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.

Coastal

Coastal habitats are exposed to sea-level rise and storm erosion. Where hard sea defences sit behind them, there's nowhere landward to retreat to — a squeeze that keeps compressing the habitat no matter how well it's managed.

Geology & landscape

Geological Period: Cambrian · Rock Type: Gneiss

Landscape processes: Coastal

Description

Loch Glencoul Loch Glencoul Site of Special Scientific Interest (SSSI) lies in the west of Sutherland about 4km south-east of Kylestrome, at the head of Loch Glencoul. This site is nationally important for Moine geology and birch woodland. Moine geology This site contains nationally important rocks from the Moine Thrust Belt. The Moine Thrust is a major feature of the geology of the northern Highlands which runs from the north coast of Sutherland to Skye. To the west of the Moine Thrust is the Foreland. This is an area of ancient Lewisian Gneiss (1700 million years old), overlain by undeformed younger Torridonian (100-800 million years old) and Cambrian (500 million years old) sedimentary rocks. Around 430 million years ago the Moine Thrust carried the rocks of the Moine Supergroup westwards so that they are now found on top of the younger sedimentary rocks of the Foreland. Below the Moine Thrust, a number of other major thrusts, including the Glencoul Thrust and the Sole Thrust, carried slices of the Foreland rocks westward during the same mountain-building episode, to form a stack of thrusts known as the ‘Moine Thrust Belt’. The western end of Loch Glencoul SSSI contains exposures of Lewisian Gneiss and the overlying Torridonian and Cambrian sediments of the Foreland, which were not affected by movements in the Moine Thrust Belt. These Foreland rocks are separated from the Moine Thrust Belt by the Sole Thrust. Eastwards of the Sole Thrust, is a well-exposed zone of imbrication. Here, rock slices stacked up by movements along small-scale thrust faults developed in relatively soft Cambrian rocks between the Sole Thrust and the overlying Glencoul Thrust. The Glencoul Thrust is magnificently exposed on the southern shores of Loch Glencoul. Here, Lewisian Gneisses of the Glencoul Thrust Sheet have been carried westwards by movement on the Glencoul Thrust, so that they are now on top of the much younger dolomites of the Cambrian ‘Durness Group’. In the extreme east of the site, the Stack of Glencoul provides a famous and comprehensive section through mylonitised Moine psammites. Psammites are rocks that formed from muddy sediments that have been heated, compressed and sheared by thrusting to form a fine-grained, platy rock. The Moine psammites were carried westwards by movement on the Moine Thrust and now overlie the Lewisian and Cambrian rocks of the Glencoul Thrust Sheet. Much of the most important evidence for understanding the Moine Thrust Belt is found within this site. Notably, the small-scale thrust faults between the Glencoul Thrust and the Sole Thrust are interpreted as having formed successively, with new thrusts forming below old ones. This is crucial to understanding the sequence in which the thrust faults in the Moine Thrust Belt formed. This classic area also enables Lewisian rocks from the Foreland, unaffected by movements in the Moine Thrust Belt, to be compared directly with Lewisian rocks involved in the Moine Thrust Belt. Upland birch woodland There is scattered birch woodland on the south and north sides of Loch Glencoul. Of particular note are the two areas of woodland which are situated on the crags. The main tree species are downy birch Betula pubescens, rowan Sorbus aucuparia, aspen Populus tremula and hazel Corylus avellana with some wych elm Ulmus glabra, holly Ilex aquifolium and goat willow Salix caprea. Honeysuckle Lonicera periclymenum and dog rose Rosa canina are well established throughout the woodland. Because of this unusually diverse understory, this is the best example of this type of woodland in north-west Sutherland. Due to the varied geology, the ground flora is well developed and contains a wide range of species such as black spleenwort Asplenium adiantum-nigrum, brittle bladder-fern Cystopteris fragilis and hard shield-fern Polystichum aculeatum, hart's tongue fern Asplenium scolopendrium, wood false-brome Brachypodium sylvaticum, hairy-brome Bromopsis ramosa, red fescue Festuca rubra and bearded couch Elymus caninus. At the east end of the northern area of woodland, several springs create permanently wet, nutrient-rich habitats which encourage the growth of the mosses Palustriella commutatum and Philonotis calcarea.

Species mentioned

English name
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Latin name
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IUCN / Red List Type Family
black spleenwort Asplenium adiantum-nigrum LC fern aspleniaceae
hart's-tongue fern Asplenium scolopendrium LC fern aspleniaceae
brittle bladder fern Cystopteris fragilis CR fern woodsiaceae
hard shield-fern Polystichum aculeatum LC fern dryopteridaceae
wood false brome Brachypodium sylvaticum LC grass poaceae
hairy brome Bromopsis ramosa LC grass poaceae
bearded couch Elymus caninus LC grass poaceae
red fescue Festuca rubra LC grass poaceae
honeysuckle Lonicera periclymenum LC herb caprifoliaceae
dog-rose Rosa canina LC herb rosaceae
curled hook moss Palustriella commutatum Not listed in GB list moss hypnales
thick nerved apple moss Philonotis calcarea LC moss bryales
downy birch Betula pubescens LC tree betulaceae
hazel Corylus avellana LC tree corylaceae
holly Ilex aquifolium LC tree aquifoliaceae
aspen Populus tremula LC tree salicaceae
rowan Sorbus aucuparia LC tree rosaceae
wych elm Ulmus glabra LC tree ulmaceae
goat willow Salix caprea LC tree shrub salicaceae

Insects to look out for

These moths, butterflies and beetles are known to feed on plants recorded at this site, and carry a notable UK conservation status — but a host-plant being present doesn't mean the insect has actually been recorded here. Treat this as "worth watching for," not a confirmed sighting.

SpeciesStatusVia host-plant
Chequered skipper
Carterocephalus palaemon
Endangered Brachypodium sylvaticum, Bromopsis ramosa
Figure of eight
Diloba caeruleocephala
Endangered Rosa spp.
Dark bordered beauty
Epione vespertaria
Endangered Populus tremula
The lappet
Gastropacha quercifolia
Endangered Salix spp.
Scarce vapourer
Orgyia recens
Endangered Betula spp., Corylus avellana, Rosa spp., Salix spp., Ulmus spp.
White-letter hairstreak
Satyrium w-album
Endangered Ulmus glabra, Ulmus spp.
Mouse moth
Amphipyra tragopoginis
Vulnerable Salix caprea
The sprawler
Asteroscopus sphinx
Vulnerable Betula spp., Corylus avellana, Populus spp., Salix spp., Ulmus spp.
Broom moth
Ceramica pisi
Vulnerable Betula spp., Rosa canina, Ulmus spp.
Scarce chocolate-tip
Clostera anachoreta
Vulnerable Populus spp., Populus tremula, Salix spp.
Mottled umber
Erannis defoliaria
Vulnerable Betula spp., Corylus avellana, Lonicera periclymenum, Populus tremula, Rosa canina, Salix spp., Sorbus aucuparia, Ulmus spp.
Marsh fritillary
Euphydryas aurinia
Vulnerable Lonicera periclymenum
Satyr pug
Eupithecia satyrata
Vulnerable Salix spp.
Grayling
Hipparchia semele
Vulnerable Brachypodium sylvaticum, Festuca rubra
White admiral
Limenitis camilla
Vulnerable Lonicera periclymenum
The lackey
Malacosoma neustria
Vulnerable Corylus avellana, Rosa canina, Salix spp., Ulmus spp.
Pale brindled
Phigalia pilosaria
Vulnerable Betula pubescens, Corylus avellana, Populus spp., Rosa spp., Salix caprea, Ulmus glabra
Grizzled skipper
Pyrgus malvae
Vulnerable Rosa canina
Pale eggar
Trichiura crataegi
Vulnerable Betula spp., Corylus avellana, Populus spp., Salix spp.
No common name
Zeugophora turneri
Vulnerable Populus tremula
Flounced chestnut
Agrochola helvola
Near Threatened Betula spp., Salix spp., Ulmus spp.
Beaded chestnut
Agrochola lychnidis
Near Threatened Salix spp.
Grey chi
Antitype chi
Near Threatened Salix caprea
Purple emperor
Apatura iris
Near Threatened Populus tremula, Salix caprea
Garden tiger
Arctia caja
Near Threatened Sorbus aucuparia
Minor shoulder-knot
Brachylomia viminalis
Near Threatened Populus tremula, Salix caprea
Dusky-lemon sallow
Cirrhia gilvago
Near Threatened Ulmus glabra
The sallow
Cirrhia icteritia
Near Threatened Populus spp., Salix spp., Ulmus glabra
Small heath
Coenonympha pamphilus
Near Threatened Festuca spp.
Dingy mocha
Cyclophora pendularia
Near Threatened Salix caprea
Kentish glory
Endromis versicolora
Near Threatened Betula pubescens
Large thorn
Ennomos autumnaria
Near Threatened Betula spp., Corylus avellana, Populus spp., Salix spp., Ulmus spp.
September thorn
Ennomos erosaria
Near Threatened Betula spp.
Autumnal rustic
Eugnorisma glareosa
Near Threatened Betula spp.
Grey pug
Eupithecia subfuscata
Near Threatened Populus tremula, Salix spp.
Double dart
Graphiphora augur
Near Threatened Betula spp., Salix spp., Ulmus spp.
Wall
Lasiommata megera
Near Threatened Brachypodium sylvaticum
White prominent
Leucodonta bicoloria
Regionally Extinct Betula spp.

Host-plant data: Cook et al. (2025), Traits data for the butterflies and macro-moths of Great Britain and Ireland, 2024, UK Centre for Ecology & Hydrology / Butterfly Conservation; and Padovani et al. (2020), Database of Insects and their Food Plants (DBIF), UK Centre for Ecology & Hydrology (both Open Government Licence). Contains data supplied by UK Centre for Ecology & Hydrology.

Plant communities

W11 — Altantic hazel wood, Atlantic oak wood, Caledonian forest, Upland birch wood, Wood pasture

Quercus petraea-Betula pubescens-Oxalis acetosella woodland

Matches 7 species from the description above: Betula pubescens, Brachypodium sylvaticum, Corylus avellana, Festuca rubra, Ilex aquifolium, Lonicera periclymenum, Sorbus aucuparia

Acer campestre, Ilex aquifolium, Betula pendula, Betula pubescens, Corylus avellana, Fagus sylvatica, Quercus hybrid, Quercus petraea, Quercus robur, Fraxinus excelsior, Larix decidua, Sorbus aucuparia, Calluna vulgaris, Erica cinerea, Juniperus communis, Vaccinium myrtillus, Cytisus scoparius, Crataegus monogyna, Rubus saxatilis, Carex pilulifera, Luzula campestris, Luzula multiflora, Luzula pilosa, Luzula sylvatica, Mnium hornum, Plagiomnium affine, Plagiomnium undulatum, Dicranum majus, Dicranum scoparium, Cirriphyllum piliferum, Eurhynchium striatum, Hylocomium splendens, Hypnum cupressiforme, Isothecium myosuroides, Kindbergia praelonga, Loeskeobryum brevirostre, Plagiothecium denticulatum, Plagiothecium undulatum, Pleurozium schreberi, Pseudoscleropodium purum, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Rhytidiadelphus triquetrus, Thuidium tamariscinum, Atrichum undulatum, Polytrichum commune, Polytrichum formosum, Polytrichum longisetum, Sphagnum capillifolium, Diplophyllum albicans, Lophocolea bidentata, Plagiochila asplenioides, Plagiochila spinulosa, Angelica sylvestris, Conopodium majus, Campanula rotundifolia, Lonicera periclymenum, Succisa pratensis, Cerastium fontanum, Stellaria holostea, Pyrola minor, Vaccinium vitis-idaea, Lathyrus montanus, Geranium robertianum, Hypericum pulchrum, Ajuga reptans, Teucrium scorodonia, Convallaria majalis, Hyacinthoides non-scripta, Oxalis acetosella, Digitalis purpurea, Veronica chamaedrys, Veronica officinalis, Rumex acetosa, Lysimachia nemorum, Primula vulgaris, Trientalis europaea, Anemone nemorosa, Ranunculus acris, Ranunculus repens, Potentilla erecta, Rubus fruticosus agg., Rubus idaeus, Galium aparine, Galium saxatile, Melanpyrum pratense, Viola riviniana, Agrostis capillaris, Agrostis vinealis, Anthoxanthum odoratum, Brachypodium sylvaticum, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Festuca rubra, Holcus lanatus, Holcus mollis, Poa pratensis, Poa trivialis, Blechnum spicant, Pteridium aquilinum, Dryopteris borreri, Dryopteris dilatata, Dryopteris filix-mas, Thelypteris limbosperma, Athyrium filix-femina

W17 — Altantic hazel wood, Atlantic oak wood, Caledonian forest, Upland birch wood, Wood pasture

Quercus petraea-Betula pubescens-Dicranum majus woodland

Matches 6 species from the description above: Betula pubescens, Corylus avellana, Ilex aquifolium, Lonicera periclymenum, Salix caprea, Sorbus aucuparia

Hedera helix, Salix caprea, Acer pseudoplatanus, Ilex aquifolium, Betula pendula, Betula pubescens, Corylus avellana, Fagus sylvatica, Quercus hybrid, Quercus petraea, Quercus robur, Fraxinus excelsior, Sorbus aucuparia, Calluna vulgaris, Erica cinerea, Erica tetralix, Juniperus communis, Rhododendron ponticum, Vaccinium myrtillus, Crataegus monogyna, Carex pilulifera, Luzula multiflora, Luzula pilosa, Luzula sylvatica, Andreaea rupestris, Mnium hornum, Rhizomnium punctatum, Campylopus flexuosus, Dicranella heteromalla, Dicranodontium denudatum, Dicranum fuscescens, Dicranum majus, Dicranum scoparium, Dicranum scottianum, Leucobryum glaucum, Ptychomitrium polyphyllum, Racomitrium fasciculare, Racomitrium heterostichum, Racomitrium lanuginosum, Eurhynchium striatum, Heterocladium heteropterum, Hylocomiastrum umbratum, Hylocomium armoricum, Hylocomium splendens, Hypnum callichroum, Hypnum cupressiforme, Hypnum jutlandicum, Isothecium myosuroides, Kindbergia praelonga, Loeskeobryum brevirostre, Plagiothecium denticulatum, Plagiothecium undulatum, Pleurozium schreberi, Pseudoscleropodium purum, Pseudotaxiphyllum elegans, Ptilium crista-castrensis, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Rhytidiadelphus triquetrus, Sematophyllum demissum, Sematophyllum micans, Thuidium delicatulum, Thuidium tamariscinum, Polytrichum commune, Polytrichum formosum, Sphagnum capillifolium, Sphagnum fimbriatum, Sphagnum palustre, Sphagnum russowii, Sphagnum subnitens, Tetraphis pellucida, Adelanthus decipiens, Anastrepta orcadensis, Barbilophozia attenuata, Barbilophozia floerkei, Bazzania tricrenata, Bazzania trilobata, Blepharostoma trichophyllum, Calypogeia fissa, Calypogeia muelleriana, Cephalozia bicuspidata, Diplophyllum albicans, Frullania tamarisci, Fuscocephaloziopsis lunulifolia, Harpanthus scutatus, Jamesoniella autumnalis, Jungermannia gracillima, Lepidozia pearsonii, Lepidozia reptans, Lophocolea bidentata, Lophocolea heterophylla, Lophozia ventricosa, Marsupella emarginata, Microlejeunea ulicina, Mylia taylorii, Nowellia curvifolia, Plagiochila asplenioides, Plagiochila atlantica, Plagiochila killarniensis, Plagiochila porelloides, Plagiochila punctata, Plagiochila spinulosa, Ptilidium ciliare, Saccogyna viticulosa, Scapania gracilis, Scapania nemorea, Scapania umbrosa, Tritomaria exsectiformis, Tritomaria quinquedentata, Cladonia arbuscula, Cladonia chlorophaea, Cladonia digitata, Cladonia furcata, Cladonia impexa, Cladonia polydactyla, Cladonia squamosa, Cladonia squamules, Cladonia subcervicornis, Parmelia saxatilis, Sphaerophorus fragilis, Sphaerophorus globosus, Solidago virgaurea, Lonicera periclymenum, Succisa pratensis, Cornus suecica, Hypericum pulchrum, Teucrium scorodonia, Hyacinthoides non-scripta, Goodyera repens, Oxalis acetosella, Digitalis purpurea, Rumex acetosa, Lysimachia nemorum, Trientalis europaea, Anemone nemorosa, Potentilla erecta, Rubus fruticosus agg., Rubus idaeus, Galium saxatile, Melanpyrum pratense, Viola riviniana, Agrostis capillaris, Agrostis stolonifera, Agrostis vinealis, Anthoxanthum odoratum, Dactylis glomerata, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Holcus lanatus, Holcus mollis, Molinia caerulea, Poa nemoralis, Poa pratensis, Blechnum spicant, Pteridium aquilinum, Dryopteris aemula, Dryopteris borreri, Dryopteris dilatata, Dryopteris filix-mas, Hymenophyllum tunbrigense, Hymenophyllum wilsonii, Polypodium vulgare, Thelypteris limbosperma, Athyrium filix-femina

W4 — Raised bog, Upland birch wood, Wet woodland

Betula pubescens-Molinia caerulea woodland

Matches 6 species from the description above: Betula pubescens, Corylus avellana, Ilex aquifolium, Lonicera periclymenum, Salix caprea, Sorbus aucuparia

Hedera helix, Salix aurita, Salix caprea, Salix cinerea, Salix pentandra, Ilex aquifolium, Betula pendula, Betula pubescens, Corylus avellana, Quercus hybrid, Quercus petraea, Quercus robur, Fraxinus excelsior, Pinus sylvestris, Sorbus aucuparia, Alnus glutinosa, Calluna vulgaris, Erica tetralix, Myrica gale, Vaccinium myrtillus, Vaccinium oxycoccos, Crataegus monogyna, Carex laevigata, Carex nigra, Carex rostrata, Eriophorum angustifolium, Eriophorum vaginatum, Juncus acutiflorus, Juncus effusus, Aulacomnium palustre, Mnium hornum, Orthodontium lineare, Pohlia nutans, Campylopus flexuosus, Dicranella heteromalla, Dicranum scoparium, Leucobryum glaucum, Brachythecium rutabulum, Calliergonell cuspidatum, Drepanocladus fluitans, Hypnum cupressiforme, Hypnum jutlandicum, Kindbergia praelonga, Plagiothecium denticulatum, Pleurozium schreberi, Pseudoscleropodium purum, Pseudotaxiphyllum elegans, Rhytidiadelphus squarrosus, Straminergon stramineum, Polytrichum commune, Polytrichum formosum, Sphagnum capillifolium, Sphagnum cuspidatum, Sphagnum fallax, Sphagnum fimbriatum, Sphagnum palustre, Sphagnum papillosum, Sphagnum squarrosum, Sphagnum subnitens, Calypogeia fissa, Chiloscyphus polyanthos, Lophocolea bidentata, Lophocolea heterophylla, Angelica sylvestris, Hydrocotyle vulgaris, Cirsium palustre, Lonicera periclymenum, Succisa pratensis, Valeriana officinalis, Equisetum fluviatile, Equisetum palustre, Lotus pedunculatus, Menyanthes trifoliata, Chamerion angustifolium, Epilobium palustre, Oxalis acetosella, Rumex acetosa, Comarum palustre, Filipendula ulmaria, Potentilla erecta, Rubus fruticosus agg., Galium palustre, Galium saxatile, Galium uliginosum, Viola palustris, Agrostis canina, Agrostis capillaris, Agrostis stolonifera, Anthoxanthum odoratum, Deschampsia cespitosa, Deschampsia flexuosa, Holcus lanatus, Holcus mollis, Molinia caerulea, Poa trivialis, Blechnum spicant, Pteridium aquilinum, Dryopteris carthusiana, Dryopteris cristata, Dryopteris dilatata, Athyrium filix-femina