Llynoedd Ieuan

Site of Special Scientific Interest · 52.4130, -3.7693

Open in the interactive map →

Also within

Dyfed County

Climate exposure

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

Peatland

Peat habitats store centuries of carbon and depend on a stable, waterlogged water table. Warmer, drier summers dry out peat, making it far more vulnerable to wildfire and to carbon release — a pressure that can undo years of restoration work regardless of how well the site is otherwise managed.

Habitats

High montane heath and snow bed

Geology & landscape

Geological Period: Silurian

Landscape processes: Peatland / Mire

Description

Description An extensive area of submontane heathland and blanket mire containing three upland lakes with associated areas of actively growing basin mire. This entire site, at approximately 550 metres above sea level, overlies the Upper Llandovery Series of Silurian rocks which underlie most of the Ceredigion District. The heathland mainly consists of heather Calluna vulgaris, cowberry Vaccinium vitis-idaea and bilberry Vaccinium myrtillus, with scattered crowberry Empetrum nigrum, bellheather Erica cinerea and alpine clubmoss Diphasiastrum alpinum. Associated with the heathland is a luxuriant growth of bryophytes and lichens, and plants commonly found on moorland pastures, namely sheep’s fescue Festuca ovina, purple moor-grass Molinia caerulea, mat-grass Nardus stricta, heath rush Juncus squarrosus and heath bedstraw Galium saxatile. Three acidic upland lakes occur, containing such aquatic plants as water lobelia Lobelia dortmanna, quillwort Isoetes lacustris and shoreweed Littorella uniflora. Associated with these lakes, and also in the lower-lying wetter depressions, are blanket and basin mire communities dominated by purple moor-grass, common cotton-grass Eriophorum angustifolium and several Sphagnum moss species.

Species mentioned

English name
search for this in other sites		 Latin name
search with Google		 IUCN / Red List Type Family
lake quillwort Isoetes lacustris LC fern isoetaceae
sheep's fescue Festuca ovina LC grass poaceae
purple moor grass Molinia caerulea LC grass poaceae
mat grass Nardus stricta LC grass poaceae
heath bedstraw Galium saxatile LC herb rubiaceae
shoreweed Littorella uniflora LC herb plantaginaceae
water lobelia Lobelia dortmanna LC herb campanulaceae
cowberry Vaccinium vitis-idaea LC herb ericaceae
alpine clubmoss Diphasiastrum alpinum LC moss club lycopodiaceae
heath rush Juncus squarrosus LC rush juncaceae
common cottongrass Eriophorum angustifolium NT sedge cyperaceae
billberry Vaccinium myrtillus LC shrub ericaceae
bell heather or ling Calluna vulgaris NT shrub dwarf ericaceae
crowberry Empetrum nigrum LC shrub dwarf empetraceae
bell heather Erica cinerea NT shrub dwarf ericaceae

Plant communities

CG12 — Alpine and subalpine calcareous grassland, High montane heath and snow bed

Festuca ovina-Alchemilla alpina-Silene acaulis dwarf-herb community

Empetrum nigrum, Calluna vulgaris, Kalmia procumbens, Vaccinium myrtillus, Salix herbacea, Carex bigelowii, Carex demissa, Carex panicea, Carex pilulifera, Carex pulicaris, Juncus trifidus, Juncus triglumis, Luzula campestris, Luzula multiflora, Luzula spicata, Luzula sylvatica, Diphasiastrum alpinum, Huperzia selago, Selaginella selaginoides, Andreaea alpina, Aulacomnium turgidum, Bartramia ithyphylla, Breutelia chrysocoma, Mnium hornum, Dicranum scoparium, Ditrichum flexicaule, Racomitrium canescens sens.lat., Racomitrium fasciculare, Racomitrium lanuginosum, Ctenidium molluscum, Hylocomium splendens, Hypnum callichroum, Hypnum cupressiforme, Hypnum hamulosum, Lescuraea incurvata, Pleurozium schreberi, Pseudoscleropodium purum, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Rhytidiadelphus triquetrus, Sanionia uncinata, Thuidium delicatulum, Thuidium tamariscinum, Pogonatum urnigerum, Polytrichastrum alpinum, Tortella tortuosa, Barbilophozia hatcheri, Barbilophozia lycopodioides, Diplophyllum albicans, Frullania tamarisci, Nardia scalaris, Plagiochila asplenioides, Ptilidium ciliare, Scapania subalpina, Tritomaria quinquedentata, Cetraria islandica, Cladonia arbuscula, Cladonia gracilis, Cladonia pyxidata, Cladonia uncialis, Peltigera canina, Achillea millefolium, Antennaria dioica, Gnaphalium supinum, Hieraclium spp., Scorzoneroides autumnalis, Solidago virgaurea, Taraxacum officianalis, Myosotis alpestris, Cardamine pratensis, Draba norvegica, Campanula rotundifolia, Succisa pratensis, Cerastium alpinum, Cerastium fontanum, Minuartia sedoides, Sagina saginoides, Silene acaulis, Sedum rosea, Vaccinium vitis-idaea, Thymus praecox, Linum catharticum, Epilobium anagallidifolium, Euphrasia frigida, Euphrasia officinalis, Oxalis acetosella, Plantago maritima, Veronica alpina, Veronica officinalis, Veronica serpyllifolia, Armeria maritima, Polygonum viviparum, Rumex acetosa, Anemone nemorosa, Ranunculus acris, Thalictrum alpinum, Trollius europaeus, Alchemilla alpina, Alchemilla filicaulis, Filipendula ulmaria, Geum rivale, Potentilla crantzii, Potentilla erecta, Sibbaldia procumbens, Galium boreale, Galium saxatile, Saxifraga aizoides, Saxifraga hypnoides, Saxifraga nivalis, Saxifraga oppositifolia, Saxifraga stellaris, Viola lutea, Viola palustris, Viola riviniana, Agrostis canina, Agrostis capillaris, Anthoxanthum odoratum, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Festuca rubra, Festuca vivipara, Nardus stricta, Poa pratensis, Botrychium lunaria

U7 — High montane heath and snow bed

Nardus stricta-Carex bigelowii grass-heath

Empetrum nigrum, Calluna vulgaris, Vaccinium myrtillus, Vaccinium uliginosum, Salix herbacea, Carex bigelowii, Carex nigra, Carex panicea, Carex pilulifera, Eriophorum vaginatum, Trichophorum cespitosum, Juncus squarrosus, Juncus trifidus, Luzula multiflora, Luzula sylvatica, Diphasiastrum alpinum, Huperzia selago, Campylopus flexuosus, Dicranum fuscescens, Dicranum scoparium, Kiaeria starkei, Racomitrium lanuginosum, Hylocomium splendens, Hypnum cupressiforme, Plagiothecium undulatum, Pleurozium schreberi, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Polytrichastrum alpinum, Polytrichum commune, Polytrichum juniperinum, Polytrichum piliferum, Polytrichum strictum, Sphagnum capillifolium, Anastrepta orcadensis, Anastrophyllum donianum, Barbilophozia floerkei, Barbilophozia hatcheri, Bazzania tricrenata, Diplophyllum albicans, Lophozia sudetica, Pleurozia purpurea, Ptilidium ciliare, Scapania gracilis, Scapania nemorea, Cetraria delisei, Cetraria islandica, Cladonia arbuscula, Cladonia bellidiflora, Cladonia coccifera, Cladonia gracilis, Cladonia impexa, Cladonia leucophaea, Cladonia pyxidata, Cladonia rangiferina, Cladonia tenuis, Cladonia uncialis, Gnaphalium supinum, Solidago virgaurea, Cornus suecica, Vaccinium vitis-idaea, Thymus praecox, Narthecium ossifragum, Rumex acetosa, Alchemilla alpina, Potentilla erecta, Galium saxatile, Viola palustris, Agrostis capillaris, Agrostis vinealis, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Nardus stricta

U8 — High montane heath and snow bed

Carex bigelowii-Polytrichum alpinum sedge-heath

Vaccinium myrtillus, Salix herbacea, Carex bigelowii, Juncus trifidus, Luzula spicata, Huperzia selago, Pohlia nutans, Dicranum fuscescens, Dicranum scoparium, Racomitrium canescens sens.lat., Racomitrium fasciculare, Racomitrium lanuginosum, Hylocomium splendens, Pleurozium schreberi, Sanionia uncinata, Polytrichastrum alpinum, Sphagnum compactum, Ptilidium ciliare, Cetraria delisei, Cetraria islandica, Cladonia arbuscula, Cladonia bellidiflora, Cladonia coccifera, Cladonia floerkeana, Cladonia gracilis, Cladonia macrophylla, Cladonia pyxidata, Cladonia rangiferina, Cladonia squamosa, Cladonia uncialis, Cornicularia aculeata, Ochrolechia frigida, Galium saxatile, Saxifraga stellaris, Agrostis capillaris, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Nardus stricta

U9 — High montane heath and snow bed

Juncus trifidus-Racomitrium lanuginosum rush-heath

Empetrum nigrum, Kalmia procumbens, Vaccinium myrtillus, Vaccinium uliginosum, Salix herbacea, Carex bigelowii, Carex pilulifera, Juncus trifidus, Luzula spicata, Diphasiastrum alpinum, Huperzia selago, Dicranum fuscescens, Racomitrium lanuginosum, Pleurozium schreberi, Polytrichastrum alpinum, Polytrichum piliferum, Barbilophozia floerkei, Diplophyllum albicans, Ptilidium ciliare, Cetraria delisei, Cetraria islandica, Cetraria nivalis, Cladonia arbuscula, Cladonia bellidiflora, Cladonia coccifera, Cladonia crispata, Cladonia gracilis, Cladonia pyxidata, Cladonia rangiferina, Cladonia uncialis, Cornicularia aculeata, Ochrolechia frigida, Sphaerophorus globosus, Stereocaulon vesuvianum, Thamnolia vermicularis, Silene acaulis, Vaccinium vitis-idaea, Armeria maritima, Polygonum viviparum, Alchemilla alpina, Galium saxatile, Agrostis capillaris, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Nardus stricta, Nitella flexilis

U10 — High montane heath and snow bed, Lowland dry acid grassland, Upland dry heath

Carex bigelowii-Racomitrium lanuginosum moss-heath

Empetrum nigrum, Kalmia procumbens, Vaccinium myrtillus, Salix herbacea, Carex bigelowii, Carex panicea, Carex pilulifera, Juncus squarrosus, Juncus trifidus, Luzula spicata, Diphasiastrum alpinum, Huperzia selago, Selaginella selaginoides, Andreaea alpina, Aulacomnium turgidum, Pohlia nutans, Campylopus flexuosus, Dicranum fuscescens, Dicranum scoparium, Kiaeria starkei, Racomitrium fasciculare, Racomitrium heterostichum, Racomitrium lanuginosum, Hylocomium splendens, Hypnum callichroum, Hypnum cupressiforme, Hypnum hamulosum, Pleurozium schreberi, Rhytidiadelphus loreus, Sanionia uncinata, Polytrichastrum alpinum, Polytrichum juniperinum, Polytrichum longisetum, Polytrichum piliferum, Polytrichum strictum, Anastrepta orcadensis, Diplophyllum albicans, Nardia scalaris, Ptilidium ciliare, Alectoria nigricans, Cetraria islandica, Cladonia arbuscula, Cladonia cervicornis, Cladonia coccifera, Cladonia crispata, Cladonia furcata, Cladonia gracilis, Cladonia impexa, Cladonia pyxidata, Cladonia rangiferina, Cladonia squamosa, Cladonia uncialis, Cornicularia aculeata, Ochrolechia frigida, Peltigera canina, Sphaerophorus globosus, Thamnolia vermicularis, Achillea millefolium, Antennaria dioica, Gnaphalium supinum, Solidago virgaurea, Campanula rotundifolia, Succisa pratensis, Minuartia sedoides, Silene acaulis, Vaccinium vitis-idaea, Thymus praecox, Armeria maritima, Polygonum viviparum, Rumex acetosa, Alchemilla alpina, Potentilla erecta, Sibbaldia procumbens, Galium saxatile, Viola palustris, Viola riviniana, Agrostis capillaris, Agrostis vinealis, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Nardus stricta

U11 — High montane heath and snow bed, Lowland dry acid grassland, Upland dry heath

Polytrichum sexangulare-Kiaeria starkei snow-bed

Empetrum nigrum, Salix herbacea, Carex bigelowii, Juncus trifidus, Huperzia selago, Conostomum tetragonum, Pohlia drummondii, Pohlia ludwigii, Pohlia nutans, Dicranum fuscescens, Kiaeria falcata, Kiaeria starkei, Racomitrium canescens sens.lat., Racomitrium fasciculare, Racomitrium heterostichum, Racomitrium lanuginosum, Pleurozium schreberi, Rhytidiadelphus loreus, Oligotrichum hercynicum, Polytrichastrum alpinum, Polytrichastrum sexangulare, Anthelia juratzkana, Barbilophozia floerkei, Lophozia sudetica, Marsupella emarginata, Moerckia blyttii, Nardia scalaris, Pleurocladula albescens, Cetraria islandica, Cladonia bellidiflora, Cladonia pyxidata, Cladonia uncialis, Solorina crocea, Gnaphalium supinum, Cerastium cerastoides, Silene acaulis, Alchemilla alpina, Sibbaldia procumbens, Galium saxatile, Saxifraga stellaris, Viola palustris, Agrostis capillaris, Deschampsia cespitosa, Deschampsia flexuosa, Festuca vivipara, Nardus stricta, Cryptogramma crispa, Blechnum spicant, Athyrium distentifolium

U12 — High montane heath and snow bed, Upland dry heath

Salix herbacea-Racomitrium heterostichum snow-bed

Salix herbacea, Carex bigelowii, Juncus trifidus, Luzula spicata, Huperzia selago, Andreaea rupestris, Conostomum tetragonum, Pohlia nutans, Dicranum scoparium, Kiaeria starkei, Racomitrium fasciculare, Racomitrium heterostichum, Racomitrium lanuginosum, Oligotrichum hercynicum, Polytrichastrum alpinum, Polytrichastrum sexangulare, Polytrichum piliferum, Barbilophozia floerkei, Diplophyllum albicans, Gymnomitrion concinnatum, Gymnomitrion corallioides, Lophozia sudetica, Marsupella brevissima, Nardia scalaris, Cetraria delisei, Cetraria islandica, Cladonia bellidiflora, Cladonia coccifera, Cladonia gracilis, Cladonia pyxidata, Cladonia uncialis, Cornicularia aculeata, Ochrolechia frigida, Gnaphalium supinum, Silene acaulis, Alchemilla alpina, Galium saxatile, Agrostis canina, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Nardus stricta

U13 — High montane heath and snow bed, Upland dry heath

Deschampsia cespitosa-Galium saxatile grassland

Vaccinium myrtillus, Salix herbacea, Carex bigelowii, Carex pilulifera, Luzula multiflora, Luzula sylvatica, Diphasiastrum alpinum, Huperzia selago, Selaginella selaginoides, Pohlia nutans, Kiaeria starkei, Racomitrium lanuginosum, Hylocomium splendens, Hypnum callichroum, Hypnum cupressiforme, Plagiothecium undulatum, Pleurozium schreberi, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Rhytidiadelphus triquetrus, Sanionia uncinata, Polytrichastrum alpinum, Polytrichum commune, Sphagnum capillifolium, Sphagnum russowii, Anastrepta orcadensis, Barbilophozia floerkei, Barbilophozia lycopodioides, Nardia scalaris, Ptilidium ciliare, Cetraria islandica, Cladonia gracilis, Peltigera canina, Achillea millefolium, Gnaphalium supinum, Saussurea alpina, Campanula rotundifolia, Cerastium alpinum, Cerastium fontanum, Minuartia sedoides, Silene acaulis, Vaccinium vitis-idaea, Thymus praecox, Euphrasia frigida, Oxalis acetosella, Armeria maritima, Polygonum viviparum, Rumex acetosa, Ranunculus acris, Alchemilla alpina, Alchemilla filicaulis, Alchemilla glabra, Potentilla erecta, Sibbaldia procumbens, Galium saxatile, Saxifraga hypnoides, Saxifraga stellaris, Viola palustris, Viola riviniana, Agrostis canina, Agrostis capillaris, Anthoxanthum odoratum, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Festuca rubra, Nardus stricta, Blechnum spicant, Dryopteris dilatata

U14 — High montane heath and snow bed, Upland dry heath

Alchemilla alpina-Sibbaldia procumbens dwarf-herb community

Vaccinium myrtillus, Salix herbacea, Carex bigelowii, Carex pilulifera, Juncus trifidus, Luzula multiflora, Luzula spicata, Diphasiastrum alpinum, Huperzia selago, Selaginella selaginoides, Andreaea alpina, Pohlia nutans, Dicranum scoparium, Racomitrium aquaticum, Racomitrium canescens sens.lat., Racomitrium fasciculare, Racomitrium heterostichum, Racomitrium lanuginosum, Ctenidium molluscum, Hylocomium splendens, Hypnum callichroum, Pleurozium schreberi, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Rhytidiadelphus triquetrus, Sanionia uncinata, Oligotrichum hercynicum, Pogonatum urnigerum, Polytrichastrum alpinum, Polytrichum piliferum, Barbilophozia floerkei, Diplophyllum albicans, Lophozia sudetica, Nardia scalaris, Ptilidium ciliare, Cetraria islandica, Cladonia arbuscula, Cladonia bellidiflora, Cladonia pyxidata, Achillea millefolium, Gnaphalium supinum, Scorzoneroides autumnalis, Campanula rotundifolia, Cerastium alpinum, Cerastium fontanum, Minuartia sedoides, Sagina saginoides, Silene acaulis, Thymus praecox, Euphrasia officinalis, Armeria maritima, Polygonum viviparum, Rumex acetosa, Ranunculus acris, Thalictrum alpinum, Trollius europaeus, Alchemilla alpina, Alchemilla filicaulis, Alchemilla glabra, Potentilla erecta, Sibbaldia procumbens, Galium saxatile, Saxifraga hypnoides, Saxifraga oppositifolia, Saxifraga stellaris, Viola palustris, Agrostis canina, Agrostis capillaris, Anthoxanthum odoratum, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Festuca rubra, Nardus stricta, Blechnum spicant, Botrychium lunaria