Glaswelltiroedd Trelogan / Trelogan Grasslands

Site of Special Scientific Interest · 53.3130, -3.3220

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Clwyd County

Habitats

Calaminarian grassland, Mixed scrub, Montane scrub, Purple moor grass and rush pasture

Geology & landscape

Mining / Industrial: Calaminarian, Mine Spoil · Geological Period: Carboniferous · Rock Type: Chert, Glacial Till, Mudstone, Sandstone

Landscape processes: Glacial

Description

Description Glaswelltiroedd Trelogan/Trelogan Grasslands SSSI is of special interest for its open vegetation on soils rich in heavy metals. This heavy metal tolerant grassland is often referred to as Calaminarian grassland. Glaswelltiroedd Trelogan/Trelogan Grasslands is located to the east and north east of the village of Trelogan. It lies at an altitude of between 110 and 190m above mean sea level. The underlying geology mainly comprises cherts belonging to the Lower Carboniferous Pentre Chert Formation. However, the north-eastern part of the site is underlain by mudstone and sandstone of the Pennine Coal Measures Group. The whole area is dissected by faults with a north-east trending fault running along the length of the site. A veneer of glacial till covers the majority of the area. The site contains metalliferous spoil arising from former mining for heavy metals, such as lead and zinc. The spoil is fragmented across the site. Its extent was undoubtedly much greater in the past but mine spoil reclamation has reduced its area significantly in the locality. Much of the soil material on site has not therefore been derived from the underlying bedrock. Glaswelltiroedd Trelogan/Trelogan Grasslands is the second largest remaining example within North East Wales, after the Halkyn Common cluster of localities, for open vegetation on soils rich in heavy metals. The vegetation is characteristically open and typically includes heavy-metal tolerant higher plant, moss and lichen species. Higher plants include sheep’s fescue Festuca ovina, common sorrel Rumex acetosa, ribwort plantain Plantago lanceolata, common mouse-ear Cerastium fontanum, mountain pansy Viola lutea and the nationally scarce spring sandwort Minuartia verna. More locally, thyme Thymus praecox, and kidney vetch Anthyllis vulneraria are also present. A number of mosses are present including Weissia controversa var densifolia, Brachythecium velutinum and Bryum pallescens. Additionally a number of nationally uncommon lichen species are present including the nationally scarce Cladonia cariosa, Vezdaea retigera and Peltigera neckeri and the nationally rare Gyalidea subscutellaris. Where the sward is more closed grasses predominate including sheep’s fescue, sweet vernal grass Anthoxanthum odoratum and common bent Agrostis capillaris. This assemblage of species shows stronger affinities with mining areas in northern England with similar geology, such as Derbyshire and the northern Pennines, than with other Welsh metalliferous mine sites in mid and north Wales. The North East Wales sites show development on more calcareous substrates than elsewhere in Wales. Glaswelltiroedd Trelogan/Trelogan Grasslands contrasts with other similar sites in North East Wales in the spoil occurrence of locally frequent mountain pansy and more rarely kidney vetch. This grassland is interspersed with areas of neutral, often rank, grassland and scrub particularly of gorse and bramble but several other species are present with the occasional broadleaved tree in an intimate mosaic. Locally there are small stands of common reed Phragmites australis and marshy grassland with purple moor grass Molinia caerulea. A number of plant and animal species of more local interest have been recorded including the dingy skipper butterfly Erynnis tages. Much of the site is ungrazed by domestic livestock and part is registered common land. Parts of the site have been subject to extensive scientific studies by researchers from Liverpool University looking at metal tolerant ecotypes, particularly of certain grasses, to assist with the reclamation of difficult substrates. Remarks Calaminarian grassland is listed on Annex 1 of the EC Habitats Directive (Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora).

Species mentioned

English name
search for this in other sites		 Latin name
search with Google		 IUCN / Red List Type Family
dingy skipper Erynnis tages LC butterfly hesperiidae
common bent Agrostis capillaris LC grass poaceae
sweet vernal grass Anthoxanthum odoratum LC grass poaceae
sheep's fescue Festuca ovina LC grass poaceae
purple moor grass Molinia caerulea LC grass poaceae
common reed Phragmites australis LC grass poaceae
lady's fingers (kidney vetch) Anthyllis vulneraria NT herb fabaceae
common mouse ear Cerastium fontanum LC herb carophyllaceae
spring sandwort Minuartia verna Not listed in GB list herb carophyllaceae
ribwort plantain Plantago lanceolata LC herb plantaginaceae
common sorrel Rumex acetosa LC herb polygonaceae
creeping thyme Thymus praecox Not listed in GB list herb lamiaceae
yellow vetch Viola lutea LC herb violaceae
split-peg lichen Cladonia cariosa LC lichen no common name
black saddle lichen Peltigera neckeri LC lichen no common name
lichen Vezdaea retigera LC lichen vezdaeaceae
velvet feather moss Brachythecium velutinum Not listed in GB list moss hypnales
tall clustered thread moss Bryum pallescens LC moss bryales
green tufted stubble moss Weissia controversa LC moss pottiales

Plant communities

M22 — Coastal floodplain grazing marsh, Lowland fen, Purple moor grass and rush pasture

Juncus subnodulosus-Cirsium palustre fen-meadow

Salix cinerea, Solanum dulcamara, Carex acutiformis, Carex disticha, Carex elata, Carex flacca, Carex hirta, Carex lepidocarpa, Carex nigra, Carex panicea, Carex rostrata, Cladium mariscus, Eriophorum angustifolium, Eleocharis palustris, Eleocharis uniglumis, Juncus articulatus, Juncus effusus, Juncus inflexus, Juncus subnodulosus, Luzula multiflora, Plagiomnium affine, Plagiomnium rostratum, Plagiomnium undulatum, Rhizomnium punctatum, Brachythecium rutabulum, Calliergonell cuspidatum, Cratoneuron filicinum, Pseudoscleropodium purum, Lophocolea bidentata, Angelica sylvestris, Berula erecta, Oenanthe lachenalii, Thyselium palustre, Hydrocotyle vulgaris, Achillea ptarmica, Caltha palustris, Centaurea nigra, Cirsium arvense, Cirsium dissectum, Cirsium palustre, Eupatorium cannabinum, Pulicaria dysenterica, Myosotis laxa, Myosotis scorpioides, Cardamine pratensis, Succisa pratensis, Valeriana dioica, Valeriana officinalis, Cerastium fontanum, Silene flos-cuculi, Stellaria palustris, Calystegia sepium, Equisetum fluviatile, Equisetum palustre, Lathyrus pratensis, Lotus pedunculatus, Trifolium pratense, Trifolium repens, Vicia cracca, Hypericum tetrapterum, Iris pseudacorus, Triglochin palustre, Ajuga reptans, Lycopus europaeus, Mentha aquatica, Lemna minor, Lythrum salicaria, Menyanthes trifoliata, Epilobium hirsutum, Epilobium palustre, Epilobium parviflorum, Dactylorhiza fuchsii, Dactylorhiza incarnata, Dactylorhiza praetermissa, Epipactis palustris, Pedicularis palustris, Rhinanthus minor, Plantago lanceolata, Veronica beccabunga, Polygonum amphibium, Rumex acetosa, Rumex conglomeratus, Rumex sanguineus, Lysimachia vulgaris, Primula vulgaris, Ranunculus acris, Ranunculus flammula, Ranunculus repens, Thalictrum flavum, Comarum palustre, Filipendula ulmaria, Potentilla anserina, Potentilla erecta, Potentilla reptans, Galium palustre, Galium uliginosum, Scrophularia auriculata, Scutellaria galericulata, Agrostis stolonifera, Anthoxanthum odoratum, Arrhenatherum elatius, Briza media, Calamagrostis canescens, Cynosurus cristatus, Deschampsia cespitosa, Festuca rubra, Holcus lanatus, Molinia caerulea, Phalaris arundinacea, Phleum pratense, Phragmites australis, Poa trivialis, Schedonorus arundinaceus, Ophioglossum vulgatum, Thelypteris palustris

M23 — Coastal floodplain grazing marsh, Purple moor grass and rush pasture, Upland rush pasture

Juncus effusus/acutiflorus-Galium palustre rush-pasture

Carex demissa, Carex echinata, Carex nigra, Carex panicea, Juncus acutiflorus, Juncus articulatus, Juncus bulbosus, Juncus conglomeratus, Juncus effusus, Luzula campestris, Luzula multiflora, Aulacomnium palustre, Brachythecium rivulare, Brachythecium rutabulum, Calliergon cordifolium, Calliergonell cuspidatum, Kindbergia praelonga, Rhytidiadelphus squarrosus, Polytrichum commune, Calypogeia fissa, Lophocolea bidentata, Pellia epiphylla, Angelica sylvestris, Carum verticillatum, Hydrocotyle vulgaris, Achillea ptarmica, Caltha palustris, Cirsium palustre, Senecio aquaticus, Taraxacum officianalis, Myosotis laxa, Myosotis secunda, Cardamine flexuosa, Cardamine pratensis, Succisa pratensis, Valeriana officinalis, Cerastium fontanum, Silene flos-cuculi, Stellaria alsine, Stellaria graminea, Equisetum fluviatile, Equisetum palustre, Lathyrus pratensis, Lotus pedunculatus, Trifolium repens, Iris pseudacorus, Mentha aquatica, Scutellaria minor, Lythrum salicaria, Narthecium ossifragum, Epilobium obscurum, Epilobium palustre, Dactylorhiza maculata, Plantago lanceolata, Veronica scutellata, Polygonum hydropiper, Rumex acetosa, Primula vulgaris, Ranunculus acris, Ranunculus flammula, Ranunculus repens, Comarum palustre, Filipendula ulmaria, Potentilla anserina, Potentilla erecta, Galium palustre, Viola palustris, Agrostis canina, Agrostis capillaris, Agrostis stolonifera, Anthoxanthum odoratum, Cynosurus cristatus, Deschampsia cespitosa, Festuca rubra, Glyceria fluitans, Holcus lanatus, Molinia caerulea, Poa pratensis, Poa trivialis, Dryopteris expansa, Athyrium filix-femina

M24 — Coastal floodplain grazing marsh, Lowland fen, Purple moor grass and rush pasture

Molinia caerulea-Cirsium dissectum fen-meadow

Salix cinerea, Salix repens, Alnus glutinosa, Calluna vulgaris, Erica tetralix, Carex hostiana, Carex nigra, Carex panicea, Carex pulicaris, Cladium mariscus, Eriophorum angustifolium, Schoenus nigricans, Juncus acutiflorus, Juncus articulatus, Juncus conglomeratus, Juncus effusus, Juncus subnodulosus, Luzula multiflora, Aulacomnium palustre, Brachythecium rutabulum, Calliergonell cuspidatum, Hypnum cupressiforme, Kindbergia praelonga, Pseudoscleropodium purum, Thuidium tamariscinum, Sphagnum auriculatum, Sphagnum subnitens, Angelica sylvestris, Hydrocotyle vulgaris, Achillea ptarmica, Centaurea nigra, Cirsium arvense, Cirsium dissectum, Cirsium palustre, Eupatorium cannabinum, Leontodon saxatilis, Pulicaria dysenterica, Senecio aquaticus, Serratula tinctoria, Cardamine pratensis, Succisa pratensis, Valeriana dioica, Cerastium fontanum, Silene flos-cuculi, Drosera rotundifolia, Equisetum palustre, Lathyrus pratensis, Lotus pedunculatus, Trifolium pratense, Vicia cracca, Hypericum tetrapterum, Hypericum undulatum, Mentha aquatica, Scutellaria minor, Linum catharticum, Lythrum salicaria, Narthecium ossifragum, Dactylorhiza fuchsii, Dactylorhiza incarnata, Dactylorhiza maculata, Epipactis palustris, Gymnadenia conopsea, Pedicularis sylvatica, Plantago lanceolata, Polygala vulgaris, Rumex acetosa, Anagallis tenella, Primula vulgaris, Ranunculus acris, Ranunculus flammula, Filipendula ulmaria, Potentilla anserina, Potentilla erecta, Potentilla reptans, Rubus fruticosus agg., Galium palustre, Galium uliginosum, Galium verum, Viola palustris, Agrostis canina, Agrostis stolonifera, Anthoxanthum odoratum, Briza media, Danthonia decumbens, Deschampsia cespitosa, Festuca rubra, Holcus lanatus, Molinia caerulea, Phragmites australis

M25 — Blanket bog, Coastal floodplain grazing marsh, Lowland fen, Purple moor grass and rush pasture, Upland acid grassland

Molinia caerulea-Potentilla erecta mire

Salix cinerea, Calluna vulgaris, Erica tetralix, Myrica gale, Vaccinium oxycoccos, Ulex europaeus, Ulex gallii, Carex echinata, Carex flacca, Carex nigra, Carex panicea, Eriophorum angustifolium, Schoenus nigricans, Juncus acutiflorus, Juncus articulatus, Juncus effusus, Juncus subnodulosus, Luzula campestris, Luzula multiflora, Aulacomnium palustre, Pohlia nutans, Calliergon giganteum, Calliergonell cuspidatum, Hypnum jutlandicum, Kindbergia praelonga, Pleurozium schreberi, Pseudoscleropodium purum, Rhytidiadelphus squarrosus, Polytrichum commune, Sphagnum auriculatum, Sphagnum capillifolium, Sphagnum fallax, Sphagnum palustre, Sphagnum papillosum, Sphagnum subnitens, Calypogeia fissa, Cephalozia bicuspidata, Lophocolea bidentata, Lophozia ventricosa, Angelica sylvestris, Carum verticillatum, Hydrocotyle vulgaris, Achillea ptarmica, Centaurea nigra, Cirsium palustre, Eupatorium cannabinum, Pulicaria dysenterica, Serratula tinctoria, Cardamine pratensis, Lobelia urens, Succisa pratensis, Valeriana officinalis, Equisetum palustre, Lotus pedunculatus, Hypericum pulchrum, Hypericum tetrapterum, Mentha aquatica, Scutellaria minor, Menyanthes trifoliata, Narthecium ossifragum, Epilobium palustre, Dactylorhiza maculata, Rumex acetosa, Ranunculus acris, Ranunculus flammula, Filipendula ulmaria, Potentilla erecta, Rubus fruticosus agg., Galium palustre, Viola palustris, Agrostis canina, Agrostis capillaris, Agrostis curtisii, Agrostis stolonifera, Anthoxanthum odoratum, Danthonia decumbens, Deschampsia cespitosa, Festuca ovina, Festuca rubra, Holcus lanatus, Molinia caerulea, Nardus stricta, Phragmites australis, Dryopteris carthusiana, Osmunda regalis

M26 — Limestone pavement, Purple moor grass and rush pasture

Molinia caerulea-Crepis paludosa mire

Carex appropinquata, Carex disticha, Carex echinata, Carex flacca, Carex hostiana, Carex nigra, Carex panicea, Carex pulicaris, Juncus acutiflorus, Juncus articulatus, Juncus conglomeratus, Aulacomnium palustre, Plagiomnium undulatum, Calliergonell cuspidatum, Campylium elodes, Climacium dendroides, Ctenidium molluscum, Hylocomium splendens, Pseudoscleropodium purum, Rhytidiadelphus squarrosus, Thuidium tamariscinum, Lophocolea bidentata, Plagiochila asplenioides, Angelica sylvestris, Caltha palustris, Centaurea nigra, Cirsium palustre, Crepis paludosa, Leontodon hispidus, Serratula tinctoria, Succisa pratensis, Valeriana dioica, Silene flos-cuculi, Equisetum fluviatile, Equisetum palustre, Lathyrus pratensis, Trifolium repens, Menyanthes trifoliata, Rhinanthus minor, Plantago lanceolata, Rumex acetosa, Primula farinosa, Primula vulgaris, Anemone nemorosa, Ranunculus acris, Ranunculus auricomus, Trollius europaeus, Comarum palustre, Filipendula ulmaria, Geum rivale, Potentilla erecta, Sanguisorba officinalis, Galium palustre, Galium uliginosum, Agrostis stolonifera, Anthoxanthum odoratum, Briza media, Deschampsia cespitosa, Festuca ovina, Festuca rubra, Holcus lanatus, Molinia caerulea, Phragmites australis

OV37 — Calaminarian grassland

Festuca ovina-Minuartia verna community

Calluna vulgaris, Carex caryophyllea, Carex flacca, Bryum pallens, Pohlia nutans, Dicranum scoparium, Rhytidiadelphus squarrosus, Weissia controversa, Cladonia arbuscula, Cladonia chlorophaea, Cladonia furcata, Cladonia gracilis, Cladonia portentosa, Cladonia pyxidata, Cladonia rangiformis, Coelocaulon aculeatum, Parmelia saxatilis, Achillea millefolium, Cirsium vulgare, Jacobaea vulgaris, Pilosella officinarum, Noccaea caerulescens, Campanula rotundifolia, Cerastium fontanum, Minuartia verna, Anthyllis vulneraria, Lotus corniculatus, Trifolium repens, Geranium robertianum, Thymus praecox, Linum catharticum, Euphrasia officinalis, Plantago lanceolata, Rumex acetosa, Galium saxatile, Galium sterneri, Viola lutea, Agrostis capillaris, Agrostis stolonifera, Anthoxanthum odoratum, Arrhenatherum elatius, Avenula pratensis, Dactylis glomerata, Festuca ovina, Festuca rubra, Koeleria macrantha

W20 — Montane scrub

Salix lapponum-Luzula sylvatica scrub

Salix arbuscula, Salix cinerea, Salix lapponum, Salix myrsinites, Salix phylicifolia, Salix reticulata, Empetrum nigrum, Calluna vulgaris, Salix lanata, Vaccinium myrtillus, Vaccinium uliginosum, Carex atrata, Carex bigelowii, Carex binervis, Carex flacca, Luzula multiflora, Luzula sylvatica, Huperzia selago, Selaginella selaginoides, Aulacomnium palustre, Mnium hornum, Philonotis fontana, Plagiomnium undulatum, Rhizomnium punctatum, Dicranum bonjeanii, Dicranum majus, Dicranum scoparium, Fissidens adianthoides, Racomitrium lanuginosum, Calliergonell cuspidatum, Ctenidium molluscum, Hylocomium splendens, Hypnum callichroum, Hypnum cupressiforme, Palustriella commutatum, Plagiothecium denticulatum, Plagiothecium undulatum, Pleurozium schreberi, Ptilium crista-castrensis, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Rhytidiadelphus triquetrus, Sanionia uncinata, Scorpidium revolvens, Thuidium tamariscinum, Atrichum undulatum, Polytrichastrum alpinum, Sphagnum capillifolium, Sphagnum fallax, Sphagnum girgensohnii, Sphagnum palustre, Sphagnum russowii, Sphagnum squarrosum, Sphagnum subnitens, Sphagnum teres, Barbilophozia barbata, Chiloscyphus polyanthos, Diplophyllum albicans, Lophocolea bidentata, Plagiochila porelloides, Ptilidium ciliare, Scapania undulata, Cladonia squamosa, Peltigera canina, Angelica sylvestris, Caltha palustris, Hieraclium spp., Saussurea alpina, Solidago virgaurea, Campanula rotundifolia, Succisa pratensis, Valeriana officinalis, Rhodiola rosea, Vaccinium vitis-idaea, Thymus praecox, Epilobium anagallidifolium, Dactylorhiza viridis, Euphrasia officinalis, Rhinanthus minor, Oxalis acetosella, Oxyria digyna, Polygonum viviparum, Rumex acetosa, Anemone nemorosa, Ranunculus acris, Thalictrum alpinum, Alchemilla alpina, Alchemilla glabra, Filipendula ulmaria, Geum rivale, Galium boreale, Galium saxatile, Saxifraga aizoides, Saxifraga hypnoides, Saxifraga oppositifolia, Saxifraga stellaris, Viola riviniana, Agrostis canina, Agrostis capillaris, Anthoxanthum odoratum, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Festuca rubra, Nardus stricta, Dryopteris dilatata, Phegopteris connectilis

W21 — Hedgerow scrub, Mixed scrub

Crataegus monogyna-Hedera helix scrub

Hedera helix, Salix cinerea, Acer pseudoplatanus, Ilex aquifolium, Betula pendula, Corylus avellana, Fagus sylvatica, Quercus robur, Fraxinus excelsior, Malus sylvestris, Sorbus aria, Taxus baccata, Ulmus glabra, Ulmus procera, Sambucus nigra, Viburnum lantana, Euonymus europaeus, Cornus sanguinea, Juniperus communis, Ligustrum vulgare, Clematis vitalba, Rhamnus cathartica, Crataegus laevigata, Crataegus monogyna, Prunus spinosa, Juncus effusus, Plagiomnium undulatum, Brachythecium rutabulum, Kindbergia praelonga, Rhynchostegium confertum, Tamus communis, Heracleum sphondylium, Torilis japonica, Arum maculatum, Arctium minus, Cirsium arvense, Lonicera periclymenum, Moehringia trinervia, Silene dioica, Stellaria graminea, Stellaria holostea, Stellaria media agg., Calystegia sepium, Mercurialis perennis, Geranium robertianum, Iris foetidissima, Glechoma hederacea, Lamium purpureum, Origanum vulgare, Stachys sylvatica, Teucrium scorodonia, Allium ursinum, Hyacinthoides non-scripta, Circaea lutetiana, Rumex sanguineus, Anemone nemorosa, Ranunculus repens, Fragaria vesca, Geum urbanum, Potentilla sterilis, Poterium sanguisorba, Rosa arvensis, Rosa canina, Rubia peregrina, Rubus fruticosus agg., Galium aparine, Urtica dioica, Viola riviniana, Anisantha sterilis, Arrhenatherum elatius, Brachypodium pinnatum, Brachypodium sylvaticum, Bromopsis erecta, Dactylis glomerata, Elytrigia repens, Holcus lanatus, Holcus mollis, Poa trivialis, Asplenium scolopendrium, Pteridium aquilinum, Dryopteris filix-mas

W22 — Hedgerow scrub, Mixed scrub

Prunus spinosa-Rubus fruticosus scrub

Hedera helix, Acer campestre, Corylus avellana, Ulex europaeus, Prunus spinosa, Plagiomnium undulatum, Brachythecium rutabulum, Eurhynchium striatum, Kindbergia praelonga, Thuidium tamariscinum, Atrichum undulatum, Lophocolea bidentata, Achillea millefolium, Cardamine flexuosa, Lonicera periclymenum, Moehringia trinervia, Silene dioica, Silene uniflora, Stellaria media agg., Mercurialis perennis, Geranium robertianum, Stachys sylvatica, Teucrium scorodonia, Hyacinthoides non-scripta, Oxalis acetosella, Digitalis purpurea, Plantago lanceolata, Veronica chamaedrys, Armeria maritima, Rumex acetosa, Filipendula ulmaria, Geum urbanum, Rosa canina, Rubus fruticosus agg., Rubus idaeus, Galium aparine, Urtica dioica, Viola riviniana, Agrostis capillaris, Brachypodium sylvaticum, Dactylis glomerata, Festuca rubra, Holcus lanatus, Holcus mollis, Poa trivialis, Asplenium scolopendrium, Pteridium aquilinum, Dryopteris borreri, Dryopteris filix-mas