Ceunant Dulyn

Site of Special Scientific Interest · 53.1981, -3.8634

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Also within

Clwyd County Eryri / Snowdonia National Park

Habitats

Bracken scrub, Fast flowing river and stream

Geology & landscape

Geological Feature: Gorge / Ravine · Geological Period: Ordovician

Landscape processes: Fluvial, Volcanic / Igneous

Description

Description A wooded river valley and ravine on the Afon Dulyn. The underlying rocks are a mixture of acidic Ordovician sediments and calcareous pumice tuff; this is reflected by the soil and vegetation types. Acid soils support oak Quercus petraea and birch Betula pubescens woodland with a sparse shrub layer and a ground flora with such species as bracken Pteridium aquilinum and wavy hair grass Deschampsia flexuosa. On more basic soils, oak again dominates, but with ash Fraxinus excelsior, wych elm Ulmus glabra and alder Alnus glutinosa. A shrub layer including hazel Corylus avellana occurs and a ground flora rich in such species as creeping buttercup Ranunculus repens, wild Angelica Angelica sylvestris, sanicle Sanicula europaea and male fern Dryopteris filix-mas. The Atlantic bryophyte flora is only moderately rich. Although high humidity is retained within the gorge, flow in the river is affected by the Dolgarrog Hydro-electric scheme. Remarks: Within the Snowdonia National Park.

Species mentioned

English name
search for this in other sites		 Latin name
search with Google		 IUCN / Red List Type Family
male fern Dryopteris filix-mas LC fern dryopteridaceae
bracken Pteridium aquilinum LC fern dennstaedtiaceae
wavy hair grass Deschampsia flexuosa Not listed in GB list grass poaceae
wild angelica Angelica sylvestris LC herb apiaceae
creeping buttercup Ranunculus repens LC herb ranunculaceae
sanicle Sanicula europaea LC herb apiaceae
alder Alnus glutinosa LC tree salicaceae
downy birch Betula pubescens LC tree betulaceae
hazel Corylus avellana LC tree corylaceae
ash Fraxinus excelsior LC tree oleaceae
sessile or durmast oak Quercus petraea LC tree fagaceae
wych elm Ulmus glabra LC tree ulmaceae

Plant communities

A9 — Fast flowing river and stream, Marginal and inundation, Pond ditch and canal, Sluggish river and stream

Potamogeton natans community

Schoenoplectus lacustris, Juncus bulbosus, Sparganium angustifolium, Sparganium erectum, Sparganium minimum, Alisma plantago-aquatica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Elodea canadensis, Lemna minor, Lemna trisulca, Nymphaea alba, Callitriche platycarpa, Callitriche stagnalis, Littorella uniflora, Potamogeton natans, Ranunculus trichophyllus, Glyceria fluitans, Chara subspinosa

A14 — Fast flowing river and stream

Myriophyllum alterniflorum community

Isolepis fluitans, Juncus bulbosus, Fontinalis antipyretica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Lemna minor, Callitriche stagnalis, Littorella uniflora, Potamogeton filiformis, Potamogeton gramineus, Potamogeton natans, Ranunculus peltatus, Chara spp., Nitella hyalina

A17 — Chalk river and stream, Fast flowing river and stream

Ranunculus penicillatus ssp. pseudofluitans community

Berula erecta, Nasturtium officinale, Elodea canadensis, Lemna minor, Callitriche stagnalis, Veronica beccabunga, Polygonum amphibium, Polygonum hydropiper, Potamogeton crispus, Potamogeton pectinatus, Ranunculus penicillatus ssp. pseudofluitans

A18 — Fast flowing river and stream

Ranunculus fluitans community

Fontinalis antipyretica, Fontinalis squamosa var. curnowii, Myriophyllum alterniflorum, Myriophyllum spicatum, Elodea canadensis, Mentha aquatica, Lemna gibba, Lemna minor, Potamogeton perfoliatus, Ranunculus fluitans, Glyceria fluitans, Phalaris arundinacea

W25 — Bracken scrub

Pteridium aquilinum-Rubus fruticosus underscrub

Hedera helix, Acer pseudoplatanus, Fagus sylvatica, Quercus robur, Fraxinus excelsior, Sambucus nigra, Ulex europaeus, Crataegus monogyna, Prunus spinosa, Luzula multiflora, Mnium hornum, Brachythecium rutabulum, Kindbergia praelonga, Angelica sylvestris, Conopodium majus, Heracleum sphondylium, Arum maculatum, Cirsium arvense, Lonicera periclymenum, Silene dioica, Stellaria holostea, Mercurialis perennis, Geranium robertianum, Glechoma hederacea, Teucrium scorodonia, Hyacinthoides non-scripta, Chamerion angustifolium, Circaea lutetiana, Digitalis purpurea, Rumex acetosa, Anemone nemorosa, Ficaria verna, Potentilla erecta, Rosa arvensis, Rosa canina, Rubus fruticosus agg., Rubus idaeus, Galium aparine, Galium mollugo sens.lat., Galium saxatile, Urtica dioica, Viola riviniana, Agrostis capillaris, Anthoxanthum odoratum, Arrhenatherum elatius, Dactylis glomerata, Festuca rubra, Holcus lanatus, Holcus mollis, Poa trivialis, Pteridium aquilinum, Dryopteris dilatata, Dryopteris filix-mas