Garn Wood, Kilkiffeth Wood & Dan-Deri-Cwm Felin-Ban

Site of Special Scientific Interest · 51.9728, -4.8964

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Also within

Dyfed County Arfordir Penfro / Pembrokeshire Coast National Park

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.

Habitats

Ancient woodland, Coppiced woodland, Fast flowing river and stream

Geology & landscape

Geological Feature: Gorge / Ravine · Geological Period: Ordovician

Landscape processes: Coastal, Fluvial, Glacial, Volcanic / Igneous

Description

Description These three areas of semi-natural broadleaved woodland, with their numerous small waterfalls and gorges, clothe the steep valley sides in the middle reaches of the River Gwaun. Nationally important epiphytic lichen communities occur, with many species indicative of ancient woodland. Scarce woodland ferns are also present. At Garn Wood, the Gwaun has carved a low, boulder-strewn gorge through hard volcanic rocks. Elsewhere, on Ordovician shales, the dry acidic slopes are dissected by steep-sided, bryophyte-rich stream valleys or gorges with numerous damp flushed areas. Overgrown sessile oak Quercus petraea coppice with some hybrid oak Quercus robur x petraea dominates the tree canopy. Downy birch Betula pubescens and, in the more base-rich or flushed areas, ash Fraxinus excelsior and alder Alnus glutinosa, are frequent. Several non-native tree species, including sycamore Acer pseudoplatanus, beech Fagus sylvatica and hornbeam Carpinus betulus also occur. hazel Corylus avellana and holly Ilex aquifolium are important components of the shrub layer. The ground flora exhibits many species which seldom occur away from ancient woodland sites in West Wales, such as woodruff Galium odoratum, wood melick Melica uniflora, wood millet Milium effusum, common cow-wheat Melampyrum pratense and bearded couch Elymus caninus. The rich epiphytic lichen flora features 21 species that are indicators of woodland sites with a long history of continuity. The paucity of lichens throughout the neglected coppice re-growth contrasts with the abundance in gorge and steep stream-sides where old oak standards, ash, hazel and holly persist. Cwm Felin-Ban and an area in Kilkiffeth adjacent to the abandoned enclosures are of particular note. At the latter, the pollution-sensitive beard lichen Usnea articulara festoons ancient hazel stems and other suitable phorophytes in quantities unusual for West Wales. Many species characteristic of the Lobarion and pre-Lobarion communities are found at Cwm Felin-ban on the larger standard oaks which may be 200 years or so old. Carillaria pulverea, C. sphaeroides, Lecanactis premnea, Pannaria conoplea, Phyllopsora rosei, Lobaria pulmonaria, Leptogium lichenoides and Sticta fuliginosa thrive in the humid, gladed conditions of the Cwm. Smooth bark species of the Pyrenuletum on holly and hazel may also be found in the coppiced areas where these shrubs survive in suitably sheltered and moist conditions. These include Biatorina atropurpurea, Porina leptalea, Enterographa crassa and Thelotrema lepadinum. A rare species of moist woodland, Ochrolechia inversa, is also present in Cwm Felin-ban. More widespread old forest species occurring throughout these woodlands include Dimerella lutea, Stenocybe septata, Arthonia vinosa, Pyrenula chlorospila and Usnea ceratina. Of western Atlantic distribution, the diminutive Tunbridge filmy-fern Hymenophyllum tunbrigense flourishes amongst shaded hard rock outcrops in the high humidity of the sheltered gorge at Garn Wood, where it carpets near vertical rock faces in the largest known ‘Pembrokeshire’ population. Another uncommon oceanic fern, hay-scented buckler-fern Dryopteris aemula, is found by the small waterfall that cascades through Kilkiffeth Wood. Documentary evidence supporting the antiquity of these woodlands is provided by the Elizabethan historian, George Owen, who mentions ‘Killkythed’ amongst others as ‘woodes of divers gentlemen sufficient to serve their houses of fuell and some for buildings’ in his ‘Description of Pembrokeshire’. Remarks: The site lies within the Pembrokeshire Coast National Park.

Species mentioned

English name
search for this in other sites		 Latin name
search with Google		 IUCN / Red List Type Family
hay-scented fern Dryopteris aemula LC fern dryopteridaceae
Tunrbidge filmy-fern Hymenophyllum tunbrigense VU fern hymenophyllaceae
bearded couch Elymus caninus LC grass poaceae
wood melick Melica uniflora NT grass poaceae
wood millet Milium effusum LC grass poaceae
woodruff Galium odoratum LC herb rubiaceae
common cowwheat Melampyrum pratense VU herb orobanchaceae
no common name Arthonia vinosa LC lichen no common name
no common name Biatorina atropurpurea Not listed in GB list lichen no common name
no common name Carillaria pulverea Not listed in GB list lichen no common name
orange dimple lichen Dimerella lutea Not listed in GB list lichen no common name
no common name Enterographa crassa LC lichen no common name
lichen-no common name Lecanactis premnea Not listed in GB list lichen tba
tattered jellyskin Leptogium lichenoides Not listed in GB list lichen no common name
tree lungwort Lobaria pulmonaria LC lichen no common name
no common name Ochrolechia inversa Not listed in GB list lichen no common name
mealy-rimmed shingle lichen Pannaria conoplea LC lichen no common name
lichen Phyllopsora rosei LC lichen ramalinaceae
lichen-no common name Porina leptalea LC lichen tba
lichen-no common name Pyrenula chlorospila LC lichen tba
Stenocybe septata LC lichen mycocaliciaceae
a stinky sticta Sticta fuliginosa LC lichen no common name
barnacle lichen Thelotrema lepadinum LC lichen no common name
sycamore Acer pseudoplatanus Not listed in GB list tree aceraceae
alder Alnus glutinosa LC tree salicaceae
downy birch Betula pubescens LC tree betulaceae
hornbeam Carpinus betulus LC tree betulaceae
hazel Corylus avellana LC tree corylaceae
beech Fagus sylvatica LC tree fabiaceae
ash Fraxinus excelsior LC tree oleaceae
holly Ilex aquifolium LC tree aquifoliaceae
sessile or durmast oak Quercus petraea LC tree fagaceae
common oak Quercus robur LC tree fagaceae

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