Blaentrothy Meadows (Caeau Blaentroddi)

Site of Special Scientific Interest · 51.8916, -2.9151

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Gwent 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

Fast flowing river and stream

Geology & landscape

Geological Period: Devonian

Landscape processes: Peatland / Mire

Description

Description Blaentrothy Meadows lie mid-way between the villages of Pandy and Grosmont in the north of Gwent at an altitude of approximately 175 metres. The site straddles the steep east and west facing slopes of the headwaters of the River Trothy. Soils are clayey brown earths of the Bromyard Association which have developed on the underlying Devonian rocks. The meadows support one of the largest remaining areas of unimproved neutral grassland in Gwent. At least two grassland sub-communities and a number of plant species with a restricted distribution in Gwent are present. Two sub-communities of the Centaurea nigra - Cynosurus cristatus (common knapweed -crested dog's-tail) type of neutral grassland occur. The most westerly field supports a species-rich example of the Danthonia decumbens (heath-grass) sub-community. The most frequent grasses are common bent Agrostis capillaris, sweet vernal-grass Anthoxanthum odoratum, red fescue Festuca rubra, heath-grass, Yorkshire-fog Holcus lanatus and crested dog's-tail. Glaucous sedge Carex flacca is occasional. Herbs include common knapweed, dyer's greenweed Genista tinctoria, fairy flax Linum Catharticum and betony Betonica officinalis. Burnet-saxifrage Pimpinella saxifraga, and pepper-saxifrage Silaum silaus also occur and have a restricted distribution in Gwent.The remaining area is dominated by a less species-rich example of the Lathyrus pratensis (meadow vetchling) sub-community and perennial rye-grass Lolium perenne is more common here. Both sub-communities are characterised by plants typical of more flushed conditions such as sharp-flowered rush Juncus acutuflorus, sneezewort Achillea ptarmica and common fleabane Pulicaria dysentrica which give the vegetation affinities to wetter mire communities. A plant characteristic of more calcaerous conditions that occurs occasionally on the site is common centaury Centaurium erythraea.

Species mentioned

English name
search for this in other sites		 Latin name
search with Google		 IUCN / Red List Type Family
common bent Agrostis capillaris LC grass poaceae
sweet vernal grass Anthoxanthum odoratum LC grass poaceae
crested dog's tail Cynosurus cristatus LC grass poaceae
heath grass Danthonia decumbens NT grass poaceae
red fescue Festuca rubra LC grass poaceae
Yorkshire fog Holcus lanatus LC grass poaceae
perennial rye-grass Lolium perenne LC grass poaceae
sneezewort Achillea ptarmica LC herb asteraceae
betony Betonica officinalis VU herb lamiaceae
black knapweed Centaurea nigra LC herb asteraceae
common centuary Centaurium erythraea LC herb gentianaceae
dyer's greenweed Genista tinctoria LC herb fabaceae
meadow vetchling Lathyrus pratensis LC herb fabaceae
burnet saxifrage Pimpinella saxifraga NT herb apiaceae
fleabane Pulicaria dysentrica Not listed in GB list herb asteraceae
pepper saxifrage Silaum silaus EN herb saxifragaceae
sharp flowered rush Juncus acutuflorus Not listed in GB list rush juncaceae
glaucus sedge Carex flacca LC sedge cyperaceae

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