Nedern Brook Wetlands, Caldicot
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Climate exposure
This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.
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.
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
Geology & landscape
Geological Period: Carboniferous, Quaternary, Triassic · Rock Type: Conglomerate, Limestone
Landscape processes: Coastal, Glacial, Peatland / Mire
Birds & fish recorded
Birds
| Species | Season |
|---|---|
| lapwing | Breeding |
| lapwing | Wintering |
| mute swan | Breeding |
| mute swan | Wintering |
| redshank | Breeding |
| redshank | Wintering |
| shelduck | Breeding |
| shelduck | Wintering |
| wigeon | Wintering |
| yellow wagtail | Breeding |
Description
Description This site is comprised of the low lying tract of land on either side of the Nedern Brook forming a shallow valley of wet meadowland about two miles long to the east of Caerwent and Caldicot. There is a matrix of habitats including improved grassland, unimproved pasture with tall herb communities and small pockets of woodland and scrub. The area is subject to seasonal flooding from the Nedern Brook so that as much as a third to half of the total area can be flooded between November and April in most years. Productive meadows which are regularly flooded are now very rare in Wales. The soils are a mixture of heavy clays with local areas of peat, overlying Pleistocene glacial and estuarine deposits of gravel and mud which in turn overlie Dolomitic Conglomerate (Keuper) of the Triassic period in the west and Drybrook Limestone of the Carboniferous period in the east. The winter flooding represents the upper layer of water in the limestone aquifer beneath and to the north of the site. This area is an important site for breeding birds, particularly waders, and was identified as a site of regional importance in a national survey of breeding waders of wet meadows carried out in 1982. It is of regional importance for breeding redshank, while other notable breeding species include lapwing, mute swan, shelduck, yellow wagtail and reedbunting. The winter flooding makes this an important site for birds overwintering in the area. It is regularly used by Bewicks swans from the group which is centred on Slimbridge but ranges over a series of other sites. The Nedern Brook Wetlands and Llandegfedd Reservoir SSSI are their most important sites in Monmouthshire, and the only other regular winter population of Bewicks swans in Wales is to be found in Anglesey. In most years the maximum number at Nedern Brook is in the region of 20-30 birds but 70 were recorded in January 1983. The site is also important for other wintering species of wildfowl and waders. There are regular counts of up to 300 redshank, unusually high numbers for a freshwater site, and records of up to 1,000 wigeon. These figures illustrate the importance of this winter area of inland freshwater and its close inter-relationship with the Severn Estuary which is less than 3 miles away at its closest point.
Species mentioned
Show the 6 species mentioned in the description, with red-list status| English name search for this in other sites |
Latin name search with Google |
IUCN / Red List | Type | Family |
|---|---|---|---|---|
| wigeon | Mareca penelope | LC (NonBreeding), NT (Breeding) | bird-duck | anatidae |
| shelduck | Tadorna tadorna | EN (NonBreeding), EN (Breeding) | bird-duck | anatidae |
| mute swan | Cygnus olor | LC (NonBreeding), LC (Breeding) | bird-swan | anatidae |
| redshank | Tringa totanus | EN (NonBreeding) | bird-wader | scolopacidae |
| lapwing | Vanellus vanellus | VU (NonBreeding), EN (Breeding) | bird-wader | charadriidae |
| yellow wagtail | Motacilla flava | NT (Breeding) | bird-wagtail | motacillidae |
Plant communities
W20 — Montane scrub
Salix lapponum-Luzula sylvatica scrub
Show 107 indicator speciesSalix 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
Show 81 indicator speciesHedera 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
Show 49 indicator speciesHedera 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