|Scientific name||Salix cinerea – Urtica dioica woodland|
|Common name||Grey Willow – Common Nettle woodland|
Download full pdf synopsis: WL3D
This rather variable community comprises wet woodland dominated by Salix spp. There is usually a low canopy in which Fraxinus excelsior typically accompanies the willows while Alnus glutinosa and Acer pseudoplatanus are also frequent. In the diverse field layer Rubus fruticosus agg., Hedera helix, Filipendula ulmaria, Angelica sylvestris, Urtica dioica and Dryopteris dilatata are constants while frequently found plants include Ranunculus repens, Galium aparine, Cardamine flexuosa, Agrostis stolonifera, Carex remota, Galium palustre, Chrysosplenium oppositifolium and Mentha aquatica. The bryophyte layer is composed mostly of Kindbergia praelonga, Brachythecium rutabulum and Hypnum cupressiforme. Further variation is discussed under ‘Sub-communities’ below.
This community mainly occurs on wet gley soils but also on basin peats and well-drained mineral soils. It is found almost always on flat ground in the lowlands. Conditions are relatively base-rich and quite fertile.
Two quite distinct sub-communities have been described for this community. The Salix fragilis – Calystegia sepium sub-community (WL3Di) differs chiefly in the presence of one or more species of willow that are regarded as archaeophytes in Ireland (Salix fragilis, Salix alba, Salix viminalis or Salix triandra), although Salix cinerea is still frequent. The field layer is usually a dense tangle including Calystegia sepium, Iris pseudacorus, Oenanthe crocata, Rumex sanguineus, Phalaris arundinacea, Valeriana officinalis and Solanum dulcamara. This sub-community is rare in Ireland and restricted to periodically inundated lowland river islands and banksides. In the more common Crataegus monogyna – Dryopteris dilatata sub-community (WL3Dii), Salix cinerea is usually the only willow present and Crataegus monogyna sometimes occurs in a scanty understorey. The field layer differs in the occurrence of species less tolerant of inundation such as Geum urbanum, Geranium robertianum, Dryopteris dilatata, Athyrium filix-femina and Circaea lutetiana.
Sub-community WL3Dii is related to the willow woodlands of WL3E and WL3F (c.f.)
This is quite a species-rich woodland community with a reasonable bryophyte flora. Stands along rivers and lakes which are subject to periodic inundation qualify as EU Annex I habitat 91E0 Residual alluvial forests*. These include stands of sub-community GL3Dii which are dominated by non-native willow species and might otherwise be deemed to be of lower conservation value.
The main threats to these woodlands include changes to hydrological regimes, overgrazing by livestock (usually cattle), woodland clearance and invasion by non-native species such as Impatiens glandulifera.