WL2B Fraxinus excelsior – Geum urbanum woodland
Vegetation
Fraxinus excelsior is the main canopy species of this high forest community (mean canopy height = 19.6 m, n = 111). It is frequently accompanied by Acer pseudoplatanus and occasionally by Quercus robur, Betula pubescens or Fagus sylvatica. Crataegus monogyna is a constant in the understorey, frequently joined by Corylus avellana and Ilex aquifolium. Rubus fruticosus agg. and Hedera helix are the main components of the field layer, although Dryopteris dilatata and Geum urbanum are also usually found and Geranium robertianum and Circaea lutetiana are frequent. Earlier in the year, Primula vulgaris may be spotted. There is fairly good cover of bryophytes with Eurhynchium striatum, Thuidium tamariscinum, Kindbergia praelonga, Thamnobryum alopecurum and Neckera complanata being the main species.
Ecology
This is a base-rich woodland community usually found on well-drained mineral soils but sometimes on gleys (mean organic content = 18.6%, n = 123). It occurs on flat or sloping ground, usually in the lowland landscape (mean slope = 6.2°, n = 123; mean altitude = 78 m, n = 123). Soils are quite fertile.
Sub-communities
No sub-communities have been described for this community
Similar communities
This community is quite similar to WL2C, but it occurs on slightly damper, less fertile soils. Acer pseudoplatanus is less frequent here than in WL2C and indicators of nitrogen-rich soils, such as Sambucus nigra, Urtica dioica and Heracleum sphondylium, are usually absent, as is the shade-loving Phyllitis scolopendrium. From the wet ash woodlands (WL3A and WL3C) this community differs in the rarity of Alnus glutinosa and Salix cinerea.
Conservation value
This is a fairly species-rich woodland community (total species/100 m2 = 32.4, n = 143) with a reasonably diverse bryophyte flora (bryophyte species/100 m2 = 10.6, n = 143).
Management
The main threats to these woodlands include woodland clearance and invasion by non-native species such as Fagus sylvatica. They may be grazed by livestock so overgrazing can be an issue. Undergrazing may also occur, however, resulting in dense thickets of bramble that reduce field layer diversity.