WL1D Quercus petraea – Vaccinium myrtillus woodland
Vegetation
This is a high forest community (mean canopy height = 17.2 m, n = 63) dominated by Quercus petraea. Sorbus aucuparia and Betula pubescens accompany the oaks, with Ilex aquifolium usually beneath in the understorey. The field layer is rather species-poor but contains a characteristic suite of constant species: Blechnum spicant, Vaccinium myrtillus, Oxalis acetosella and Luzula sylvatica. Bilberry can form extensive patches. The bryophyte layer is well developed and contains Thuidium tamariscinum, Rhytidiadelphus loreus, Isothecium myosuroides, Polytrichum formosum, Mnium hornum, Plagiothecium undulatum, Dicranum majus and Dicranum scoparium.
Ecology
This is an acidophilous oakwood community of podzols and well-drained mineral soils (mean organic content = 42.9%, n = 63) found on hillsides and valley sides in the uplands (mean slope = 12.7°, n = 63; mean altitude = 100 m, n = 63). Soils are highly acidic and very nutrient-poor.
Sub-communities
Two sub-communities are described for this community. The Agrostis spp. – Galium saxatile sub-community (WL1Di) has a grassier field layer reflecting heavier grazing and more open light conditions. Agrostis canina/vinealis, Agrostis capillaris, Anthoxanthum odoratum, Galium saxatile, Sphagnum quinquefarium and Holcus mollis are characteristic here. The Ilex aquifolium – Hedera helix sub-community (WL1Dii) occurs where there is less heavy grazing: Ilex aquifolium, Hedera helix, Lonicera periclymenum, Dryopteris dilatata and Kindbergia praelonga are more frequent.
Similar communities
This community differs from communities WL1B and WL1C in the high frequency of Vaccinium myrtillus, Betula pubescens and Sorbus aucuparia and the low frequency of Corylus avellana. From WL1A it is easily distinguished by the presence here of Quercus petraea. There are affinities between this community and the oceanic birch woodlands of WL4B, but in those stands oak is generally absent.
Conservation value
This is a fairly species-rich woodland community (total species/100 m2 = 35.9, n = 146) with a high proportion of the diversity contributed by the bryophyte flora (bryophyte species/100 m2 = 16.9, n = 146). Almost all of these stands qualify as EU HD Annex I habitat 91A0 Old oak woodlands.
Management
These woodlands are commonly grazed, particularly by deer, and overgrazing is an acknowledged problem. Locally, woods have been fenced and deer culling employed to try to promote woodland regeneration. Invasion by non-native species and woodland clearance are also threats. Rhododendron ponticum thrives in these moist, acidic conditions. Spraying with herbicide, cutting and removal of seedlings have been used to combat the spread of this species within these woods.