Title
British pedunculate oak-ash forests (Fraxinus excelsior, Quercus robur) with Acer campestre, Ulmus glabra, partly with Carpinus betulus and Tilia cordata, with Mercurialis perennis
Geographical distribution
Country/territory
Great Britain: north and south coast of Wales, central, east England (east Anglia): from Tyne to Essex
area frequency
18 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Fraxinus excelsior-Acer campestre-Mercurialis perennis woodland (W8) Rodwell 1991.
Structural feature of the main community(ies) (layers, life-forms, etc.)
Polymorphous high forests (up to 35 m in height), usually dominated by a mixture of Fraxinus excelsior, Quercus robur, Acer campestre and Corylus avellana, with scattered Ulmus glabra and naturalised Acer pseudoplatanus, that increases towards the north and west. Tilia cordata, Carpinus betulus and sometimes Betula spp. and other tree species occasionally form a second tree layer. The shrub layer consists mainly of Corylus avellana with scattered Crataegus and other shrub species. The herb layer is in parts very luxuriant and contiguous. The moss layer is usually not particularly well developed, especially in drier areas, but it increases towards the north and west.
Dominant and most frequent species in different layers
Tree layer
Fraxinus excelsior, Quercus robur, Acer campestre, regionally Ulmus glabra, Ulmus minor, Acer pseudoplatanus (introduced), Carpinus betulus, Tilia cordata, Betula pendula, Quercus petraea
Shrub layer
Corylus avellana, Crataegus monogyna, Crataegus laevigata, Sambucus nigra, Sorbus aucuparia, Ilex aquifolium, Viburnum opulus, species of the tree layer, Cornus sanguinea, Prunus spinosa, Euonymus europaea
Lianas
Tamus communis, Clematis vitalba, Lonicera periclymenum, Hedera helix
Herb layer
Mercurialis perennis, Hyacinthoides non-scripta, Circaea lutetiana, Geum urbanum, Arum maculatum, Allium ursinum, Melica uniflora, Primula acaulis, Glechoma hederacea, Viola reichenbachiana, Urtica dioica, Galium aparine, Geranium robertianum, Brachypodium sylvaticum, Rubus fruticosus agg., Dryopteris filix-mas, Dryopteris affinis subsp. borreri, Anemone nemorosa, Ranunculus ficaria, Lamium galeobdolon, Stachys sylvatica, Hedera helix, Asplenium scolopendrium, Carex sylvatica
Moss layer (incl. lichens)
Eurhynchium praelongum, Brachythecium rutabulum, Plagiomnium undulatum, Fissidens taxifolius, Atrichum undulatum, Mnium hornum, Eurhynchium striatum, Thamnobryum alopecurum, Thuidium tamariscinum, Eurhynchium hians
Diagnostically important species
Fraxinus excelsior, Acer campestre; Corylus avellana; Mercurialis perennis, Hyacinthoides non-scripta, Brachypodium sylvaticum, Viola reichenbachiana, Arum maculatum, Eurhynchium praelongum
Ecological variants
On moist sites depending on trophy there are forms with Deschampsia cespitosa or Allium ursinum. On stony, dry sites there are forms with Teucrium scorodonia, while at rocky sites and in ravines, where Tilia platyphyllos appears very locally, the unit conforms to the Tilio-Acerion.
Geographical variants (geogr. differential species)
Towards the west and north thermophilous plants recede while increases in Ulmus glabra, Asplenium scolopendrium, ferns and bryophytes mark the transition to the Alno-Ulmion.
Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
In different habitat complexes with Carpinion, Alno-Ulmion and Alnion forests as well as Salicion albae forests.
Adjoining climax and permanent vegetation (with numbers of mapping units)
coastal rocky heaths (E11), acidophilous mixed oak forests (F2, F3, F8), mixed oak-ash forests (F32), species-rich beech forests (F104), dune vegetation (P6), salt vegetation (P19), birch forests and degraded raised bogs (T6), alluvial and moist forests (U7, U28).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
Very extensive wide-stemmed trees (particularly oak) and low forest usage (Corylus, Tilia, Carpinus), pure planted stands of naturally dominant species (particularly oak and ash) as well as introduced trees (particularly Acer pseudoplatanus and Fagus outside of their natural range).
grassland (meadows, pastures, herb-rich communities)
Primarily use as grazing grounds (fertilized Cynosurion), more rarely semi-natural Arrhenatherion, Calthion (on heavy loam soils) or Mesobromion (on humus carbonate soils) grassland.
arable land (characteristic weed communities)
Mainly intensive cereal and vegetable cultivation, while locally Chenopodietea, Secalietalia, Plantaginetea or Artemisietea vegetation is still present.
settlements (typical ruderal vegetation)
In settlements Artemisieta or Plantaginetea vegetation, locally Violetea calaminariae on spoil originating from lead mines above limestone.
Site conditions of the mapping unit
Landscape type, geomorphology
Flat or gently undulating valleys and plains within the range of Fagus, on more steeply inclined limestone slopes and in valleys in the north and west.
Altitudinal belt and/or altitudinal range
lowland to colline; mostly lower than 180 m, at the most 300 m
Geology (bedrock)
Cretaceous, Jurassic, Triasssic; Permian, Carboniferous, Devonian
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
Mull-rendzines and base-rich mull-brown soils consisting of limestone; (eutric cambisols; mollic humus carbonate soils)
soil texture
loamy to clayey with mull as humus form
soil moisture, water balance
fresh to moderately dry
soil reaction
neutral to weakly alkaline
soil fertility
meso-eutrophic to eutrophic
Climate incl. local climate
climate type (following Walter & Lieth)
V(VI)2, VI1b, VI2, VI3a, VI(V)2
average annual temperature
9-10 EC
average annual precipitation
600 to >1200 mm
average temperature of the warmest month
July 16-18 EC
average temperature of the coldest month
February -1 to 1 EC
local climate or other climatic peculiarities
Below 180 rain days per year.
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
These forest types are well represented in certain areas that have been placed under protection, of which some are old stands.
endangered communities, species worthy of protection in natural vegetation
Rare species: Cardamine impatiens, Daphne mezereum, Festuca altissima, Ribes alpinum, Primula elatior, Primula acaulis x elatior, Tilia platyphyllos.
causes of endangerment
Middle and low forest management, forest clearing, spreading of urban development, road construction, eutrophication from neighbouring crop fields, elm disease, drought years.
required measures for protection and restitution
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Localities of representative stands (loci typici) with state of protection
of the natural vegetation
Great Britain: Aston Rowant, Avon Gorge, Axmouth-Lyme Regis, Castle Eden Dene, Castor Hanglands, Derbyshire Dales, Ebbor Gorge, Hales Wood, Lady Park Wood, Roudsea, Wyre Forest and many National Trust- and locally nature reserves.
of characteristic substitute communities worthy of protection
In regions mentioned above.
Most important references (author, year)
Birse 1980; Klötzli 1970; Moss 1907; Moss 1911b; Moss 1913; Moss, Rankin & Tansley 1910; Peterken 1981; Rackham 1980; Tansley (Ed.) 1911; Tansley & Rankin 1911
Compiled by
J.S. Rodwell
