Title
West Armorican oak forests (Quercus petraea, Quercus robur) with Sorbus torminalis, Pyrus cordata, Mespilus germanica, Ruscus aculeatus
Geographical distribution
Country/territory
France: basin of Rennes, Loire Atlantique, Maine et Loire, Vendée, Deux Sevres, southeastern Morbihan
area frequency
11 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Rusco-Quercetum Noirfalise ass. nov. prov. (nom. inval.).
Structural feature of the main community(ies) (layers, life-forms, etc.)
Species deficient oak forests with dominant Quercus robur in flatlands and together with Quercus petraea in the Rennes basin and on inland elevations. Sorbus torminalis and Castanea sativa (naturalized) are frequently added. Tilia cordata is relatively rare. Fagus sylvatica is largely absent. The shrub layer features Ilex aquifolium, Mespilus germanica and Frangula alnus. The herb layer consists particularly of acidophilous grasses and herbs, while Pteridium aquilinum sometimes forms a fascies.
Dominant and most frequent species in different layers
Tree layer
Quercus robur predominating, with different admixture of Quercus petraea, Sorbus torminalis, Castanea sativa (introduced), Fagus sylvatica, locally Tilia cordata, Betula pubescens
Shrub layer
Ilex aquifolium, Pyrus cordata, Frangula alnus, Juniperus communis, Mespilus germanica, Corylus avellana, Ruscus aculeatus
Lianas
Hedera helix, Lonicera periclymenum, Rubus fruticosus agg.
Herb layer
Pteridium aquilinum, Melampyrum pratense, Deschampsia flexuosa, Calluna vulgaris, Carex pilulifera, Molinia caerulea, Holcus mollis, Teucrium scorodonia, Hypericum pulchrum, Hieracium umbellatum, Hieracium laevigatum, Hieracium sabaudum, Convallaria majalis, Polygonatum multiflorum
Moss layer (incl. lichens)
Polytrichum formosum, Dicranum scoparium, Hypnum cupressiforme, Dicranella heteromalla, Leucobryum glaucum, Scleropodium purum, Thuidium tamariscinum, Rhytidiadelphus triquetrus, Eurhynchium praelongum
Diagnostically important species
Quercus robur, Quercus petraea, Sorbus torminalis; Pyrus cordata, Mespilus germanica, Ilex aquifolium, Ruscus aculeatus; Pteridium aquilinum, Deschampsia flexuosa, Teucrium scorodonia, Hieracium umbellatum, Hieracium sabaudum, Hieracium laevigatum, Convallaria majalis
Ecological variants
Form on dry, oligotrophic soils with Viola riviniana and Polygonatum multiflorum; form on moist soils with Betula pubescens and Molinia caerulea.
Geographical variants (geogr. differential species)
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Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
On mesotrophic luvisols small enclaves of the Endymio-Carpinetum, along the coast protected by dunes oak forest with Quercus robur and Rubia peregrina.
Adjoining climax and permanent vegetation (with numbers of mapping units)
coastal heaths (E11, E13), mixed oak-hornbeam forests (F34), species-poor beech forests (F75, F76), species-rich beech forests (F106), downy oak forests (G37), dune vegetation (P6, P7), salt vegetation (P23), freshwater-tall sedge swamps (R1), alder carrs (T1), alluvial and moist forests (U8, U24, U25, U28).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
Degraded forests with Betula pendula on dry and Betula pubescens on moist sites. The forests are often degraded to heaths by grazing and plagues and are later afforested with Pinus pinaster, Pinus sylvestris and Pinus radiata; Low forest sometimes with Carpinus betulus; Mixed cultivation in a closed bocage landscape consisting of Quercus robur and Castanea sativa, in moist hollows with Salix atrocinerea.
grassland (meadows, pastures, herb-rich communities)
Dry heaths with Ulex europaeus, Calluna vulgaris, Erica cinerea and Erica scoparia; fresh heaths with Ulex minor, Ulex gallii and Erica ciliaris; wet heaths with Erica tetralix and Molinia caerulea. Wet hollows with Sphagnum spp., Narthecium ossifragum, Drosera intermedia, Pinguicula lusitanica, Hammarbya paludosa, Eriophorum vaginatum, Eriophorum gracile.
arable land (characteristic weed communities)
No details
settlements (typical ruderal vegetation)
No details
Site conditions of the mapping unit
Landscape type, geomorphology
Depressions and low hilly country
Altitudinal belt and/or altitudinal range
lowland-colline; 0 to 250 m
Geology (bedrock)
Precambrian, Silurian and Ordovician rocks in the basin of Rennes; granites or gneiss in Morbihan and the Vendée
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
acidic, base-poor brown soils and gray-brown podzolic soil, partly pseudogleyed; (dystric cambisols; orthic and gleyic luvisols)
soil texture
loamy sand; partly gravely
soil moisture, water balance
fresh to periodically moist
soil fertility
oligotrophic
Climate incl. local climate
climate type (following Walter & Lieth)
V(IV)2
average annual temperature
11-11,5 EC
average annual precipitation
600-700 mm
average temperature of the warmest month
July 16-17 EC
average temperature of the coldest month
January 4-6 EC
local climate or other climatic peculiarities
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
Forests are mostly degraded.
endangered communities, species worthy of protection in natural vegetation
Nearly natural forest communities.
causes of endangerment
Soil degradation due to excessive use and fires, afforestation with Pinus species.
required measures for protection and restitution
Regeneration of semi-natural forests through forest conversion and succession.
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
France: Nature park Grande Brière (north of the Loire mouth).
of characteristic substitute communities worthy of protection
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Most important references (author, year)
Corillion 1962; Corillion 1968; Corillion 1970; Rameau 1996b
Compiled by
A. Noirfalise; revised by J.R. Cross, J. Pallas, U. Bohn
