Title
Calciphilous beech forests (Fagus sylvatica) with Quercus pubescens, Buxus sempervirens and Acer opalus, with Carex alba in the Causses
Geographical distribution
Country/territory
France: Grands Causses
area frequency
2 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Buxo-Fagetum Braun-Blanquet ex Br.-Bl. et Susplugas 1937.
Structural feature of the main community(ies) (layers, life-forms, etc.)
In the moderately tall tree layer Fagus sylvatica is dominant, and their are individual admixtures of other, sometimes thermophilous deciduous tree species. The species-rich shrub layer is dominated by Buxus sempervirens. The species-rich herb layer features numerous thermophilous species.
Dominant and most frequent species in different layers
Tree layer
Fagus sylvatica dominating, admixed Quercus pubescens, Acer opalus, Acer campestre, Sorbus aria, Tilia platyphyllos, isolated Ulmus minor, Acer pseudoplatanus
Shrub layer
Buxus sempervirens, Lonicera xylosteum, Viburnum lantana, Rhamnus cathartica, Daphne laureola, Hippocrepis emerus, Ruscus aculeatus, Ilex aquifolium, Corylus avellana, Cornus sanguinea, Crataegus monogyna, Ligustrum vulgare, Amelanchier ovalis, Ribes alpinum, occasionally Taxus baccata, Juniperus communis
Lianas
Hedera helix, Clematis vitalba, Tamus communis, Rubia peregrina
Herb layer
thermophilous species: Cephalanthera rubra, Cephalanthera longifolia, Cephalanthera damasonium, Carex alba, Carex flacca, Carex montana, Polygonatum odoratum, Vincetoxicum hirundinaria, Helleborus foetidus, Melittis melissophyllum, Tanacetum corymbosum; further Hepatica nobilis, Melica uniflora, Viola reichenbachiana, Euphorbia amygdaloides, Euphorbia dulcis, Poa nemoralis, Mercurialis perennis, Neottia nidus-avis, Anemone nemorosa, Geranium nodosum, Aquilegia vulgaris, Primula veris, Primula acaulis, Lilium martagon, Cardamine heptaphylla, Doronicum pardalianches, Solidago virgaurea, Hieracium murorum
Moss layer (incl. lichens)
No details
Diagnostically important species
Fagus sylvatica, Quercus pubescens, Acer opalus; Buxus sempervirens, Daphne laureola; Cephalanthera damasonium, Cephalanthera rubra, Carex alba, Helleborus foetidus, Melittis melissophyllum, Geranium nodosum, Cardamine heptaphylla
Ecological variants
On shady slopes with Scilla lilio-hyacinthus, Polystichum aculeatum, Asplenium adiantum-nigrum, Conopodium majus and Rosa arvensis.
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)
downy oak forests, lime forests of drier habitats, limestone debris vegetation, rock crevice communities, dry calcareous grassland.
Adjoining climax and permanent vegetation (with numbers of mapping units)
species-poor beech and mixed beech forests (F82, F92), species-rich beech forests (F140), downy oak forests (G41, G42).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
Secondary open Pinus sylvestris forests and plantations with a species-rich herb layer (Pino-Buxetum Lacoste 1967; Serie mesophile du Pin sylvestre Ozenda 1966 p.p.); Buxus scrub.
grassland (meadows, pastures, herb-rich communities)
Extensive chalk grassland (Brometalia) in various forms, e.g. facies of Brachypodium pinnatum, Bromus erectus, Festuca arvernensis, Festuca brevipila, Sesleria albicans or Stipa pennata, used as extensive sheep and goat pastures.
arable land (characteristic weed communities)
Occasional cereal cultivation, vineyards.
settlements (typical ruderal vegetation)
No details
Site conditions of the mapping unit
Landscape type, geomorphology
Karsted lime plateaus with dolinas and deeply carved river valleys (Lot, Tarn, Jonte, Dourbie, Vis)
Altitudinal belt and/or altitudinal range
montane; 600-1000 m
Geology (bedrock)
limestone (Jurassic)
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
rendzines, limestone brown loam, locally base-rich brown soils; (rendzic leptosols; chromic and orthic luvisols; chromic, eutric and stony cambisols)
soil texture
clayey, often stony loam
soil moisture, water balance
moderately dry to dry
soil reaction
neutral to weakly alkaline
soil fertility
meso-eutrophic, eutrophic
Climate incl. local climate
climate type (following Walter & Lieth)
V(VI), X
average annual temperature
8-11 EC
average annual precipitation
900 to >1000 mm
average temperature of the warmest month
July 18-20 EC
average temperature of the coldest month
January 0-4 EC
local climate or other climatic peculiarities
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Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
High locations on plateaus of the Causses have already long been deafforested. The remaining forests serve as erosion protection forests. Restoration of natural forests is complicated and must originate from the remaining forest remnants on the slopes or in hollows where deeper soils are still present.
endangered communities, species worthy of protection in natural vegetation
All natural forest communities.
causes of endangerment
Deforestation, grazing, coniferous tree plantation.
required measures for protection and restitution
No details
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
No details
of characteristic substitute communities worthy of protection
No details
Most important references (author, year)
Braun 1915; Braun-Blanquet 1979; Dupias & Cabaussel 1966; Gaussen, Cabaussel, Dupias & Mestre 1964; Hubert 1982; Vanden Berghen 1963
Compiled by
A. Noirfalise; completed by C. Hettwer referring to the Carte de la végétation de la France, revised by U. Bohn
