Title
Atlantic-subatlantic hygrophilous birch-pedunculate oak forests (Quercus robur, Betula pubescens) with Frangula alnus, Molinia caerulea, partly Myrica gale, Carex nigra
Geographical distribution
Country/territory
France: Payes de Bray, Sologne, Revermont, upper course of the Loire; Netherlands: Drentheim (whole Pleistocene region in the east of the country); Germany: northwestern Pleistocene lowland, especially at the margins of broad valley lowlands (Lower saxony, North Rhine-Westphalia, Schleswig-Holstein), southwestern Mecklenburg-Hither Pomerania, northwestern and southern Brandenburg; Poland: Stettin Haff (eastern margin)
area frequency
55 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Molinio caeruleae-Quercetum roboris (Tüxen 1937) Scamoni & Passarge 1959 (syn: Betulo pendulae-Quercetum roboris molinietosum R. Tüxen 1937).
Structural feature of the main community(ies) (layers, life-forms, etc.)
Quercus robur, Betula pubescens and Betula pendula form the tree layer (60-80 %). Sometimes Fagus sylvatica, Sorbus aucuparia and Populus tremula may be added. In the poorly to moderately developed shrub layer Frangula alnus, Sorbus aucuparia and upgrowths of the stand forming tree species are encountered in particular. The herb layer (80-100 %) consisting of undemanding hygrophilous and hygrotolerant grasses and herbs is often dominated by Molinia. The moss layer is relatively species-rich and features many moisture indicators.
Dominant and most frequent species in different layers
Tree layer
Quercus robur, Betula pubescens, Betula pendula, locally Pinus sylvestris, partly Alnus glutinosa
Shrub layer
Young growth of trees, Sorbus aucuparia, Frangula alnus, Populus tremula, Myrica gale
Lianas
Lonicera periclymenum (especially in the Atlantic floral province)
Herb layer
Pteridium aquilinum, Melampyrum pratense, Deschampsia flexuosa, Dryopteris dilatata, Dryopteris carthusiana, Potentilla erecta, Carex pilulifera, Rubus fruticosus agg., Holcus mollis, Lonicera periclymenum, Galium saxatile, Ceratocapnos claviculata, Vaccinium myrtillus, Vaccinium vitis-idaea, Maianthemum bifolium, Rubus idaeus, Trientalis europaea, Oxalis acetosella, Athyrium filix-femina; moist indicator species: Molinia caerulea, Erica tetralix, Carex nigra, Lysimachia vulgaris, Juncus effusus, Agrostis canina, Hydrocotyle vulgaris
Moss layer (incl. lichens)
Hypnum cupressiforme, Dicranum scoparium, Polytrichum formosum, Dicranella heteromalla, Pohlia nutans, Pleurozium schreberi, Leucobryum glaucum, Lophocolea heterophylla, Calypogeia neesiana, Plagiothecium laetum, Aulacomnium androgynum, Scleropodium purum, Atrichum undulatum, Brachythecium rutabulum, Plagiothecium denticulatum, Lophocolea bidentata, Eurhynchium striatum, Mnium hornum, Eurhynchium praelongum; indicators of moisture: Polytrichum commune, Aulacomnium palustre, Sphagnum palustre, Sphagnum fallax, Sphagnum fimbriatum
Diagnostically important species
Quercus robur; Molinia caerulea, Erica tetralix, Carex nigra, Pteridium aquilinum, Lonicera periclymenum, Polytrichum commune, Aulacomnium palustre, Sphagnum spp., differential species towards F3: Frangula alnus, Maianthemum bifolium
Ecological variants
With increasing soil moisture, water balance, poor forms tend towards birch carrs with high proportions of Betula pubescens and Sphagnum spp., while richer forms tend towards peatmoss alder forests.
Geographical variants (geogr. differential species)
The unit has quite a broad geographic amplitude: In the Atlantic region and subatlantically near to the coast with Ilex aquifolium, Lonicera periclymenum, Ceratocapnos claviculata, in the southwest (central France) sometimes with Quercus pyrenaica, Peucedanum gallicum, Tamus communis, Erica scoparia, Festuca heterophylla, Luzula forsteri; in the central-European province (East Germany, northwest Poland) without Ilex aquifolium and Galium saxatile, sometimes with Pinus sylvestris.
Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
Fago-Quercetum, Betulo-Quercetum, Betuletum pubescentis, Carici-Alnetum glutinosae, Pruno-Alnetum, Sphagnion magellanici, Ericetum tetralicis, Myricetum gale, Scheuchzerio-Caricetea.
Adjoining climax and permanent vegetation (with numbers of mapping units)
acidophilous oak forests (F5, F8, F11, F16), oak-hornbeam forests (F35, F36, F38, F52), species-poor and species-rich beech forests (F77, F78, F83, F82, F106, F107, F110, F113), raised bogs (S8), alder carrs (T1), birch carrs and degraded mires (T4, T5), alluvial and moist forests (U9, U24, U25, U28).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
Molinia and Rubus idaeus pine plantations, more rarely Molinia spruce plantations (in the northern part); Birch forest stage; Salix aurita, Frangula alnus and Myrica gale scrub.
grassland (meadows, pastures, herb-rich communities)
Wet meadows (Molinion, Juncion acutiflori, Magnocaricion), fresh and wet perennial rye-grass meadows; wet sandy heaths and cross-leaved heather.
arable land (characteristic weed communities)
Root crop and cereal fields (Aperion with moisture indicators).
settlements (typical ruderal vegetation)
No details
Site conditions of the mapping unit
Landscape type, geomorphology
Sandy locations in the lowlands, broad valley lowlands and landscape hollows, shallow lower slopes on brown dunes
Altitudinal belt and/or altitudinal range
lowland
Geology (bedrock)
Outwash of the Saale and Weichsel ice-age; ground and end moraines of the Weichsel ice-age and of the Warthe and Drenthe stage of the Saale ice-age; fluviatile sediments (Pleistocene)
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
gley- podzole, base-poor pseudogleys, stagnogleys; (humic and gleyic podzols; dystric planosols)
soil texture
sandy, locally peaty, silty
soil moisture, water balance
periodically moist to stagnating wet
soil reaction
very acidic, acidic
soil fertility
oligotrophic, oligo-mesotrophic
Climate incl. local climate
climate type (following Walter & Lieth)
V(IV)2, VI1, VI5a, VI7a, VI7c
average annual temperature
7-11EC
average annual precipitation
550-850 mm
average temperature of the warmest month
July 16-19 EC
average temperature of the coldest month
January -2 to 3 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)
Semi-natural stands are rarely preserved, and strongly endangered.
endangered communities, species worthy of protection in natural vegetation
All units of the natural vegetation.
causes of endangerment
Low forest usage, clear cutting and clearing with complete upheaval; transformation of semi-natural forests into plantations; drainage and eutrophication.
required measures for protection and restitution
Complete protection of the remaining semi-natural stands is necessary. Restoration on suitable sites by natural succession and/or plantation of indigenous tree species.
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
Netherlands: Boerskotten, Twickel, Lieverder Noordbos, Bruntingerbos near Roden; Germany: primeval forest reserve Elze, primeval forest reserve Stüh, Reisbruch (Lower Saxony), nature reserve “Magdeburgerforth” (Mecklenburg-Hither Pomerania); Poland: national parks “Wollin” and “Leba”.
of characteristic substitute communities worthy of protection
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Most important references (author, year)
Fukarek 1961a; Härdtle, Heinken, Pallas & Welss 1997; Krause & Schröder 1979; Libbert 1940; Matuszkiewicz 1988; Pallas 1996; Passarge 1957; Passarge & Hofmann 1968; Piotrowska 1955; Piotrowska 1960; Prusinkiewicz 1961; Rameau 1996b; Scamoni 1960; Scamoni (Hrsg.) 1964; Tüxen 1937; Tüxen 1975b; Werf van der 1991
Compiled by
U. Bohn; W. Matuszkiewicz; H. Schlüter; revised by J.R. Cross, completed by R. Haveman, J. Pallas
