Title
Pannonian-Danubian Balkan oak-bitter oak forests (Quercus cerris, Quercus frainetto) with Acer tataricum, Crocus flavus
Geographical distribution
Country/territory
Romania: large-scaled in the south and west; Bulgaria: pre-Carpathian plateau, Stara Planina, Strandža mountain, Struma-valley, Rhodope mountains (not on the map)
area frequency
14 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Quercetum frainetto-cerris (Georgescu 1945) Rudski 1949 geticum Pop 1967.
Structural feature of the main community(ies) (layers, life-forms, etc.)
Moderately high two- to three-layered forests with a closed tree layer and a sometimes absent shrub or herb layer with continental and thermophilous species.
Dominant and most frequent species in different layers
Tree layer
Quercus cerris, Quercus frainetto, Acer tataricum, Acer campestre, Ulmus minor, Pyrus pyraster
Shrub layer
Crataegus monogyna, Ligustrum vulgare, Euonymus verrucosa, Cornus mas, Rhamnus cathartica, Rhamnus saxatilis subsp. tinctoria, Prunus spinosa
Herb layer
Polygonatum hirtum, Silene coronaria, Crocus flavus, Lathyrus niger, Tanacetum corymbosum, Digitalis lanata, Silene viridiflora, Dactylis polygama, Brachypodium sylvaticum, Potentilla micrantha, Potentilla alba (rare)
Moss layer (incl. lichens)
No details
Diagnostically important species
Quercus cerris, Quercus frainetto, Acer tataricum; Crocus flavus, Potentilla micrantha, Potentilla alba, Silene coronaria, Digitalis lanata, Silene viridiflora, Carex praecox
Ecological variants
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Geographical variants (geogr. differential species)
Eastern variant with less thermophilous species, western variant with Helleborus odorus, Sorbus domestica, Fraxinus ornus.
Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
No details
Adjoining climax and permanent vegetation (with numbers of mapping units)
acidophilous oak forests (F22), oak-hornbeam forests (F60, F66), species-rich beech forests (F124, F125, F126), mixed pedunculate oak forests (G4), Quercus polycarpa-oak forests (G8, G9, G10), sessile oak-bitter oak forests (G16), Balkan oak-bitter oak forests (G21), Balkan oak forests (G25), mixed downy oak-bitter oak- grey oak forests (G34), salt vegetation (P32), alluvial forests (U16, U17, U18).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
Degraded, cleared forests, false acacia and Pinus forestry, Pruno spinosae-Crataegetum.
grassland (meadows, pastures, herb-rich communities)
Cynodonti-Poetum angustifoliae, Medicagini-Festucetum valesiacae.
arable land (characteristic weed communities)
Arable land.
settlements (typical ruderal vegetation)
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Site conditions of the mapping unit
Landscape type, geomorphology
plains and hilly country
Altitudinal belt and/or altitudinal range
lowland-colline; 100-300 m
Geology (bedrock)
Tertiary sediments
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
parabrown soils and pseudogleys; (chromic and gleyic luvisols)
soil texture
clayey, clayey-loamy
soil moisture, water balance
periodically dry
soil reaction
weakly acidic
soil fertility
mesotrophic, meso-eutrophic
Climate incl. local climate
climate type (following Walter & Lieth)
VI(VII)
average annual temperature
9-11 °C
average annual precipitation
550-650 mm
average temperature of the warmest month
July 22-23 °C
average temperature of the coldest month
January -2 to 3 °C
local climate or other climatic peculiarities
Dry seasons and droughts possible in summer
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
Small-area, usually degraded oak forests; the entire unit is greatly endangered.
endangered communities, species worthy of protection in natural vegetation
No details
causes of endangerment
Forest grazing, low forest management with excessive use, considerable oak decline (particularly Quercus frainetto) from the years 1982 to 1996.
required measures for protection and restitution
Ecological restitution of the forest, protection of the still well preserved stands.
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
Romania: Comana (Giurgiu district), Buzoaş (Timiş district).
of characteristic substitute communities worthy of protection
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Most important references (author, year)
Georgescu 1941a; Georgescu 1941b; Georgescu & Constantinescu 1945; Păun 1964; Păun 1966; Pop 1967; Popescu, Sanda, Doltu & Nedelcu 1984
Compiled by
N. Doniţă based on documents by A. Popescu, V. Sanda
