Title
Thracian mixed downy oak-grey oak forests (Quercus pedunculiflora, Quercus pubescens, Quercus virgiliana) with Periploca graeca, Smilax excelsa, Fritillaria pontica
Geographical distribution
Country/territory
Bulgaria: west of Sofia, Thracian basin, hill country around Burgas
area frequency
7 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Querceta pedunculiflorae-tataricosa Gančev 1965, Querceta cerridis-tataricosa Gančev 1965, Querceta cerridis fruticosa Gančev 1965, Quercus cerris + Quercus virgiliana-Cotinus coggygria-community Gančev 1965.
Structural feature of the main community(ies) (layers, life-forms, etc.)
Low-growing, two- to three-layered forests with many thermophilous and some Fagetalia species.
Dominant and most frequent species in different layers
Tree layer
Quercus pedunculiflora, Quercus cerris, Quercus virgiliana, Quercus pubescens, Ulmus minor, Fraxinus angustifolia subsp. oxycarpa, Fraxinus ornus, Acer tataricum
Shrub layer
Crataegus monogyna, Cornus mas, Cornus sanguinea, Ligustrum vulgare, Prunus spinosa, Euonymus europaea
Lianas
Clematis vitalba, Clematis viticella, Vitis vinifera subsp. sylvestris, Periploca graeca, Smilax excelsa
Herb layer
Lithospermum purpurocaeruleum, Lathyrus niger, Fritillaria pontica, Tanacetum corymbosum, Dianthus arenarius, Viola alba, Viola odorata, Geum urbanum, Dactylis glomerata, Ajuga reptans, Galium mollugo, Ranunculus repens
Moss layer (incl. lichens)
---
Diagnostically important species
Quercus pedunculiflora, Acer tataricum, Clematis viticella, Periploca graeca, Smilax excelsa, Vitis vinifera subsp. sylvestris, Fritillaria pontica
Ecological variants
No details
Geographical variants (geogr. differential species)
No details
Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
Quercus frainetto forests.
Adjoining climax and permanent vegetation (with numbers of mapping units)
oak-hornbeam forests (F67), species-rich beech forests (F124), mixed Quercus polycarpa-oak forests (G9), Balkan oak-bitter oak forests (G23, G24), downy oak-bitter oak forests (G31), flowering ash-downy oak- forests (G46), Oriental hornbeam-downy oak forests (G59), dune vegetation (P14), salt vegetation (P29, P33), alluvial forests (U18).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
Robinia pseudoacacia forestry, degraded low forest, Paliurus scrub.
grassland (meadows, pastures, herb-rich communities)
Lolium perenne pastures.
arable land (characteristic weed communities)
Maize, orchards.
settlements (typical ruderal vegetation)
Echinochloa crus-galli, Digitaria sanguinalis, Brachiaria eruciformis, Chenopodium album, Amaranthus retroflexus, Amaranthus albus, Sorghum halepense amongst others.
Site conditions of the mapping unit
Landscape type, geomorphology
plains, hilly country
Altitudinal belt and/or altitudinal range
lowland-colline; 50-200 m
Geology (bedrock)
Tertiary sediments, bluff formation
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
parabrown soils- chernozem, parabrown soils; (chromic luvisols; luvic chernozems; pellic vertisols)
soil moisture, water balance
moderately dry to dry
soil reaction
weakly acidic
soil fertility
meso-eutrophic
Climate incl. local climate
climate type (following Walter & Lieth)
IV(VII), VI(VII)
average annual temperature
10-11 °C
average annual precipitation
500-600 mm
average temperature of the warmest month
July 22-23 °C
average temperature of the coldest month
January 0 to 1 °C
local climate or other climatic peculiarities
sub-continental-sub-Mediterranean transition climate.
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
Only a few preserved forest fragments; greatly endangered.
endangered communities, species worthy of protection in natural vegetation
The whole formation is endangered.
causes of endangerment
Degradation of the forests by low forest management, forest grazing.
required measures for protection and restitution
All still preserved forest stands should be protected.
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
---
of characteristic substitute communities worthy of protection
---
Most important references (author, year)
Bondev 1991; Gančev 1965a; Gančev 1965b
Compiled by
N. Doniţă based on documents by I. Bondev and Z. Neuhäuslová
