Title
Thracian thorn-cushion vegetation (Astragalus aitosensis, Astragalus angustifolius, partly Astragalus thracicus) with steppe elements (Bromus riparius, Stipa capillata, Agropyron cristatum subsp. brandzae)
Geographical distribution
Country/territory
East Bulgaria: near Aitos, (very small-scaled also in the west, but not shown on the map); in north Greece assumed, but unsurveyed
area frequency
2 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Astragalus aitosensis-Bothriochloa ischaemum-association.; Astragalus aitosensis-Festuca dalmatica-ass.; Astragalus aitosensis-Agropyron brandzae-ass.; Astragalus aitosensis-Melica ciliata-ass.; Astragalus aitosensis-Alyssum tortuosum-ass.; Astragalus aitosensis-Poa bulbosa-ass.; Astragalus aitosensis-Bromus riparius + Agropyron brandzae-ass.
Structural feature of the main community(ies) (layers, life-forms, etc.)
Open stands (35-85 % degree of cover) of thorn-cushion-type Astragalus species with grasses.
Dominant and most frequent species in different layers
Herb layer
Astragalus aitosensis, Bothriochloa ischaemum, Poa bulbosa, Festuca dalmatica, Agropyron cristatum subsp. brandzae, Melica ciliata, Alyssum tortuosum, Bromus riparius
Moss layer (incl. lichens)
No details
Diagnostically important species
Astragalus aitosensis, Agropyron cristatum subsp. brandzae, Bromus riparius, Koeleria splendens, Stipa capillata, Minuartia setacea, Euphorbia myrsinites, Eryngium campestre, Asperula cynanchica, Achillea coarctata, Cleistogenes bulgarica, Tragopogon balcanicus, Festuca thracica
Ecological variants
No details
Geographical variants (geogr. differential species)
In the eastern part with Cleistogenes bulgarica, Agropyron cristatum subsp. brandzae, Melica ciliata, Artemisia austriaca, Alyssum tortuosum etc.; in the western part with Artemisia alba, Helianthemum oelandicum subsp. incanum, Sideritis montana, Teucrium montanum, Hyacinthella leucophaea, Sternbergia colchiciflora
Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
Forests with Quercus cerris, Quercus pubescens, Quercus virgiliana, Quercus frainetto (rare).
Adjoining climax and permanent vegetation (with numbers of mapping units)
Balkan oak-bitter oak forests (G24), downy oak-bitter oak forests (G31).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
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grassland (meadows, pastures, herb-rich communities)
Near Aitos secondary Astragalus stands instead of forests.
arable land (characteristic weed communities)
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settlements (typical ruderal vegetation)
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Site conditions of the mapping unit
Landscape type, geomorphology
hilly country
Altitudinal belt and/or altitudinal range
colline
Geology (bedrock)
limestone, andesite (Tertiary, Cretaceous)
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
very shallow humus carbonate soil-soils on limestones, in the east on andesites; (rendzic leptosols)
soil texture
stony, grouany
soil moisture, water balance
fresh to dry
soil reaction
weakly acidic, neutral
soil fertility
oligotrophic, oligo-mesotrophic
Climate incl. local climate
climate type (following Walter & Lieth)
VII
average annual temperature
12 °C (east); 8-10 °C (west)
average annual precipitation
550-600 mm
average temperature of the warmest month
July 22 °C (east); 20 °C (west)
average temperature of the coldest month
January 1 °C, around 2 °C (west)
local climate or other climatic peculiarities
sub-Mediterranean-subcontinental climate in the eastern part of Bulgaria.
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
Quite heavily damaged in small-areas.
endangered communities, species worthy of protection in natural vegetation
Astragalus aitosensis-communities with Astragalus aitosensis, Stipa capillata, Tragopogon balcanicus, Cleistogenes bulgarica very worthy of protection.
causes of endangerment
Soil erosion.
required measures for protection and restitution
No details
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
Bulgaria: Astragalus aitosensis-communities near Aitos, east Bulgaria; Astragalus angustifolia-communities near Zemenska planina, Golo brdo.
of characteristic substitute communities worthy of protection
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Most important references (author, year)
Bondev 1991; Velčev & Bondev 1975
Compiled by
Z. Neuhäuslová based on documents by I. Bondev
