19G1
Steppic woods of Pedunculate oak (Quercus pedunculiflora)
Relationships with habitat classifications. EUNIS: G1.7A1 Euro-Siberian steppe [Quercus] woods; PAL. CLASS.: 41.7A1 Euro-Siberian steppe [Quercus] woods; HD 92/43: 91I0 *Euro-Siberian steppic woods with Quercus spp.; Bondev (1991): 141 Mixed forests of Quercus pedunculiflora with cerris oak (Q. cerris) or with Virgilian oak (Quercus virgiliana) – only on Dobrudzha plateau.
Conservation status. BDA, BC, HD.
Category. Critically endangered [CR – A1, 2 C3 D3 E3 F2 G2 H2].
General characteristics. This habitat type encompasses remnants of isolated woods of Quercus pedunculiflora in Dobrudzha plateau. These communities develop on typical Chernozems, mainly in some depressions limited area. Soil layers that retain water in spring develop due to the thick layer of clayey loess on the karst mother rock of the plateau. Such lowlands, called “chairi” provide the favourable conditions for the development of forest communities in the waterless Dobrudzha plateau, for which mainly the xerothermic (steppe) herbaceous vegetation is typical. The continental climate with limited precipipation and strong eastern winds in winter also has its impact on the local vegetation.
Due to the fertile chernozem soils the Dobrudzha plateau is almost completely occupied by arable land. The steppic woods of Quercus pedunculiflora cover very limited areas. They are isolated and degraded. Sometimes only small groups or single trees of Quercus pedunculiflora have remained from these forests. They are scattered on a large area from the coast in the East to the valley of Suha Reka River (northwards from Dobrich town) to the West and the valley of Batova River to the South. The coenoses of Quercus pedunculiflora that have survived are monodominant. Most of the trees are 70–80 years old. The woods are light, and the distance between the trees is relatively big. Acer campestre, A. tataricum,Cerasus mahaleb (= Prunus mahaleb), Pyrus pyraster, Ulmus minorand more rarely Quercus cerris and Tilia tomentosa also occur in the tree layer apart from Quercus pedunculiflora. The shrub layer is well developed and includes Crataegus monogyna, Cornus sanguinea, Cotinus cogyggria, Euonymus europaeus, E. verrucosus, Ligustrum vulgare, Prunus spinosa, Rhamnus catharticus, Sambucus nigra, and Viburnum lantana. Literature data show also the presence of Amygdalus nana.The latter species supports the steppic characteristics of these woods. Widely distributed species participate in the herbaceous layer: Betonica officinalis(= Stachys officinalis), Brachypodium sylvaticum, Buglossoides purpurocaerulea, Clinopodium vulgare, Filipendula vulgaris, Geum urbanum, Myrrhoides nodosa, Urtica dioica,and Viola hirta.
The steppic woods of Quercus pedunculiflora belong to the alliance Aceri tatarici-Quercion, distributed mainly along the Danube and the Northwest coast of the Black Sea in Southeast Europe. The forests in Bulgaria that belong to this alliance occur very rarely in the lowlands of East Bulgaria.
The steppic woods of Quercus pedunculiflora have never been widely distributed on Dobrudzha plateau, but rather used to occupy suitable places in a typical treeless, wood-steppic region. As the anthropogenic pressure increases, a process that has started in ancient times, both the forest and herbaceous natural vegetation in Dobrudzha region has been almost completely destroyed. Only some fragments are still preserved but they are invaded by a number of ruderal nitrophytes as a result of the grazing by domestic animals.
Characteristic taxa.
- Vascular plants: Acer campestre, A. tataricum, Amygdalus nana, Betonica officinalis, Brachypodium sylvaticum, Buglossoides purpurocaerulea,Cerasus mahaleb (= Prunus mahaleb), Clinopodium vulgare, Cornus sanguinea, Cotinus cogyggria, Crataegus monogyna, Euonymus europaeus, E. verrucosus, Filipendula vulgaris, Geum urbanum, Ligustrum vulgare, Myrrhoides nodosa, Prunus spinosa, Pyrus pyraster, Quercus cerris, Q. pedunculiflora, Q. pubescens, Rhamnus catharticus, Sambucus nigra, Tilia tomentosa, Ulmus minor, Urtica dioica, Viburnum lantana, Viola hirta.
- Animals: Vertebrates – reptiles: Eurotestudo hermanni.
Distribution in Bulgaria. Dobrudzha plateau – eastwards from the line connecting Dobrich town and Krushari village southwards reaching the valley of Bativa River; up to 250 m alt.
Conservation importance. These forests are of high conservation importance because they are threatened by extinction and have a very fragmented distribution in Bulgaria. The species composition of the most of them is strongly changed.
Threats. Destruction of the woods to increase the arable land, logging, replacing by forest plantations with species not typical for the area, grazing, changes in the floristic composition as a consequence of the invasion of ruderal species, low restoration potential, climate change, mainly related to aridisation.
Conservation measures taken. The habitat is in Annex № 1 of BDA and is of conservation priority. Some small and preserved coenoses are within Kobaklaka (“The oaks”) urban park of Dobrich town. The attempts to create plantations of Quercus pedunculiflora have been successful near Bezvoditsa village and in some other places..
Conservation measures needed. Study, mapping and monitoring of the woods of Quercus pedunculiflora in Dobrudzha region. Proclamation of these localities as protected areas and promotion of activities related to their conservation and restoration.
References. Radkov & Minkov 1963; Stoyanov et al. 1955.
Authors: Rossen Tzonev, Georgi Hinkov
