Plant Formations in the Eastern European BioProvince

Peter Martin Rhind

Eastern European Danube Delta Coastal Dunes and Strandline In the upper littoral zone the pioneer vegetation is typically dominated by Crambe maritima. This zone is moderately saline and vegetation is usually open with very limited ground cover. Other characteristic species include Agropyron junceum, Argusia sibirica, Atriplex hastata, Centaurea arenaria, Eryngium maritima, Euphorbia seguierana, Glaucum flavum, Leymus sabulosus, Medicago falcata, Polygonum maritimum, Salsola ruthenica and Secale sylvestris. However, on newly created sandbars on the Ukrainian side, a different assemblage of pioneer species occurs. Here the main species are Artemisia annua, Bidens tripartita, Chenopodium album, C. ambrosioides, C. rubrum, Echinochloa crus-galii, Polygonum patulum, Rumex maritimus and Suaeda prostata. At slightly higher levels of newly developed foredunes Elymus giganteus often becomes the dominant species. In this zone the vegetation becomes slightly more diverse with additional species such as Anchusa leptophylla, Artemisia arenaria, Centaurea odessana, Cynanchum acutum, Gypsophila perfoliata, Lactuca tatarica, Leymus arenarius, Linaria genistifolia, Linum austriacum, Medicago kotovii, Picris rigida and the endemic or near endemic Cakile euxina (Brassicaceae) and Syrenia cana (Brassicaceae). On the high dunes above the littoral zone there are a variety of dune communities, but some of the characteristic species include Carex colchica, Poa bulbosa, Secale sylvestris and the endemic or near endemic Alyssum borzaeanum (Brassicaceae) and Festuca beckeri (Poaceae). Bushes of Elaeagnus angustifolia and Hippophae rhamnoides are also characteristic. On the old dunes of the Zhebryansky Ridge (Ukraine) there are a number of unusual dune associations rich in endemic or near endemic species. On the riverside sand the dominant species include Artemisia scoparia, Euphorbia seguierana, Leymus arenarius, Secale sylvestre together with the endemic or near endemic Artemisia tschernieviana (Asteraceae), Asperula setulosa (Rubiaceae), Polygonum novoascanicum (Polygonaceae) and Tragopogon borysthenicum (Asteraceae). Other more widespread species include Apera maritima, Centaurea orientalis, Cerastium sivashicum, Condrilla juncea, Polypogon monspeliensis and the endemic or near endemic Arenaria zozii (Caryophyllaceae), Corispermum ucrainicum (Chenopodiaceae) and Syrenia cana (Brassicaceae).

Eastern European Danube Delta Halophytic Formations Salt tolerant vegetation forms extensive patches particularly in depressions in old dunes such as on the Caraoman, Letea, Saraturile and Zhebryansky ridges where saline conditions prevail. In the most saline areas only the two annuals Salicornia patula and Suaeda maritima tend to occur, but in slightly less saline areas Salicornia prostrata often becomes the main species. Common associates include Aeluropus littoralis, Aster tripolium, Hordeum hystrix, Limonium gmelini, Obione verrucifera, Parapholis incurva, Podospermum canum, Salsola soda and Trifolium fragiferum. In humid dune depressions with low salinity, the rushes Bolboschoenus maritimus or Juncus maritimus usually predominate with the latter being more tolerant than the former. Other species that may be encountered here, especially in association with Bolboschoenus, include Artemisia santonicum, Butomus umbellatus, Cyperus pannonicus, Odontites rubra and Sium latifolium.

Eastern European Danube Delta Dune Forest This diverse forest can be found in the Caraorman and Letea dune complexes. The Caraorman (or Black Forest) is aptly named since the old oaks with their impressive branches and other rich vegetation give their sub canopies a very dark appearance. On Copyright © 2010 Peter Martin Rhind the old dunes of Letea, which is the largest maritime sandbank in the Danube Delta, they occur as a series of bands up to 250m long and 10m wide with trees up to 35 m in height. The main trees include Fraxinus ornus, F. angustifolia, F. pallisae, Populus alba, P. nigra, Pyrus pyraster, Quercus pedunculiflora, Q. robur, Tilia tomentosa species of Ulmus and the occasional Alnus glutinosa. Among the shrubs are Berberis vulgaris, Cornus mas, C. sanguinea, Crataegus monogyna, Euonymus europea, Hippophae rhamnoides, Rhamnus frangula, R. catharctica, Viburnum opulus species of Tamarix and occasional Corylus avellana. A distinctive feature is the abundance of climbing plants including Clematis vitalba, Humulus lupulus, Periploca graeca and Vitis sylvestris. In fact, the many creepers and climber plants give these forests an almost subtropical aspect. In spring, the ground is carpeted with Convallaria majalis, while other ground layer species are likely to include Allium ursinum, Cardamine bulbifera, Epipactis helleborine, Equisetum sylvaticum, Euphorbia amygdaloides, Galium odoratum, Geranium phaeum, Viola odorata and many more. Plants found in these forests considered to be rare and threatened in this part of the world include Convolvulus persica, Ephedra distachya, Merendera sobolifera, Plantago coronopus and Petunia parviflora.

Eastern European Stipa capillata – Festuca sulcata Steppe Steppe grassland dominated by tussocks of Stipa capillata and Festuca sulcata appear to be largely confined to drier, usually south facing slopes, and can be seen, for example, in the rolling hills of Ukraineʼs Kharkiv Province. Characteristic species also include Astragalis onoblychis and Bromopsis riparia. In slightly wetter areas shrubby species of Adonis vernalis, Agropyron intermedium, Calamagrostis epioides, Caragana frutex and Thalictrum minus become conspicuous. Endemic or near endemic species found here include Euphorbia stepposa (Euphorbiaceae), Lotus ukurainica (Fabaceae), Medicago romanica (Fabaceae), Melica transsilvanica (Poaceae), Plantago schwarzenbergiana (Plantaginaceae), Salvia nutans (Lamiaceae) and Syrenia cana (Brassicaceae).

Eastern European Poa angustifolia – Festuca sulcata Steppe Like Stipa capillata – Festuca sulcata steppe, grasslands dominated by Poa angustifolia and Festuca sulcata can be seen in the hills of Ukraineʼs Kharkiv Province, but require slightly wetter conditions and are mainly confined to north facing slopes. Characteristic species also include Achillea millefolium, Carex praecox, Euphorbia virgultosa, Falcaria vulgaris, Frangula vulgaris, Genista tinctoria, Hierachium pilosella, Knautia arvensis, Trifolium montanum and Veronica austriaca. In the wettest areas species such as Artemesia marschalliana, Asyneuma canescens, Bupleurum falcatum, Chamaecytisus ruthenicus, Inula ensifolia, Linum flavum, Polygala commosa and Seseli annum become more conspicuous. Endemic or near endemic species found here include Euphorbia stepposa (Euphorbiaceae), Lotus ukurainica (Fabaceae), Medicago romanica (Fabaceae), Melica transsilvanica (Poaceae), Plantago schwarzenbergiana (Plantaginaceae), Salvia nutans (Lamiaceae) and Silene ukurainica (Caryophyllaceae).

Further information required

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Copyright © 2010 Peter Martin Rhind