Title
Sand steppes of Danubian Delta (Stipa anomala, Festuca arenicola, Carex colchica, Scabiosa argentea) alternating with ash-oak forests (Quercus pedunculiflora, Quercus robur, Fraxinus pallisae, Fraxinus angustifolia s. l.)
Geographical distribution
Country/territory
Romania: small-scaled in the Danube Delta (on the islands Letea and Caraorman)
area frequency
2 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Scabioso ucranicae-Caricetum ligericae (Simon 1960) Krausch 1965, Elymetum gigantei Morariu 1957, Secaletum silvestris Popescu & Sanda 1973, Ephedro-Caricetum colchicae (Morariu 1959) Krausch 1965, Saliceto rosmarinifoliae-Holoschoenetum vulgaris With. et al. 1973, Aperetum spica-venti Soó 1953 ponticum Popescu & Sanda 1972, Dauco guttati-Chrysopogonetum grylii Popescu & Sanda 1978, Fraxinetum pallisiae (Simon 1960) Krausch 1965, Quercetum robori-pedunculiflorae Simon 1960.
Structural feature of the main community(ies) (layers, life-forms, etc.)
Coastal dune areas with a small vegetation mosaic consistent with site conditions that change over very small areas: more or less closed sand steppes on the dunes and more or less closed forests in the dune valleys. In the sand steppes Festuca arenicola or Apera spica-venti dominate, while in the liana-rich forests Fraxinus angustifolia or Quercus pedunculiflora dominate. The sequence of the vegetation units: a) dry siliceous grassland on high dunes with Carex colchica and locally Ephedra distachya as well as Festuca arenicola; b) open psammophytic steppes on lower dunes with Stipa borysthenica and Festuca arenicola; c) low dunes with quite closed grassland communities consisting of Apera spica-venti subsp. maritima and Agrostis gigantea subsp. pontica, occasionally with Chrysopogon gryllus and Cynodon dactylon; d) in dune valleys (between the high and middle dunes) stands of Salix rosmarinifolia and Scirpoides holoschoenus; e) in hollows between the dunes ash-oak mixed forests, sometimes with poplars and/or alders, with a luxuriant shrub layer and lianas and mainly hygrophilous alluvial plants in the herb layer; f) in permanently wet hollows reed vegetation and willow scrub, and sometimes halophytic vegetation.
Dominant and most frequent species in different layers
Tree layer
in forests: Quercus pedunculiflora, Quercus robur, Fraxinus pallisae, Fraxinus angustifolia subsp. danubialis, Populus alba, Populus x canescens, Populus tremula, locally Alnus glutinosa, in the underwood Acer tataricum, Acer campestre, Ulmus minor, Pyrus pyraster, Malus sylvestris
Shrub layer
in forests: Crataegus monogyna, Prunus spinosa, Viburnum lantana, Cornus sanguinea, Berberis vulgaris, Ligustrum vulgare, Euonymus europaea, Euonymus verrucosa, Rhamnus cathartica, here and there Viburnum opulus, Sambucus nigra, Rubus caesius, Frangula alnus, Salix cinerea
Lianas
in forests: Periploca graeca, Vitis vinifera subsp. sylvestris, Clematis vitalba, Humulus lupulus
Herb layer
in forests: Eupatorium cannabinum, Stachys palustris, Lysimachia vulgaris, Lycopus europaeus, Carex acutiformis, Carex elata, Carex hirta, Symphytum officinale, Galium rubioides, Brachypodium sylvaticum, Polygonatum hirtum, Convallaria majalis, Astragalus glycyphyllos, Heracleum sphondylium subsp. sibiricum;
in steppes: Carex colchica, Ephedra distachya, Festuca arenicola, Stipa borysthenica, Koeleria glauca, Secale sylvestre, Astragalus varius, Centaurea arenaria, Scabiosa argentea, Euphorbia seguieriana, Kochia laniflora, Helichrysum arenarium, Artemisia arenaria, Apera spica-venti subsp. maritima, Silene conica, Onosma arenaria, Convolvulus persicus, Polygonum arenarium
Moss layer (incl. lichens)
No details
Diagnostically important species
in sand steppes: Festuca arenicola, Stipa borysthenica, Carex colchica, Secale sylvestre, Scabiosa argentea, Convolvulus persicus, Ephedra distachya, Apera spica-venti subsp. maritima; in forests: Quercus pedunculiflora, Fraxinus pallisae; Periploca graeca, Galium rubioides
Ecological variants
No details
Geographical variants (geogr. differential species)
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Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
Leymus racemosus subsp. sabulosus communities (Elymetum gigantei); reed vegetation and sedge reeds (Phragmithes australis, Typha angustifolia, Carex elata); Salix cinerea scrub; halophytic vegetation (Juncus maritimus, Limonium gmelinii, Puccinellia convoluta, Plantago crassifolia, Salicornia spp.).
Adjoining climax and permanent vegetation (with numbers of mapping units)
tall sedge swamps and tall reed vegetation (R1, R3, R4), alluvial forests (U20).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
Drier areas with Tamarix ramosissima, Elaeagnus angustifolia; Poplar forestry.
grassland (meadows, pastures, herb-rich communities)
Pastures with Cynodon dactylon, Agropyron cristatum subsp. pectinatum, Artemisia austriaca.
arable land (characteristic weed communities)
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settlements (typical ruderal vegetation)
No details
Site conditions of the mapping unit
Landscape type, geomorphology
Coastal dune relief with dunes and dune valleys
Altitudinal belt and/or altitudinal range
lowland; 0-15 m
Geology (bedrock)
fluviatile and eolian sediments (Holocene)
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
poor fixed sand soils; (calcaric regosols; arenosols; calcaric fluvisols)
soil moisture, water balance
in steppes: dry, in forests: fresh to moist
soil reaction
weakly acidic, neutral
soil fertility
mesotrophic
Climate incl. local climate
climate type (following Walter & Lieth)
VI(VII)
average annual temperature
10-12 °C
average annual precipitation
350-400 mm
average temperature of the warmest month
21-22 °C
average temperature of the coldest month
-1 to 0 °C
local climate or other climatic peculiarities
summer-warm, semi-arid climate.
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
Sand steppes and dune forests are sometimes well preserved and sometimes degraded.
endangered communities, species worthy of protection in natural vegetation
No details
causes of endangerment
Timber use, grazing.
required measures for protection and restitution
No details
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
Romania: biosphere reserve Danube Delta (above all Letea, Caraorman).
of characteristic substitute communities worthy of protection
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Most important references (author, year)
Ivan, Doniţă, Coldea, Sanda, Popescu, Chifu, Boşcaiu, Mititelu & Paucă-Comănescu 1993; Hanganu, Gridin, Drost, Chifu, Ştefan & Sărbu 1994; Krausch 1965b; Morariu 1957
Compiled by
N. Doniţă, completed by U. Bohn referring to the vegetation map of the biosphere reserve 'mouths of the Danube' (Hanganu et al. 1994)
