Included here is a zone along the southern part of the Black Sea most of which is in Turkey but extends west along the Black Sea shores of Bulgaria as far as the Gulf of Burgas. This part has been described as the Euxinic zone. In the east it includes the western Caucasus in western Georgia and the coastal zone as far north as Tuapse. This is the so-called Colchic zone.

Mixed Broad-Leaved Forest

In the western Caucasian (Colchic) zone up to an altitude of about 600 m humid, thermophilous mixed forest occurs dominated by Castanea sative, Fagus orientalis, Quercus hartwissiana, Zelkova carpinifolia and the Caucasian endemic Carpinus caucasica (Betulaceae). The under story is typically Colchic with species such as Laurocerasus officinalis, Rhododendron ponticum and the endemic Ruscus colchicus (Ruscaceae). Typical lianas are Hedera helix, Vitis sylvestris and the endemic or near endemic Dioscorea caucasica (Dioscoreaceae) and Hedera colchica (Araliaceae).

Oak-Hornbeam Forest

Dominated by the Carpinus betula and the Caucasian endemic Quercus iberica (Fagaceae), these deciduous forests are mainly found on sandstone on west and southern slopes. In the Euxine zone they occur, for example, in the region between Kastamonu, Inebolu and Cide. Here other characteristic trees include Acer campestris and Sorbus umbellata var. cretica. The shrub layer includes Daphne pontica and Phyracantha coccinea, while Scutellaria velenonvskyi is characteristic of the herb layer. Associated endemic species include Dianthus carmelitarum (Caryophyllaceae) and Rubus canescens (Rosaceae). On the dryer, lower slopes of the western Caucasian (Colchic) zone the dominant trees are Carpinus orientalis and the Caucasian endemics Carpinus caucasica (Betulaceae) and Quercus iberica (Fagaceae).

References

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