The ecoregion is divided into two sub-regions. The Colchic or Colchian forests are found around the southeast corner of the Black Sea in Turkey and Georgia. The Colchian forests are mixed, with deciduous Black Alder (Alnus glutinosa), hornbeam (Carpinus spp.), Oriental Beech (Fagus orientalis), and Sweet Chestnut (Castanea sativa), together with evergreen Nordmann Fir (Abies nordmanniana, the tallest tree in Europe at 78m), Caucasian Spruce (Picea orientalis) and Scots Pine (Pinus sylvestris). The Colchic region has high rainfall, averaging 1,500-2,500 mm annually, with a maximum in excess of 4,000 mm, and is home to some of Europe's temperate rain forests.
The drier Euxine or Euxinic forests lie west of the Melet River, and extend across the Bosporus along the Black Sea coast of European Turkey to Bulgaria. The Euxine forests receive an average of 1,000 to 1,500 mm precipitation annually.
Rare habitat types include coastal sand dunes and peatlands.