Abies nordmanniana and Picea orientalis forests from the Colchic region (Western Caucasus) and new concept of Euxine dark coniferous forests classification in the Braun-Blanquet system

A classification system of the Colchic spruce-fir forests (the Western Caucasus) was developed using the Brawn-Blanquet method. Two new associations Dryopterido caucasicae–Abietetum nordmannianae ass. nov., Pruno laucerasi–Abietetum nordmannianae ass. nov. and new alliance Dryopterido caucasicae–Abietion nordmannianae all. nov. were proposed after the comparative syntaxonomic analysis of dark coniferous forests from the Euxine province. Diagnostic species of the alliance are Acer pseudoplatanus, Actaea spicata, Athyrium filix-femina, Dentaria bulbifera, Dryopteris carthusiana, D. filix-mas, Fagus orientalis, Geranium robertianum, Gymnocarpium dryopteris, Impatiens noli-tangere, Oxalis acetosella, Paris incompleta, Polystichum aculeatum, Ranunculus grandiflorus, Rubus caucasicus, Salvia glutinosa, Symphytum grandiflorum. All described Colchic associations and alliance were placed in the order Abieti nordmannianae– Piceetalia orientalis Coban et Willner 2019 and the class Asaro europaeai–Abietetea sibiricae Ermakov et al. in Willner et al. 2016 uniting West Palearctic dark coniferous subnemoral forests from Europe, Asia Minor, Southern Urals and Western Siberia.