Communities of broadleaved woodlands of the lower part of the forest belt of the Belaya river basin (North-Western Caucasus)

Abstract

The study of phytocoenotic diversity of oak and oak-hornbeam forests of the lower part of the forest belt in the Belaya river basin (Western Caucasus) was performed using the Braun-Blanquet approach. Five floristically different groups of releves were identified based on quantitative classification (Ward's method, Jaccard Distance Measure). An association rank was established for each group. According to the results of comparative syntaxonomic analysis, three associations of moderately masic oak and oak-hornbeam forests - Geranio sanguinei-Quercetum petraeae ass. nova hoc loco (diagnostic species: Pinus sylvestris, Calamagrostis arundinacea, Rhododendron luteum, Geranium sanguineum, Vaccinium arctostaphylos), Inulo salicinae-Quercetum petraeae ass. nova hoc loco (diagnostic species: Brachypodium pinnatum, Inula salicina, Dorycnium graecum, Laser trilobum, Trifolium medium, Viola alba, Stachys officinalis, Pyrethrum poteriifolium, Phleum phleoides, Teucrium chamaedrys, Genista patula) and Acero tatarici-Carpinetum betuli ass. nova hoc loco (diagnostic species: Phalacroloma annuum, Thalictrum minus, Torilis japonica, Prunus divaricata, Physalis alkekengi, Lamium maculatum, Acer tataricum) were included in the alliance Crataego-Carpinion Passarge 1981, order Lathyro-Carpinetalia Passarge 1981, class Carpino-Fagetea Jakucs et Passarge 1968. The correct syntaxonomic position of two associations of mesic hornbeam and oak-hornbeam forests - Dryopterido filicis-maris-Carpinetum betuli ass. nova hoc loco (diagnostic species: Dryopteris filix-mas, Circaea lutetiana, Aegopodium podagraria, Paris incompleta, Abies nordmanniana, Impatiens noli-tangere, Festuca gigantean, Symphytum grandiflorum, Dipsacus pilosus, Aconitum orientale, Asperula caucasica, Moehringia trinervia, Polygonatum orientale) and Vincetoxico scandentis-Carpinetum betuli ass. nova hoc loco (diagnostic species: Viola hirta, Vincetoxicum scandens, Ligustrum vulgare, Lathyrus vernus, Polygonatum multiflorum, Rubus caucasicus, Euphorbia squamosa) has not been determined, however their relations to beech and beech-hornbeam forests of the order Rhododendro-Fagetalia orientalis Passarge 1981 were noted. The described associations of oak-hornbeam forests correspond to the regional ecological series of communities along the moisture gradient.