North American woody plants in the cultivated phytocoenoses of the Volyn region

Abstract

The inventory of cultural phytocoenoses of the Volyn region conducted in 2019-2023 revealed 53 species of North American woody plants belonging to the divisions Pinophyta and Angiospermae, 24 families and 35 genera. The families with the most species are Pinaceae, Cupressaceae, Fabaceae and Rosaceae. The richest genera are Picea and Pinus. According to their biomorphs, the woody plants studied belong to the phanerophytes (51 species) and the chamefites (2 species). Among the phanerophytes, the group of microphanerophytes is the most numerous – 26 species. There are 48 species of woody plants that are completely hardy. Only 4 species have one- to two-year-old shoots that can freeze (Abies concolor, Liriodendron tulipifera (young plants), Mahonia aquifolium, Phyladelphus grandiflorus). The leaf tips of Yucca filamentosa are damaged in cold winters. 25 species in culture are not able to reproduce independently. Only 16 species go through a complete life cycle and are capable of self-seeding. Vegetatively propagated in culture are 12 species of woody plants. The degree of naturalisation is dominated by ephecophytes that spread in anthropogenically altered areas. These include Parthenocissus quinquefolia, Acer saccarinum, Gleditsia triacanthos, Physocarpos opulifolia, Gymnocladus dioicus, Cercis canadensis, Celastrus scandens, Rhus typhina, etc. The agriophyte group includes 8 species and the colonophyte group 6 species. Agriophytes that have overcome the reproductive barrier, become fully naturalised and are able to spread from cultivated areas into semi-natural and natural phytocoenoses, altering their structure, pose a potential threat to the region's biodiversity. These include Aser negundo, Amorpha fruticosa, Robinia pseudoacacia and Padus serotina. Floristic studies of the natural habitats of Volyn Polissia carried out in recent years have shown the spread of other North American species in the forests: Quercus rubra, Aronia melanocarpa, Amaelanchier spicata.