Abstract
The research work is devoted to the study of the biodiversity of woody and shrubby plants of the floodplain forests of the Yesil River on the territory of the Kyzylzhar district of the North Kazakhstan region. A list of tree and shrub species, taxonomic composition, distribution and occurrence in the floodplain of the river has been compiled. Based on our research work, 22 species from 18 genera and 9 families were identified. A large family is Rosaceae, with 11 species (50.0%) of trees and shrubs. The second largest number of species is the family Salicaceae, with 4 species or 18.18% of the species composition of trees and shrubs. The flora of birch forests on riverine terraces is characterized by a large species diversity, high projective coverage, the presence of boreal species, as well as rare and subject to protection. Rare species of shrubs include Cotoneaster melanocarpus Fisch. ex Blytt., Frangula alnus Mill., Viburnum opulus L.