This article presents the findings from research conducted on poplar forests within the Lena Pillars National Park. Prior to this study, there had been no detailed research on the poplar forests in the park; only general characteristicsand brief descriptions of forest types were available. The article provides a comprehensive description of tree stands, analyzes the ecological structure of the flora in poplar forests, examines the dynamics of floodplain vegetation, and traces the succession series in the floodplains of the Buotama, Kuranakh, and Labyya rivers within the National Park. At different stages of development, the forests formed by the poplar tree stand are serial (temporary) types, naturally progressing from rare-herb association, mix herb + Equisetum pretense + Calamagrostis langsdorffii (in young poplar stands) → mix herb + shrubs (middle-aged stands, ripening stands) → tall herb + shrub associations with spruce and larch (in ripening, and overmature forests). As the floodplain emerges, the development of poplar forests inevitably transitions to being replaced by coniferous forests. When the overmature poplar tree stand collapses, spruce and larchspruce and birch forests form in its place. Poplar forests in the Lena Pillars National Park are characterized by high productivity; forest stands develop according to Bonitat classes 3-4. Research on the taxation of poplar forests has allowed for the evaluation of the interdependence of different morphometric traits of poplar trees. The correlation has verified the existence of consistent relationships between specific tax indicators. The findings from the study will contribute to understanding the plant life and vegetation in Lena Pillars National Park and the poplar forests of Yakutia. This data can be used to evaluate how the vegetation in the park’s poplar forests may change in the future.