Active economic development of the Lower Angara zone requires the creation of a scientific basis for long-term monitoring of the state of natural ecosystems. The paper gives an assessment of the diversity of vegetation cover in the zone of potential influence of the Nizhneboguchanskaya HPP. An analysis of its typological structure on a landscape-ecological basis is given. The results of the DCA ordination and the interpretation of the leading axes of variation demonstrated the presence of four distinct groups of forest types that form ecological series according to the leading factors - the richness and hydrothermal regimes of soils. The dendrogram of forest types in the study area reflects the floristic integrity of the identified groups of forest types and the floristic relationships between them.