The ecoregion is one of the largest tracts of virgin boreal forest in the world, due to the very sparse population and difficult access.

Their upper slopes and peaks are too cold and dry to support the forests and flora of the lowlands in the Northeast Siberian taiga ecoregion.

The dominant trees are Larix cajanderi (Dahurian larch), Larix sibirica, Larix × czekanowskii, Betula dahurica, Betula pendula (silver birch), Pinus sibirica, Pinus sylvestris, Pinus koraiensis, Picea obovata, Abies sibirica, Juniperus communis, Quercus acutissima, Quercus mongolica, Ginkgo biloba, Prunus serrulata, Prunus padus, Tilia amurensis, Salix babylonica, Acer palmatum, Populus tremula, Ulmus davidiana, and Ulmus pumila, with a ground cover of Pinus pumila (Siberian dwarf pine) Haloxylon ammodendron (saxaul), Elaeagnus angustifolia, Tamarix ramosissima, Prunus sibirica, and lichen.

Further development of the forest is limited by the continuous permafrost of the area, and by the harsh cold winters and relatively low precipitation.

[9] In the lowland floodplains there are steppe floral communities that feature fescue (Festuca), wheatgrass, alpine oatgrass (Helictotrichon), cinquefoils (Potentilla tollii), Orostachys spinosa, Carex pediformis, and others.

Over one million individuals from 15 species are seen in the area, and is one of the only breeding grounds for the Little curlew and the critically endangered Siberian crane.

Populations of black-billed capercaillies (Tetrao urogalloides) and hazel grouse (Tetrastes bonasia) tend to inhabit forested habitat.