Range-habitat relationships of vascular plant species at the taiga forest-steppe borderline in the western Khentey Mountains, northern Mongolia

World distribution of 488 out of 619 vascular plant species known from an area of 500 km2 within the western Khentey Mountains, northern Mongolia is analyzed. Most species belong to Eastern Asian (29%) or Asian, Eurasian, or circumpolar temperate species (24%) supporting the classification of the Khentey Mountains as part of the temperate zone of Eurasia. Seventeen percent of species are boreal plants. Circumpolar temperate-boreal (9%), Central (-Eastern) Asian (9%), Continental mountain species (5%), Middle-Central Asian (3%), arctic-alpine (3%) as well as Western Eurasian and western Siberian species are of lower significance for the flora of the western Khentey Mountains. Eastern Asian species occur in all types of habitats, whereas plants of other distribution types are focused on certain habitats. Boreal species preferably grow in the dark taiga, which prevails in the upper montane belt and on northern and eastern slopes of the most humid parts of the lower montane belt. Temperate and temperate-boreal species prefer subtaiga forests, which are found on northern and eastern slopes in drier parts of the lower montane belt as well as in upper parts of sun-exposed, southern and western slopes of the lower montane belt. Central (-Eastern) Asian and Middle-Central Asian species primarily inhabit forest steppe habitats, such as meadow and mountain steppes, Ulmus pumila open woodlands and dry Pinus sylvestris forests on steep, southern slopes.