Field investigations were performed in four areas forming a vegetation gradient from a treeless mountainous tundra (16-KP-04; Lake Rauchuagytgyn area) via tundra-taiga transition zone (16-KP-01, Lake Ilirney area; 16-KP-03, Nutenvut lakes area) to a northern taiga (16-KP-02, Bolshoy Anyuy river area). In total, 57 sites were investigated. The sites were chosen to cover a large NDVI gradient (0.3 - 0.8). The sites differ in elevation (100-900 m a. s. l.), slope angle (0-54°) and aspect (overall south aspects prevail). For every field site a detailed description of the vegetation was made. Foliage projective cover for all major taxa estimated as percent and averaged from five representative 2 x 2 m plots within circular sites with a diameter of 30 m: one at the centre and four 7.5 m away in each of the cardinal directions (south, north, west, east). Presence of deadwood and open soil were also recorded.All data was collected by scientists from Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research and University of Potsdam, Germany, The Institute for Biological problems of the Cryolithozone, Russian Academy of Sciences, Siberian branch, and The Institute of Natural Sciences, North-Eastern Federal University of Yakutsk, Yakutsk, Russia.