Aggregated ground vegetation above-ground biomass at 56 sites in Central and Eastern Yakutia, in Summer 2021 (RU-Land_2021_Yakutia)

Aggregated above-ground biomass for ground vegetation is given in g per m² for each taxon at 56 sites. Total ground vegetation biomass in g per m² and in kg for the entire site. The vegetation surveys were carried out in four different study areas in the Sakha Republic, Russia: in the mountainous region of the Verkhoyansk Range within the Oymyakonsky and Tomponsky District (Event EN21-201 - EN21-219), and in three lowland regions of Central Yakutia within the Churapchinsky, Tattinsky and the Megino-Kangalassky District (Event EN21220 - EN21264). The study area is located within the boreal forest biome that is underlain by permafrost soils. The aim was to record the projective ground vegetation in different boreal forest types studied during the RU-Land_2021_Yakutia summer field campaign in August and September 2021. The ground vegetation above-ground biomass was measured for different vegetation types within a circular forest plot of 15m radius. Depending on the heterogeneity of the forest plot, multiple vegetation types (VA, VB, or VC) were chosen for the survey. One quadrat of 50x50 cm was harvested per vegetation type. All vegetation smaller than 40 cm was harvested. Biomass harvest was conducted just outside the circular forest plots, which will serve as long-term monitoring sites. Fresh weights were recorded in field and sub sampling conducted if necessary. Samples were later dried at 60°C until a constant weight was achieved and dry weight was recorded. Average ground vegetation biomass per plot was calculated by using a weighted average for each vegetation type. In total, 79 quadrats at 56 forest plots were harvested. All data were collected by scientists form the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) Germany, the University of Potsdam Germany, and the North-Easter Federal University of Yakutsk (NEFU) Russia.