Abstract: An investigation was conducted on the below- and aboveground  biomass and its spatial distribution of Vaccinium uliginosum community  under Larix olgensisforests in Changbai Mountains. The above-ground biomass of the V. uliginosum community was mainly distributed below the height of 50 cm, and the biomass of the branches with a diameter of 3-5 mm occupied the largest portion. The belowground  biomass accounted for 75.2%-92.6% of the total, and was mainly (66.3%-85.0%) distributed in dead moss layer where the biomass of fine roots (<1 mm) accounted for 42.6%-82.7% of the total. In peat layer, the root biomass accounted for 12.3%-29.7% of the total. The root biomass of V. uliginosum accounted for 8.8%-60.7% of the total root biomass of all plant species, and the fine root biomass of V. uliginosum occupied a great portion. This study provided basis for the rational protection and utilization of V. uliginosum resources and the evaluation of the carbon sequestration of the ecosystem.

Key words: Ankang Reservoir, phytoplankton, community structure, environmental factor, water quality.