Abstract: Electroshocking is an environment-friendly approach for earthworm sampling. However, the application of this approach is limited by the varied efficiency of electroshocking across stand conditions and earthworm community composition. In early November of 2017, we investigated earthworm community composition in the poplarbirch forests at three different developmental stages in Changbai Mountains using electroshocking and hand-sorting extraction. We examined the effects of potential factors, such as forest developmental stage, ecological group, population size, life stage of earthworms, soil temperature, and soil moisture on electroshocking efficiency. The electroshocking efficiency of earthworm varied across different stages of forest development. The electroshocking efficiency of earthworms was the highest in the 40-year-old poplar-birch forest, being 68.5% and 57.4% for earthworm number and biomass, respectively.Eisenia nordenskioldi, an epigeic species, was most active and had an electroshocking efficiency of 100%. In contrast, Drawida changbaishanensis, an endo-anecic species, was dormant during the experiment, with electroshocking efficiency down to 0. The electroshocking efficiency of the slow endogeic species Eisenia andrei ranged from 22.2% to 58.3%. There was no significant correlation between Eisenia andrei population size and electroshocking efficiency for both the number (r=0.139, P=0.381) and the biomass (r=0.025,P=0.877). The electroshocking efficiency of adults of Eisenia andrei was significantly higher than that of juveniles (P=0.014). Soil temperature had a significant effect on the electroshocking efficiency, with the value being 0 when soil temperature <6 ℃, 34.6%±13.1% when soil temperature 6-10 ℃, and 46.0%±8.7% when soil temperature>10 ℃. Soil moisture did not affect electroshocking efficiency of earthworms. Overall, the electroshocking efficiency was closely related to the activity of earthworms. Earthworm ecological group, life stage, and soil temperature affected earthworm activity, and consequently changed the electroshocking efficiency of earthworms. Due to different sensitivity of earthworms to electroshocking, long-term experimental study on the ecological functions of different earthworm groups can be performed through different manipulations of earthworm community structure using the electroshocking approach.

Key words: Solenocera melantho, diet composition, feeding intensity, feeding change, trophic-level.