Abstract: Analysis on the quantitative characteristics of regenerated tree species in34 gaps of Korean pine broad-leaved mixed forest in Changbai Mountains shows that the frequency of regenerated arbor species was 7.27%, and that of shrub species was 21.02%.After gap formation, the light demanding pioneer tree species invaded first in gaps, with high frequency and wide niche.With the aging of the gaps, the competition among tree species became strong, the growth of light demanding tree species was limited and meanwhile, the shade-tolerant tree species became dominant.There was a negative relationship between gap age and its canopy density and area, and between gap area and emergence frequency of tree species.The distribution of gap age was mainly in two periods, from 5 to 15 years and from 46 to 55 years.There was a close relationship between species frequency and gap age.The relationship was positive when gap age was less than25 years, negative when gap age was from 25 to 40 years, and the emergence frequency of tree species tended towards stable when gap age was more than40 years.Among the 34 gaps, the diameter at breast height(DBH) of 4 major regenerated arbor species and 4 major regenerated shrub species was a normal distribution.The DBHof the highest regenerated arbor species was 4～6cm, and that of the highest regenerated shrub species was 1.2cm.

Key words: Gap, Regeneration, Korean pine broad-leaved mixed forest, Changbai Mountains, Schima superba, neighbor competition, growth, root plasticity, provenance