Study On The Natural Regeneration In Gaps In Spruce-Fir Mixed Stands In Over-cutting Forest Area In Changbai Mountains

The paper is mainly on over-cutting Spruce-Fir mixed stands in Jingouling Farm, Wangqing Forest Bureau, JinLin Procince. The research object is to investigate the regeneration rules of Korean pine, Fir and Spruce regenerated in forest gaps and under crown, then we can direct forest production with these theories, it is important in maintaining forest sustain management.This paper mainly includes several aspects as follows: regeneration density, age structure, tree-height growth curve and base diameter growth curve of three conifers regenerated in forest gaps and under crown. Compared the renovation characters and growth rules of three conifers in gaps with that under crown, we can find the best suit gap-size and gap-age for forest regeneration.We conclude that, forest gaps can promote the regeneration of spruce, fir and Korean pine on a certain extent. Forest gaps can accelerate the tree-height and base diameter growth of fir over 19 years, have little effect in the tree-height and base diameter growth of spruce under 15 years and Korean pine under 17 years. This research also indicated that the environment in 20-30 year-old gaps and 15-40m~2 size gaps is fit for conifer regeneration.