中文摘要：

本文在搜集大量国内外文献的基础上,综合讲述了择伐对北方森林的更新、生物多样性、生长的影响,并对比了国内外北方森林择伐的强度与周期。结果表明,合理择伐可以促进北方森林的更新,可以有效地维持生物多样性和森林生态系统的主要功能,可以促进林分的生长,加速演替进程。合理择伐强度应该控制在10%~30%之间。择伐周期应在10年到30年之间。

英文摘要：

After collecting a large quantity of publications in and abroad,the effects of selective cutting on regeneration,biodiversity,and growth in boreal forests were stated,and also the optimal cutting intensity and cycle were compared.The result indicated that,the regeneration,biodiversity,and growth can be enhanced by reasonable selective cutting.At last,the optimal cutting intensity and cycle is discussed,and optimal cutting intensity should be within 10%-40%,cutting cycle should be within 10-30 years.