Damage to lower-story Betula maximowicziana trees caused by logging of upper-story Larix kaempferi trees in a two-storied stand

Abstract

Damage to lower-story Betula maximowicziana trees caused by logging of upper-story Larix kaempferi trees was investigated in a two-storied stand which had been brought by the regeneration of B. maximowicziana after intensive thinning accompanied with ground surface disturbance by a wheel tractor. The lower-story B. maximowicziana trees were severely damaged by logging involving the use of a harvester for felling and limbing: 75% of them sustained serious damage such as uprooting and stem breakage, while those undamaged and slightly damaged amounted to only 16 and 9%, respectively, located by local. The damage sustained by B. maximowicziana was more serious than other broad-leaved tree species such as Quercus crispula, characterized by the dominance of uprooting. Almost all seriously-damaged B. maximowicziana trees subsequently perished without recovery by sprouting. Such a high risk of damage to lower-story trees suggests that the B. maximowicziana regeneration system in L. kaempferi plantations by intensive thinning accompanied with scarification is unfavorable, due to the need to remove upper-story trees after establishing B. maximowicziana.