2002 Volume 19 Issue 1 Pages 43-53
Growth process and age structure of Korean pine (Pinus koraiensis Sieb. et Zucc.) populations were studied in two developing mixed Korean pine-hardwood forests in northeasten China. In a plot located in Mudanfeng Forestry Area, not only Korean pine but also other species regenerated after a strong canopy disturbance in the 1950's. In Dalianzihe Forestry Area, dominant Korean pine trees in the canopy layer were established during the 1820's to 1860's. The regenerating trees in both plots originated from both seedlings and advance regenerations. However, new seedlings and saplings were not observed under the closed canopies of both plots, and only a few seedlings grew in small canopy gaps (< ca. 40 m^2 in area) created by the death of suppressed trees in the Mudanfeng plot. Thus, during the development of young Korean pine forests initiated by large canopy disturbances, seedling establishment under closed canopy or in small gaps is inhibited by insufficient light conditions. In contrast, abundant saplings regenerating in canopy gaps of old-growth forests have been also reported in several studies, and the two contrasting regeneration processes, i.e. episodic simultaneous regeneration and gap-phase regeneration were recognizable. These two regeneration processes could be located on different positions of the chrono-sequence of the development of mixed Korean pine-hardwood forests. The former process not only initiates even-aged forests, but also results in the lack of new generations in the following several hundred years. The latter process is prevalent in forests which attain the old-growth stages.
