Abstract
Rhus trichocarpaMiq. is a short-statured pioneer tree species that creates patch communities during the early successional stages of some pine forests in Japan. A 0.6 ha sample plot was established in a Japanese red pine (Pinus densifloraSieb, et Zucc.) stand to evaluate the influence of patch structure on regeneration of R. trichocarpaand other tree species. The plot included 47 patches of R. trichocarpa.The survivorship of R. trichocarpaseedlings was high in small patches, but low in large ones. The small patches expanded, transforming into large ones over several years. Several tree species such as Quercus serrataThunb., Primus apetalaFranch. et Sav., Sorbus commixiaHedl., and Magnolia obovataThunb. invaded the patches after the fruiting of R. trichocarpa.They grew faster than R. trichocarpain these patches and broke through the R. trichocarpacrown layer after about 10 years.
The fruits of R. trichocarpaattract birds which disperse seeds produced by other tree species. Thus, the R. trichocarpapatch plays a vital role in changing from pioneer tree species to shade-tolerant tree species.