부산대학교 도서관

In order to clarify the regeneration processes of natural Japanese beech (Fagus japonica Maxim.) forest under different scales of canopy disturbances, we studied 20 years change of stand structure in secondary and natural Japanese beech forests in the Chichibu Mountain in the Pacific Ocean side of central Japan. Tree surveys were conducted in 40m×40m quadrat (CQ) in the secondary Japanese beech forest that was subjected to a large-scale canopy disturbance by clear-cutting 16 years ago, and 50m×70m quadrat (NQ) in the natural Japanese beech forest where a small-scale canopy disturbance by a few dead and fallen trees have occurred. In the clear cutting quadrat, the pioneer species such as Betula maximowicziana, Acer runiferve and B. grossa dominated in the canopy layer (H≧7m) and sprouts and a large number of seedlings (1,431 seedlings per ha) of Japanese beech dominated in lower layer (H<7m). Betula maximowicziana did not have any seedlings. In the natural forest quadrat, responding to canopy opening, Magnolia obovata, Cornus controversa, A. micranthum, which occurred in the lower layer before the gap formation, and C. controversa and Stewartia puseudo-camellia, which were recruited after the gap formation, grew rapidly than the sprouts of Japanese beech that occurred from their stools under the canopy gap. These results suggested that, under the large-scale canopy disturbance, the pioneer species reach the forest canopy in the early stage following the regeneration of canopy trees by the sprouts and seedlings of Japanese beech. In contrast, under the small-scale canopy disturbance, canopy trees in lower layer occurred before the gap formation and recruited trees after the gap formation reach the forest canopy in the early stage following the canopy closure by sprouts regeneration of Japanese beech.