Abstract
In order to clarify population structure and dynamics in a 1.0-ha lucidophyllous forest in southwestern Japan, we conducted two successive censuses of trees with DBH≥5 cm in 1998 and 2001. The overall annual mortality of 1.54% was higher than recruitment rate of 1.32%. Distylium racemosum, the most dominant species in the plot, showed in verse-J shaped DBH class frequency distribution, and was expected to be maintain their population and dominance in the future. Quercus salicina, the second most dominant species, had small trees (DBH<15 cm), and showed similar structure as Distylium racemosum. However, distribution pattern of small trees implied that Quercus salicina could not regenerate without gap formation. As compared with neighboring old-growth forest (about 18 km northwest of the plot), some species decrease (e.g. Persea japonica and Actinodaphne longifolia) or lack of their dominance (e.g. Pasania edulis) in the plot, and these differences may reflect the past disturbances. The structural differences and lack of very large trees (i.e. DBH >70 cm) suggested that this forest was an old secondary forest.
