All woody stems ≥ 10 cm diameters were measured in 1991 and 2002 in the whole area (9.08 ha) of Tadasu-No-Mori Forest to clarify interactions among 4 dominant species, Aphananthe aspera, Celtis sinensis, Zelkova serrata and Cinnamonum camphora, where invasion of C. camphora had been concerned. Relative growth rates and mortality rates of these species were calculated and size-dependencies of these rates were examined. Consequently, the most dominant species in Tadasu-No-Mori Forest has changed from A. aspera in 1991 to C. camphora in 2002. The high growth rate and the low mortality rate of C. camphora led to increase of the species. The growth and mortality rate differed among Ulmaceae species. A. aspera showed the low growth rate and the low mortality rate, C. sinensis showed the high growth rate and the high mortality rate. On the other hand Z. serrata showed the low growth rate and the high mortality rate. These results predict that A. aspera and C. sinensis will tend to increase slightly but Z. serrata will tend to decrease in the near future.
