Field experiments were conducted at the Yodogawa river in Osaka Pref. in 1988 and 1989 to clarify the effects of different frequency cutting on growth and species composition of the Solidago altissima community. Six plots differing in cutting frequency were examined. This community was retrogressive at three or more cuttings per year. As cutting frequency increased, not only did the number of component species increase, the number and percentage of annual plants per plot increased also. The percentage of annual plants attained 50 percent or more in plots cut three times or more. Seasonal succession was recognized in the floristic composition of this community, whose spring aspect was characterized by winter annual plants, the autumn aspect being characterized by summer annual plants. Though winter annual plants grew in the non-cut plot, summer annual plants did not.
