Abstract
The population density of newly germinated plants of Eisenia bicyclis was monitored in the populations where the density of adult plants was artificially controlled, in Tomari-Hama, Oshika Peninsula, Miyagi Prefecture from June 1986 through June 1989. At the site where adult plants were thinned, the rate of recruitment was conspicuously high even in the years when the recruitment was low in the control site, and the considerable year class was established after two years. It seemed that artificial control of population density, less than five plants/m2 by thinning out adult plants older than four years, is effective for high recruitment.
