Abstract
With the exception of preservation areas, the natural stand of Japanese cedar grown in the east of Kochi Prefecture called YANASESUGI is currently decreasing by some causes such as cutting. Moreover, it is in difficult situation to restore the mature forest of YANASESUGI by natural regeneration because of lack of young growths. To revitalize natural regeneration, the Forest Technology Center of Shikoku Regional Forest Office has commenced the study on the regeneration by natural seeding of YANASESUGI. The following results were obtained from one year of study: i) the larger the number of young growth at the beginning of the study the larger the increase in the number of young growth during the study period, ii) the number of the young growth survived during the study period was larger in the gap of smaller area ("heli-gap") than in the gap of larger area ("wire-gap")- iii) In most of the study plots, the number of young growth increased during the study period, but it decreased in the plots with transmittance of scattered light exceeding 50%. iv) a tendency was observed that the higher the ratio of light shielding by litter was, the smaller the number of young growths was. v) Influence of light shielding by litter varied depending on gap area.
