Abstract
Line-thinning is one of the ways to facilitate mechanization of extraction of thinned timber, but its biological influences on the stand are not yet well known. To get information on the influences of line-thinning on biological requirements of trees, an experiment was made for the first thinning of a Cryptomeria plantation so that the thinned lines are to be used as racks in the later thinnings. However, on the way of the experiment, the plots were destroyed by an exceptionally heavy snowfall, and the experiment could not be finished.
Significant difference was not found between the line and selective thinning in growth in the basal area and in the mean diameter for the first two growing seasons after the thinning. Snow damage was far severer in the line-thinning than in the selective thinning, and the cause of the severer damage was proved to be the thinned lines themselves.
