Abstract
Based on the system volume equation presented previously, a new index was proposed for analyzing the change of stem taper within a stand in competitive situations. Using this index, the stem taper variations was analyzed over time within a stand for Cryptomeria japonica and Chamaecyparis obtsusa. In both species, the stem taper was highly correlated with the diameter at breast height. The change in stem taper variations over time was examined in this paper and was found to be different between species.
