An analytical study on stem growth of Chamaecyparis obtusa

Considering the recent trend toward the development of multiple-use of forest trees, investigations for comprehensive information on these young stands of Hinoki cypress are necessary for rational forest management. From this point of view, 83 sample trees were selected and cut down from 23-year old stands of Hinoki cypress at Changsung-gun, Chonnam-do. Various stem growth factors of felled trees were measured and canonical correlation analysis, principal component analysis and factor analysis were applied to investigate the stem growth characteristics, relationships among stem growth factors, and to get potential information and comprehensive information. Canonical correlation coefficient between stem volume and quality growth factor was 0.9877. Coefficient of canonical variates showed that DBH among diameter growth factors and height among height growth factors had important effects on stem volume. From the analysis of relationship between stem-volume and canonical variates, which were linearly combined DBH with height as one set, DBH had greater influence on volume growth than height. The 1st-2nd principal components were adopted to fit the effective value of 85% from the pincipal component analysis for 12 stem growth factors. The result showed that the 1st-2nd principal component had cumulative contribution rate of 88.10%. The 1st and the 2nd principal components were interpreted as "size factor" and "shape factor", respectively. From summed proportion of the efficient principal component for each variate, information of variates except crown diameter, clear lenght and form height explained more than 87%. Two common factors were set by the eigen value obtained from SMC (squared multiple correltion) of diagonal elements of canonical matrix. There were 2 latent factors, f1 and f2. The former was interpreted as nature of diameter growth system. In inherent phenomenon of 12 growth factors, communalities except clear length and crown diameter had great explanaory power of 78.62-98.30%. Eighty three sample trees could be classified into 5 stem types