Growth Competition and Crown Spatial Statistics in Plantation of Cryptomeria japonica in Ren-Lun

• Main Authors: Jing-Ru Chen, 陳敬儒
• Other Authors: Tian-Ming Yen
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/91140511405972408940

碩士 === 國立中興大學 === 森林學系所 === 97 === The purpose of this study is to discuss stand structure, crown spatial statistics, and growth competition of Cryptomeria japonica plantations after thinned at compartment no.74, Luan-Da working circle. The summary of obtained result is as follows: The significant difference of four thinning treatments is stand density, average DBH, total Height, and tree volume. The rate of volume growth, maximal is in 35% thinning plot from above, secondly is in 45% thinning plot from below, thirdly is in no thinning plot, and the minimum is 35% thinning plot from below. The simulated curve of stand diameter distribution is maximum likelihood method better than percentile estimator method. Similarly, there is statistically significant difference of four thinning treatments for average crown radius, absolute displacement of crown, and relative displacement of crown. Absolute displacement of crown is conspicuous related to diameters and increase with diameter. Relative displacement of crown is related to stand density. Besides, spatial structure of stems and crowns shows regularly distributed overall, and the results suggested that trees of a stand can adapt to their environment in order to find a trade-off between different function like mechanical stability, access to light and the physiological cost associated with adaptive growth. The significant parameters of DBH growth model that has no competition index are initial DBH, tree height, and relative displacement. The significant parameters of volume growth model that has no competition index are initial BA, initial DBH, tree height, and relative displacement. Models of Cryptomeria japonica growth indicated variable performance among stands and indices tested. Competition accounted for up to 10% of growth variation, with some of the results provided by Lorimer’s, and Alemdag’s. The addition of initial size and relative displacement of crown gravity as a second and third explanatory variable increased the predictive ability of growth models.