论文部分内容阅读
通过对I-72杨在豫南地区不同地位级的胸径、树高、材积的调查和生长过程研究,结果表明:不同的立地条件对5年生I-72杨生长量影响不大,9年生以后生长量影响极显著,Ⅱ地位级相对于Ⅲ地位级更有利于I-72杨的生长。I-72杨的生长过程可分为3个时期:1~5年生时为幼林期,材积生长极为缓慢。6~12年生时为速生期,胸径、树高、材积生长急速上升。12~15年生时为近熟期,胸径、树高、材积生长趋缓。
Based on the investigation of I-72’s DBH, tree height and volume at different positions in southern Henan, the results showed that different site conditions had little effect on the growth of 5-year-old I-72. After 9 years The effect of growth was very significant. The status of Ⅱ status was more favorable to the growth of I-72 than that of status Ⅲ. I-72 Yang growth can be divided into three periods: 1 to 5 years old as young forest period, volume growth is extremely slow. 6 to 12 years old as fast-growing period, diameter at breast height, tree height, rapid increase in volume growth. 12 to 15 years of age as the maturity, DBH, tree height, volume growth slowed.