尾叶桉短轮伐期经营林分生长研究

对尾叶桉短轮伐期经营林设置好、中、差三类立地调查林分生长及进行树干解析，以研究尾叶桉的生长情况。结果表明：立木平均胸径、平均树高及平均单株材积在三类立地的生长差异均显著，好立地的平均单株材积达到0．2410m^3，分别是中等、差立地的1．56倍和2．52倍。三类立地解析木胸径、树高、单株材积总生长量，均随着年龄的增加而增加，6年生胸径总生长量好立地达到19．95cm，分别是中等、差立地的1．24倍和1．50倍；树高总生长量6年生达到22．80m，分别是中等、差立地的1．17倍和1．27倍；单株材积总生长量达到0．3025m^3，分别是中等、差立地的1．82倍和2．85倍。3个指标的平均年生长量和连年生长量均有随着年龄增加而下降的趋势。了解短轮伐期林分林木生长的变化趋势，才能合理经营、维护地力和持续经营。

A Study on the Growth of Short Rotation Stands Management for Eucalyptus urophylla

In this paper, the dynamic change of tree height growth, DBH growth and volume growth in the stands of Eucalyptus urophylla had been researched in different sites. The results indicated that different sites could be merged in 3 types (good, medium, bad), (1) The height,DBH,the volume growth per stem of three different sites had a same effect, the effect is order of site G (good)>M (medium) >B (bad). After 6 years growth, the average highest of volume growth per stem is 0.2410 m 3 on G site including all stem, is 1.56 times that of on M site and 2.52 times that of on B site. (2) The highest of height is 22.80 m of the research stem on G site, is 1.17 times that of on M site and 1.27 times that of on B site. The highest of DBH is 19.95 cm of the research stem on G site, is 1.24 times that of on M site and 1.50 times that of on B site. the highest of volume growth per stem is 0.3025 m 3, is 1.82 times that of on M site and 2.85 times that of on B site. (3) The height,DBH,the volume growth per stem in different sites had a same conclusion, wihch is in inversely proportion to age of stands.(4) To short rotation stands, we must avoid destroying the site quality.