苏柳932等5个柳树优良无性系幼林生长及干形的初步研究

Preliminary study of the young forest growth and trunk shape of five willow clones

为进一步了解柳树优良无性系的生长特点,为无性系的合理利用提供依据,对苏柳932,799,795,797和172等5个柳树优良无性系2年生幼林的树高、胸径、材积等生长指标以及生物量和形率进行了测定分析。结果表明,苏柳5个无性系的胸径平均值为4.28 cm,其中苏柳172的平均胸径最大(4.71 cm);树高平均值为6.97 m,其中苏柳795平均树高最高(7.75 m)。苏柳795的形率q0.5、q0.7值分别为0.68,0.44,是各无性系中形率的最高值,主干生物量占单株地上部分总生物量的比例最高(76.02%),出材率高,是优良的用材林树种;而苏柳932的总生物量最高,为12.35 kg/株,枝量、叶量占总生物量的比例最大,为42.0%,14.4%,属于防风防浪和生物能源林的造林良种。

To make good use of willow clones, the growth characteristics of five 2 - year - old willow clones （ Suliu 172,795, 799,797 and 932） were investigated in such growth parameters as plant height, diameter at breast height, stem volume, trunk biomass and form quotient. We found that different willow clones showed remarkable differences in growth. The mean values of diameter at breast height, plant height of 5 willow clones were 4.28 cm and 6.97 in respectively. Among them, Suliu 172 had the biggest diameter at breast height （4.71 cm） while Suliu 795 had the biggest tree height of （7.75 m）. Moreover, form quotient values （ %.5, %7 ） of Suliu 795 were O. 68, 0.44, higher than other willow clones. The trunk bio- mass accounted for 76.02% of the total above ground biomass, indicating that it was an ideal tree species for using as tim- ber production forest. Suliu 932 had a high total biomass （ 12.35 kg per tree） , but with high proportion of branches and leaves, indicating that it was an ideal tree species for using as biological energy forest.