短周期桉树人工林的生长效应及生长过程划分

调查测定了雷州半岛短轮伐期尾叶桉、尾叶桉无性系U6、刚果12号桉无性系W5、巨尾桉无性系EC14个桉树品系林分各生长因子的生长差异性,研究分析了4个桉树品系林分速生性及生长过程,并应用系统聚类分析法对各品系的生长阶段进行了划分。结果表明:各品系之间的林分生长差异显著,树高、胸径、单株材积及蓄积量生长大小排序为EC1>U6>W5>尾叶桉,6a生EC1,U6,W5,尾叶桉单位面积蓄积量分别达243.8557,238.4578,172.7508,130.9949m3/hm2;EC1,U6,W5与尾叶桉的数量成熟龄分别在4.9,4.2,3.0和4.2a;短周期桉树人工林的林分生长过程可划分为快速生长期、一般生长期和缓慢生长期3个阶段,不同品系到达各生长期的林龄不同。林分生长期的划分可为桉树人工林分阶段科学营林提供理论依据。

GROWTH EFFECTS AND GROWING PROCESS OF SHORT ROTATION EUCALYPTUS PLANTATIONS

The growth factors of the stands of 4 Eucalyptus clones (U 6, W 5, EC 1 and Eucalyptus urophylla) of short rotation were investigated. The data were treated with cluster analysis. Marked differences were observed among the genotypes studied in tree height, DBH, single tree volume and growing stock, being in the order of EC 1 > U 6 > W 5 > E. urophylla. The growing stock of 6-year-old U 6, W 5, EC 1 and E. urophylla was 243.8557, 238.4578, 172.7508 and 130.9949 m3/hm2, respectively. Their number mature age was 4.9, 4.2, 3.0 and 4.2 years, respectively. The growth process of the short rotation plantation was divided into 3 stages: fast growth stage, average growth stage and slow growth stage and the stand age for different clones to reach their different stages was also different.