尾巨桉人工林能量动态分析

Analysis on the Energy Dynamics of Eucalyptus urophylla×E.grandis Plantations

采用空间代替时间的方法,对广西高峰林场界牌分场1～6年生的尾巨桉人工林各组分（树叶、树枝、干皮、干材和树根）的能量动态进行了研究.结果表明,不同林龄尾巨桉人工林各组分的能量分配均是干材（55.47％～70.36％）＞树根（11.70％～22.53％）＞干皮（8.62％～11.40％）＞树枝（6.15％ ～7.97％）＞树叶（1.74％～2.63％）.尾巨桉人工林各组分的能量均随林龄的增大而逐步增加,其中干材的能量随着林龄增加而明显增大.林分各组分的能量增长率都在5年生时达到最小,若只从能量的角度考虑,尾巨桉人工林收获周期应为5a.

By the method of space-for-time substitution, the various components （leaf, branch, bark, stem and root） energy dynamics of Eu- calyptus urophylla ~ E. grandis plantations aged 1 - 6 years in Jiepai Branch of Gaofeng Forest Farm, Guangxi Province were investigated. The results showed the order of the energy distribution of various components in the studied plantations were stem （55.47% - 70.36% ） 〉 root （11.70% -22.53 % ） 〉 bark （8, 62% - 11.40% ） 〉 branch （6.15% -7.97% ） 〉 leaf（ 1.74% -2.63% ）. The energy of various compo- nents increased as the stand ages increased, while the stem energy was the highest among five components of different stand ages. The energy increment rate of various components was the lowest at the stand age 5, which means that it is best to harvest E. urophylla ~ E. grandis planta- tions at age 5 when their standing energy are considered.