雷州半岛桉树生物质能源林生长的密度效应研究

以雷州半岛2年生桉树无性系DH201(Eucalyptus grandis  E. tereticornis)能源林为研究对象，对6种不同密度配置下的林分生长量、生物量以及热值等进行了分析，探讨密度对桉树生物质能源林生长的影响。结果表明，密度对桉树胸径和树高生长量影响极显著，在林分不同发育阶段对林分蓄积量的影响不同；单株生物量随密度增大而减小。1年生的林分蓄积量和生物量均以密度为10000 ind. hm-2的最大，分别为52.57 m3 hm-2和32.02 t hm-2；2年生的林分蓄积量和生物量均以密度为2500 ind. hm-2的最大，分别为75.85 m3 hm-2和45.66 t hm-2；密度对热值及灰分含量的影响不显著。因此，1年生和2年生的桉树能源林的最优密度分别为10000 ind. hm-2和2500 ind. hm-2。

Effects of Density on Growth of Eucalypt Bio-energy Plantations in Leizhou Peninsula

The growth, biomass and calorific values of 2-year-old Eucalyptus hybrid clone DH201 (Eucalyptus grandis  E. tereticornis) as an energy forest in Leizhou Peninsula were studied under different densities. The results showed that the effects of density on diameter at breast height (DBH) and height (HT) were significant, and which stand volumes were different at different development stages. The individual biomass was decreased with increment of density. The stand volume and biomass in 1-year-old were biggest at density of 10000 ind. hm-2 for 52.57 m3 hm-2 and 32.02 t hm-2, respectively, and which those in 2-year-old were biggest at 2500 ind. hm-2 for 75.85 m3 hm-2 and 45.66 t hm-2, respectively. The effects of densities on wood calorific values and ash contents were not different significantly. It suggested that the optimal densities for bio-engery plantations at 1- and 2-year-old were 10000 and 2500 ind. hm-2, respectively.