中文摘要：

以元谋干热河谷20年生赤桉纯林、新银合欢纯林以及赤桉×新银合欢混交林为研究对象,对其林木单株进行树干解析,研究不同造林模式下2个树种的生长特性。结果表明：1）新银合欢的混植促进了赤桉的生长。2）赤桉、新银合欢树高平均生长量和连年生长量总体均呈下降趋势,胸径的平均生长量和连年生长量在5～10年呈下降趋势,在10～15年期间呈上升趋势（除混交林内赤桉）,之后又下降。3）根据Logistic生长曲线的变化率,可将赤桉、新银合欢5～10年划分为生长初期,10～25年为生长快速期,之后为生长稳定期;经模型预测：赤桉纯林在23年时达到数量成熟,赤桉混交林在25年时达到数量成熟,纯林以及混交林内新银合欢均在24年时达到数量成熟。针对赤桉、新银合欢生长特点,提出在生长初期和生长快速期增加水肥供给并进行适当疏伐等措施以促进林木生长。

英文摘要：

The growth characteristics of 20-year-old Eucalyptus camaldulensis Dehuh and Leucaena leucocephala （Lam.） Dewit in the monocultures and their mixed-species plantations in the Yuanmou Dry-hot Valley of southwestern China were investigated by a stem analysis. The results showed that all the DBH, height and volume of timber of E. camaldulensis in the mixed-species plantations grew faster than those in monoculture. The average increment and current annual increment of height of both the species declined. DBH of the two species declined during 5-10 years but increased during 10-15 years beside E. camaldulensis in the mixed-species plantations, and then all decreased. The changing rates of Logistic growth curve could scale 5-10, 10-25,and 〉 25 years as the early growth period, rapid growth period and stationary growth stage, respectively. Based on this model, E. camaldulensis in the monoculture and mixed-species plantations will obtain the quantitative maturity at the 23 years and 25 years after the trees were planted, respectively, and both the 24 years for L. leucocephala in the monocuhure and mixed- species plantations. Some management measures such as thinning and increasing water and fertilizer supply in the early and rapid growth period were recommended based on this study.