中文摘要：

以滇池流域5种主要人工林（柏木林、桉树林、银荆林、华山松林和云南松林）为研究对象，通过样方调查，分析群落结构特征，并构建了由植被、枯落物、土壤、地形4个因子组成的水土保持功能评价指标体系，在对所选取的8个指标进行标准化、确定权重的基础上，运用理想点综合评价方法评价其水土保持效益。结果表明：各人工林群落优势种重要值（IV）分别为：柏木89．69、桉树74．27、银荆96．35、华山松84．93、云南松65．65。桉树林、云南松林分层物种多样性表现为灌木层〉草本层〉乔木层，柏木林、银荆林和华山松林分层物种多样性表现为草本层〉灌木层〉乔木层。云南松林的群落总体物种多样性最高，华山松林和桉树林次之，柏木林较低，银荆林最低。各人工林水土保持效益依次为：云南松林〉华山松林〉柏木林〉桉树林〉银荆林，表明乡土树种作为水土保持林具有一定的优势。不同人工林在物种多样性及水土保持效益等方面存在明显差异，应根据立地条件选择适宜的造林树种及搭配方式，提升其生态功能，控制水土流失。

英文摘要：

A plot investigation was made on the community structure of five main man-made for ests （Cupressus duclouxiaua, Eucalyptus globules, Acacia dealbara, Piuus armaudii, and P. yunnanensis plantations） in the Dianehi Lake watershed of Yunnan Province, Southwest China. A functional evaluation index system of soil and water conservation, which consisted of four fac tors （vegetation, litter, soil, and landform） , was established. Based on the normalization and weighting of 8 selected indices, and using ideal point comprehensive evaluation method, the soil and water conservation benefits of the plantations were evaluated. The importance value （IV） of the dominant species in the five plantations was 89.69 for C. duclouxiana, 74.27 for E. globu lus, 96.35 for A. dealbara, 84.93 for P. armandii, and 65.65 for P. yunuanensis. Among the five plantations, the species diversity in different layers of E. globules and P. yunnanensis plan- tations was shrub layer 〉 herb layer 〉 tree layer, and that in different layers of C. duclouxiana, A. dealbara, and P. arrnandii plantations was herb layer 〉 shrub layer 〉 tree layer. P. yun- nauensis plantation had the highest overall community diversity, followed by P. arrnaudii, E. globules, C. louxiana, and A. dealbara plantation. The soil and water conservation benefits of the plantations were P. yunnauensis 〉 P. armaudii 〉 C. duclouxiana 〉 E. globulus 〉 A. deal bara, which revealed that native tree species had more advantages in soil and water t~on.qervatlan.There existed obvious differences in the species diversity and soil and water conservation benefits between different plantations, and thus, it would be needed to select suitable tree species and their reasonable combinations for the local sites to improve their ecosystem functioning and to con trol soil and water loss.