中文摘要：

选用7个导向曲线模型对标准地内南方型杨树平均优势木的树干解析资料进行拟合。经筛选，确定Richards函数作为最佳导向曲线模型。在分析杨树高生长在各指数级间的多形性特征的基础上，建立了多形地位指数模型，并编制了多形地位指数表。经检验表明，所得多形地位指数具有较好的精度，可适用于江苏杨树林分的立地评价、生产力测定与预估。

英文摘要：

The best guiding curves were selected from seven models with data of stem analysis. Based on analyzing the characters of tree height growth in each index, the standard site index function with multiform and the index table were formed. The results showed that the multiform site index table could be used to guide the management of real forest in Jiangsu province. Although the object tree of this paper is black poplar , the site index table could be used as a reference for other kinds of poplar in Jiangsu province. The study could offer the quality basis for the management of the growing artificial forest of poplar in Jiangsu province.