中文摘要：

以黄土区的3种主要幼树油松、元宝枫和侧柏为研究对象，研究树木高的年生长规律。用Logistic方程对树木的高生长进行拟合，划分3种幼树的生长时期，为生长前期、速生期和生长后期。应用灰色关联度分析关键因子的方法，准确判断出关键气候因子对树高生长的影响程度，并显示出因子间的相对重要性。气候因子影响程度排序为相对湿度〉空气温度〉光照强度。

英文摘要：

The principal goal of this study was to analysize the height growth of three kinds of drought-resistance tree species,namelg Pinus tabulaeformis, Acer truncatum and Platycladus orientalis on the Loess Plateau. Based on the Logistic equation, annual growth of seedlings could be divided into three growth stages, early-growth stage, fast-growth stage and late-growth stage. According to the gray correlation analysis three kinds of key climate factors influencing seedling growth including air temperature, relative humidity and illuminating intensity were found. The results showed that the effect degree of every climate factor exhibited the following order： relative humidity〉air temperature 〉 illuminating intensity