【摘要】 用数学模型描述不同产地的河北杨（Populus hopeiensis）苗期生长过程,以 Logi-stic 曲线模拟其年生长特点,估计其日生长量的最大点,以确定速生期。并对不同产地的生长型进行分析。用正交多项式逼近不同产地的增长曲线,对组成二次抛物线的正交多项式的系数β₀、β₁、β₂检验结果表明:苗高增长曲线差异是显著的,地径增长曲线在各个系数上存在着差异,而在整体上却是不显著的。更多还原

【Abstract】 The growth processes during nursery of Populus hopeiensis He et Chow from different growing places were described by mathematical model. The properties of annual growth from different growing places were stimul- ated by Logistic curve,and the maximum points of growth rate per day and the lengths of fast-growing stage were also estimated.On this basis the gr- owth patterns of different places were analysed.The growth curves of diffe- rent places were approached by cross cut polynomiad and coefficients β₀, β₁,β₂ which made up the growth curves were tested.The results indicated that the differences of the growth curves of height were significant in whole and each coefficients,these of diameter significant in each coefficients.更多还原