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应用逐步回归方法,通过电子计算机分析南方型杨树三个无性系的树高和胸径生长量与当地21个组合气象因子的相关性。结果表明,引起生长差异的主导生态因子为年平均温度(x_1),极端最低温度(x_3),寒冷指数(x_8),日均温≥10℃积温(x_9),年降水量(x_(10))和无霜期(x_(14))。经逐步回归组建的最佳方程如下: lnY_H=4.12201-0.37742x_1-0.12085x_3+0.08949x_8+0.00096x_9 +0.00729x_(20) (R_(y12m)=0.93,F=13.57,I-69/55) lnY_H=1.56430-0.17273x_3 + 0.01334x_6-0.02141x_7 + 0.054196x_8 +0.00103x_9+0.00075x_(10)-0.00453x_(14) (R_(y12m)=0.95,F=10.19,I-72/58) 以此为依据,运用模糊数学方法,计算46个站的六个气候要素与固定样本(湖南汉寿)之间的相似程度。最后按和数值“S”的大小,结合南方型杨树的生态学特性,划出3类适宜引种区和1个不适宜引种区。
The stepwise regression method was used to analyze the correlation between tree height and DBH growth of three southern poplar clones and 21 local meteorological factors by computer. The results showed that the dominant ecological factors causing the difference in growth were annual mean temperature (x_1), extreme minimum temperature (x_3), cold index (x_8), daily average temperature ≥10 ℃ accumulated temperature (x_9), annual precipitation (x_ (10) ) And frost-free period (x_ (14)). The best regression equation is as follows: lnY_H = 4.12201-0.37742x_1-0.12085x_3 + 0.08949x_8 + 0.00096x_9 + 0.00729x_ (20) (R_ (y12m) = 0.93, F = 13.57, I_69 / 55) lnY_H = 1.56430-0.17273x_3 + 0.01334x_6-0.02141x_7 + 0.054196x_8 + 0.00103x_9 + 0.00075x_ (10) -0.00453x_ (14) (R_ (y12m) = 0.95, F = 10.19, I-72/58) Based on this, a fuzzy mathematics method was used to calculate the similarities between the six climatic elements at 46 stations and the fixed sample (Hunan Hanshou). Finally press and the value of “S” size, combined with the ecological characteristics of southern poplar, draw three kinds of suitable introduction area and an unsuitable introduction area.