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山杨,广泛分布于小兴安岭和张广才岭林区,为我省速生乡土树种,笔者对五营林业局山杨林分的生长,主要病害及其经营措施作如下探讨。 1.山杨林分生长特点 标准地调查材料表明,山杨林分生长有以下几个特点。 1.幼林高径生长快,15年生的山杨林分,平均高17米左右,高生长高峰比径生长高峰大约提早12年,树高连年生长量高峰出现在15年,23年左右接近平均生长量,直径生长量高峰在25年,32年以后低于平均生长量。 2.林分蓄积生长量,中龄林生长量占毛生长量的1/2左右,近熟龄往后占1/4左右。中龄
Populus euphratica, widely distributed in the Xiaoxing’anling and Zhangguangcailing forest area, for the fast-growing native tree species in our province, the author of Populus euphratica forest growth, major diseases and management measures for the following discussion. 1. Poplar growth characteristics of a standard survey of the material shows that Populus alba stand growth has the following characteristics. 1. Rapid growth of young forest height, 15-year-old poplar stand, with an average height of about 17 meters, the height growth peak than the diameter growth of about 12 years earlier, the annual growth of tree height peak appeared in 15 years, near 23 years average Growth, diameter growth peaked at 25 years, 32 years later than the average growth. 2. Stand volume growth, middle-aged forest growth accounts for about 1/2 of the amount of hair growth, nearly mature age accounted for about 1/4. Middle age