正形数和胸高形数的关系及特性的讨论  

THE DISCUSSIONS OF THE RELATIONSHIP BETWEEN THE NORMAL FORM FACTOR AND THE BREAST HEIGHT FORM FACTOR AND THEIR SPECIATITIES

作　　者：李悦黎[1] 

机构地区：[1]西北林学院

出　　处：《林业科学》1995年第5期467-473,共7页Scientia Silvae Sinicae

摘　　要：胸高形数ｆ１．３是一系列正形数ｆｎ的一个子集，具有ｆｎ的特性。根据数学推导和伐倒木计算；ｆｎ的特性与相对高ｎ和形状指数ｒ、ｆ１．３与树高ｈ和ｒ的关系如下：当ｒ固定时，ｆｎ随ｎ的增大而增大，ｆ１．３随ｈ的增大而减小；当０．０３≤ｎ≤０．２２时，同一ｎ的ｆｎ、当５．８７≤ｈ≤４３．３３ｍ时，同一ｈ的ｆ１．３均可反映体型，它们的值越大则体型越饱满，亦可作为材积换算因子；当０．２２＜ｎ≤０．３７时，同一ｎ的ｆｎ、当３．５１≤ｈ＜５．８７ｍ时，同一ｈ的ｆ１．３仅作为材积换算因子比较合适；当０．３７＜ｎ＜１时，同一ｎ的ｆｎ、当１．３＜ｈ＜３．５１ｍ时，同一ｈ的ｆ１．３除一小部分（其大小团树种不同而异）可作为材积换算因子外，大部分无论是反映体型还是作为材积换算因子均不理想。The breast height form factor (f1.3) is a subset on a series of the normal form factor (fn), which has the specialities of fn. Based on the mathematic derivation and calculation of a felled tree, the relationships between the specialities of fn .and relative height (n), form index (r), and between the specialities of f1.3 and total height (h), r are as follows: 1. To the same r,fn, increases with increasing n, however f1.3 decreases as h rises. 2. When0. 03≤n≤0. 22 for fn. to the same n, 5. 87≤h≤43. 33m for f1.3 to the same h,the larger the value of fn. and f1.3, is the plumper the stem form is so that the stem form may be reflected. fn and f1.3 are used as conversion factors for volume; When 0. 22<n≤0. 37 the same n for fn, 3. 51≤h<5. 87m, thesame h for f1.3 only apply to conversion factors for volume; When 0. 37<n<1for jfn, or 1. 3<h<3. 51m for f1.3, a fraction of fn. or f1.3 (it is various in different tree species) is used as a conversion factor for volume, but most ofthem are not ideal for applying to the reflection of stem form or conversion factors for volume.

关 键 词：正形数 胸高形数 干形 测树学 

分 类 号：S758[农业科学—森林经理学]