正形数系列变化规律的初步研究

A PRELIMINARY STUDY ON CHANGE LAW OF A SERIES OF NORMAL FORM FACTOR

用陕南、陕北林区16个油松标准地材料,计算各相对高处(0.0,0.02,0.04.0.06,0.08,0.1,0.15,0.2,0.25,0.3,0.4,0.5,0.6,0.7,0.8,0.9)的林分正形数系列样本平均值、标准差和变异系数,初步得出正形数系列在林分内和林分间的变化规律。林分间带皮正形数系列中稳定的是f_(0.25H),去皮正形数系列中则是 f_(0.30H),林分因子对它们均无显著影响。为便于(?)_(0.5H)和(?)_(0.3H)在实际中应用,给出了两个相对高处直径与胸径之间的回归关系式。

Sample means,standard deviations and coefficients of variations of a series of stand normal form factor based on diameters at each height relative to total height(0.0,0.02,0.04,0.06,0.08,0.1,0.15,0.2,0.25, 0.3,0.4,0.5,0.6,0.7,0.8,0.9)were computed for 16 standard plots of Pinus tabulaeformis Carr in Shaanxi forest region.The change law of a series of normal form factor within stand and among stands were preliminary obs- tained,(?)_(0.25H(0.b))was stable in over-bark,(?)_(0.3H(i.b))in inside-bark of a series of normal form factor separately.They were not remarkable effected by stand factors.For putting (?)_(0.25(0.b))and (?)_(0.3H(i.(?)))in volume estimate of Pinus tabulaeformis Carr stands,two regression equations between diameters at heights relative to total height and diameter at breast height were given.