林木株距按正方形分布格局的森林密度抽样技术

Forest Density Sampling Techniques for Tree Plants Spacing in a Square Distribution Pattern

在株距相等正方形排列模拟林中,选任意一株为0号木,以0号木至最近第一株木的距离(如距离相等视为同株)为基准株距以"0-1"表示,并分别被0号木至最近1-10株的距离除,得出10个株距比值用Kj表示(其中K的下标:j=1、2、3……10株)。经过验证r估测值推算出单位面积的林分株数密度,接近实测林分的真值并优越于国内外一些相拟的估测方法,比常规有边样地具有更满意的效果。经X^2检验,ri的总体分布有可能是遵从参数a、b正态分布。

In the square-arranged simulated tree stands with equal plant spacing, any one tree is selected as No. 0 wood, and the distance from No. 0 wood to the nearest first tree(if equal distance is considered as the same plant) as the reference, the plant spacing is represented by "0-1". Divided by the distance from No. 0 wood to the nearest 1-10 strains, the ratio of ten plant spacing was expressed by Kj(wherein the subscript of K: j=1, 2, 3...10).After verifying the r-estimate value, the number density per unit area of the stand is estimated. It is close to the true value of the actual stand and superior to some similar domestic and foreign estimation methods. It has a more satisfactory effect than the conventional bordered plot. The X^2 test shows that the overall distribution of ri may be in accordance with the normal distribution of parameters a and b.