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利用邻近树间的株距或平均株距(在某种意义上)估计单位面积上树木株数的想法,曾吸引过许多人。他们在这方面进行了研究,提出过各种计算公式。这些公式都是事先假定树木以某种格局配置在林地上(如正方形格局、六边形格局、或随机格局等)为基础推导出来的。各种公式只有在相应的格局或近似于相应格局的林分中应用,才能得到较正确的结果。对于一般的林分,有人采用一个度量偏离随机格局的程度指标来修正从随机格局模型推导出的公式,用以计算林地内单位面积的株数。更为一般的用邻近点间的距离估计点密度的公式是由Loftsgaarden,D.和Que-senberry,C.推导出的,并且已在图象识别中得到应用。但要求条件较多,还未见用于森林调查(参看福永圭之介著《统计图形识别导论》)。《模拟样地抽样调查法》(以下称《模》文)一文的发表,引起了我国林业工作者对利用株距估计单位面积株数这一方法的兴趣。在《模》文中提出的主要不同于前人的论点
The idea of estimating the number of trees per unit area using, in some sense, the spacing between adjacent trees or the average spacing (in some sense) has attracted many people. They conducted research in this area and proposed various calculation formulas. These formulas are based on the assumption that the trees are arranged on the woodland in a certain pattern, such as a square pattern, a hexagonal pattern, or a random pattern. All kinds of formulas can only get more correct results if they are applied in the corresponding pattern or stand in the similar pattern. For a typical stand, a measure of the deviations from the stochastic pattern was used to correct the formula derived from the stochastic pattern model to calculate the number of trees per unit area in the forest. The more general formula for estimating the dot density using the distance between adjacent points is derived from Loftsgaarden, D. and Que-senberry, C., and has been used in image recognition. However, the requirements are high and have not been used for forest surveys (see Fu Yonggui’s Introduction to Statistical Graph Recognition). The publication of the “Sample Survey of Simulated Species” (hereinafter referred to as the “Mold”) aroused the interest of our forestry workers on the method of estimating the number of trees per unit area using the plant spacing. In the “model” the main points different from the previous one