墨西哥瓦瓦州州东北部橡树商品材材积核算系统

比较了Kozak（1988），Bi（2000）和Fang等（2000）的削度模型，形成了橡树商品材材积核算系统。在所研究的不同树龄、不同密度的松树．橡树混交林内，采集了298株橡树削度数据。结果表明，Fang等（2000）建立的可兼容分段模型可以很好地描述实验数据，可用于估测树木在指定树高的直径、树高一指定直径比、商品材材积量和总体积。本研究建立的公式可作为该研究区内森林调查的基本工具，简便、易于操作。统计分析结果表明，尽管本研究所建立的公式具有局地适应性，但仍可应用于其他区域。图4表4参53。

A system for calculating the merchantable volume of oak trees in the northwest of the state of Chihuahua, Mexico

The taper functions of Kozak (1988), Bi (2000) and Fang et al. (2000) were comparatively analyzed in the present paper to develop a system for calculating the merchantable volume of oaks in the northwestern region of the state of Chihuahua (Mexico). Taper data corresponding to 298 trees were collected in mixed and uneven-aged pine-oak stands located throughout the study area, and covering the existing range of ages, stand densities and sites. Results show that the compatible segmented model developed by Fang et al. (2000) best described the experimental data and is therefore recommended for estimating tree diameter at a specific height, height to a specific diameter, merchantable volume, and total volume for oaks. The equation developed in this study is a fundamental tool for use in forest surveys in the study region and is simple enough to ensure its operational implementation. The results of the statistical analysis show that the equation can be recommended for other regions, although some local adaptations may be needed.