一、英国森林工作者研究收获量模型作如下的分类: 林分收获量模型SYM(Stand yield model)是最老的和最简单的模型,适用于同龄林或林分密度没有发生大变化的人工林。直接由树高,年龄与立地之间,或由树高、林分密度与材积之间的相关关系来预估林木蓄积。可以用临时 First, the UK forest workers harvest yield model for the following classification: Stand yield model SYM (Stand yield model) is the oldest and the simplest model for the same age forest or stand density has not changed greatly in the artificial forest. The tree stock is estimated directly from tree height, age and site, or from the correlation between tree height, stand density and volume. Can be used temporarily