An understanding of the relationship between volume increment and stand density (basal area, stand density index, etc.) is of utmost importance for properly managing stand density to achieve specific management objectives. There are two main approaches to analyse growth–density relationships. The first relates volume increment to stand density through a basic relationship, which can vary with site productivity, age, and potentially incorporates treatment effects. The second is to relate the volume increment and density of thinned experimental plots relative to that of an unthinned experimental plot on the same site. Using a dataset of 229 thinned and unthinned experimental plots of Norway spruce, a growth model is developed describing the relationship between gross or net volume increment and basal area. The models indicate that gross volume increases with increasing basal area up to 50 m² and thereafter becomes constant out to the maximum basal area. Alternatively, net volume increment was maximized at a basal area of 43 m² and decreased with further increases in basal area. However, the models indicated a wide range where net volume increment was essentially constant, varying by less than 1 m³ ha⁻¹ year⁻¹. An analysis of different thinning scenarios indicated that the relative relationship between volume increment and stand density was dynamic and changed over the course of a rotation.

中文翻译：

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挪威云杉人工林数量增加与林分密度之间的关系

了解体积增量与林分密度（基础面积，林分密度指数等）之间的关系对于正确管理林分密度以实现特定的管理目标至关重要。有两种主要方法可以分析增长－密度关系。首先是通过基本关系将体积增加与林分密度联系起来，该关系可能随场地生产力，年龄而变化，并可能包含处理效果。第二个是将变薄的实验地块的体积增量和密度与同一位置上未变薄的实验地块的体积增量和密度相关联。使用挪威云杉的229个稀疏和未稀疏实验区的数据集，开发了一个增长模型，该模型描述了总体积或净体积增量与基础面积之间的关系。²，然后变为恒定的最大基底面积。可选地，净体积增量在43 m ²的基础面积处最大，并随着基础面积的进一步增加而减小。但是，模型显示的范围很宽，净体积增量基本恒定，变化幅度小于1 m ³ ha ^-1  year ^-1。对不同间伐情景的分析表明，体积增加与林分密度之间的相对关系是动态的，并且在旋转过程中发生了变化。