This study focused on tree mortality in spruce-dominated stands managed using the single-tree selection method in southern Finland. Together with regeneration and tree growth, mortality is one of the basic elements of the stand structure and dynamics in selection stands. The study was based on data acquired from a set of 20 permanent experimental plots monitored with repeated measurements for 20 years. The average mortality in the number of stems ( N ) was 4.45 trees ha −1 a −1 , in basal area ( G ) 0.07 m 2 ha −1 a −1 , and in stemwood volume ( V ) 0.56 m 3 ha −1 a −1 . In relative terms it was 0.50% of N , 0.30% of G and 0.27% of V , respectively. Wind and snow were the most common causes of mortality, while deaths by biotic causes (mammals, insects, pathogens) were extremely rare. Some 6–10% of the total loss in the number of stems and volume was attributable to the loss or removal of trees that sustained serious damage in harvesting. Most of the mortality occurred in the smallest diameter classes of up to 20 cm. Such a high mortality among small trees can have an adverse influence on the sustainability of selection structures if not successfully checked in harvesting and management.

中文翻译：

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芬兰南部不均匀树龄的挪威云杉林动态和管理中的树木死亡率

这项研究的重点是在芬兰南部使用单树选择方法管理的以云杉为主的林分中的树木死亡率。与再生和树木生长一起，死亡率是选择林地林分结构和动态的基本要素之一。该研究基于从一组 20 个永久实验地块中获得的数据，这些地块通过 20 年的重复测量进行监测。茎数（N）的平均死亡率为4.45棵树 ha -1 a -1 ，基部面积（ G ）为0.07 m 2 ha -1 a -1 ，茎材体积（ V ）为0.56 m 3 ha -1一 -1 。相对而言，它分别是 N 的 0.50%、G 的 0.30% 和 V 的 0.27%。风和雪是最常见的死亡原因，而生物原因（哺乳动物、昆虫、病原体）造成的死亡极为罕见。茎干数量和体积总损失的 6-10% 可归因于在采伐过程中遭受严重损害的树木的损失或移除。大多数死亡发生在最大 20 厘米的最小直径等级中。如果在收获和管理中没有成功检查，小树的如此高的死亡率会对选择结构的可持续性产生不利影响。