ABSTRACT Effects of species composition on the growth of Norway spruce – Scots pine mixtures had earlier only been studied in unthinned stands. Individual-tree thinning responses in mixed stands were studied to test for the presence of mixture effects in more open stands. Data were collected from 28 temporary sample plots with varying species proportions in 7 thinned spruce-pine stands on medium fertile sites in Eastern Norway. Effects of neighborhood species composition on the individual-tree basal area growth before and after thinning were tested for to detect mixture effects. Spatially-explicit competition indices were used to describe release during thinning in the growth models. Neighborhood species composition only had a minor effect on the thinning response of spruce. Growth before thinning of both species and the thinning response of pine were not affected by species composition. Release had a strong effect on the thinning response of both species. Low density of the studied stands and the more dominant position of pine compared to spruce in mixture, even after the thinning from below, explained some of the observed effects.

中文翻译：

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挪威云杉和苏格兰松混交林单株间伐反应

摘要 物种组成对挪威云杉生长的影响 - 苏格兰松混合物早些时候仅在未稀释的林分中进行过研究。研究了混交林中的个体树木间伐反应，以测试在更开放的林分中混合效应的存在。数据是从 28 个临时样本地块中收集的，这些样本地块在挪威东部中等肥沃地区的 7 个稀疏云杉林中具有不同的物种比例。测试了邻域物种组成对间伐前后单棵树基面积生长的影响，以检测混合效应。空间明确的竞争指数用于描述生长模型中细化期间的释放。邻域物种组成对云杉的变薄反应只有很小的影响。两种树种间伐前的生长和松树的间伐反应不受物种组成的影响。释放对两种物种的变薄反应都有很强的影响。与云杉相比，研究林的低密度和松树在混合物中的主导地位，即使在从下面变薄之后，也解释了一些观察到的影响。