Large-scale replacements of native birch with spruce have been carried out in Western Norway for economic reasons. This tree species shift potentially affects biotic components such as the eucaryome, consisting of microscopic animals (Metazoa), protists and fungi, which are key players in the functioning of forest ecosystem. The impact on the belowground eukaryome and its interactions with vegetation and soil properties is not well assessed. We examined the impact of replacing native birch with Norway spruce plantations on the eukaryome of the boreal forest floor in Western Norway using 18S rDNA metabarcoding. The tree species shift from birch to spruce had significant impacts on the eukaryome at both taxonomic (Metazoa) and functional categories (phagotrophs, phototrophs, parasites and osmotrophs). The distinct differences in eukaryome communities were related to changes in understorey vegetation biomass and soil chemistry following the tree species shift. This had a negative effect on eukaryome richness, particularly affecting phagotrophs and parasites, while the opposite was observed for osmotroph richness. Our results indicated that the spruce plantations altered the eukaryome communities and their food-web patterns compared to what was found in the native birch forest soil. This information should be taken into consideration in forest management planning.

中文翻译：

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从桦树到云杉的树种更替影响北方森林土壤中的真核细胞

出于经济原因，挪威西部已大规模用云杉替代本地桦木。这种树种转变可能会影响生物成分，例如由微观动物（后生动物）、原生生物和真菌组成的真核生物，它们是森林生态系统功能的关键参与者。对地下真核细胞的影响及其与植被和土壤特性的相互作用尚未得到很好的评估。我们使用 18S rDNA 元条形码研究了用挪威云杉种植园替代原生桦树对挪威西部北方森林地面真核细胞的影响。树种从桦树到云杉的转变对真核生物的分类（后生动物）和功能类别（吞噬生物、光养生物、寄生虫和渗透营养生物）产生了重大影响。真核群落的明显差异与树种转变后林下植被生物量和土壤化学的变化有关。这对真核生物丰富度产生负面影响，特别是影响噬菌体和寄生虫，而渗透营养体丰富度则相反。我们的结果表明，与原生桦树林土壤中发现的情况相比，云杉种植园改变了真核群落及其食物网模式。在森林管理规划中应考虑这一信息。