In the tundra, woody plants are dispersing towards higher latitudes and altitudes due to increasingly favourable climatic conditions. The coverage and height of woody plants are increasing, which may influence the soils of the tundra ecosystem. Here, we use structural equation modelling to analyse 171 study plots and to examine if the coverage and height of woody plants affect the growing-season topsoil moisture and temperature (< 10 cm) as well as soil organic carbon stocks (< 80 cm). In our study setting, we consider the hierarchy of the ecosystem by controlling for other factors, such as topography, wintertime snow depth and the overall plant coverage that potentially influence woody plants and soil properties in this dwarf shrub-dominated landscape in northern Fennoscandia. We found strong links from topography to both vegetation and soil. Further, we found that woody plants influence multiple soil properties: the dominance of woody plants inversely correlated with soil moisture, soil temperature, and soil organic carbon stocks (standardised regression coefficients = − 0.39; − 0.22; − 0.34, respectively), even when controlling for other landscape features. Our results indicate that the dominance of dwarf shrubs may lead to soils that are drier, colder, and contain less organic carbon. Thus, there are multiple mechanisms through which woody plants may influence tundra soils.

在苔原，由于气候条件日益有利，木本植物正向较高的纬度和海拔扩散。木本植物的覆盖率和高度在增加，这可能会影响苔原生态系统的土壤。在这里，我们使用结构方程模型来分析171个研究样地，并检查木本植物的覆盖率和高度是否影响生长季节的表层土壤水分和温度（<10厘米）以及土壤有机碳储量（<80厘米）。在我们的研究环境中，我们通过控制其他因素来考虑生态系统的层次结构，例如地形，冬季降雪深度以及整个植物覆盖范围，这些因素可能会影响芬诺斯堪迪亚北部这个矮灌木丛景观中的木本植物和土壤特性。我们发现从地形到植被和土壤都有很强的联系。此外，我们发现木本植物会影响多种土壤特性：木本植物的优势与土壤水分，土壤温度和土壤有机碳储量成反比（标准回归系数分别为− 0.39; − 0.22; − 0.34），即使当控制其他景观特征。我们的结果表明，矮灌木丛的优势可能导致土壤更干燥，更冷且有机碳含量更低。因此，木本植物可以通过多种机制影响苔原土壤。22; −分别为0.34），即使在控制其他景观特征时也是如此。我们的结果表明，矮灌木丛的优势可能导致土壤更干燥，更冷且有机碳含量更低。因此，木本植物可以通过多种机制影响苔原土壤。22; −分别为0.34），即使在控制其他景观特征时也是如此。我们的结果表明，矮灌木丛的优势可能导致土壤更干燥，更冷且有机碳含量更低。因此，木本植物可以通过多种机制影响苔原土壤。