Dataset associated with: Increasing presence of non-native plants and arbuscular mycorrhizal fungi during a 10-year survey along subarctic mountains roads

Roads in cold climate mountains are known to be important vectors in the introduction and spread of non-native plant species. In the same context, mycorrhizal fungi communities are also altered by roads with a known positive effect on arbuscular mycorrhizal (AM) fungi diversity and abundance in disturbed roadsides. However, to what degree these two effects of roads are intertwined and how they are evolving over time is not well understood. In this study we conducted repeated surveys of non-native plants and AM fungi between 2012 and 2022, in the northern Scandes mountains to investigate temporal changes and interactions between roads, mycorrhizal fungi, and non-native plants. We found that the upward spread of non-native plants and lateral spread away from the roadside into the natural vegetation were so far extremely limited, with only two out of 23 non-native species showing an increase in their upper elevational limit. However, non-native plant species cover did increase over the ten year period, especially at lower elevations, and non-native richness increased from 17 to 23 species. Likewise, we saw an increase in AM fungal abundance over the last four years along the roadsides at lower elevations. Furthermore, our results suggest that increases in non-native species are unlikely to be the driving cause of the observed increase in AM fungal abundance, as AM fungi colonization varied independently of non-native species cover dynamics. This is the associated datasets and R-code. Check out the ReadMe.txt-file for information on the different files.寒冷气候山地中的道路，向来被认为是非本土植物物种（non-native plant species）引入与扩散的重要媒介。同理，道路也会改变菌根真菌（mycorrhizal fungi）群落结构，且已有研究表明，其对受干扰路边的丛枝菌根（arbuscular mycorrhizal, AM）真菌的多样性与丰度具有正向影响。然而，道路的这两类影响之间的关联程度，以及二者随时间的演化规律，目前仍未得到充分阐明。本研究于2012至2022年间，在北斯堪的纳维亚山地针对非本土植物与丛枝菌根真菌开展重复调查，以探究道路、菌根真菌与非本土植物之间的相互作用，以及三者随时间的变化规律。研究结果显示，截至目前，非本土植物的向上扩散以及从路边向自然植被的侧向扩散均极为有限：23种非本土植物中仅2种的海拔上限出现上升。不过，在十年研究周期内，非本土植物的盖度有所提升，尤其在低海拔区域；同时非本土植物的物种丰富度从17种增至23种。同样，在过去四年间，低海拔区域的路边丛枝菌根真菌的丰度亦有所增加。此外，本研究结果表明，非本土植物物种的增加并非观测到的丛枝菌根真菌丰度提升的驱动因素，因为丛枝菌根真菌的定殖水平与非本土植物盖度的动态变化相互独立。本研究附带相关数据集与R语言代码，各类文件的详细说明请参阅ReadMe.txt文档。