Vegetation data
Here we combined 1) historical vegetation data (1903, 1913, and 1983) from along the Rallarvägen with 2) a new resurvey of the Rallarvägen in 2021 and 3) an additional survey performed in 2016 by the Mountain Invasion Research Network (MIREN; Haider et al. 2022) along two hiking trails leading from the Rallarvägen into the mountains: the Björkliden and Låktatjåkka trail (Wedegärtner et al. 2022).
The vegetation surveys by Sylvén in 1903 and 1913 focused on the establishment of ruderal species after the railroad construction (Sylvén, 1904 and 1915-17). During its construction, the surrounding vegetation was destroyed, leaving bare soil whereupon construction materials were transported and assembled. Near the end of railroad construction in 1903, Sylvén’s observation of an influx of ruderal species along the Rallarvägen, most notably near the settlements of Abisko, Björkliden, and Vassijaure where construction efforts led to various dump piles of horse manure and rubbish, compelled him to survey the vegetation (Sylvén, 1904). Upon his return to the Abisko region in 1913, Sylvén observed remarkable changes in human influences on vegetation composition. Houses had greatly expanded in numbers and size, often with lawns and gardens, around the Abisko Tourist Station and the train stations. In Riksgränsen, where no outstanding developments in the vegetation had been observed in 1903, large areas now had to be considered ruderal-dominated vegetation. Only in Vassijaure, the vegetation structure had remained in the same state as in 1903. These new observations led him to perform a follow-up survey, this time including Riksgränsen (Sylvén 1915-17). Both publications did not specify their survey methods.
Expecting possible changes in the vegetation composition due to the building of the E10 in 1982, Lewejohann and Lorenzen (1983) re-surveyed the trail following an earlier publication from the 1950s (Asplund, 1950). They documented all vascular plant species in 20 areas of unspecified size in the broader Abisko region, using Flora Europaea vol. I (Tutin et al. 1980). We include the following surveyed areas intersecting the Rallarvägen: Björkliden, Kopparåsen, Låktatjåkka, Vassijaure, and Riksgränsen. From this publication, the Abisko area, although including the Abisko settlement and train station, was not included in our investigation as the covered survey area lay outside our area of interest: from Abiskojåkka to Tjuonavaggejåkka – about 25 km distance from the Rallarvägen – which includes other hiking trails and encompasses the Abisko National Park.