MIREN dataset
Vegetation composition along mountain roads has been recorded by the MIREN network since 2007 across 18 mountain regions on 5 continents (Haider et al. 2022). For the current study we focused on eleven mountain regions, as the remaining seven did not offer plant cover data both along the roadside and in the neighboring natural vegetation at the time of analyses. These regions cover environmental gradients with elevations ranging from 0 to 4000 m above sea level (m a.s.l) and mean annual soil temperatures ranging from -5.8 to 27.9 °C. The studied mountain regions were: the Argentine Andes in Argentina; the Caucasus Mountains in Armenia; the Australian Alps in Australia; the Chilean Andes in Chile; the Changbai Mountains in China; the Himalayas in India; the Northern Scandes in Norway; Mount Teide in the Canary Islands (Spain); the European Alps in Switzerland; the Rocky Mountains in Montana (USA); the Blue Mountains in Oregon (USA). In each of these 11 regions, three roads which covered large elevational gradients, were accessible by the local research teams, were asphalted or covered by gravel, and were actively used by motorized traffic were selected. The surveyed road edges were typically highly disturbed, with shallow soils and often altered surface material due to the road construction, and reduced vegetation cover (Müllerová et al. 2011), see Figure S1 for examples. All surveys were first executed between 2007 and 2018, depending on the region. Surveys are repeated every 5 years, resulting in currently one (two regions), two (five regions) or three (four regions) repeated surveys depending on the region.