Comparison of the differences in the composition of ruderal flora between conventional tram tracks and managed green tram tracks in the urban ecosystem of the city of Bratislava

Abstract Green infrastructure (GI) brings many benefits to urban ecosystems. Green tram tracks can be considered to be a part of GI. The presented study is focused on the comparison of the species’ frequency and composition between conventional tram tracks and green tram tracks in Bratislava, Slovakia, Central Europe. This comparison also provides an insight into the changes of the flora of tram tracks over time, as we compare the results of the older research with recent research on green tram tracks. The results revealed significant differences in the composition of flora between conventional tram tracks and green tram tracks. In particular, the total number of species has decreased over time, as green tram tracks host fewer spontaneously growing taxa than conventional ones. The frequency of occurrence of archaeophytes and neophytes has decreased on the strict rail yard while on the tracksides it has increased. Green tram tracks deliver positive features to ecosystems, but may also have negative aspects because they present a pool of alien, potentially invasive plants.