Impact of invasive Aster lanceolatus populations on soil and flora in urban sites

摘要

Invasive plants are one of the major treat to local communities and ecosystems in urban habitats. Aster lanceolatus Wild. is one of the most spreading invasive plant species in Serbia and to examine its impact on soil, flora and aboveground biomass in urban habitats we investigated the pH, electrical conductivity and concentration of trace elements (Zn, Cu, Ni, Mn) in four invaded and four uninvaded plots in urban habitats. We also studied floristic composition and floristic richness regarding these invasive plant populations. These parameters were assessed along transects arranged in the cross shape, running from the centre of the invaded area towards the peripheral uninvaded area. Trace elements were analysed using atomic absorption spectrophotometer. Statistical differences were analysed using ANOVA and post-hoc LSD-tests. The results showed an important decrease of the number of species and herbaceous cover under A. lanceolatus populations. There were no statistically significant differences between invaded and uninvaded patches when soil pH and electrical conductivity were considered. The concentration of Zn, Mn and Ni in the soil was higher in invaded areas. The content of Zn in aboveground biomass collected from invaded compare to uninvaded areas was higher. This study raises the possibility that invasive species changes soil characteristics and create conditions for their spreading.