Accumulation of Potentially Toxic Metals in Ryegrass (Lolium perenne, L.) and Other Components of Lawn Vegetation in Variously Contaminated Sites of Urban Areas

Green areas, in particular lawns, play important roles in cities. Unfortunately, they are often arranged in sites contaminated with heavy metals. This study analyzed soils and lawn swards in three districts of the city of Wrocław. Three different categories of lawns were examined: residential areas, street lawns and parks. Particular focus was placed on soil contamination with the metals Zn, Cu, Cd and Pb and their accumulation in the aboveground biomass of the perennial ryegrass Lolium perenne, the main grass species, and in the biomass of other components of the lawn sward. The research revealed local occurrence of elevated metal concentrations in soils, although in most of the studied sites, they did not exceed the safe values set byPolish law. The accumulation of metals in the aboveground parts of ryegrass and other plants forming the lawn sward depended primarily on the type of metal. The study confirmed the high phytoavailability of cadmium and zinc and the very low phytoavailability of lead. Perennial ryegrass accumulated considerably lower amounts of lead and copper compared with other components of the lawn sward, which indicates the potential suitability of this species for the phytostabilization and sustainable development of areas contaminated with these two metals.