Wplyw natezenia ruchu pojazdow mechanicznych na udzial Lolium perenne w runi przyulicznych trawnikow Lublina i Zamoscia

The aim of studies was to evaluate the share of Lolium perenne in a sward of lawns situated in zones of strong influence of exhausting gases emitted by mechanical vehicles. Studies were performed in 1997-1998 on by-road lawns in Lublin (11 streets) and Zamość (9 streets). The basis for separation the study stands was the intensity of movement of mechanical vehicles (number of cars per hour): up to 100, 101-350, and 751-1250. Plant samples were taken from 0.5 square meter area in four replications from every study stand in spring (second decade of May) and in auturnn (end of September till beginning of October). Percentage of Lolium perenne in lawn’s sward as well as share of other grasses and papilionaceous and dicotyledonous plants were recorded by means of botanical-weighing method. The total contents of the following items were determined in dry matter of Lolium perenne and soil samples taken in late autumn from the upper layer (0-20 cm) from under perennial ryegrass sward: Cd, Pb, Ni, Zn, Mn, Fe, Cu and Mg. Moreover, N, P, K, Ca and Na levels were determined in plant material. Soil material was subjected to analyses for available phosphorus and potassium contents as well as pH. Regardless the traffic intensity, share of Lolium perenne in lawn’s sward was greater in autumn than in spring. Higher percentage of Lolium perenne was found in the sward of 2-3-year lawns than older ones. Lawn’s sward near less intensive traffic contained higher share of Lolium perenne (2.1-29.3%) than that near more intensive traffic (0.0-20.6%). Remarkably low percentage of Lolium perenne (0.0-0.4%) was observed in the sward of lawns situated along Głęboka street in Lublin. lt was proved very strong association (applying correlation coefficients) between traffic intensity and total content of particular heavy metals in the soil as well as those metals levels in dry matter of Lolium perenne and the species share in the sward of lawns studied.