Impact of expressway on physiology of plants and accumulation of risk elements in forest ecosystems

Abstract

This study analyses the effects of expressways on physiology and risk elements content in plants (Quercus cerris L., Prunus spinosa L., Melica uniflora Retz.) and soils. Study forest stands are located at a distance of 30 m to 8100 m from the expressway 'R1 Nitra - Tekovské Nemce' (southwest Slovakia). The effect of distance from the road on the content of cadmium (Cd) in soils indicated an increase of the element in mineral layers in the 30 m variant; excessive Cd values were recorded in O-horizons and in the background zone. Also copper (Cu) showed a marked enrichment of surface horizons caused by car traffic. The results of redundancy discriminant analysis showed that the most important environmental variables related to physiological parameters of plants were the content of Cd and Cu in plants (P < 0.05) and the content of Cu in soils (P < 0.05). However, M. uniflora species responded most sensitively to a decrease of average chlorophyl content as a consequence of excessive accumulation of Cd in leaf tissues. The obtained results indicate risk of exposure to risk elements in soils and plants of forest stands under conditions of polluted air, but also under specific environmental conditions.

Keywords

• road traffic
• accumulation of toxic elements
• air pollution
• soil contamination
• photosynthesis