Bioindication of road salting impact on Norway spruce (Picea abies)
Winter chemical road maintenance has a significant negative influence on the environment. The application of chemical de-icing salts affects the trees growing near the road. Sodium and chlorine ions which are washed out into the environment are absorbed by the ambient vegetation; the increased concentration of these ions has a negative influence on the vegetation health. The determination of sodium and chlorine ions content in assimilative organs of conifers is used as a bioindicator of the impacts of winter chemical maintenance. The presented research paper evaluates the influence of the contamination potential on these ions content in needles of the Norway spruce (Picea abies). This species of spruce was chosen because of its abundant occurrence and heightened sensitivity towards salinization. The study was conducted in the north of the Czech Republic in the Liberec Region. To assess the damage potential of the winter chemical road maintenance, samples of the Norway spruce first- and second-year needles were collected and the sodium and chlorine ions concentrations were determined. At the same time, the research assessed the contamination potential of the region and the health condition of the analysed spruce trees. The results of ions concentrations (Na, Cl) were evaluated depending on four factors: the contamination potential, the health of the tree, the distance from the road and the age of the needles. Based on the evaluation of the results, a scale with framework concentration values was designed. This scale can be used for practical assessment of the degree of contamination.