The evaluation of hazardous element content in the needles of the Norway spruce (Picea abies L.) that originated from anthropogenic activities in the vicinity of the native habitats

The aim of this research was to quantify the content of hazardous elements in the needles of Norway spruce (Picea abies L.) in the natural habitats that were accumulated from thermal power plants, mines, and metal processing industry. Fifteen natural populations of the Norway spruce were sampled from the mountain ranges in Southeastern Europe (Dinaric Alps and Balkan Mountains). Two-year-old spruce needles were evaluated the content of the following hazardous elements: heavy metals cadmium, mercury, nickel, lead and zinc, and metalloid arsenic. The effect of the distance between air pollution emitters and the Norway spruce natural habitats on the hazardous elements content in needles was also evaluated. The results of the analysis of variance confirmed interpopulation differences in the content of all analyzed hazardous elements. The effect of the air pollution source (thermal power plants, mines, and industry) on the content of hazardous elements in the spruce needles was also assessed. Significant correlation was found between the distance of air pollution emitters and the amount of zinc. This study could serve as the startup point of future monitoring programs and provide new prospect of using Norway spruce needles as the bioindicator of air pollution with hazardous elements on Balkan Peninsula since the fact that the Norway spruce natural populations inhabit wide geographic range of the continental Europe, from the Balkan Peninsula, over European Alps to Scandinavia and a large-scale of altitude from 980 to 1860 m above sea level.