Macro- and Microelements and the Impact of Sub-Mediterranean Downy Oak Forest Communities on Their Composition in Rainwater

Abstract

In this study, we analyzed the content of chemical elements in rainwater and investigated the influence of forest cover on the composition of precipitation. The results obtained showed that the concentration of some elements in the rainwater collected under the forest canopy was higher than that in the open area. As part of the work, we calculated the enrichment factor and examined the sources of chemical elements in rainwater. We found that all macro-elements had increased values of the enrichment factors compared to the supporting elements of the Earth’s crust. Ca had the highest value. The values of the remaining elements (Sr, Pb, Mn, Cr, Ba, V, Fe) indicated their lithogenic and anthropogenic origins. We noted that the enrichment factor under the forest canopy was significantly lower than in the open area, indicating the dilution of these elements during water passage through the canopy. Elements such as Zn, Co, Cu, and Ni also had high enrichment factors, which indicate their anthropogenic origin. In the open area, most elements had an inverse relationship with pH, except for the alkali metals Na, Mg, and Ca, which had a positive relationship with the pH value. The concentration of K was not dependent on pH. In rainwater that had passed through the forest canopy, the concentrations of Na, Mg, and Ca were also not dependent on pH, while the concentration of K had an inverse relationship with pH. As the concentration of heavy metals in rainwater increases, the role of Na, Mg, and Ca in the process of water neutralization decreases.