Improving the Content of Chemical Elements from the Soil of Waste Heaps Influenced by Forest Vegetation—A Case Study of Moldova Nouă Waste Heaps, South-West Romania

The present article emphasizes the influence of forest vegetation on improving the content of toxic elements from soil, increasing the content of micro and macro elements as well as correlating these variations with characteristics of forest vegetation from the studied areas—Moldova Nouă waste heaps, South-West Romania. The research involved comparing and observing the differences in the content of micro, macro, and toxic elements (Fe, Pb, Zn, and Cd) between the soil of waste heaps from Moldova Nouă from areas with forest vegetation and the content of these elements analyzed 31 years ago during the projection of afforestation works, when forest vegetation was missing. The differences were correlated with stand characteristics of forest vegetation. We observed a significant increase for Fe and a significant decrease for Zn and Cd. The influence of forest vegetation of the variation on the soil’s chemical composition was studied for the chemical elements that previously showed significant differences (Fe, Zn, and Cd). The averages of the statistically significant differences for the concentration of each analyzed element (Fe, Zn, and Cd) were correlated with the characteristics of the stands from the studied sampling points. The variation in time for Fe, Zn, and Cd and actual content of P, Cu, Mg were correlated especially with the average height of trees.