###### Abstract  
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 Noua 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 Noua from areas with forest vegetation and the content of these elements analyzed 31 years ago during the projection of afrogestation 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. forest plantations; heavy metals; mining sterile; copper ore; soil elements; stand characteristics  
of heavy metals that contaminate soil substrates, destroying their texture and causing groundwater pollution and a decline in biological diversity [4]. Waste generated by mining activity poses a serious issue due to its large amount, being often associated with risks posed by its storage for environmental management [5]. From these formed waste heaps, high concentrations of potentially toxic elements can spread on arable fields and meadows nearby, leading to heavy metal pollution. Acid drainage and eolian dust transportation are the main causes of pollution dispersion. In some cases, acid drainage from mine waste dumps can be partly responsible for relatively high acidity (pH < 5.0) measured in samples collected from arable land and pastures [6]. Solid metal compounds can deposit at a distance of up to a few km [7]. Regarding flood transportation of pollution, another important cause of pollution dispersion is proven by the fact that the direction of flow of surface water on the slopes explains the downstream spread of pollution in some studied areas in other research [6]. Geochemical transformations of the mineral content from waste heaps can significantly impact the soil's chemical properties [8; 9]. Some investigations have shown that sterile samples have an extremely variable content of potentially toxic elements (Cu, Pb, Zn, Bi, Cd, and As) [10]. This highlights the necessity to phytoremedy the areas polluted in this way as fast as possible. Heavy metals pollute soil and water resources, being harmful to human health [11; 12]. Some toxic elements at high concentrations can inhibit plant growth [13]. In order to obtain lasting development, mining areas are restored, with this being an important phase of mining activities [14]. In order to fight against the negative effects of pollution, some investigations have demonstrated the feasibility of using black locust (_Robinia pseudoaccia_ L.) in the phytoremedy of waste heaps [15]. Currently, there are numerous restoration solutions, but the most important one remains afforestation, considered the most friendly towards the environment [16]. Statistical analysis of the chemical fluctuations of Pb, Zn, Cu, As, and Mn concentrations has shown that the highest concentrations of heavy metals are usually found on the waste heap's central plateau [17].