# Native Plant Capacity for Gentle Remediation in Heavily Polluted Mines
## 3 Results
### Efficiency in Plant-Element Accumulation  
The values of the bioaccumulation factor in leaves (BCFl) and roots (BCFr) proved very low and in all cases less than 1 (Figure 2). The highest values were found in the samples of uncontaminated soils, both for BCFl and BCFr but only with significant differences for _D. viscosa_ in all the elements analyzed in leaves, and for Zn, Pb, and Mn in roots. On the contrary, the translocation factor (TF) was in general higher in samples collected from contaminated soil than in samples from uncontaminated soils (Figure 3), except for _E.pthyusa_, in which all TF values were higher in individuals from uncontaminated soils, although significant differences were detected only for Cu and Fe. The TF value for Pb in _D. viscosa_ was notable for being almost three-fold higher in contaminated soils than in non-contaminated ones. It stands out that both in contaminated and uncontaminated soil, the three species showed concentrations of Fe in roots that were considerably lower than in leaves.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Trace-Metal Pool for Leaves (ppm)**} \\ \hline  & **Zn** & **Pb** & **Cu** & **Mn** & **Fe** \\ \hline
**C** & 369932 \(\pm\) 49054a & 121225 \(\pm\) 21383a & 8208.1 \(\pm\) 477.8a & 46000 \(\pm\) 15977a & 1231575.6 \(\pm\) \\  & (273599-434192) & (93807-163357) & (7504.5-9120.0) & (22500-76502) & (855413-1529368) \\
**NC** & 45102 \(\pm\) 7640.3b & 38974 \(\pm\) 4625.1b & 7139.9 \(\pm\) 1762.2a & 37373 \(\pm\) 7165.3a & 873957 \(\pm\) 129870 a \\  & (36464-60337) & (29728-43853) & (3837.2-9857.3) & (28888-51614) & (711915-77917.6) \\
**P-value** & **0.049** & **0.049** & 0.827 & 0.827 & 0.126 \\ \hline  & \multicolumn{4}{c}{**Trace-metal pool for roots (ppm)**} \\ \hline
**C** & 35263 \(\pm\) 13431a & 49311 \(\pm\) 6044a & 89.000 \(\pm\) 89.000a & 4857.1 \(\pm\) 1033.9a & 51810 \(\pm\) 9746.0a \\  & (97746-55353) & (40879-61028) & (0.0-267) & (2827.2-6213.5) & (32551-64042) \\
**NC** & 4578.1 \(\pm\) 275.5b & 78089 \(\pm\) 2703.9b & & 8297.2 \(\pm\) 550.4b & 92641 \(\pm\) 21079b \\  & (4239.1-5123.8) & (73030-82273) & 0 & (7220.9-9036.0) & (66301-134318) \\
**P-value** & **0.049** & **0.049** & 0.317 & 0.49 & **0.049** \\ \hline \hline \end{tabular}
\end{table}
Table 4: Trace-element pools (ppm) for leaves and for roots of _Dittrichia viscosa_ in contaminated soil (C) and uncontaminated soil (NC). The mean value \(\pm\) SE is indicated and as well as the minimum and maximum values in brackets. The non-parametric Kruskal–Wallis test was applied. Different letters indicate significant differences at a significance level! 0.05 within each element and plant fraction.  
Figure 2: Bioaccumulation factor for leaves (**a**) and roots (**b**) of _C. saluifolius_, _D. viscosa_, and _E. pithyusa_ in contaminated soil (C) and uncontaminated soil (NC). The mean and standard error bars of the mean are indicated. The non-parametric Kruskal-Wallis test was applied. Different letters indicate significant differences at a significance level <0.05 for the same plant growing on contaminated and uncontaminated soil.