## 3 Results
### Magnetic Measurements  
Magnetic susceptibility of _E. prunastri_ transplants (Table 2) ranged between 7.8 and 35.8 \(\times\) 10\({}^{-8}\) m\({}^{3}\) kg\({}^{-1}\), always exceeding 6-29 times the value of the control sample (1.2 \(\times\) 10\({}^{-8}\) m\({}^{3}\) kg\({}^{-1}\)) (Figure 2).  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Sample** & **Al** & **As** & **Cd** & **Cr** & **Cu** & **Fe** & **Pb** & **Sb** & **Zn** \\ \hline
1 & 422 & 0.28 & 0.072 & 3.7 & 11.4 & 841 & 4.4 & 0.49 & 42.8 \\
2 & 723 & 0.35 & 0.065 & 5.4 & 28.6 & 1269 & 5.6 & 0.95 & 36.8 \\
3 & 5  
All the hysteresis loops (Figure 3a,d) were similar in shape, narrow, saturated well before 1T, with a modest variability of both coercivities [4.4 mT \(<\) Bc \(<\) 7.1 mT; 32.8 mT \(<\) Bcr \(<\) 40.9 mT]  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Sample** & **k** & **Ms** & **Mrs** & **Bc** & **Bcr** & **Bcr/Bc** & **Mrs/Ms** & **SIRM/k** \\ \hline
1 & 13.31 & 9.06 & 0.52 & 5.84 & 37.20 & 6.37 & 0.06 & 3.93 \\
2 & 26.10  
(Table 2). The concentration-dependent magnetic parameters (Table 2) varied less than one order of magnitude [6.0 \(<\) Ms (mAm\({}^{2}\)kg\({}^{-1}\)) \(<\) 32.7; 0.4 \(<\) Mrs (mAm\({}^{2}\)kg\({}^{-1}\)) \(<\) 1.7] and, similarly to susceptibility measurements, were 4-24 and 4-19 times in excess of the values of the control sample (Ms = 1.4 mAm\({}^{2}\)kg\({}^{-1}\); Mrs = 0.1 mAm\({}^{2}\)kg\({}^{-1}\)) (Figure 2).  
Overall, the hysteresis parameters indicated slightly variable concentrations of very similar soft ferrimagnetic minerals, presumably ascribable to magnetite. Consistently with susceptibility measurements, Ms and Mrs values were always higher than in the control sample. It was not possible to estimate the Curie temperature by means of magnetothermic curves, given the low susceptibility values and the noisy behaviour caused by burning of organic matter during heating.  
Mrs (SP)% was estimated for samples 11 and 22 (Figure 3e,f), the most and the least intense of the dataset, respectively, and showed that the contribution of rapidly decaying components to the overall magnetization is about 5%-6%. This result is only indicative, as errors are large due to the relatively low values of magnetization and the short averaging time (100 ms).  
The Mrs/Ms vs. Bcr/Bc ratios (Figure 4) indicated that the samples were distributed in the middle-right side of the plot, between the theoretical curves calculated for mixtures of single domain (SD) and multidomain (MD) magnetite grains and that calculated for a mixture of SD and superparamagnetic (SP) magnetite grains [19; 20].  
Figure 3: Hysteresis loops corrected for high-field linear trend (**a,d**), isothermal remanent magnetization and backfield application (**b,e**) and Mrs decay in 100 s (**c,f**) for samples 11 and 22, the most and the least intense of the dataset, respectively. Original data, not divided by mass.  
FORC diagrams (Figure 5) were made for two samples (11 and 20), selected for their relatively intense magnetic properties; the distribution peaked close to the origin of the diagram and was dominated by viscous components of magnetization, typical for MD grains, without the asymmetrical features which usually suggest the presence of SP ultrafine particles. The two FORC diagrams are substantially identical, confirming that the samples contain variable concentrations of alike magnetic particles.