highly significantp < 0.001
Kruskal–Wallis tests revealed highly significant differences in pollutant accumulation across plant organs ( Figure 3 ) (H = 29.31, p < 0.001), with descending concentrations ranked as roots (0.259 ± 0.134 mg/kg) > bark (0.216 ± 0.091 mg/kg) > branches (0.128 ± 0.063 mg/kg) > leaves (0.094 ± 0.046 mg/kg).