Assessment of Mercury Uptake by Plants in Former Cinnabar Mining Areas

Assessment of the plant’s ability to take up mercury (Hg) from polluted soil was affected by location, plant family, and species in two former cinnabar mining areas in the Czech Republic. At each location, seven sampling points were marked out in the vicinity of former shafts and dumpsites connected to the mining activity, where representative soil samples and dicotyledonous plants were collected. The individual locations were characterized by specific plant communities, where, in most cases, different plant species were found within one family at both locations. The total Hg content in the soil, as well as gaseous elemental mercury (GEMsoil-air), confirmed elevated levels of this element in the mining-affected environment, with high variability of the data. The low Hg accumulation ability of plants, especially the low root–shoot translocation in most of the plant species, indicated the predominant occurrence of excluders. Among the families, the results showed the exceptional position of the Fabaceae family regarding soil Hg pollution, as the highest Hg content in both shoots and roots was determined for Onobrychis viciifolia. Therefore, the behavior of Fabaceae plants in polluted soil, the mechanisms of their tolerance to high Hg content, and their Hg accumulation ability deserve further research.