Lithium and strontium accumulation in native and invasive plants of the Sava River: Implications for bioindication and phytoremediation

Abstract

The objective of this study was to investigate the potential of native and invasive plant species for the uptake and accumulation of lithium (Li) and strontium (Sr) along the Sava River, focusing on their bioindication and phytoremediation capabilities. Sampling was carried out in riparian zones exposed to different pollution sources in Slovenia, Croatia, and Serbia. Plant samples of native (Salix alba, Populus alba, Populus nigra, Ulmus glabra, Juglans regia) and invasive (Amorpha fruticosa, Reynoutria japonica, Solidago canadensis, Impatiens glandulifera) species were collected. The content of Li and Sr was analyzed in the soils, roots, and leaves of the selected plants, as well as physical and chemical soil properties. Both Li and Sr content in the soils increased from the source to the mouth of the Sava River. The native species showed significant potential for Li and Sr accumulation based on the metal accumulation index. The highest Sr accumulation was measured in the leaves of Salix alba and the roots of Juglans regia, while the highest Li accumulation was measured in Ulmus glabra. Native species, especially Salix alba, proved to be better bioindicators of Li and Sr. Invasive species, especially Amorpha fruticosa and Impatiens glandulifera, showed a remarkable ability to translocate Sr and Li, respectively, to leaves. These results provide valuable insight into the suitability of plants for biomonitoring soil contamination and potential applications in phytoremediation strategies. In summary, the study shows the importance of native species in the context of the accumulation and bioindication of soil pollution.

Keywords: Invasive species; Lithium; Native species; PTE accumulation; Remediation; Strontium.