Effect of tailings on wetland vegetation in Rautuvaara, a former iron–copper mining area in northern Finland

Mine tailings are potential sources of metal pollution to adjacent ecosystems. Recognition of plant species that tolerate high concentrations of toxic elements is essential to phytostabilize tailings and metalliferous effluents. We studied soil chemical variables and plant species compositions in the wetlands influenced by tailings effluents of the closed Rautuvaara iron–copper mine in Finnish Lapland. We found that the tailings plumes contained substantial amounts of Ca, Mg and P as well as high concentrations of toxic elements such as As, Co, Cu, S, and Zn. Contamination has altered vegetation compositions and reduced plant diversity more than 50% in the most severely contaminated area. We found that Carex rostrata, i.e. bottle sedge, Equisetum palustre, i.e. marsh horsetail, and Eriophorum angustifolium, i.e. common cottongrass, tolerated high concentrations of soil As, Co, Cu, S, and Zn. Multiple metal tolerances and generally low shoot translocation rates indicate that these species are potentially useful for phytostabilization of metalliferous soils and effluents.

► We examined tailings-contaminated wetlands in Rautuvaara, Finnish Lapland.
► High metal contamination reduced plant diversity by over 50%.
► Carex rostrata, Equisetum palustre and Eriophorum angustifolium were metal tolerant.
► Metal tolerances indicate the potential of the species in phytostabilization use.