Survival, growth and element translocation by 4 plant species growing on acidogenic gold mine tailings in Québec

Abstract

Mining activities create nutrient-poor sites that can be impacted by heavy metal solubilization. The introduction of plants into these environments can lead to organic matter deposition that can bind metals and limit their migration in the environment. This study aimed to determine which of four pioneer plant species (Alnus alnobetula ssp. crispa, Alnus incana ssp. rugosa, Larix laricina and Picea glauca) could survive and grow on undisturbed acidogenic gold mine tailings in Northwestern Québec. After three growing seasons, all four outplanted species successfully established on the tailings without the use of organic amendments. Spruce and larch showed lower growth than the two species of alders, which had high survival rates and aerial biomass production per plot. None of the studied species had high metal translocation rates into leaf tissue despite high metal concentrations in the tailings. This study demonstrates the importance of preliminary field trials to optimize plant biomass and biodiversity on reclamation sites and to mitigate the risk of heavy metal translocation into plant tissues. Our results suggest that the reclamation of acidogenic tailings, without the use of capping materials, warrants further study.