An assessment of metal accumulation and tolerance in herbaceous woodlot plants adjacent to a nickel refinery in southern Ontario

Between 1918 and 1984, Inco Limited operated a nickel refinery in Port Colborne Ontario. This research focused on a woodlot, adjacent to the refinery that has elevated nickel levels that range from 2, 620 mg Ni/kg to 34, 500 mg Ni/kg. Bioaccumulation factors indicate that plants in this woodlot provide a barrier to nickel, copper, cobalt and arsenic uptake from soil. However, two fern species (Onoclea sensibilis and Athyrium filix-femina) had nickel concentrations >1000 mg Ni/kg dry weight in their fronds. The feasibility of using ferns (Onoclea sensibilis, Athyrium filix-femina, and Matteuccia struthiopteris) to phytoextract nickel from Port Colborne soils was studied. Metal tolerance of Impatiens capensis was also examined. On uncontaminated soil, I. capensis seedlings from Uxbridge had significantly (P=0.002) greater shoot length than Port Colborne seedlings. On contaminated soil, seedlings from Port Colborne exhibited significantly (P<0.01) greater shoot length than Uxbridge seedlings, indicating traits of metal tolerance.