SEARCH

SEARCH BY CITATION

Summary

An investigation was conducted into the multi-element tolerance of the grass Deschampsia cespitosa growing around a nickel/copper smelting complex at Coniston, near Sudbury, Ontario. Tolerances for nickel, copper, aluminium, zinc, lead and cadmium in this population were compared with those of control populations growing on uncontaminated pastures. Distinctive population differences were found in distributions of copper and nickel tolerances, indicating that elevated tolerance to these elements had evolved in the Coniston population. More subtle differences between the populations in aluminium, zinc and lead tolerance were also noted, with increased tolerances showing in the smelter area population, despite a lack of elevation in zinc and lead levels in the soils. Various individuals in the Coniston population demonstrated a positive response to nickel and copper at levels as high as 0.3 μg cm-3 in water culture. This ‘need’ for the metals was reflected in the seed population from Coniston which germinated and survived better in the copper/nickel-contaminated soils than in the control soil. In contrast, germination of the control seed population was uniformly good, but seedling survival was poor on the metal contaminated soils compared with that of the Coniston seedlings. The relevance of these findings to evolution of multi-metal tolerances and the possible uses of the species for reclamation are discussed. The occurrence of coincidental metal tolerances is considered.