DIFFERENCES IN UPTAKE AND TOLERANCE TO HEAVY-METALS IN SALIX FROM UNPOLLUTED AND POLLUTED AREAS

Differences in tolerance to and accumulation of heavy metals between d ifferent Salix clones, grown on heavy metal polluted and unpolluted ar eas, were investigated. The concentrations of Cd, Cu and Zn in total a nd exchangeable fractions of the soils were 6-100 times higher in poll uted than in unpolluted areas. Stems of different clones of 5 Salix sp ecies were collected and analysed for Cd, Cu and Zn, and investigated for tolerance and uptake properties. There were no differences between the unpolluted and the polluted areas, either in concentrations of Cd , Cu and Zn in the collected stems, or in the tolerance of Salix to th e metals. Clones from the polluted area had higher accumulations of Cd , Cu and Zn in their roots and a lower transport of heavy metals to th e shoots than clones from the unpolluted area. (C) 1996 Elsevier Scien ce Ltd