PLANT-SPECIES AS INDICATORS OF GEOCHEMICAL ANOMALIES - EXPERIENCES ONILEX AQUIFOLIUM (HOLLY)

The distribution of Zn, Cd, Pb, and Cu, in plants growing in mineraliz ed and sterile areas of Tuscany has been studied to verify if and to w hat extent metal-accumulating species represent evidence of geochemica l anomalies in soils. Samples of leaves and twigs from trees were coll ected, and analyzed by means of differential pulse anodic stripping vo ltammetry (DPASV). Hollies, brambles, and Helm oaks in particular were considered in the mineralized area of Bottino, and the special aptitu de of hollies in concentrating Cd with respect to the other metals has been verified. Cadmium has been previously recognized as a pathfinder for zinc ore bodies; the results of this investigation appear to poin t out the relevance of holly as a bioindicator of geochemical zinc ano malies. Lower metal concentration characterizes the same species from other mineralized and sterile zones, with the exception of the urbaniz ed area of Florence, where relatively higher Zn concentrations in holl ies appear to be due to atmospheric pollution.