Trace elements in soils exist as components of several different fractions. In this work we
have analyzed the relationship between these fractions. Specifically, total
and extractable (with EDTA, calcium chloride and deionized water) Zn, Pb and Cu concentrations have
been studied. In addition, their correlation with the concentration
of these elements in plant leaves has been investigated. Soil and plant samples have been taken from
Sulcis-Iglesiente, in southwest Sardinia (Italy), an area rich in mining tailings. This has made that the
concentrations of the trace element under
study in soils were varied. Three plants have been studied: Dittrichia viscosa, Cistus salviifolius and
Euphorbia pithyusa subsp. cupanii. Soil samples beneath each of them at depths of 0-30 and 30-60 cm
have been considered. The highest concentration of trace elements in the leaves of the studied species
have been found for Zn. In general, the calcium-carbonate content and the crystalline and amorphous
forms of iron in the soil have determined the concentration of metal in plant leaves. The soil
concentrations that have been found with the extraction methods are uncorrelated with Pb and Cu
concentrations in plants, but Zn is correlated with the fraction extracted with EDTA and calcium
chloride
