Comparison of heavy-metal bioaccumulation properties in <i>Pinus</i> sp. and <i>Quercus</i> sp. in selected European Cu deposits

Abstract

Heavy-metal contamination of Pinus pinaster, P. sylvestris, Quercus robur, and Q. rotundifolium was studied in four abandoned historic Cu deposits from Italy (Libiola, Caporciano), Portugal (São Domingos), and Slovakia (L'ubietová). The highest Cu and Mn contents in anthropogenic soil were described in Libiola and Caporciano whereas the highest Pb, Zn, As, and Sb contents in São Domingos. The anthropogenic soil in L'ubietová shows the highest Co contents. The area of São Domingos is the most acidified. There are important differences between the bioaccumulation of plants from individual deposits. Bioavailability of the heavy metals is generally independent of the pH values. The high Ca and Mg contents in soil are able to block the transport of heavy metals to the plant tissues. The bioconcentration factor values of all plant taxa, in all deposits, indicate a predominant strategy of excluders. Only Ag shows excellent bioconcentration ability. In L'ubietová, Pinus sylvestris has a strategy as an accumulator of Pb (2.43) and Zn (2.49); Pinus pinaster of Mn (4.97), Cd (1.85), and Co (5.62) and Quercus rotundifolium of Mn (3.54) in São Domingos. The predominantly low translocation factor values indicate that in most cases the heavy metals are accumulated in roots; only in a few rare cases do they migrate to shoots (e.g. Zn in Pinus sp. from all localities, Co in P. pinaster in São Domingos).