RESUMO
Aim: To evaluate tolerance of two tree species, Jatropha curcas and Acacia burkei, to an acidic and highly Cu/Ni-contaminated soil. Methodology: Above-ground growth of Jatropha and Acacia were monitored for six months in two different soil types; a typical field soil (FS) and acidic and Cu/Ni-rich soil (ACNS), the latter containing 58- and 14-fold higher levels of Cu and Ni, respectively, than FS. Results: Growth of Acacia was markedly inhibited in ACNS, as evidenced by low number of petioles and branches, thinner stem diameter, and low chlorophyll content compared with plants grown in FS. In contrast, tree height, stem diameter and length of emerged branches of Jatropha showed no significant differences between growth in FS and ACNS. In Jatropha, foliar Cu content grown in ACNS was not statistically different from that in FS whereas a small increase in foliar Ni content was observed in ACNS. Interpretation: These observations suggested that Jatropha possess strong resistance to acidic and Cu/Ni-enriched soil. This trait might be advantageous for dual-purpose, utilization of Jatropha for renewable energy production and afforestation of Cu/Ni-polluted wastelands.