Abstract: To assess the absorption and enrichment of heavy metals by Casuarina equisetifolia, the concentrations of heavy metals including Cr, Cu, Zn, Cd and Pb in branchlet, fine root, litter and soil of C. equisetifolia forests at four ages (10, 16, 20, 30) were determined. The results showed that the enrichment degree of the heavy metals in C. equisetifolia ranked as Zn>Cr>Pb>Cu>Cd. Correlation analysis showed that Cr and Cu, Pb, Fe and Cu, Zn and Cd had significant synergies in the fine roots of C. equisetifolia. C. equisetifolia had a higher capability of absorbing and accumulating heavy metals. Annual accumulation of heavy metals was highest in 20 years old C. equisetifolia. Our results indicate that C. equisetifolia has a great potential for reducing the pollution of heavy metals, especially for the 20 years old forest.

Key words: petroleum pollutants, purification ability, simulation, wetland, optimization