Metal levels in soils and cattail(Typha latifoliaL.) plants in a pyrites mine area at Lousal, Portugal

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Abstract
Typha latifolia L. is one of the major plant species occurring in a pyrites mine tailing‐derived, waterlogged soil at Lousal, south of Portugal. Levels of Fe, Mn, Zn, Cu and Pb were measured in both below‐ and above‐ground tissues of Typha latifolia, as well as in the substrate supporting the plants. Metal levels in the soil, excluding Mn, were found to be substantially higher than in control soils, showing relative enrichment of Cu and Pb of the order of 20–70 times and 10–20 times, respectively. Compared to Typha latifolia controls collected from a nearby creek, upstream from the pyrites mine zone, the plants growing in the contaminated soil showed higher metal levels in their organs, with exception of Mn. Similarly to previous findings from other authors, we observed that the roots of Typha latifolia presented iron contents that were often much higher than those measured in the soil, which is probably due to the formation of a ferric hydroxide plaque at the root surface. Rhizome stripping showed that a large fraction of the Fe measured in this organ was associated with its external layer, supporting the view that varying, but significant amounts of this metal were adherent to the subterranean plant organs. Typha latifolia plants showed great capacity to accumulate manganese against a concentration gradient and to selectively prevent potentially toxic metal levels from reaching the shoot.