Distribution and Accumulation of Heavy Metals in Plants and Rhizosphere Sediments at Tidal Flat in Changjiang Estuary

Based on the analysis of the contents of Cu, Pb, Mn, Zn, and Cr in the rhizosphere sediments of Phragmites australis and Scirpus mariqueter at tidal flat in Changjiang Estuary, the following conclusions can be drawn. Roots of the two plants have higher contents of Cu, Pb, Zn and Cr, while less content in the stems and leaves. The content of Mn in stems and leaves can account for up to 55%. Scirpus mariqueter can accumulate more heavy metals than Phragmites australis. And the heavy metal contents have seasonal changes in both of the plant and the sediments. Metals in plants are mainly accumulated in winter. Heavy metals in Phragmites australis rhizosphere sediment have lower contents in autumn, but are accumulated in winter. In Scirpus mariqueter rhizosphere sediment, Cu, Pb, Mn are mainly accumulated in winter, while Zn, Cr have the highest contents in winter.