The Formation of Iron Plaque on the Roots of <i>Carex cinerascens</i> in Poyang Lake and its Effect on the Lead Accumulation

Abstract

Iron plaque is portal of the pollutants into the plant body and plays an important role in reducing pollutants. A pot experiment was conducted to investigate the formation of iron plaque, and lead accumulation and distribution in Carex cinerascens. The data showed that the amounts of iron plaque increased with Fe additions. Under the condition of 0 —100 mg kg-1 lead concentration for Poyang Lake wetland soil, it was the most beneficial condition for the formation of iron plaque when iron concentration was 500 mg kg-1. There was a significantly correlation between the concentrations of Fe and Pb in iron plaque on the root surfaces of Carex cinerascens (r=0.68). Most of the lead accumulated in the roots of Carex cinerascens, a few of lead accumulated in the shoots of Carex cinerascens. Iron plaque promoted the migration of lead from soil to roots, it played a role to eliminate heavy metals pollution of Poyang Lake wetland soil to some extent.