LAUSR

Abstract We determined the biomass and concentrations of Cr, Pb, Cu, Zn and Mn in the roots, stems and leaves of Spartina alterniflora Loisel ( S. alterniflora ) in the coastal zone of northern Jiangsu Province bimonthly. From these results, we calculated the annual metal primary accumulation and output. To calculate the annual output of heavy metals in S. alterniflora , a new method that calculates the annual rate of biomass loss and decomposition was introduced. The aim of the present study was to quantitatively analyze the regular pattern of accumulation and output and verify that S. alterniflora can be a source of metals in the environment. Our results indicated that the annual primary accumulation of Cr, Pb, Cu, Zn and Mn was 19.1, 84.2, 63.7, 442.6 and 774.7 mg m −2 , respectively, and the annual output released by S. alterniflora to the surrounding environment was 4.0, 18.1, 14.0, 97.1 and 164.3 mg m −2 , respectively. S. alterniflora only provides temporary storage, and its characteristic of absorption of heavy metal is used to remediate contaminated soil and for phytomining by harvesting. Moreover, the output of heavy metals released by S. alterniflora to the environment cannot be ignored, and S. alterniflora may be considered a source of metal contaminants. Thus, when we evaluated the remarkable ability of certain plant species to concentrate metals in their tissues, the balance between accumulation and output of the heavy metals should be considered.