Seasonal changes in metal accumulation and distribution in the organs of Phragmites australis (common reed) from Lake Skadar, Montenegro

Due to its ability to accumulate metals, availability throughout the year and large biomass, Phragmites australis (common reed) is suitable for biomonitoring studies for the evaluation of load levels of trace metals in aqueous ecosystems. The heavy metals concentration in P. australis tissue can be several ten to several thousand times higher than those in the surrounding water. In this study, the content of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, Sr and V) in sediment, water and different organs of Phragmites australis collected from Lake Skadar, Montenegro, during different seasons of the year 2011, were examined. The highest concentrations of Sr were found in the leaves, while the other studied metals showed their highest concentrations in the roots. Thus, P. australis is considered a root bioaccumulation species. For most metals, the concentrations in the roots and stems increased over time until the end of the growing season and then decreased, while the concentrations in the leaves increased even after the growing season of the plant. If P. australis is used for phytoremediation purposes, then it should be harvested after the growing season because then the concentrations of metals in the above-ground parts are maximal.