In our survey, the two plants Scirpus tripueter and Cyperus malaccensis are the majority communities of emergent aquatic plants in riparian wetlands in the PRE. The metal concentrations in the plants from riparian wetlands are listed in Fig. 2. The metal concentrations of Cu, Ni and Zn in Cyperus malaccensis were higher than those in Scirpus tripueter at most of sample sites. For two plants, Zn was the mostly accumulated in the plants, followed by Cu, Cr, Ni and Pb and the least was Cd.