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The present study aims at developing a regression model for biomass estimation of Pluchea dioscoridis and investigating its ability to accumulate heavy metals from urbanized soils in order to be used as a potential bio-indicator of contaminated soils. In each of three residential sites, seven permanent quadrats (10 × 10 m) were selected for investigating the phenological behavior of P. dioscoridis, while an additional three quadrats were sampled for soil and plant analysis during March to November 2015. The flowering time of P. dioscoridis covers 7 months, with a peak in July. The above- and below-ground biomass attained their highest values in July. Concentrations of macro-nutrients in the shoot were significantly higher than in the root. However, concentrations of most heavy metals were significantly higher in the roots than in the shoots. The regression equations based on plant size index, as a predictor variable, was the best equation for different shoot compartments, while that based on plant diameter was the best equation for root biomass estimation. Based on the results of the bio-accumulation and translocation factors, P. dioscoridis can phytostabilize Cu, Pb, Cd, and Zn and can be used in a phytoextraction strategy for Cr. The significant positive correlations between Cd and Cr in soil with those in P. dioscoridis tissues suggest its potential use as a bioindicator and biomonitor for Cd and Cr pollution. |
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