A field study was undertaken on Phragmites australis (Cav.) Trin. Ex Steudel, Typha angustifolia L., Sparganium erectum L., Juncus acutus L., J. maritimus Lam., Scirpus litoralis Schrader, S. maritimus L., Lemna gibba L. and L. minor L. communities, in order to evaluate and compare their biomass production and NPK retention rates in unpolluted and polluted wetlands of northwest Morocco. This was undertaken to select species with the potential for macrophyte-based wastewater treatment systems. The highest total biomass values were observed for T. angustifolia, P. australis and S. erectum, which accumulated 56.5, 52.7 and 20.1 t dry weight ha-1 year-1, respectively. They also retained in their tissues nitrogen and phosphorus at the rates of 922,561 and 375 kg N ha-1; and 114,72.1 and 84.8 kg P ha-l, respectively. The above-ground annual net productivity estimated under Mediterranean climate exceeds that reported for Phragmites australis occurring under an oceanic climate. But it is similar if compared to the continental climate for Sparganium erectum and Typha angustifolia. As for NPK accumulation, Phragmites australis and Typha angustifolia did not differ in their natural sites, or according to P. australis applied in constructed wetlands for wastewater treatment. Keywords: Macrophyte community; Biomass production; NPK retention; Morocco; Net productivity.
عبد السلام النبيلي | Abdeslam Ennabili | 5780