B i o m a s s a n d N P K retention in Scirpus litoralis a n d S. mariti-mus from Smir-Negro swamps (NW of Morocco). Among the freshwater or brackish-swamps bulrushes, Scirpus litoralis Schrader and S. maritimus L. are the most common in the Tingitan Peninsula (North-west of Morocco); they occur in mono-and bispecific communities. Five Scirpus spp. beds were studied in order to assess biomass production and NPK retention in these species. In fact, the mixed bed (i.e. Scirpus maritimus and S. litoralis dominated bed) presents the highest values of total peak bio-mass (48.2 t dry weight ha -1) and aerial NP-retention (98.4 kg N and 11.1 kg P ha -1) compared to monospecific beds. Under-to aboveground bio-mass ratio (S/A) has been estimated to 3.84. Moreover, Scirpus maritimus total biomass was influenced by site conditions and its total peak biomass attains 4.41 to 23.2 t dw ha -1 . The ratio "S/A" varies from 0.89 to 3.90 in this species.
عبد السلام النبيلي | Abdeslam Ennabili | 5774