Planning effects on wetland vegetation (Spermatophyta) from Tetouan littoral (NW of Morocco) Changes of Mediterranean wetlands, due mainly to draining and pollution, endanger the diversity of indigenous wetland flora. The littoral of the NW of Morocco is considered among the zones the most targeted by urbanisation and tourism planning. Rupture of river/sea balance and waste and wastewater evacuation represent the principal factors affecting wetland plant communities in the Tétouan littoral (NW of Morocco). During the 1994-1997 period, a study of 20 sites along this coastal zone allowed us to identify 121 wetland species of Spermatophyta, including 92 species inventoried in the lagoon-swamp complex of Smir-M’Diq. Gramineae, Cyperaceae, Polygonaceae, Compositae, Ranunculaceae, Juncaceae and Salicaceae are the most represented families. Wetland plant communities characterise particularly swamps and river mouths, while the riparian units are generally reduced to scraps or stalks insulated along the river beds. Assessment of effects of wetland changes on wetland Spermatophyta underlines the backwaters invasion by Ruppia maritima, Potamogeton nodosus and P. pectinatus. Arthrocnemum meadow replaces the Scirpus-Juncus beds, and the upstream Tamarix units are decaying because of soil salinity increase. Sites receiving wastewater are occupied by Sparganium community to the detriment of Scirpus one. Other aspects of space-time successions of wetland plant communities are also discussed. Although the diversity of the wetlands studied attains 60 % of the ecological conditions, several species like Eryngium corniculatum, Iris pseudacorus, Juncus articulatus, J. subulatus, Carex trinervis, Cyperus laevigatus and Triglochin bulbosa become rarefied. Riparian species like Vitex agnus-castus and Fraxinus angustifolia regress strongly. The various wetland changes highlighted in this study would disadvantage the ecological and socio-economic roles of local wetlands: ecosystemic diversity, paleobotanical interest, use values, etc.
عبد السلام النبيلي | Abdeslam Ennabili | 5780