Structure écologique des peuplements végétaux des dunes fixées par des graminées vivaces, dans le Maroc Oriental

The research presented here, concerns the ecological structure of vegetal planting of sandy formations (dunes, nebkha,…) fixed by hardy gramineous plants, in the oriental Morocco, shows groupings of species where the station of Saïdia (Mediterranean littoral) becomes individualized very clearly. On the continent , the station of Figuig (sahara) is distinguished clearly enough by a group of species properly saharian ; whereas, the stations of Tendrara and Bouârfa were little different on the level of the division of flora. Two species were new for the Moroccan flora : Dactyloctenium aegyptium Ash. harvested at Figuig station and Onopordon algeriense Pomel. harvested at Tendrara and at Bouârfa stations. Besides, 24 vegetal species were new for the region. The Poaceae and the Asteraceae plants dominate in number of species in the continental stations ; whearas, in the littoral station it’s the Fabaceae which takes the relay