Vegetation along a transect in the Hijaz mountains (Saudi Arabia)

Vegetation was studied along ac. 450 km transect between Makkah and Medina (21° 26′–24° 31′ N, 39° 46′–39° 42′ E) crossing the Hijaz mountains with elevation ranging between 270 and 930 m. A total of 106 species of vascular plants, belonging to 35 families was identified. Altogether 20 communities were recognized on the basis of floristic and ecological features in the three ecogeomorphological sectors identified. The present paper describes the floristic composition of the plant communities where frutescent and suffrutescent species form the main framework of the communities. Relationships between the different sectors and their communities are explored