Floristic Composition, Life Form and Chorology of Plant Life at Al-Saoda, Asir Region, South-Western Saudi Arabia

Abstract

Asir highlands constitute a major part of south-western Saudi Arabia, and have a temperate climate at elevations above 2500 m a.s.l. This area has a complicated topography. The variations in elevation and topography have resulted in distinctive vegetational zones.  Floristic composition, life form and chorology of plant life at Al-Saoda region south – western Saudi Arabia was studied. Three  major  wadis (sites) were investigated , every site was represented by three localities representing up-stream , mid-stream and down-stream portions of each site. Nine field trips were carried out during 18 months  .Vegetation of  three localities ( Wadi Tahlal , Wadi Al-Moght  and Beni Mazen ) was studied .  Results revealed that the region considers a hot-spot in the Kingdom in term of plant diversity and more diverse compared with other well studied regions in Saudi Arabia. A total of 103 plant species belonging to 40  families were recorded in study area. The major plant families that contributed in the formation of vegetation of the area in question were Asteraceae ( 22.3%) followed by Papilionaceae( 8.7%) ,poaceae,  ( 6.7%), Lamiaceae  ( 5%), Mimosoaceae ( 4%) while other families each was represented by two or one species. Therophytes exhibited the maximum number of species (35%), followed by chaemophytes (32%), hemicryptophytes (15%) and phanerophytes (9.8%), while the least frequent life form class was geophytes and epiphytes .Chorological characteristic of the recorded flora showed that Saharo-Arabian and Sudanian elements constitute % of  the total flora.

Keywords: dsfloristic composition , vegetation , Asir region ,chorology , diversity