Edaphic properties and soil cyanobacteria of South Western Saudi Arabia.

Abstract

Three sites at each of five localities, in the South Western Region of Saudi Arabia were surveyed during 1992, for their soil physico-chemical properties, and cyanobacterial communities. The soils were moderately calcareous, and characterized as sandy loam textured and alkaline. Electrical conductivity and total soluble salts ranged between 0.196-2.228 mmhos cm -1 and 137.2-1559.6 ppm, respectively. Calcium was the major soluble cation, and sulphate, chloride and bicarobonate were the principal anions. A total of 22 cyanobacterial and algal species were identified from the 15 soil samples following rehydration and culture in different enriched media. The species included 19 cyanobacteria, 2 Chlorophyta and 1 Bacillariophyta. 7 cyanobacteria: Nostoc edphicum, N. muscorum, Phormidium bohneri, P. favcolarum, P. tenue, Pleurocapsa minor and Synechococcus aeruginosus are new records for the Saudi Arabian Flora.