Vegetation structure and environmental gradients at Wadi Al-Afreet, North Western Coast, Egypt. -

The present investigation was carried out on Wadi Al-Afreet, North Western Coast of Egypt. The study area lies between Buqbuq and Sidi Barrani on the Egyptian-Libyan frontier. It is included in the semi-desert vegetation zone with an attenuated desert climate. An analysis of vegetation along environmental gradients that prevail in the study area using the importance values of 44 perennials and 1 biennial in 16 stands, followed by multivariate data analysis was presented. Altogether, 73 species belonging to 68 genera and 23 families of the flowering plants were recorded. Asteraceae had the highest contribution, followed by Chenopodiaceae and Fabaceae. Therophytes and chamaephytes were the most frequent, denoting a typical desert life-form spectrum. Phytochorological analysis revealed that 49.32% of the studied species were bioregional. Seven groups were resulted after the application of TWINSPAN, each of definite floristic composition and environmental characteristics, and could be linked to a specific habitat. Ordination technique (CCA) was used to examine the relationship between the vegetation and the studied ʺenvironmental parametersʺ. The most important environmental variables correlated with vegetational groups in Wadi Al-Afreet were very fine sand, fine sand, coarse sand, silt & clay, HCO3ˉ, Ca+², pH, Mg+², and Clˉ.