Effect of edaphic factors on the vegetation zonation in some littoral and inland salt marshes of Egypt

Abstract

Shawky R., 2018: Effect of edaphic factors on vegetation zonation in some littoral and inland salt marshes of Egypt. - Botanica, 24(2): 202-210. The segregation of a few dominant plant species into distinctive zones is characteristic of salt marshes. Vegetation zonation was investigated in the littoral salt marshes (South Marsa Alam region) and the inland salt marshes (Wadi El-Natrun region) of Egypt. Twenty taxa belonging to 18 genera and 11 families were recorded and classified into two sets at the two studied sites and subdivided into four groups by TWINSPAN, according to a relevance value: group A) co-dominated by Juncus acutus and Juncus rigidus; B) - dominated by Aeluropus lagopoides; C, D) - Limonium axillare. The analysis of species diversity in the inland salt marshes as well as the Shannon and the Simpson indices showed the highest species richness compared to that in the littoral salt marshes. The soil of the inland salt marshes was characterized by high percentages of silt, clay, also the soluble anion SO4-2was the highest. While the most effective factor in the littoral salt marshes was EC, sand fractions, moisture content, soluble cations as Na+, Ca+2, soluble anions as Cl-, organic matter and CaCO3. The proximity matrix between the two types of salt marshes indicated that they were different, except for the stands of Juncus rigidus, the elucidation distance was the smallest and they were similar together.