Assessing Soil-Vegetation Relationships in South Western Sinai, Egypt

The present work aims to study the vegetation analysis related to soil factors affecting species distribution and community types in South Western Sinai, Egypt. A total of 77 stands were studied, using 10 quadrats (10 m x10 m) per stand. Different physical and chemical soil factors (soil texture, electrical conductivity, total dissolved salts, pH, moisture content, chlorides, carbonates, sodium, potassium, organic carbon, calcium, and magnesium) were investigated to determine the significant factors that may affect the distribution of species throughout the study area. The majority of the soil classes in the study area were a mixture of coarse sand, fine sand, and gravel. The vegetation analysis was dominated by five plant communities; Zygophyllum coccineum, Haloxylon salicornicum, Zilla spinosaa, Zygophyllum album, and Anabasis articulata. TWINSPAN was used to classify the study area's stands and to reveal each group's indicator species. The classification resulted in five vegetation groups (1, 2, 3, 4, and 5) each group with its distinct indicator species. Using DECORANA to clarify the relation between soil factors and vegetation, showed that the stands and their groups were related to both axis 1 and 2. Groups 1, 2, and 3 were related to axis 2, while groups 4 and 5 were related to axis 1. ANOVA was used to detect the most significant factors affecting species distribution. Organic carbon with P value = 0.036 was the most significant factor in determining different ecological groups followed by sodium with P value = 0.033 followed by magnesium with P value = 0.02 followed by Simpson diversity with P value = 0.007 followed by chloride, EC, T.D.S, species richness and Shannon diversity with P value = 0.001.