The present study provided an investigation of the floristic analysis, vegetation composition and species
distribution along 100 m intervals of the elevation gradient (<1500 m a.s.l.- >2000 m a.s.l.) on Jabal
Musa (south Sinai, Egypt), and assessed the role of elevation and other soil parameters controlling plant
diversity. It is a study on altitudinal variation in vegetation in a very dry climate. The vegetation
structure, growth forms, and species diversity were analyzed within the 7 elevation belts on Jabal Musa
area, 44 sample plots, 81 species (including one bryophyte), and 17 examined environmental factors
including altitude. Asteraceae, Lamiaceae, Zygophyllaceae and Brassicaceae contributed about 41% of
the species, represented in all belts. Based on the Bray-Curtis dissimilarity coefficients, it exhibited
floristically homogeneous higher belts than the lower belts. Along moisture gradient, the Non Metric
Multidimensional Scaling (NMDS) ordination was able to distinguish the different vegetation belts along
the altitudinal gradient. The vegetation groups of the lower elevations occupied the negative side of Axis
1 while those of elaqsaa higher elevations occupied the positive end. CCA was applied to assess the
relationships between soil parameters, species composition and vegetation groups. Altitude, coarse and
fine sand fractions, magnesium and bicarbonates had significant correlations with diversity indices more
than the others.