Abstract
Ants (Hymenoptera: Formicidae) captured in pitfall traps were compared within and among three altitudinal gradients in St. Catherine Protectorate, south Sinai, Egypt, to study the ant diversity patterns and their relationship with environmental factors. A total of 26,165 specimens of ants belonging to 17 different species were sampled. Our main findings were that (1) there were no significant differences in ant species richness, evenness and Shannon's diversity index between the three elevation plots; while ant abundance was significantly different between low-elevation plots and both mid- and high-elevation plots, there was no significant difference between mid- and high-elevation plots in terms of ant abundance. (2) TWINSPAN analysis and detrended correspondence analysis (DCA) of the ant fauna indicated that the high-elevation plots were distinctly separated from both mid- and lower-elevation plots according to their ant species composition. (3) CCA showed that both the elevation and the two plant species Acacia raddiana and Casuarina sp. were the significant factors separating the ant species community along their altitudinal gradients. (4) Lepisiota nigra ((Dalla Torre, 1893) (P<0.01), Tetramorium depressiceps Menozzi, 1933 (P<0.05), and Cataglyphis ruber (Ford, 1903) were found at the high-elevation plots; while Camponotus aegyptiacus Emery, 1915 (P<0.02), Cataglyphis sabulosus Kugler, 1981 (P<0.03), and Messor foreli Santschi, 1923 (P<0.05) favoured the low-elevation plots.