Vegetation and landforms of the Saint Catherine area, southern Sinai, Egypt

Floristically, the Sinai peninsula is represented by four main phytogeographical chorotypes: Saharo–Arabian, Irano–Turanian, Sudanian, and Mediterranean. The Saint Catherine area, in the southern Sinai, is characterized by a unique vegetation due to its geomorphological formations and altitudinal climatic variations. The origin of the vegetation is primarily Irano–Turanian, dominated by Seriphidium herba-alba and accompanied by Atraphaxis spinosa, Agatophora alopecuroides and Gymnocarpos decandrum at high elevations (Gebel Catherina, 2641 m). Lower elevations (1500–1700 m) are dominated by Seriphidium herba-alba, Zilla spinosa and Fagonia mollis on stony alluvium and cobble deposits. The vegetation is relatively diverse in sub-shrubs and trees, with few annuals. Vegetation is sparse and characterized by a variety of chasmophytic and endemic species. Six landforms are distinguished in the area: gorges, slopes, terraces, ridges, wadis, and plains. Narrow wadis and gorges are relatively floristically rich and are dominated by phanerophytes (Crataegus sinaica, Ficus pseudosycomorus and Lycium shawii) and chamaephytes (Phlomis aurea, Conyza stricta, Plantago sinaica, and Teucrium polium). The character of the soil surface, altitudinal gradients, and landform types provide microhabitats dominated by characteristic vegetation.