Altitudinal changes in photosynthetic pathways of floristic elements in southern Sinai, Egypt

High altitude profoundly influenced plant diversity and distribution on mou ntains of southern Sinai (Egypt). Plants exhibiting the C-3-mode of photosy nthesis were widely distributed along the altitudinal transect. Plants exhi biting the C-4-mode were restricted below an altitude of about 1400 m above sea level. The transition from C-3-dominated areas to C-4-dominated areas occurred between 1200 and 1400 m a.s.l.