Chapter 5

Abstract

Major changes have occurred in the flora of the Nile system in Egyptian Nubia in recent years, following the completion of the Aswan High Dam in 1964. In 1963, the area of the Nile Valley which was to become Lake Nasser had a relatively rich submerged and emergent flora (57 species, of which 6 were euhydrophytes) before the construction of the Aswan High Dam (AHD) (Boulos 1966). After the construction of AHD, Springuel & Murphy (1991) during 1980-1986 recorded 9 species of euhydrophytes, while Ali (1987) recorded 7 species only. Changes in aquatic vegetation may be due to changes in the water level regime and/or changes in the physico-chemical factors following waterbody regulation (Ali et al. 1995). The latter author discussed the effect of physico-chemical factors of both water and hydrosoil on the distribution of macrophyte vegetation in the River Nile in Upper Egypt (Lake Nasser, Aswan Reservoir and the Nile).