Thesis (M.Sc.) - Cairo University - Institute of African Research and Studies - Department of Natural Resources

Wadi El Rayan located in the Sahara ecoregion which is part of the Palearctic ecozone which is the world's largest hot desert, located in northern Africa. The desert of wadi El Rayan consists of arid vegetation (xerophytic and halophytic plants) with a sparse plant cover except in wetlands ecosystem at shoreline of lakes consists of some of hydrophytic and halophytic plants. The field survey recorded 13 plant families within the study area; species recorded a total of 17 species were recorded in the various habitats of the around the two lakes. The family with the highest number of species was Poaceae followed by Chenopodiaceae, and Zygophyllaceae. The results showed that Phragmites australis, Tamarix nilotica, Juncu rigidus and Alhagi graecorum were the most frequently recorded species, and Tamarix nilotica and Juncu rigidus represented the highest cover. The field observations reached to that a clear variation was recorded for vegetation surrounding the lakes and a dramatic decrease in the water level is now taking place in Wadi El Rayan lower lake; and there is low diversity and number of plant species in wetland habitats around the shoreline in southern sector of lower lake, also most the existed natural vegetation has died such as Phragmites australis, except the woody species Tamarix nilotica, that spread in a large area with a good condition due to the dramatic decrease of the water level and to the high salinity of in this area. The classification the ecosystems around the lakes of Wadi El Rayan divided into two main ecosystems: (1) Wetland ecosystem and (2) Desert ecosystem. According to the IUCN criteria (IUCN red list threatened category), the Calligonum polygonoides subsp.comosum species falls into the "C" category (Small population size and decline)

Issued also as CD