Geografie 1969, 74, 15-21
Phytogeographical Distribution in Egypt
In spite of a rich variety of natural conditions, the flora of Egypt is not very rich in the number of species; a considerable number of species is limited to certain territories only (Mediterranean, Sinai, Gebel Elba). Consequently, there are some 700 common species, meanwhile other species are rare or very rare. The total number of species makes about 2 000. Botanical life in Egypt is predominantly concentrated to the Cairo and Alexandria Universities. A leading personality is Prof. Dr. V. Täckholm, the author of the "Flora of Egypt", the co-foundress of the herbarium collections at the botanical library, and an outstanding pedagogue at the Cairo University who has educated a new generation of botanists in Egypt. A prevailing part of the Egyptian territory is covered by deserts with arid conditions. Phytogeographical distribution is mentioned in books by Muschler, Hassib, Täckholm. All these classifications are based upon the natural geographical reality. The Nile Valley is considered a single whole yet it is evident at first sight that its northern part differs greatly from the southern one, both in quantitative and qualitative presence of species. These problems are at the present the subject of studies of Egyptian botanists. Similar natural conditions occur in the Nile delta where there are vast areas of saline soils and shore communities of brackish lakes. From the botanical point of view the most interesting phenomenon is the weed vegetation which serves as basis for a more detailed phytogeographical distribution of the Nile Valley, and differentiation of the delta from the valley itself. The coast of the Mediterranean is divided into two parts: the east pelusitic part, affected strongly by the vegetation of the eastern Mediterranean, and the west mareotic part displaying a relationship to the coastal vegetation of North Africa. Thanks to a rich rainfall, the Mediterranean is one of the territories in Egypt which display the richest variety of species. The Libyan desert, situated to the west of the Nile, is he easternmost extremity of the Sahara desert. The vegetation is predominantly concentrated on the flat wadi beds whereas the vast plateau and the moving sand dunes most often have no vegetation. The Arabic desert to the east of the Nile is a typical rocky desert with an intensely rugged relief. The vegetation displays a closer relationship to similar deserts on the Arabian peninsula than to the Libyan desert. The smallest desert is the Isthmic desert, situated to the north of the Arabic desert, and continuing in Asia in the central part of the peninsula of Sinai. The vegetation of this desert does not show any great differences being much influenced by the vegetation of the Libyan as well as Arabic desert; moreover the influence of the Negev desert may be also felt on the peninsula of Sinai. Oases form isolated islands in the Libyan desert. With regard to its position, the largest basis Fajtúm is a phytogeographical part of the Nile Valley. Other oases occur at greater distances from the Nile Valley. Since the primeval times there has existed an intensive agriculture in these parts; remains of original vegetation may be found in places with spontaneous issues of water which forms small lakes. Remarkable are climax communities including the palm Hyphaena thebaica. At the present time, the oases Charga and Dachla are strongly affected by the intensive agricultural development which makes the number of introduced weed species increase. Sinai, the mountainous part of the southern territory of the peninsula of Sinai, belongs to the most distinguished botanical territories of Egypt. There are many endemic species concentrated here together with a series of species occurring isolated from the territory of their distribution. The vegetation of the coast of the Red Sea does not display any rich variety of species as do the territories along the Mediterranen. There are, however, more marine Angiosperms. In the southern part of the coast occurs mangrove shrubbery, Gebel Elba, a mountain ridge along the Egypto-Sudanese boundary is the only territory with original accacia forests. For many species this is the northernmost point of their distribution. The mountain ridge Abenat, most probably is a separate phytogeographical whole situated on the boundary of Egypt, Libya and Sudan. It is quite possible that some relationship will be found to the neighbouring although higher mountain ridges, such as Tibesti or Gebel Marra.
