Vegetation composition of a threatened hypersaline lake (Lake Bardawil), North Sinai Magdy El-Bana 1, * , Abdel-Hameid Khedr 2 , Piet Van Hecke 1 and Jan Bogaert 1 1 Biology Department, Research Group of Plant and Vegetation Ecology, University of Antwerp (UIA), Universiteitsplein 1, Wilrijk, B-2610, Belgium; 2 Department of Botany, Mansoura University, Faculty of Science at Damietta, Box 34517, New Damietta, Egypt; *Author for correspondence (e-mail: mbana@uia.ua.ac.be; phone: ++32-3-8202282; fax: ++32-3-8202271) Received 3 October 2000; accepted in revised form 8 March 2001 Key words: Calcareous islands, Life forms, Mediterranean coast, Multivariate analysis, RAMSAR, Sabkhahs, Sand dunes Abstract Lake Bardawil is the only oligotrophic hypersaline lagoon along the Mediterranean coast of Egypt. Its ecological significance is increasing due to the progressive degradation of comparable wetlands in the region. The aim of this study is to analyse the structure and life forms of the vegetation along the lake before the execution of the North Sinai Agricultural Development Project (NSADP) which will threaten the ecosystem of the lake. A data set of 150 stands was analysed using multivariate procedures (TWINSPAN, DCAand CCA), to classify the lake’s vegetation, and to determine the relationship between the plant community structure and the environmental fac- tors. The classification and ordination resulted in a clear demonstration of nine vegetation groups associated with four habitat types: submerged sea grasses, salt marshes and sabkhahs, eastern and middle calcareous dunes, and western non-calcareous dunes. The first axis of the CCA-ordination separates the salt marshes and sabkhahs spe- cies from those of the sand dunes along the soil salinity, water table depth, cations, and pH gradients. CaCO 3 and soil texture showed highly significant correlation with the second axis of CCA which was an important predictor for the psammophytic species distribution. The life forms ranged from hydrophytes (sea grasses) to phanero- phytes with the dominance of therophytes and chamaephytes. Geophytes and chamaephytes dominate the saline habitats, while therophytes and hemicryptophytes dominated the sandy dunes. Eventhough the eastern section of the lake (Lake Zaraniq) was declared as a RAMSAR site, Lake Bardawil needs urgent management to prevent its pollution by the new land use system. Introduction Five natural lakes are situated along the Mediterra- nean coast of Egypt: Maruit (west of the Nile-delta), Idku, Burollos and Manzala (middle deltaic section) and Bardawil (Sinai section). The lake Bardawil environment differs from that of the other Mediterranean Egyptian lakes in terms of climatic factors, geomorphology and salinity. Lake Bardawil is of tectonic origin (Neev 1975) and its sediments resemble that of inland desert wadis (Shukri and Philip 1960) and River Nile (Shaheen 1998). Lake Bardawil is the only oligotrophic hyper- saline lake along the Mediterranean coast of Egypt (Krumglaz et al. 1980). There is no fresh water sup- ply into the lake and the only non-marine water source orginates from scarce winter rain. Conse- quently, it is the most saline (hypersaline) of the northern Egyptian lakes (Zahran and Willis 1992). The vegetation of the western and the deltaic lakes has frequently been studied (e.g. Montasir (1937); Tadros and Atta (1958); Khedr (1989, 1999)). How- ever, few studies have been reported on the flora and vegetation of the Mediterranean coast of Sinai (e.g. Kassas (1955); Danin (1983); Gibali (1988); Dargie and El-Demerdash (1991)). Moreover, there are no 63 Plant Ecology 163: 63–75, 2002. © 2002 Kluwer Academic Publishers. Printed in the Netherlands.