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Vegetation composition of a threatened hypersaline lake (Lake Bardawil), North Sinai

El-Bana, M., Khedr, A.H., Hecke, P. van., Bogaert, J.
Plant ecology 2002 v.163 no.1 pp. 63-75
vegetation, lakes, salinity, calcareous soils, dunes, wetlands, environmental protection, ecosystems, plant communities, population structure, habitats, pH, soil salinity, water table, soil pH, soil texture, calcium carbonate, Egypt
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, DCA and CCA), to classify the lake's vegetation, and to determine the relationship between the plant community structure and the environmental factors. 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 species from those of the sand dunes along the soil salinity, water table depth, cations, and pH gradients. CaCO3 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 phanerophytes 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.