Vegetation and soil relationships in the inland wadi ecosystem of central Eastern Desert, Egypt

In January 2010, torrential rains that had suddenly swept away a limited area in the Eastern Desert facing Qena Province in Upper Egypt resulted in the enriching of the vegetation of some extremely dry wadis at this location. A vegetation survey carried out shortly after this event, in April, revealed the prevalence of annuals in considerable abundance, which are hardly recognisable in such usually dry habitats. The normally scarce perennial vegetation had flourished, too. A total of 32 species, 11 annuals, and 21 perennials that belong to 27 genera and 15 families were recorded. The life-form spectrum in the present study is characteristic of an arid desert region with the dominance of chamaephytes (31% of the recorded species) and therophytes (28%), followed by hemicryptophytes and phanerophytes (19% for each). Phytogeographically, the Saharo-Arabian element forms the major component of the floristic structure. The investigation revealed that the wadis studied are potential shelters of 4 vegetation groups. Detrended correspondence analysis represented the distribution of the 4 vegetation groups along the first 2 axes. Canonical correspondence analysis indicated that the distribution of vegetation in the study area was mainly controlled by gravel, pH, SO4-2, chlorides, K+1, Mg+2, and total soluble salts.