Cycling of metals in desert soils: effects of Tamarix nilotica and inundation by lake water

Concentrations of Ca, Mg, K, Na, Cu, Zn, Al, Fe and Mn were measured in soi ls and in Tamarix nilotica from Wadi Allaqi on the shore of Lake Nasser in the Eastern Desert of Egypt. All of the elements were concentrated in the l eaves of Tamarix relative to the stems and roots. Leaf : soil concentration ratios, used as an indicator of metal accumulation in the plant, showed hi gh enrichment factors for Na (67.5), K (63.0) and Mg (35.0); of the trace e lements measured, Zn had the highest enrichment factor (7.64). Comparison w ith other desert species suggested that Tamarix was exceptional only in the accumulation of sodium. Periodic inundation of the soil by Lake Nasser cau sed dilution and dispersion of the accumulated salts.