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In the arid sand dune ecosystem of Nizzana, northwestern Negev, Israel, three perennial species were investigated far concentrations of the elements C, N, S, P, Ca, Mg, K, Na and Cl. From the dune tops (crests) to the dune valleys six different ecotopes (habitats) were discerned where the sampling took place. The soil conditions are known due to previous investigations of H.-P. Blume and his coworkers. The species Anabasis articulata and Cornulaca monacantha (both Chenopodiaceae) showed considerable variation of element contents;according to the ecotopes. In some ecotopes of the dune valleys they showed higher contents of sodium and chloride than in the ecotopes of the proper dune, and by Na/K ratios of > 1 they indicated slightly halophytic character. The glycophyte Thymelaea hirsuta (Thymelaeaceae) exhibited very low element concentrations which practically did not change between the ecotopes. The conclusion was drawn that Thymelaea is characterized by a higher selectivity of ion uptake than,the two other species.