RESUMO
The sporophore of the fungusAmanita muscaria L. contains greatiy elevated levels of cadmium (29.9 µg g(-1) dwt) and vanadium (344.9 µg g(-1) dwt) in comparison with the soil in a birch woodland (total (HNO3-extractabie Cd 0.4 µg g(-1) dwt, V 11.7 µg g(-1) dwt). The significance of this remarkable concentration of normally rare and dispersed elements in terms of their circulation in the woodland has been investigated. Both elements are released from sporophore tissue in a form which can be taken up by a test plant (lettuce), cultivated in the woodland soil amended with different quantities of sporophore tissue, Cadmium levels in all plant tissues were elevated in comparison to the non-amended controls; only root vanadium levels responded to the amendment of the soil. The results are discussed in terms of their significance for the natural cycling of both elements. It is calculated that an abundant population of sporophores could circulate 1.4% of the total cadmium and 0.65% of the total vanadium pool found in the litter layer and 0-5 cm soil horizon in the sampled woodland over a period of 14 days (mean life span of a sporophore).
RESUMO
The occurrence of vanadium in the biosphere, and the possible roles this element may play in the metabolism of living organisms, especially higher plants, are discussed. The aqueous chemistry of the element is reviewed, and the chemical properties of the element are related to those of soils and plants. Evidence is present for a biotransformation of vanadium from vanadate (VO 3 (-) ) to vanadyl (VO(2+)) during uptake by plants, based on tissue analysis and ESR spectra. The significance of this process on the potential impact of vanadium in the biosphere is discussed.
