%0 Research Notes %T Trace metal distribution in Ledum palustre %A Pakarinen, Pekka %A Mäkinen, Ahti %D 1978 %J Suo - Mires and peat %V 29 %N 5 %U http://suo.fi/article/9484 %X Concentrations of five metals — Mn, Fe, Zn, Pb, Cu — were determined in samples of a common dwarf shrub, Ledum palustre, collected from seven S. Finnish raised bogs (between 60 and 61 °N) in September-October 1977. The analyses were made separately for the twigs (stems) of last four years and for the leaves of last two years. The material was dry-ashed at 450°C, dissolved in cone. HC1 on hot plate, filtered and diluted to 50 ml with deionized H2O which solution was finally analyzed with an atomic absorption spectrophotometer (Varian Techtron AA-1200). Ash percentage and manganese showed identical distributions with maximum values on second-year leaves and a decrease of concentrations in stems with age (Figs. 2 and 3). Also the concentrations of Fe, Zn and Pb (but not Cu) increased from first- to second-year leaves. In stems, there was a fairly regular increase in Fe and Pb levels from first to fourth year, while Zn and Cu changed little or decreased with age (Fig. 3). Average concentrations in Ledum (leaves + stems of last two years) were compared with those in the substrate (Sphagnum fuscum peat). The results (Table 1) showed that manganese was the most favoured metal and iron the least. The relative enrichment of metals from the peat substrate to Ledum followed the order Mn >Cu >Zn >Pb >Fe.