| Abstract
| - Effects of pine (Pinus sylvestris) and liming (pH-changewith CaCO3) on the mobility and bioavailability of Pb (lead)in boreal forest soil, previously used as a shooting rangearea, were examined in laboratory microcosms. Solubilityand mobility of Pb were measured, and bioavailability ofPb was assessed directly using a luminescent bacterial sensorfor Pb. Results showed that pine seedlings had a majorrole in the immobilization of Pb in the contaminated soil. Thepresence of pine seedlings reduced the amount of watersoluble Pb by 0−56% in humic rich surface soil and by 12−93% in mineral soil (5−20 cm) and also decreased by 40−57% the mobility of Pb in the surface and mineral soil.Liming did not reduce the solubility, mobility or bioavailabilityof Pb in the soil. Significant positive correlation wasfound between the concentration of total water solublePb and the bioavailability of Pb in the soils. The concentrationof bioavailable Pb was not, however, predictable fromthe concentration of total water soluble Pb; bioavailablePb was only 4−6% of total water soluble Pb in humic surfacesoil and 13−43% in mineral soil.
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