title: Root uptake of lead by Norway spruce grown on 210Pb spiked soils.
abstract: The root uptake of lead (Pb) by trees and the transfer of Pb by leaf litter deposition to the forest floor were investigated through a pot experiment with Norway spruce. Natural Pb and radio isotopic lead (210Pb) were determined in needles and twigs and in the pot soil spiked with 210Pb. Calculations of the specific activity in plant material and in the supporting pot soil showed that less than 2% of the Pb content of needles and twigs originates from root uptake and approximately 98% are deposited from the atmosphere. Atmospheric Pb has declined by a factor of 7 from 1980 to 2007 but is still a major pathway of Pb to vegetation and topsoils. The conclusion from the experiment is that the internal circulation of Pb through root uptake, translocation and litterfall, gives an insignificant input of Pb to the forest floor compared to atmospheric deposition.
authors.affiliation: University of Copenhagen, Oster Farimagsgade 2D, DK-1353 Copenhagen K., Denmark. mfh@bi.ku.dk
authors.forename: M F
authors.initials: MF
authors.lastname: Hovmand
authors.forename: S P
authors.initials: SP
authors.lastname: Nielsen
authors.forename: I
authors.initials: I
authors.lastname: Johnsen
mesh_terms: D003718:Denmark; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D007854:Lead / Q000493:pharmacokinetics*; D028222:Picea / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*; D014873:Water Pollutants / Q000493:pharmacokinetics
chemical_list: D012989:Soil Pollutants; D014873:Water Pollutants; D007854:Lead