title: Root versus canopy uptake of heavy metals by birch in an industrially polluted area: contrasting behaviour of nickel and copper.
abstract: We investigated root versus canopy uptake of nickel and copper by mountain birch, Betula pubescens subsp. czerepanovi, close to a nickel-copper smelter on the Kola Peninsula, northwest Russia. To distinguish between aerial contamination of leaf surfaces by dust particles and root-derived contamination of leaves by soluble metals, we transplanted seedlings from a control site to clean and metal-contaminated soils and exposed these seedlings both in clean and polluted sites. Patterns of leaf surface contamination and root uptake were similar for nickel and copper; however, nickel but not copper was effectively translocated from roots to shoots and leaves. The majority (80-95%) of nickel and copper found in birch foliage in the heavily contaminated site was due to deposition of dust particles on leaf surfaces; 32-40% of foliar nickel and 9-19% of foliar copper were in water soluble forms. Washing of fresh leaves removed only a minor part of surface contaminants; boiling of unwashed leaves in distilled water for 15 min removed >90% of soluble nickel and copper.
authors.affiliation: Section of Ecology, University of Turku, FIN-20014 Turku, Finland. mikov@utu.fi
authors.forename: M V
authors.initials: MV
authors.lastname: Kozlov
authors.forename: E
authors.initials: E
authors.lastname: Haukioja
authors.forename: A V
authors.initials: AV
authors.lastname: Bakhtiarov
authors.forename: D N
authors.initials: DN
authors.lastname: Stroganov
authors.forename: S N
authors.initials: SN
authors.lastname: Zimina