Comparison of plant and precipitation chemistry in catchments with different levels of pollution on the Kola Peninsula, Russia

Abstract

Highly variable concentration patterns for up to 29 elements were found in three plant-groups (crowberry — Empetrum nigrum; lichen — Cladonia sp.; and terrestrial moss — Hylocomium splendens+ Pleurozium schreberi) collected in selected catchments in the central Barents region. Element concentrations in the plants are compared with those observed for rain, snow melt water and snow filter residue collected in the same catchments. Based on these results the suitability of each plant-group as a bio-indicator for atmospheric input of elements is evaluated. Lichen shows by far the lowest concentrations in most major elements (Ca, S, P, Al, Mg, Mn and Fe). The highest levels of Cr, Fe, Mg, and S appear in all three plant-groups near the nickel roaster in Zapoljarnij. In moss and lichen, Ag, Ba, Bi, Cd, and Na show the highest concentration within the impact zone of the nickel refinery in Monchegorsk. However, these plants do not survive in the immediate vicinity of this refinery where concentrations of As, Co, Cu, Mo, Ni and Pb in crowberry are higher than for all other vegetation samples in our study. The three groups react quite different to dust input (e.g. Al, Ba, Ca, K, La, Na, P, Rb, Sr and Y) from the large open cast apatite mine in Kirovsk near Apatity. For a large number of elements all three groups mirror at least a part of the elemental input via precipitation. Each plant-group reflects precipitation chemistry especially well for some elements. Moss reacts most strongly to rain, lichen is probably the best ‘integrator’ and crowberry reflects best the particulate input. Ni is the only element for which all three plant-groups directly reflect the atmospheric input pattern via precipitation. For the other elements the input patterns are often essentially altered. To reliably use plant chemistry for documenting pollution patterns a very large regional contrast in deposition appears to be necessary for most elements.