Heavy metals in soil–plant system in biogeocenoses of the Bolshezemelskaya Tundra
G.Ya. El`kina, S.V. Deneva, E.M. Lapteva
Section: Monitoring of natural and anthropogenically disturbed areas
Biological cycle, content, and stocks of heavy metals in plant organic matter are an interesting study topic for both
ecological description of biogeocenoses and ecological monitoring. The biocenosis includes three plant communities as
dwarf shrub-mossy (65.6), dwarf shrub-lichen-mossy (17.9), and dwarf shrub-lichen (16.5% of total area) communities.
Soils are Histic Turbic Cryosols under dwarf shrub-mossy community and Histic Cryosols under lichens. Weight fraction
of elements in samples was measured by the method of atomic-emission spectrometry with inductively coupled plasma
SPECTROARCOS. Soil samples for total ratio of elements were treated by the microwave frequency mineralizer Minotavr
2 (Russia, Lumex Ltd). Mobile forms were carried out of soil samples with the help of 1N ammonium acetate buffer solution
(AAB) with pH 4.8 for exchange forms, and an outflow in acid digest (1M НСl extract) for acid-soluble forms. Heavy metals in plants were assessed after they had been decomposed using nitric acid-hydrogen peroxide mixture in the microwave
frequency mineralizer Minotavr 1 for the method of spectrometry with inductively coupled plasma (PND F 16.1:2.3:3.11-98).
Copper and zinc have a high, cadmium – mean, and cobalt, nickel, lead – low frequency rate of biological cycle.
Frequency rate of cycle for the majority of elements in lichen communities is high in contrast to leafy moss communities.
Mosses slow down cycle of elements and hold them in dead material for long time. Composition of elements in soils under
communities normally is the same as that in plants. Organic soil horizon of tundra biocenoses should be considered as a
surface soil-geochemical barrier with a slow elemental cycle. Mineral soil part has high concentrations of zinc and low – of
cadmium. Besides, concentrations of copper, zinc, nickel, and cadmium is similar to worldwide mean values but concentrations of cobalt and lead slightly exceed them. Differences in profile distribution of elements relate to physical-chemical
properties of elements, complex redox conditions of soils due to permafrost and cryoturbation processes. Also, they depend
on composition of plant communities.
Keywords: Heavy metals, biogeochemical cycle, Bolshezemelskaya tundra, biogeocenosis, biomass
ISSN 1995-4301
Select viewing options
