Timofeeva Ya.O., Karabtsov A.A., Burdukovskii M.L., Purtova L.N., Martynenko E.S.
В журнале Eurasian Soil Science
Год: 2025 Том: 58 Номер: 13 Страницы: 1-13
The structure, composition, and specificity of accumulation of trace elements by rounded nodules in gleyic soddy brown-podzolic soils (Gleyic Luvisol (Manganiferric)) of nature reserves and a national park in the south of the Far East have been studied by advanced analytical methods and noninvasive techniques. The nodules are characterized by pronounced differentiation into external (brown and ocher-brown, Fe- enriched, and dense) and internal (dark brown, Mn-enriched, and loose) zones. According to the distribution of Mn compounds in the internal zone, two types of nodules are identified: with an undifferentiated internal zone and with a core (cores). The cores contain C-enriched microzones, which are centers of Fe and Mn pre- cipitation. The stages of coprecipitation of Fe and Mn and the stages with predominant precipitation of one of the elements are identified in the nodules. The nodules consist of a complex of minerals inherited from soils, as well as of nodule-specific minerals (goethite, feroxyhyte, and birnessite). The Fe content in the nodules is, on average, four times higher than that in the soil, the Mn content is 21.9 times higher, and the C content is 3.6 times higher. The most intensive accumulation in nodules is typical for Pb (EF = 5.53–12.14), which is determined by the joint participation of C- and Mn-containing compounds in its binding. Nickel (EF 0.89–5.81) and Cr (EF 1.22–2.60) are less actively accumulated; and the accumulation of V (EF 0.85–1.88) and Sr (EF 0.58–1.43) is weak. The phases accumulating Ni, Cr, V, and Sr are represented by nodules containing Fe and C. Zinc does not accumulate in the nodules. A comparison of the concentrations of water-soluble forms of trace elements reflects a decrease in the mobility of Cr, Pb, Ni, V, and Sr in nodules as compared to soils.
