Search

A middle-taiga iron-illuvial podzol (Glossic Endogleyic Albic Podzol) was studied on an ancient eolian dune in the Bol’shoi Yugan River basin (the Ob’ River tributary, Surgut region), near the large-scale archaeological research site. The radiocarbon age of 31 charcoals was determined, and 8 variants of the location of charcoal-containing soil zones relative to other morphological patterns were identified. It was proved that charcoal can help in dating the time of mosaic pattern formation, and the development of podzolic horizon coincided with intense wildfires in the second half of the Holocene. It was found that charcoal-containing soil zones first appeared in soils about 5 ka ago. Charcoals older than 5 ka cal. BP were not found. Pyrogenic events became twice more frequent at the beginning of the third millennium BP, with their maximum in the middle of the third millennium BP. The frequency of pyrogenic events decreased noticeably at the very end of the second millennium BP. Many peaks of pyrogenic events during the last five millennia coincided with the periods of archaeological cultures. An assumption that the continuous existence of forest environment leads to the permanent burial of charcoal due to fall of a tree accompanied by its uprooting was partially confirmed.

The differentiation in the cadastral value of soils in Irkutsk and Tomsk oblasts is presented. The soils of the agricultural zone of Tomsk oblast are characterized by higher indicators of the cadastral value, and, consequently, have higher values of the agroclimatic potential. The sensitiveness of calculating the cadastral value of lands to various soil and geographical conditions is shown. With the development of erosion and gleying processes the reduction in the cadastral value can reach 40 and 63%, respectively, and even 60% under conditions of soil alkalinity.

Detailed study of a peat plateau near the southern boundary of the East European permafrost zone has been performed. The botanical and palynological compositions of the peat to the depth of 10 m, its radiocarbon dates (the AMS method), and its physical and chemical characteristics have been determined. The accumulation of peat in this area began about 8300 years ago at the end of the Boreal period. In the middle of the Atlantic period, the rate of peat accumulation reached 1.44 mm/yr. During the warming phase in the Middle Subboreal period, the peat plateau was subjected to active thermal erosion; part of the peat was eroded. The processes of thermal erosion are also active at present and destroy the edges of peat mounds. At the same time, the gradual accumulation of peat on the plateau continues. An increase in the degree of peat mineralization is expected upon the establishment of aerobic conditions against the background degradation of the permafrost. Peat plateaus and large peat mounds have been the sinks of atmospheric carbon for a larger part of their history. In this context, we do not expect their significant negative influence on the climate in the future.

Soil cover patterns in the northern part of the area of aspen-fir taiga on the Tom’-Yaya interfluve at 170–270 m a.s.l. are analyzed. Landscapes of the subtaiga piedmont province are found at somewhat lower heights. The three major forms of the local mesotopography include virtually flat interfluve surfaces, slopes (that predominate in area), and the network of ravines and small river valleys. Modal soil combinations on the slopes consist of the typical soddy-podzolic soils with very deep bleached eluvial horizons and dark gray (or gray) residual-humus gleyic soils with dark humus coatings. With an increase in the degree of drainage of the territory (toward the local erosional network), the portion of gleyic soil subtypes decreases from nearly 100% on the flat interfluves to 10–15% on the slopes; the portion of soils with residual humus features decreases from 80–90 to 10–15%, respectively. These two soil subtypes can be considered intergrades between typical soils of the aspen-fir taiga (soddy-podzolic soils with very deep bleached horizons) and dark gray and gray residual-humus soils characteristic of the subtaiga zone in the south of Western Siberia.

Morphological diagnostics of soil-forming processes in the young soils of technogenic landscapes are considered. Comprehensive multilevel studies of soils developed on the tailings of coal mines of different age in a wide range of climatic conditions in Siberia are performed. The processes of the mineral substrate transformation predominate at the initial stages of soil formation. Then, with the development of the soil profiles, the processes of the organic matter transformation begin to play the major role, and the organoprofiles of the soils specific to the particular climatic zone are formed. Micro- and submicroscopic studies allow us to judge the character of major soil processes and to identify the features attesting to the activity of some associated processes.

Microzonality was studied on the model object—Shira lake depression. Geometry of the soil structures that comprise the soil cover has been revealed and characteristics of components of soil combinations have been analyzed.