Nekrasova O.A., Dergacheva M.I., Uchaev A.P.
TO RECENT BASE FOR PALEOECOLOGICAL RECONSTRUCTIONS BASED ON HUMUS OF URAL PALEOSOLS ^{[№ 12 ' 2017]}
When carrying out the reconstruction of the natural environment of the past by paleopedology methods the humus composition is used as one of the significant diagnostic features. Interpretation of materials is based on the recent basis — similar characteristics of modern soils of different formation conditions on both the territory of location of the paleosols and adjacent to them. Revealing the Holocene-Pleistocene evolution of the Ural natural environment requires the materials of exploring the specific features of the humus composition of different types of soils in its different regions including the Middle Urals for which data on humus are not generalized. On the basis of the original and literary material data generalisation of the humus composition specific features of the modern Middle Ural types of soils, the closeness of most humus characteristics and the reliable differences of some of them in the most common in this region plain sod-podzolic and brown mountain-forest soils are revealed. It was established that the differences in the content of individual groups of humus substances and the integral index Cha:Cfa are unreliable. Significant differences were revealed only for the following characteristics of humus composition: the content of total organic carbon, as well as FA1a, FA2, and FA3. The parameters of the composition of humus in gray forest soils of the Middle Urals are typical for similar soils of other regions of the Urals and adjacent territories. The obtained limits of variation of the integral indicator of the composition of humus in soddy-podzolic, brown mountain-forest and gray forest soils of the modern Middle Urals, will allow to reconstruct the conditions of humus formation in paleosols in similar bioclimatic conditions. It has been established that the sod-podzolic and brown mountain-forest soils of the Middle Urals, forming within the boundaries of a single bioclimatic zone at different positions in the relief, have close characteristics of the qualitative composition of humus.

Fedeneva I.N., Dergacheva M.I.
HUMUS OF POSTLITHOGENOUS AND SYNLITHOGENOUS PALEOSOLS AND ITS USE AT PALEOECOLOGICAL RECONSTRUCTIONS ^{[№ 8 ' 2017]}
When paleosols’ studying and their using at paleoecological reconstruction there is a problem of detection such signs of an ancient pedogenesis which would allow to compare and generalize the data characterizing the paleosols, created according to different models — as a result of synlithogenous and postlithogenous soil formation. Such signs are humus parameters, which reflect elementary processes of humus formation, depend on climatic conditions and remain during geological time. Late Pleistocene paleosols of different regions of Altai Mountains studying has shown that using of humus characteristics at paleosols diagnostics and reconstructions of paleoecological conditions can be carried out, irrespective of soil formation model. Paleosols of mountain regions can have a safe soil profile only in case of a postlithogenous pedogenesis which is characteristic of long warm stages of paleogeographic history whereas in a cold climate the pedogenesis is accompanied by active processes of sedimentation, and it is possible to speak about synlithogenous soil formation. In this case reliable reconstruction of paleoecological conditions can be carried out with using of a complex of characteristics of the humic substances remaining in deposits. For comparison of the paleosols created according to various models of a pedogenesis in the territory of Altai Mountains the indicators that are most often used at paleosols diagnostics — the characteristics of humus substances groups were used. Humus characteristics of the paleosols most widespread in a Late Pleistocene in the territory of Altai have been considered. It has allowed revealing that average humus parameters of various types and subtypes of paleosols, concerned to synlithogenous and postlithogenous models of soil formation, are similar.

Bazhina N., Ondar E., Ochur K., Dergacheva M.
HUMUS OF MOUNTAIN TUNDRA SOILS OF WESTREN PART TUVA ^{[№ 10 ' 2015]}
The features of the composition of humus mountain tundra soils depending on the position in relation to the glacier formed under different environmental conditions the western Tuva.

Dergacheva M.I., Bazhina N.L., Ondar E.E., Ochur K.O., Ryabova N.N.
ENVIRONMENTALLY INDUCED COMPOSITION AND PROPERTIES OF HUMIC ACIDS IN SOILS OF WESTERN TUVA ^{[№ 10 ' 2015]}
The correlation between the composition and properties of humic acids in western part of Tuva climatic parameters calculated for each individual object. It is shown that humic acids having a certain value of the ratio of H:C match as certain values of temperature and humidity (rain) at which the humic acids formed in such ratio of these forming elements.

Ondar E.E., Dergacheva M.I., Bazhina N.L., Ochur K.O.
HUMUS OF MOUNTAIN TAIGA SOD SOILS OF TODZHA BASIN (NORTH-EASTERN PART OF TUVA) ^{[№ 6 ' 2015]}
The composition of humus, structural features of humus profiles and specific elemental composition of humic acids of mountain taiga sod soils key area "Azas" (north-eastern part of Tuva) are discussed. According to the classification in 2014 WRB, these soils are Umbric Gleysols Dyst Soil sections are located on different positions of complex Catena that differ by relative height, expositions and a steepness of slopes. The vegetation cover is represented by light-forest of subtaiga nature-with rich grassland. The lower horizons of soil profiles are characterized by low temperatures. Analysis of materials of humus soil study showed that the features of its composition are higher value of Cha: Cfa and higher solubility (hydrolyzability) of humic substances and calcium humates share in them as well. This distinguishes these soils from analogues located in the European part of Russia. Characteristics of humus profiles depend on the exposure of slope on which the soil is formed and the soil position in the Catena, but in general the type of humus profile is characteristic as a forest soils. Specifics of of composition and ratio of elements in humic acids of the mountain taiga sod soils under study of the key area has been the lack saturation of of humic acid with nitrogen, a high proportion of carbon and relatively low values of H / C. Position in the relief has little effect on the elemental composition of soil humic acids under studied: the ratio of elements is changing the slope just as a trend. But the effect on the elemental composition of humic acid has a history of their formation which included the stage of development of steppe soils. Until now, in areas close to key sites "Azas" locally common steppe.

Dergacheva M.I, Ponomarev S.Y.
MORPHOGENETIC CHARACTERISTICS OF SOILS SINCE ANCIENT PEDOGENIC FEATURES LOCATED IN EASTERN TERRITORY OF OB PLATEAU ^{[№ 6 ' 2014]}
Data of morphological and physico-chemical soil features of eastern part of Ob plateau in order to understand the ways of forming of modern soils with ancient attributes of pedogenesis in profile are discussed. Properties of soils formed on loess-like loams and exhumed paleosols, vary in relation to the history of their formation. In whole, their characteristics are not beyond chernozem soils formed under conditions with varying degrees of humidifying.

Bazhina N.L., Ondar E.E., Ochur K.O., Dergacheva M.I.
SOIL HUMIC ACID ELEMENTAL COMPOSITION OF WESTERN PART OF THE TERRITORY TUVA ^{[№ 10 ' 2013]}
Specificity of humic acid element composition of soils of some key sites of the western part of Tuva territory located in different landscape conditions is shown. Materials and the revealed laws are of interest as a part of data bank using for paleoenvironment reconstruction based on humic acid element composition.

Dergacheva M.I., Nekrasova O.A.
URANIUM AND THORIUM CONTENT IN THE HUMIC ACIDS OF PALEOSOLS BURIED UNDER BARROWS AND CULTURAL HORIZONS OF ARCHAEOLOGICAL OBJECT STEPNOE 7 (SOUTHERN URALS) ^{[№ 10 ' 2013]}
In this paper the contribution of humic acids in the total soil pool of radioactive elements U and Th was estimated on the example of paleosols, buried in the Bronze Age, the cultural horizons of the same time and territorial localization, as well as modern background soils in forest-steppe conditions of Southern Urals.

Dergacheva M.I., Nekrasova O.A., Vasilieva D.I., Fadeeva V.P.
HUMIC ACID ELEMENTAL COMPOSITION OF DIFFERENT FORMATION CONDITION VIRGIN CHERNOZEMS ^{[№ 10 ' 2012]}
Humic acid element structure characteristics of virgin chernozems of different regions (ETR, Southern Ural, Western Siberia and Mountain Altai) and different formation conditions are discussed. It is shown that the mass percentages, share of individual element content and their relationship clearly responsible landscape conditions. Materials can serve as a basis for assessing agricultural land and use for revealing of anthropogenic transformation specificity and diagnostic environment as well.