DIVERSITY OF HUMUS PROFILES OF SOILS OF ECOTONE, TAIGA-STEPPE SOUTH-EASTERN PART OF WESTERN SIBERIA
Knowledge of the history of soil formation and building models describing or even predicting their evolution are among the main challenges of genetic soil science. Such knowledge and models may help improving the prediction of the behaviour of soils and landscapes in a changing natural and built environment. The soil integrally reflects and records the action over time of all factors of pedogenesis in its properties and performs a global function in the biosphere - the information. One of the most reliable memory carriers is soil humus, which structure remains in the soil for a long time. The humus soil profile is a kind of “archive” that holds the encrypted information about the evolution of the environment at different stages of the soil formation. The aim of this work is to determine the characteristics of humic profiles and to show the diversity and complexity of their structure, reflecting the changing natural environment on the territory of the ecotone, taiga-steppe South-Eastern part of Western Siberia. Humus profiles as carriers of “soil memory” are considered on the example of soddy-podzolic soils and gray forest of soils under- taiga on the Tom-Yaya interfluve and chernozems of forest-steppe zone on Salair plain. Humus profiles reflect the contrasting evolution and fixed the phases and stages of soil formation in its structure, associated with changes in moisture and temperature. In humus profiles revealed several maxima the relationship of carbon of humic acids to carbon of fulvic acids, which also indicates a change in climatic conditions during the formation of soils. Thus, humus profiles save information about the features of the natural environment over a period of formation of the soil body in its characteristics, and therefore can serve as a “tool” for the reconstruction of the paleogeographic environment and can be used to construct models of the behaviour of soils in the future.