Soil thermal properties of forest biogeocenoses in steppe zone as a diagnostic indicator of their soil genesis

Soil is a specific natural body, which is characterized by a number of features due to which it differs from living organisms and rocks. One of these features is its thermal properties. The most important thermal properties of the soil are thermal conductivity, thermal capacity and thermal diffusivity, which reflect the specific features of the set of properties inherent in different soils. As a result of the studies, the existence of a direct relationship between the values of thermal conductivity and thermal diffusivity of Calcic Chernozem and the content of the silt fraction in them, as well as between the thermal capacity and the content of organic matter in them. The established relations do not appear clearly in Luvic Chernozem and Chernic Phaeozem. The maximum thermal properties for Luvic Chernozem and Chernic Phaeozem were found in the eluvial horizon, which in the lower part borders on the illuvial horizon. The eluvial horizons of Luvic Chernozem and Chernic Phaeozem are characterized by lower thermal properties compared with the illuvial horizons. The thermal properties of soils can be used to clarify the distribution characteristics of the silt fraction and organic matter along the profile, as well as determination of the intensity of eluvial-illuvial processes. The establishment of these soil features is an important characteristic of their soil genesis, which is especially important for chernozem soils under forest vegetation.