How Were Chestnut Soils of the Dzhanybek Plain Transformed as a Result of Climate Change?

The period since the mid-1970s is considered as the period of modern global warming, and 1976 is conventionally taken as its beginning. Southern and arid regions are known to be especially sensitive to climate changes. In this context, the aim of our study was to identify the features of climate warming in the area of the Dzhanybek Plain and to characterize changes in soil properties associated with the established climatic trends. The object of the study is represented by a microcatena of chestnut solonetzic soils (Someric Calcic Luvic Kastanozems (Loamic, Sodic) and Mollic Salic Calcic Solonetzes (Loamic)) on the territory of the Dzhanybek Experimental Station of the Institute of Forest Science of the Russian Academy of Sciences. Data on the climate of the study area for the period of 1914-2021 are summarized. It is shown that the period from 1976 to 2021 compared to the period from 1914 to 1975 is characterized by an increase in the mean annual air temperature by 1 degrees C, the mean annual precipitation by 18.3 mm, the mean air temperature of the cold season by 1.5 degrees C, and the mean precipitation of the warm season by 39.5 mm. The results of terrain study together with micromorphological and chemical data suggest that in the past 54 years, the groundwater table has risen by 1 m, the groundwater mineralization and salinity have increased by at least two times, soil salinization and calcification have also become higher, and the depths of soil processing by mesofauna and root penetration have increased, though these changes have not yet been reflected in the soil organic carbon content. If the identified climate trends continue, the studied soils are expected to become saline and effervescent from the surface, and the content and stock of carbon in them will increase. However, to confirm this assumption, further more comprehensive study and continuation of stationary observations are required.