The spatial structure of the habitat for plant communities based on soil functions in virgin forest-steppe of the Central Russian Upland is the focus of this study. The objectives include the identification of the leading factors of soil function variety and to determine the spatial heterogeneity of the soil function. A detailed topographic survey was carried out on a key site (35 hectares), 157 soil, and 34 geobotanical descriptions were made. The main factor of soil and plant cover differentiation is the redistribution of soil moisture along the microrelief. Redistributed runoff value was modelled in SIMWE and used as a tool for spatial prediction of soils due to their role in a habitat for plant communities' functional context. The main methods of the study are the multidimensional scaling and discriminant analysis. We model the composition of plant communities (accuracy is 95%) and Reference Soil Group (accuracy is 88%) due to different soil moisture conditions. There are two stable soil habitat types: mesophytic communities on the Phaeozems (with additional water runoff more than 80 mm) and xerophytic communities on Chernozems (additional runoff less than 55 mm). A transitional type corresponded to xero-mesophytic communities on the Phaeozems with 55-80 mm additional redistributed runoff value. With acceptable accuracy, the habitat for natural plant communities based on soil function model predicts the position of contrastingly different components of biota in relation to their soil moisture requirements within the virgin forest-steppe of the Central Russian Upland.(including organic carbon and nutrients concentration), and moisture characteristics are the key properties for the plant's growth [4,[9][10][11][15][16][17]. The connection between soil properties and plant parameters are implemented in the global and regional ecological scales [18][19][20][21].Our study site is located in the virgin forest-steppe of East European plain. The climatic conditions of the forest-steppe with favorable water-air and thermal regime contribute to the formation of the most fertile soils among all the natural land areas [22]. However, the diversity of edaphic conditions determines the wide variation of soil moisture and aeration regimes and, as a result, variety in plant species composition. We suppose that the soil moisture is the leading factor controlling species composition in the virgin forest-steppe, as it has been qualitatively shown [23].The aim of our work was the digital mapping of the habitat for natural plant communities' soil function, soil moisture conditions and related plant species composition in virgin forest-steppe landscapes of V.V. Alekhin Central Chernozem State Reserve (Kursk region, Russia). The objectives were to: (1) quantitatively characterize the relationship of the water regime and soil properties, the composition of plant species; (2) define the different habitat types; (3) create and verify the habitat for a plant communities map. We characterized the soil forming factors features for each se...