Ecological Features and Resource Potential of Oak Forest Litter in the Don–Voronezh Watershed

This study examines the features of litter formation in oak forests located on different types of terrain within the Don–Voronezh watershed. Field work began in the spring of 2025. A landscape catena was created from six test sites (TS) in oak forests: TS 2 (ALTITUDE above sea level = 190 m), upper watershed terrain types (TT), Veduga-Don watershed; TS 1 (118 m), upper-terraced TT, lower terrace of the Don River; TS 3 (160 m), supramundane-terraced TM, 4th terrace of the Don River; TS 6 (160 m), TT slope, Voronezh River slope; TS 4 (90 m), floodplain TT, central floodplain of the Voronezh River; and TS 5 (114 m), floodplain-terraced TT, 2nd terrace of the Usmanka River. At the beginning of the growing season, samples of forest litter were collected at all test sites. At the beginning of the growing season, samples of forest litter were collected at all test sites. The thickness of the litter was measured, its moisture, volume density and fractional composition were determined, after which the stocks of forest litter (t/ha) were calculated. The data obtained made it possible to classify the forest floor in all the studied oak forests as destructively primitive, very low-power deciduous. The results of field and laboratory studies were processed using correlation and regression analyses, which allowed us to assess the relationship between the physical properties of the forest floor and its reserves. The strongest direct relationship was found between forest litter stocks and bulk density (R2 = 0.8539). The analysis of the fractional composition of the samples of the spring forest litter showed that it was quantitatively dominated by active fractions consisting mainly of leaves and herbaceous residues. Of the greatest interest are the revealed patterns in the differences in the intensity of destructive processes and, consequently, in the rate of return of forest litter decomposition products to the biological cycle of oak forests on different types of terrain. In accordance with this indicator, oak forests can be arranged in descending order in the following variation series: Floodplain oak forests, upper-floodplain-terraced oak forests, lowland oak forests of interfluve, sloping (riverine) oak forests. The practical significance of the results obtained lies in their applicability both for fundamental research (on the biological cycle of biophilic elements) and for scientific and practical work (assessment of the resource potential of reserves of dead organic matter in the litter of forest-steppe oak forests).