Morphological Characteristics of the Scots Pine (Pinus sylvestris L.) During Natural Regeneration in the Dumps of the Kumertau Lignite Section (Russia, the Republic of Bashkortostan)

Successful natural regeneration of Scots pine (Pinus sylvestris L.) was noted at the dumps of the Kumertau brown coal mine (KBR). The purpose of the study was to characterize the architectural features of aboveground and underground parts of pine during natural regeneration at KBR dumps. Research objectives: to describe morphological features of above- and underground pine parts during natural regeneration, to characterize crown formation and assimilation apparatus features of pine plants, and to describe formation features of root system in natural regeneration process on KBR dump sites. Model plants were excavated in October, packaged, transported, and kept in a cool, dry location to prevent needle shedding. Next, the camera treatment of plants was carried out. The root system was washed and the plant was measured along the entire length of the plant, separately measuring the length of aboveground and underground parts guided by the root neck. The width of above- and underground parts was also measured, as well as the diameter of the root neck and increments from the last year's growth (2024). The number, length, and mass of needles were measured individually, as were the amount and weight of annual increments. The age of plants was determined using a magnifying glass with x2 and x10 magnifications. The whorls were also used to determine the age of the plants. Additionally, the number of rings at the level of the root necks was used to estimate the age. An analysis of the above- and below-ground architecture of Scots pine undergrowth undergoing natural regeneration in industrial waste areas revealed uneven development patterns among plants.. It has been established that, with the successful growth of a pine tree, height and beyond the level of grass cover occurs further active growth and increase in the size of tree crown, as well as mass of axial and lateral growth. For 8-year-old pines, indicators such as length of aboveground part, width of aboveground and underground parts, size and weight of axial and laterals, as well number and weight needles differ. Individual differences in development of seedlings during natural regeneration at CBD dumps were identified, which is due to individual variability in pine plants. The practical significance of the research results lies in establishing the role of forest crops created during forest reclamation work at CBD landfills in the natural regeneration process of pine trees in disturbed landscapes. It is theoretically and practically interesting to characterize the formation of pine cenopopulation in CBD landfill during natural regeneration.