Characteristics of natural regeneration in coniferous forest plantations affected by natural disturbances in the Kardzhali region

Natural regeneration is a fundamental process in the restoration of forest ecosystems following natural disturbances and plays a key role in forming the future species composition and stability of forest stands. The present study analyzes the processes of natural regeneration in coniferous forest plantations damaged by the heavy snowfall in 2015 in the Kardzhali region, Eastern Rhodopes. The area with natural regeneration covers 367.2 ha. The assessment of the regeneration was based on data obtained from the 2019 inventory and field measurements conducted in 2026 in six sample plots, where no reforestation activities had been implemented. The study includes species composition, species proportions, height, density, origin and spatial distribution of the undergrowth. The results reveal insufficient regeneration coverage, uneven spatial distribution of the undergrowth, low density and limited participation of coniferous species. A clear tendency toward the dominance of native broadleaved species was observed, mainly Quercus petraea (Matt.) Liebl and Quercus frainetto Ten., mostly of coppice origin. Seed-origin undergrowth of Pinus sylvestris and Pinus nigra has low persistence and gradually declines due to strong competition and unfavorable light conditions. The obtained results show that, in the absence of active silvicultural interventions, the restoration processes tend toward the formation of mixed or predominantly broadleaved stands that correspond more closely to the indigenous vegetation of the region.