Detritus Inside High Density Pine Stands in the Taiga Forest-Steppe Subzone of Central Siberia

At the present time, certain harmful effects are observed that affect forest ecosystems. They are forest fires, phytopathogenic activities, and invasive influence, in addition to changes in climatic conditions, in particular an increase in temperature. The study is intended to determine the potential stock of wood and carbon compounds in detritus. The principal categories for it are snags, downed dead wood, and stumps. Additionally, it predicts the amount of wood residues in the conditions of the taiga forest-steppe subzone of Central Siberia. A coarse woody detritus was examined in the structurally pure forests of Scots pine (Pinus sylvestris L.). A circular area of constant radius was used as an accounting unit. The cause woody detritus in snag was 82 %, in downed dead wood was 16 % (1.5–18.3 m3‧ha–1), in stumps was 2 % (0–2.6 m3‧ha–1). The content of detritus was found in only 11 % of the total stock of the stand. The environmental quality at the location of growth had a strong effect on the amount of detritus because of the growth rate of the trees, which is higher in the ideal conditions. Most of the coarse woody detritus (66.4 %) was accumulated in the stands of productivity class I, which was almost double that in the stands of productivity class II (33.6 %). The carbon content in snags, downed dead wood, and stumps was higher in high-density stands (0.81 or more) than in medium-density stands (0.6–0.8). The age and average height of the stand were considerable indicators for predicting stocks of wood and carbon in snags. The amount of wood and carbon in the downed dead wood also depended on the growth density and total stock of wood at the location. The regression equations were generated to predict the volume of the coarse wood detritus. According to the results, it can be concluded that in the investigated stands the destructive processes were identified, which were determined by the concentration of detritus. The production of detritus was activated by both age composition, when a major part of the trees enters the mature or overmature stages, and biogenic factors, which were stimulated by pathogenesis and climatic changes. For citation: Vais A.A., Varaksin G.S., Mamedova S.K., Anuev E.A., Gerasimova O.A. Detritus Inside High Density Pine Stands in the Taiga Forest-Steppe Subzone of Central Siberia. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 3, pp. 9–20. (In Russ.). https:// doi.org/10.37482/0536-1036-2023-3-9-20