Закономерности роста Larics sibirica в противоэрозионных лесных полосах на южном черноземе

Abstract

The purpose of the study was to establish the growth patterns of 57-year-old Siberian larch and lanceolate ash in anti-erosion forest strips. Plantings were studied by methods of forest taxation according to OST 56‑69‑83 and the textbook S-PB of the Forestry University. Private methods of K.K. Vysotsky and S.S. Pyatnitsky were also used. Experiments have established the outstripping growth of larch (the main breed) and ash (the accompanying breed) in the flow-regulating forest strip, reinforced with a water-retaining rampart, compared with the near-drainage due to surface runoff accumulated in the rampart pond. The growth intensity index of larch increases with age by 2.95 cm/cm2, and the productivity of cambium decreases in the runoff-regulating forest strip by 0.9 dm3/m2, in the by-ravine by 3.40 cm/cm2 and 0.73 dm3/m2, respectively, which is associated with a lower moisture content in the soil. In the by-ravine forest strip, soil moisture reserves for the long-term observation period averaged 49.0‑61.1% of the lowest moisture capacity, in the runoff control zone with a rampart – 56.7‑72.3%, which additionally accumulated 34.2‑49.7 mm of moisture in 1.5 m of soil layer. The bonitet of larch when the forest strip is strengthened by a rampart exceeds the bonitet of the by-ravine strip by 1 class. It should be noted that Siberian larch is a more highly productive species compared to pedunculate oak by one or two classes of bonitet in identical conditions with soils on the flask (previously published by us, 2021). The coefficients of determination of the relationship between the growth in height of Siberian larch growing in the flow-regulating and by-ravine forest strips, from the indicators of age, growth intensity, productivity of cambium are 0.92‑0.98, which indicates a close relationship. Siberian larch, as the main species, is recommended in protective forest stands, especially on bedrock.