Discrete feeding of forest seeds is an urgent task for accurate detection of seeds during grading and reducing the seeding rate. The study used Pinus sylvestris L. seeds from cones collected in a natural stand of the Lisinsky educational-and-experimental forestry farm, Leningrad region, Russia, in 2017. Well-known methods for determining the properties of bulk materials were used; the results were processed by mathematical statistics using the MS Excel program. The physical and mechanical properties of uncalibrated seeds as a bulk material were determined. The angle of repose of Pinus sylvestris L. seeds, determined using a hollow cylinder by calculation, is 24.92°. The angle of repose of Pinus sylvestris L. seeds, determined using a hollow cylinder and a goniometer, is 32.7°. The significant discrepancy (~8°) in the values obtained by these methods is explained by the seeds shape. The flowability of Pinus sylvestris L. seeds corresponds to an excellent (free) category. The study will enable correct seed treatment protocols for sustainable forest management. However, some questions remained unresolved: how to orient a single seed in the right direction? How does seed-size calibration affect the angle of repose?

The present study analyzes the composition of pine wood cultivated on artificial plantations in the Leningrad Oblast (Region). Comparing to pine wood from natural stands, a smaller heartwood zone along the height of the pine trunk and a lower content of resinous substances are noted. The content of cellulose and lignin in the heartwood and sapwood of pine is distributed differently along the trunk. The distribution of pentosans and water-soluble substances in the heartwood and sapwood along the trunk is associated with the lignin complex. The component composition of the studied pine wood from planted stands is quite uniform in its indicators if compared to the wood of older natural stands. Sulphate pulping of planted pine wood showed a higher yield of technical cellulose than the average yield from wood obtained at natural stands of the studied region.

The article describes a three-stage hierarchical method of solving the optimization of forest road network layout problem taking into account road construction and transportation costs using a mathematical model based on the multi-commodity flow model. Optimization of the forest road network layout problem is formulated as an alternative of the Steiner tree problem in graphs. The first stage involves optimization of the forest road network layout within clusters. Many harvesting areas have already been divided into clusters using a clustering optimization model. The second stage involves solution of the similar problem between clusters. At the third stage, the final optimization is performed based on the results obtained at the first two stages. The developed methodology of heuristic solution of optimization of forest road network layout problem allows to improve solving time by 3-6 times with a deviation from the optimal result in the range of 0.5-8%.

Woodworking and pulp-and-paper mill areas accumulate significant volumes of wood debarking waste, which is stored in bark dumps with a volume of up to 1 000 000 m3. Methods for recycling bark, both fresh and stagnant, are proposed through the production of fuel briquettes and pellets, composting, building materials, and the use of combustible gases that accumulate in the depths of the old bark layers. Characteristics of extractive substances obtained from bark are given and their fields of application are considered. Possible ways of recultivation of old bark dumps, ways of waste water treatment are offered. The recommendations on reduction of technogenic hazard of bark dumps are given and the necessity of constant monitoring of such objects is grounded. The technological scheme of complex use of bark dump materials on the basis of developments of Saint-Petersburg State Forest Technical University is proposed.

The research analyzes observation materials and condition assessment of 100-year geographical Scots pine forest cultures created in 1913 by professor Ogievsky V D on drained lands of the Okhta forestry territory to study the intensity of Scots pine trees growth depending on the seeds origin. The planting material was grown from seeds collected in the northern, southern, eastern, southwestern and central parts of Russia. The growth of Scots pine cultures was studied and changes in wood stock, trees amount, annual increments, influence of meteorological factors on radial increments were analyzed depending on the origin of the planting material. The results of research show that sustainable and highly productive cultures can be grown from seeds of northern and eastern regions of Russia.