Vol 28, No 6 (2024)

The results of protective forest plantations state assessment in Predkamye of the Tatarstan Republic are presented. The state assessment was carried out using the method of continuous recalculation, determining taxation indicators and categories of trees state on trial plots in accordance with regulatory documents. In total, 20 trial plots were established and surveyed in the Sabinsky, Arsky, and Atinskiy municipal districts. It was established that, according to silvicultural and taxation indicators, the average age of the surveyed plantings equals to 48 years, forest density ranges from 0.5 to 0.9, and a quality class ranges from I to II. Based on the sanitary condition of the sites, trees of the 1st and 2nd categories were identified, on which forestry measures such as sanitary felling, a natural reforestation are recommended. An assessment of trees on trial plots shows that protective forest plantings fulfill their functions, slow down erosion and increase soil fertility, due to the accumulation of plant waste, in particular soft-wooded broadleaved trees. The average growth volumes of stem wood and carbon sequestration were calculated for each site. The largest volume of deposition was detected in mixed composition plantations of birch, pine, and poplar. It is indicated that poplar (Populus) is a promising species in carbon sequestration. This species was identified in two trial plots. According to silvicultural and taxation characteristics, the plantings are assigned to quality class II. Sanitary felling is recommended in these areas. The volume of carbon sequestration in these areas is set at 3.17 and 1.90 t/ha per year. Natural regeneration of the main forest-forming species of the Republic of Tatarstan is recorded in the areas, they are pedunculate oak, silver birch, Scots pine and Norway maple. Viable undergrowth contributes to the formation of stable mixed-composition, uneven-aged, complex-structured protective forest stands.

The paper deals with the aboveground mass and carbon sequestration of blueberry in native spruce forests of the Komi Republic middle taiga subzone. The aboveground phytomass of blueberry in blueberry–sphagnum and blueberry communities make up 21.0 and 30.6, including carbon 10.3 and 15.0 g/m², respectively. The blueberry accounts for 50 % and 58 % of the total aboveground phytomass of plants of the grass-shrub layer in the studied blueberry spruce forests. The author also considers some ecological aspects of photosynthetic carbon dioxide fixation by blueberry leaves in blueberry-sphagnum spruce forest. In summer during daylight hours, the intensity of photosynthesis largely depends on photosynthetically active solar radiation (PAR). There is a stable positive dependence of photosynthetic activity of leaves during the day and air temperatures. The correlation between the CO₂ absorption rate and relative humidity is negative. The diapasons of optimal environmental parameters (PAR intensity and air temperatures) have been identified within limits of which the highest photosynthetic activity values of plant in summer period are measured. The data obtained can be used for predictive models of the dynamics of organic matter and carbon in taiga ecosystems under both climate change and external impacts on forest communities.

The results of a study on improving the technique of clonal micropropagation of cultivars Heuchera L. (‘Autumn Leaves’, ‘Cherry Cola’, ‘Dew Drops’, ‘Marmalade’) and ×Heucherella H.R.Wehrh (‘Art Deco’, ‘Golden Zebra’, ‘Solar Eclipse’, ‘Plum Cascade’) are presented. A brief analysis of the qualitative and quantitative composition of the in vitro bank of representatives of the genera Heuchera, ×Heucherella and Tiaerella L. in the Laboratory of plant biotechnology of the MBG RAS is given. It was found that the influence of the concentration of 6-benzylaminopurine in the composition of the Murashige and Skoog nutrient medium on the quantitative characteristics of microrosettes in the structure of their general variability is dominant. With an increase in the concentration of 6-benzylaminopurine, a statistically significant increase in the multiplication rate was revealed in all cultivars studied in the experiment (with the exception of the cultivar ‘Dew Drops’). The formation of a small number of large microrosettes on the Murashige and Skoog nutrient medium with the absence of growth regulators was noted. The highest frequency of spontaneous rhizogenesis on the specified nutrient medium was recorded in all studied cultivars. It has been shown that meta-Topoline is preferred (relative to thidiazuron) as a growth regulator, an alternative to 6-benzylaminopurine, affecting the quantitative and qualitative characteristics of microrosettes of model cultivars Heuchera and ×Heucherella. The largest number of viable and well-developed microrosettes with a size of less than 1.0 cm, suitable for use at the multiplication stage, on a medium with the addition of thidiazuron, was recorded.

The article is devoted to the history of the study and use of non-cellulose wood delignification products by alkaline and sulfite methods, using substances contained in waste lyes and gas blows and carried out in wood delignification processes. The processes of regeneration of soda and sulfate delignification liquids and their instrumental design, formed at the historical stages of development, are described in detail. The methods of using by-products of alkaline delignification, which are not used as energy carriers in the processes of regeneration of lyes, as well as the entire complex of compounds formed during sulfite delignification using chemical and biochemical processing methods against the historical background of the development of chemical wood technology, are considered. This article is the sixth in the series «Wood as a chemical raw material. History and modernity»: previous parts were published earlier in the Forestry Bulletin, 2020, t. 24, no. 1, no. 5; 2021, t. 25, no. 1, no. 3, no. 5.

The paper provides a rationale for choosing the optimal method of transporting industrial chips. The calculation of transport costs for three transportation modes is given. The economic efficiency of the optimal method is justified. Wood chips are a product of processing secondary resources of a timber industry enterprise. At the same time, industrial chips are raw materials for pulp and paper production. Therefore, if the chip meets the technological requirements, it is advisable to use it for its intended purpose. The study presents two ways of transporting technological chips from CJSC Lesozavod 25 to JSC Arkhangelsk Pulp and Paper Mill. The location peculiarity of these enterprises involves a small distance from each other (the maximum distance does not exceed 60 km), transport link can be carried out in two ways either by road or by water in barges. Highway transport is currently the main mode of transportation, ensuring high speed and regularity of deliveries. However, it has a high cost. Waterborne transport carried out by barges offers significant savings, but has a limited navigation period and requires complex loading and unloading operations. To overcome the disadvantages of each method, a combined approach is proposed, using barges during the navigation period and motor vehicles during the off-season. The results of the study show that the combined method is the most economical option, providing a reduction in annual transport costs by 21.33 % compared with using only road transport.

The technological process of harvesting «energy» willow using soft containers is considered. On the basis of the device patented by the author the conceptual model of the harvesting machine is offered, which consists of a tractor, mounted equipment for cutting and chopping willow and a trailed device for installation, loading and dumping of containers on the ground. Two variants of «energy» willow harvesting technology are presented: 1) the currently used technology, when the harvesting machine works together with the transport machine; 2) the technology proposed in this paper, when the harvesting machine works independently of the transport machine with chip loading into soft containers. A mathematical model of the existing technological process of willow harvesting and the technology using soft containers has been developed. Simulation experiments on mathematical models of technological processes for the distance from 1 to 5 km from willow plantation to wood chips warehouse and for different maximum possible productivity of willow harvesting — from 5 to 15 t/h have been carried out. It is revealed that the proposed technology of willow harvesting with the use of containers does not depend on the distance from the plantation to the warehouse and allows to achieve productivity, which under equal conditions is 2–3 times higher than the productivity of the existing technology. It is established that the load factor of the harvester according to the existing technology depends on the distance from the plantation to the wood chip warehouse and varies from 0.268 to 0.823. The conditions under which the load factor of the harvester according to the declared technology is equal to 1 have been determined. It is recommended to use the technology of willow harvesting with the use of containers for small farms as minimising investment costs for the purchase of machinery.