According to the International Agenda for Botanic Gardens in Conservation about 500 species of woody plants, which represent six regions of the world, are conserved in the collection of the Research Institute of Agricultural Problems of Khakassia. The arboretum is located in the dry steppe zone of the Republic of Khakassia. There are 44 species of trees, shrubs and lianas of different rarity. Many of them are beautifully flowering, and therefore can be used for landscaping. The aim of the work is summing up the introduction of rare and endangered plants for their further usage in the improvement of residential areas of the Khakasia steppe zone. The research objects are 21 species of rare plants of the arboretum of the Institute. The periods of phenological stages of species, their growth and development rhythm, winter hardiness, period and duration of flowering, and ways of reproduction were determined. As a result, an introduction point was given to each plant and its perspectivity was estimated. The average age of rare plants was 40.7 years. All studied plants are early growing (from April 10 to May 10). In new growing conditions 72 % of species pass through a full life cycle, 19 % flower, but do not bear fruit, 9 % do not flower. According to the flowering period, 53 % of rare shrubs are early flowering (May). The longest flowering period was found in 19 % of species. The main phenological stages of plants occur during the stable periods, the low level of standard deviation confirms it. Self-seeding is typical for 28 % of the studied species. In the arboretum conditions 42 % reproduce both by seeds and vegetatively; 33 % – vegetatively and 23 % – by seeds. The introduction point shows the degree of adaptation to the new environment. As a result, 10 species have 5 and 4 points (96 %), Menispermum dahuricum, which annually freezes to the soil level, has 3 points. Perspectivity of the studied plants was identified based on the analysis of their viability parameters: 4 % of species turned to be non-perspective while 20 % are less perspective. Long-term studies of the biological features of rare woody plants indicate that rather perspective (38 %) and perspective (38 %) of the plants can be used in the improvement of residential areas of Khakasia. New species are introduced into the production for single and group planting: Deutzia glabrata, Armeniaca mandshurica, Prinsepia sinensis, Spiraea trilobata, and Rosa spinosissima. For citation: Gordeeva G.N. Effectiveness of Introduction of Rare Plants in the Arboretum of Khakassia. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 24–36. DOI: 10.37482/0536-1036-2021-3-24-36

The article presents the results of the development of a technological mode for obtaining bisulfite hardwood pulp of high yield on a magnesium base for the production of various types of containerboard. The reliable and effective chemical and heat recovery technology implemented in the bisulfite method allows to use it in independent sulfite process. The effect of the duration of stay at the final temperature on the pulp yield and kappa number was studied when developing the technological mode of cooking. It was found that the increase in the duration of stay at the final temperature of 160 °C more than 40 min leads to violations of the selectivity of the cooking process. Increasing the duration of stay at the final temperature up to 70 min is accompanied by a decrease in pulp yield by 6 % at a constant value of the kappa number of the semi-finished product. Technological cooking mode: hydromodule 5, SO2 consumption 15.0 %, cooking solution pH 4.3–4.5, impregnation time at 120 °C – 35 min, cooking duration at 160 °C – 40 min. The mode allows to get a semi-finished product with a high yield of 60–65 % with a kappa number of 58–60 units without a hot grinding stage. An assessment of the mechanical strength characteristics of the laboratory samples of bisulfite pulp was carried out in accordance with the standards of the Russian Federation. The obtained values of bursting strength, resistance to flat compression, breaking strength, and breaking stress were comparable with the values of the industrial sample of hardwood neutral sulfite semi-chemical pulp with a semi-finished product yield of 75–78 %. It is shown that the presence of bark in the technological chips in the amount of 7.5 % is accompanied by a decrease in the yield of bisulfite hardwood pulp by 4.5 % and mechanical strength by 7.8 %. For citation: Koroleva T.A., Milovidova L.A., Dryakhlitsyn A.A. Production of High-Yield Hardwood Pulp by Bisulfite Cooking. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 161–169. DOI: 10.37482/0536-1036-2021-3-161-169

The increasing consumption of pulp for chemical processing, including production of sanitary tissue products and other medical products, food packaging, as well as fillers for food products leads to new requirements for the quality of raw materials. The task of improving the characteristics of pulp has become particularly acute in connection with the COVID-19 epidemic: the demand for disposable nonwoven materials in direct contact with the human skin has increased several times over. The elemental chlorine free (ECF) sulfate pulp bleaching process, which uses chlorine dioxide as a bleaching agent, dominates bleached pulp production worldwide. The chlorine-containing compounds formed as a result of bleaching pollute not only waste water, but also the product itself. In the near future, it is expected that paper products made with chlorine-based bleaches may be banned for the production of sanitary tissue products and food packaging. If the products of the pulp and paper industry do not meet international consumer requirements, the pulp market for these purposes may face undesirable results. The most promising direction of modernization the existing bleaching schemes, both in terms of the process consumption parameters and the quality of the produced pulp, is the use of oxygen-alkaline bleaching in the first stage. Determination of total and organically bound chlorine content in pulp materials in accordance with ISO 11480:2017 on the advanced plant has shown, that the introduction of bleaching schemes using oxygen-alkaline agents will ensure the recommended content of chlorine compounds while maintaining the necessary characteristics of pulp for the manufacture of medical and sanitary tissue products, food packaging. However, high quality of finished products that meet consumers’ requirements is possible only if the chlorine content is controlled at all stages of pulp production, since the quantitative indicators of this substance content remain close to the upper allowable limit. For citation: sofronova e.D., Lipin v.A., Dubovy v.K., Sustavova t.A. Minimizing the Chlorine Content in bleached sulfate pulp for sanitary tissue products and food packaging. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 186–195. DOI: 10.37482/0536-1036-2021-3-186-195

Uncontrolled development of unfavorable vegetation during artificial reforestation reduces survival and growth rates of planted trees, and in some cases causes their death. The use of reforestation equipment is often extremely difficult, therefore the most promising solutions are those involving creation of spruce plantations using seedlings with closed roots and manual planting tools without preliminary mechanical tillage. Long-term protection of plantations from undesirable vegetation is ensured by the use of modern herbicides registered for use in the forest sector in the Russian Federation. The article presents the results of 3-year field experiments on the use of herbicides and their mixtures to supress undesirable vegetation in the first years after planting European spruce (Picea abies (L.) Karst.) in the Leningrad region. High efficiency of herbicides for long-term suppression of shrubs, and herbaceous and woody plants was found. A mixture of herbicides Roundup, WS (360 g/L glyphosate acid), Anchor-85, WDG (750 g/kg sulfometuron-methyl potassium salt) and Arsenal, WC (250 g/L imazapyr) inhibited the development of herbaceous weeds for at least two growing seasons. The processes of undesirable vegetation development after spraying plantations with herbicides, the reaction of seedlings to the use of chemicals, indicators of conditions and growth of conifers were also studied. Analysis of the obtained data proved the possibility of combining a protective chemical pretreatment with herbicides and planting seedlings in a single technological procedure or planting seedlings within a few months after chemical treatment, which significantly reduces the risk of damage to seedlings by herbicides. The survival rate of plantations created by planting one- or two-year-old seedlings with closed roots was 93–98 %; and the biometric indicators were such that spruce plants could successfully compete with undesirable vegetation. The application of the developed method ensures a substantial reduction in labor and other reforestation costs compared to traditional technologies involving preliminary mechanical tillage and subsequent agrotechnical weeding of plantations. For citation: Egorov A.B., Postnikov A.M., Bubnov A.A., Pavluchenkova L.N., Partolina A.N. Cultivation of Spruce Plantations Using Modern Herbicides without Agrotechnical Weeding. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 9–23. DOI: 10.37482/0536-1036-2021-3-9-23

The studies were carried out in stands of various degree of devastation: in the city, suburban forests and forests of the green zone. Recreational loads strongly affect the sanitary condition of spruce forests. The number of healthy trees decreases to 30–42 % with increasing recreational digression, while the number of declining and dead trees increases to 15–36 %. The state of tree stands in the forests of the green zone is estimated at 1.2–1.5 points, and 2.1–2.7 points in the suburban forests. No declining and dead trees were found in the forests of the green zone, and in the suburban forests their share was 15 and 36 % of the total number, respectively. Therefore, generally, spruce suburban forests are classified as weakened. Approximately 59 % of the area of suburban forests is in the III stage of recreational digression, and 19 % – in the IV stage. Growth studies of P. abies showed that the features of these processes are determined mainly by the seasonal variability of climatic factors. Studies have shown that the features of growth processes of P. abies are determined mainly by seasonal variation of meteorological factors. It was found that the earliest growth of shoots and needles begins and ends in the urban environment. The year-by-year variability in the timing of these phenophases reaches 1–2 weeks. Soil compaction as a result of recreational loads has a particularly negative effect on the intensity of tree growth and annual growth of vegetative organs. Shoots of P. abies in green forests (undisturbed stands) are longer than in suburban and urban plantations by 2–30 % and 6–17%, respectively. The longest needles (16.6–19.7 mm) are formed in the forests of the green zone. In urban plantations this value is 12.8–15.0 mm. The smallest needle packing was found in the city conditions, characterized by the maximum degree of recreational digression. Here, the annual radial increment of the trunk of P. abies under the influence of recreational loads decreases by 16–20 % compared to the forests of the green zone. The sequence in the growth phenophases does not depend on the degree of environmental disturbance. The shoots are the first to grow (in May), young needles after 1 or 2 weeks, and then the formation of wood in the lower part of the trunk begins. The sequence in stopping the growth processes is as follows: shoots, needles, trunks. For citation: Kishchenko I.T., Olkhina E.S. Growth of Vegetative Organs of Picea abies (L.) Karst. in Anthropogenic Environment. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 59–72. DOI: 10.37482/0536-1036-2021-3-59-72

The seasonal rhythm of height growth of young shoots of Scots pine growing in a 33-year-old shrubby-sphagnum pine forest of the northern taiga natural-climatic zone has been studied in a complex with the main physiological processes. The possibility of regulating their intensity by additional introduction of nitrogen fertilizer has been determined. It has been found that on hydromorphic excessively wet soils of the North, seasonal height growth of pine occurs with a maximum rate in late June and early July, when air temperature rises and the root system is released from excessive moisture. Unlike lichen pine forests, in which pine roots are not affected by flooding, on hydromorphic peat soils pine grows much slower and during the growing season has less intensive physiological processes. The low rate of shoot growth and physiological processes in pine in sphagnum forest site conditions is explained by dysfunction of its root system as a result of soil anoxia caused by flooding, as well as by insufficient supply of growing shoots with acronutrients from the crown as a result of violation of their normal outflow and movement in the tree. Nitrogen fertilizers positively affect growth and physiological processes in pine trees in sphagnum forest types. However, their effect in these forest site conditions is much weaker than in the dry lichen forests of the Far North. On water-logged peat soils under the influence of nitrogen fertilizer seasonal height growth of pine trees increases by 20 %, the duration of seasonal shoot growth increases by 8–10 days, the intensity of photosynthesis increases significantly, and, as a result of reduced water onsumption for transpiration, the tree water regime normalizes and the transpiration productivity increases. These positive nitrogen-induced changes ultimately improve the viability and productivity of sphagnum pine forests. For citation: Zarubina L.V., Khamitov R.S. Seasonal Growth of Scots Pine under the Conditions of Water-Logged Soils of the North. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 86–100. DOI: 10.37482/0536-1036-2021-3-86-100

Current scenarios of the consequences of global warming stimulate research on the carbon-depositing capacity of vegetation cover. The stem is the main part of the tree biomass, and the accuracy of its volume assessment determines the possibility of correct monitoring and forecasting of forest resources. In the Russian forest management system, willow was not among the main forest-forming species, and therefore there was no need to develop valuation standards for it. However, due to the increased relevance of assessing the carbon-deposing function of Russian forests and the requirement to take into account the contribution to the carbon balance of all types of vegetation, there is a necessity to develop such standards. The solution can be found in the development of a generic model (or table) that takes into account the morphology of willows within the Salix L. genus and is based on data published in different regions and countries. The object of our research is data on the volume of willow stems, which is published and freely available in Russia, Kazakhstan, Bulgaria, and Norway in the form of tables or regression models. However, the extent to which each local model is applicable in other regions is unknown. To resolve this uncertainty, we used meta-analysis as a statistical procedure that combines the results of several independent studies in order to find a common pattern. As a result, we obtained a generic model of stem volume for the Salix genus, which is characterized by a high coefficient of determination and can be applied to estimate the stem volume of any species of this genus with minimum deviations from the calculated values. The results of the work are aimed at improving the accuracy of accounting deciduous stands during forest management and monitoring activities, valuation of stands on permanent and temporary trial plots. The implementation of unified standards for the use, reproduction, conservation and protection of willow stands with all the diversity of its species will solve a number of practical issues. For citation: Usoltsev V.А., Paramonov А.А., Tretyakov S.V., Koptev S.V., Tsepordey I.S. Generic Model of Willow Stem Volume: A Meta-Analysis. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 49–58. DOI: 10.37482/0536-1036-2021-3-49-58

Wheeled forest machines currently dominate the logging industry in Russia and in the world. Every year in Russia, the share of machine-made wood harvesting using Scandinavian technology increases, which involves felling trees, delimbing, and bucking them at a swath. Moreover, this technology is used not only for conventional two-machine systems with harvester and forwarder. In some regions of Siberia three-machine systems are gaining popularity. They consist of a feller-buncher, a swath processor, and a forwarder for skidding obtained logs. The issue of increasing the efficiency of forwarders is relevant for the timber industry. Its solving is possible on the basis of a comprehensive assessment of design solutions with the use of modern modeling and process optimization tools at the stage of development design. This approach requires deep theoretical and experimental research and is of great scientific and practical interest. When determining the maximum volume of skidded wood, the following machine limitations are considered: by bearing capacity; by tangential traction force; by the traction of the mover with the soil (tangential traction force should not exceed the traction force of the mover with the driving surface – the soil of the logging site). Besides this, there are recommendations to limit the weight of the skidder with the load, based on the permissible track depth after the first pass of the machine; it is believed that this figure should not exceed 20 cm. This statement is supported by the results of studies of the track development under the cyclic influence of the wheel mover (that is when the forwarder repeatedly passes the same section of the portage). This raises the question of forwarder productivity in the skidding operation with the regard to the track depth limitation. For citation: Burmistrova O.N., Prosuzhih A.A., Khitrov E.G., Kunitskaya O.A., Luneva E.N. Theoretical Studies of Forwarder Productivity with Limited Impact on Soils. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 101–116. DOI: 10.37482/0536-1036-2021-3-101-116

The main drivers of competition among the products made with the use of adhesive compositions are the toxicity of finished products, the consumption of raw materials and energy resources, the duration of the main technological operations. These drivers can be controlled by using adhesives with different fillings and/or modifications. Adhesives based on phenol-formaldehyde and melamine-urea-formaldehyde resins are used to produce plywood with increased water resistance. Apart from resins, adhesives usually contain hardeners, fillers, and modifiers that affect the properties of the finished product. Technical aerosol is one of the modifiers of synthetic resins with a wide range of action. Aerosil is characterized by three types of interaction: physical adsorption, chemical adsorption (formation of hydrogen bridges by silanol groups), and chemical reactions on the surface layer. The chemical composition of aerosil was analyzed. Technical aluminum fluoride (AlF3) is of particular interest. It can interact with alkali metal fluorides with the formation of complex compounds that improve polymer structuring. The acids that make up aerosil reduce the pH to 2.0–3.5, so they can be catalysts for the curing process of melamine-urea-formaldehyde resins. The effect of technical aerosil on the properties of adhesive systems based on phenol-formaldehyde and melamine-ureaformaldehyde resins has been studied. Viscosity, curing time, and wetting ability of adhesive compositions were determined. The obtained results indicate the possibility of using this modifier in the composition of phenol-formaldehyde and melamine-urea-formaldehyde resins up to 15 pts. wt. The nature of the aerosil action on adhesive compositions was determined using IR spectroscopy. Analysis of the results showed that aerosil promotes deep structure formation of the polymer by increasing the molecular weight of the molecules. These bonds make it possible to form a more structured polymer with bound formaldehyde. Studies of the effect of aerosil on the properties of finished products were carried out. At the same time, an increase in performance indicators was found: the strength of adhesion increases, the toxicity of plywood decreases. The results of experiments on the effect of technical aerosil, taking into account the reduction of bonding time can be applied in the development of technological processes for obtaining plywood of high water resistance. For citation: Sokolova E.G., Rusakov D.S., Varankina G.S., Chubinsky A.N. Effect of Technical Aerosil on the Properties of Adhesive Compositions. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 133–144. DOI: 10.37482/0536-1036-2021-3-133-144

Siberian larch (Larix sibirica L.) is the main commercial species in Russia. Currently, larch woody greens are underutilized. They are considered a waste product from logging. This is due to the lack of knowledge on the composition of compounds and the variability of the raw material source itself as a result of the fall of the needles. The research purpose is to study the composition of hydrocarbons and esters from Siberian larch needles in summer and autumn collection from the Tomsk region. The shredded needles were extracted with propan-2-ol; then, after distillation of the solvent, substances soluble in petroleum ether (PE, 40–70 °С) were isolated. The latter were divided into free acids (31.5 % for green needles and 28.0 % for yellow needles) and neutral substances (59.8 and 48.1 %, respectively). Then, eutral substances were chromatographed on silica gel: hydrocarbons (2.43 and 3.02 %, hereinafter from neutral substances of green and yellow needles, respectively), esters (31.30 and 33.80 %) and triglycerides (11.70 % and 6.44 %). The ester and triglyceride fractions were exposed to alkaline hydrolysis and the acidic components of esters (9.12 and 24.80 %) and triacylglycerols (17.43 and 26.15 %) were produced. Fractions of unsaponifiable compounds, in addition to alcohols, contained unsaponifiables with unchanged Rf values on thin-layer chromatography (TLC). Fractions of unsaponifiables were chromatographed on silica gel, and then the isolated fractions were additionally chromatographed on silica gel with silver nitrate. The isolated compounds were identified by nuclear magnetic resonance (NMR) spectroscopy. In the acidic component of esters, the main components are linoleic and linolenic acids. Hydrocarbons are represented by sesquiterpenes in both collections of needles. A new aromatic hydrocarbon for coniferous plants, geranyl-p-cymene, has been identified. For the first time, polyprenols were isolated from Siberian larch greens, the structure of which differs from spruce and pine polyprenols by chain length according to NMR spectroscopy and mass spectrometry data. They contain from 14 to 20 isoprene links in the chain of molecules with predominance of prenol-17. The yield of polyprenols was 12.8–14.9 % of neutral substances of yellow and green needles, respectively. Tetracyclic triterpene alcohols and sterols were isolated from green needles. Triterpene alcohols were not found in yellow needles. For citation: Mikson D.S., Roshchin V.I. Hydrocarbons and Ethers of Extractive Substances of Siberian Larch Needles. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 170–185. DOI: 10.37482/0536-1036-2021-3-170-185