Vol 28, No 1 (2024)

The results of a study of European spruce (Picea abies (L.) Karst.), which is a primary forest species and an integral component of forest biogeocenosis in the mixed forests zone, are given. According to the data obtained, forest lands covered with spruce forests in the forest areas of the Smolensk-Moscow Uplands range from 16 to 65 %. Wood sorrel spruce forests and composite spruce forests, formed on moraine and cover loams, are predominant. Both natural and artificial spruce stands are able to grow according to Ia and I bonitet classes, reaching high stocks of stem wood (600 m³/ha and even more). The silvicultural precocity of spruce forest crops in combination with a biological short life (due to recurrent droughts) was determined. Therefore, in order to find out the trends in spruce tree productivity dynamics and on this basis to justify the appropriate cutting age of artificial spruce stands, the relevant studies were carried out in five forestries of the Smolensk-Moscow Upland. It has been established that the maximum results of wood accumulation in terms of trunk volume are characteristic of the dominant trees (I and II) of Kraft classes. For the dominant group of trees (Kraft classes I–III), an intensive increase in growth is observed up to sixty-five years, and for subordinate trees (Kraft classes IV and V) — up to fifty-five years. Given the decline in the life potential of spruce trees after 70 years of age, it is not recommended to leave spruce stands after 80 years of age.

The purpose of the research is to determine the vital state of forest crops of 2015–2018 planting growing in the green belt of Astana on limited and conditionally forest-suitable soils. Tax measurements were carried out on the test areas, the state of each tree was described by gradation — healthy, weakened and dying, then the state of the plantation was determined. It was revealed that there was a significant difference in preservation between weakened and healthy plantings. The safety of all the studied tree species in weakened plantings did not exceed 68,4 %, the lowest safety was 9,7 % in Pinus sylvеstris and 15,0 % in Pоpulus nigra. The lower limit of this indicator in healthy plantings was 15,4 % (Pinus sylvеstris), the upper limit was 83,6 % (Ulmus laеvis). It was determined that with preservation within 55 % after the phase of crop establishment, the plantings of Ulmus laеvis and Acer negundо are quite viable and can be transferred to forested lands. For the cultivation of healthy stands of European birch, preservation of at least 53 % is necessary. In the green zone, the following pests significantly weaken the condition of woody and shrubby plants such as web-spinning sawfly, hazel sawfly, mottled umber moth, belted beauty, elm flea weevil, large flea leaf.

The paper presents data on the needle morphology and anatomy of lodgepole pine (Pinus contorta Dougl.) and Scots pine (Pinus sylvestris L.) growing in experimental cultures in the middle taiga subzone of the Komi Republic. It was shown that lodgepole pine exceeds Scots pine by 28 % in needles length (p < 0,001), and by 15 % in needles cross-sectional area (p < 0,001). The number of stomata per 1 mm of needle length in lodgepole pine is 17 % less, and the number of resin canals in needles is 77 % less. Lodgepole pine is characterized by a multi-row hypodermis, thickening of the tangential and radial walls of endoderm cells, poorly developed sclerenchyma of the central cylinder, and a greater number of water-conducting xylem elements by 23 % (p < 0,01) than Scots pine. The radial dimensions of the mesophyll cells are larger, and the epidermis, hypodermis, endoderm and sieve cells of the phloem are smaller in lodgepole pine than in Scots pine (p ≤ 0,05). The large needles cross-sectional area of lodgepole pine is provided by the large size of the mesophyll cells and the multi-row nature of the hypodermis. It is shown that the foliation rate of two-year-old shoots and the proportion of brachyblasts preserved on them are 61 % higher in lodgepole pine. Three-needle brachyblasts and very rarely four-needle brachyblasts are found on the shoots of Pinus contorta more often than on Pinus sylvestris. The large size and preservation of photosynthetic organs on the shoots of the introduced species relative to the native species contribute to high growth intensity, give an advantage in biomass accumulation, and indicate successful adaptation of lodgepole pine to the conditions of the middle taiga subzone.

The article considers the physical parameters of snow cover — thickness, density and snow water equivalent in the middle taiga deciduous forests of different ages of post-harvest origin. The studies were carried out in the third decade of March in the winter of 2005–2015 and 2020–2021 at permanent plots. The taxation parameters and their dynamics for the studied stands are presented. The dependence of snow cover parameters on the species of woody plant and meteorological conditions of the year is shown. The average long-term values of the snow cover thickness within the birch-spruce forest were 75 ± 9, in the aspen-birch forest — 72 ± 7, in the open place — 70 ± 10 cm. Over the years of research, the average height of snow cover within the birch-spruce stand varied from 62 ± 3 to 97 ± 2 cm, in the aspen-birch stand from 48 ± 2 to 92 ± 3 cm. The height of the snow cover measured at the same time within the deciduous stands is uneven, which is due to the complex composition of the stand. Data on the influence of woody plant species on the height of snow cover are presented. Snow water equivalent in the snow cover of deciduous forests vary from 81 ± 3 mm to 191 ± 4 mm with average long-term values of about 140 mm. The average value of the snow cover density over the years of deciduous stands is about 0,2 g/cm³.The density and water equivalent in the snow cover in deciduous forests is higher than in the open place. The snow accumulation coefficient in snow cover of the studied deciduous forests varies from 1,0 to 1,5. The results of the research make it possible to analyze between the change in forest stand taxation parameters and the dynamics of physical parameters of snow cover in deciduous forests of post-cutting origin, contribute to modern studies of the influence of woody vegetation on snow cover, and can also be used in hydrological calculations when assessing the effect of snow cover on river runoff.

Paulownia tomentosa (Thunb.) Steud. is a perennial tall and fast-growing deciduous plant with very large leaves and beautiful fragrant inflorescences, consisting of pale purple flowers. In North America, Europe and Asia it is used as a valuable garden and park plant. The technology of clonal micropropagation, including obtaining a sterile culture, propagation of regenerated plants, their following rooting and adaptation ex vitro, has been optimized for this species. During sterilization of vegetative buds, the optimal result was achieved by using calcium hypochlorite at a concentration of 7 %. The duration of exposure was 7 minutes. The optimal culture medium at the stage of micropropagation was MS (Murashige and Skoog, 1962) supplemented with 1,5 mg/L 6-BAP and 0,05 mg/L IAA. The multiplication rate was 9,58 ± 0,81. The regenerants most successfully rooted on 1/2 MS culture medium containing 1,0 mg/L IBA and 20,0 g/L sucrose. The maximum survival rate of P. tomentosa (100 %) obtained on a substrate consisting of peat, perlite and sand in a 1:1:1 ratio. The developed technology is the basis for obtaining homogenous planting material.

Variation of Brutyskaya pine (Pinus brutia Ten.) wood density and its macrostructure parameters depending on the growth height above sea level on the Mediterranean coast within Syria, and its subspecies (Pinus brutia var. pithyusa) on the Southern coast of Crimea within the Black Sea coast is considered. The study was conducted in artificially created plantations aged 45...55 years. Four plots were surveyed within the province of Latakia in the Syrian Arab Republic (30, 190, 330, 655 m above sea level, respectively) and three sites within the South Coast of Crimea in the Russian Federation (25, 150, 200 m above sea level, respectively). The taxation characteristics were determined, as well as the basic wood density and its macrostructure parameters such as the width of late and early xylem zones from wood cores taken at a height of 1.3 m from the ground level were examined. Dispersion analysis of the data obtained was carried out. The accuracy degree of the altitude above sea level factor influence on wood density is shown. Different direction of the altitude above sea level effect on wood macrostructure parameters was found for the studied plots. It is found that at an altitude of more than 190 in Latakia, Syrian Arab Republic and more than 150 m above sea level on the South Coast of Crimea in the Russian Federation do not differ significantly in macrostructure parameters. The significance of differences in wood density in the regions under consideration as a function of altitude above sea level is indicated.

The innovative technologies to modify friction surfaces are considered. It is shown that epilamization, as a process of applying a protective multifunctional film on equipment, materials, friction parts and products components, includes the effective use of not only traditional lubricating oils based on petroleum products, but also compositions based on perfluorinated oligomers and oils of vegetable origin. The effect of multifunctional lubricating compositions based on a fluorine-containing polypropylene oxide product of the brand 6SFK-180-05 and experimental epilam Triboconcentrate on the tribological characteristics of the lubrication system based on rapeseed and tall oil has been studied. The effect of epilam concentration, mechanical load and time on the antiwear properties of the vegetable oil composition and the fluorinated additive was studied. It has been shown that oil compositions based on rapeseed oil in the presence of 2–3 % perfluorinated epilam have the highest antiwear properties. The intensity of wear, estimated during testing on a four-ball friction machine with a force load of 50– 350 N in the presence of epilaminating compositions, was acceptable for the performance of a mechanical device. The antiwear properties of oil compositions based on vegetable raw materials depended both on the properties of the applied epilamy composition and on the nature of the distribution of mechanical load values during the testing of two brands of epilams. A positive factor in the use of technology for the use of fluorine-containing epilames in lubricating mixtures is an increase in the viscosity of the working composition compared to the original oils. The results obtained are of interest for developing a methodology for the long-term operation of mechanical devices and increasing their wear resistance under mechanochemical impacts.