Trunk Wood Research Articles

Интродукция климатипов лиственницы европейской в зоне смешанных лесов

The range of European larch (Larix decidua Mill.) covers Central Europe, while in Podmoskovie this species grows out of its natural distribution area. In plantings this species is known for its fast growth, stability, good soil and water protection properties, and high wood quality. All larch species in the Moscow region have a positive reputation in terms of high adaptability, they are often more productive than the local coniferous forest-forming species. Similar results were obtained by foresters in Central and Eastern Europe. The increment in stock in a number of Polish larch populations at the age of 50–60 years can reach 10–15 m3/ha per year, that is why this wood species is widely used in silvicultural practice in these countries. The research aims at studying the growth and productivity of European larch climatypes outside its natural habitat. The research covered experimental sites of European larch introduction located in the territory of the center of the Russian Plain within the Moscow region. Of all the European larch climatypes, the Polish larch has the highest growth rates in height and diameter, as well as in the accumulation of trunk stock. It forms stands with very large trunks and has an increased value of soil-light basic increment in diameter of the trunks. The Polish larch is superior to the European larch of Sudeten origin in terms of silvicultural effect. As a result, Polish larch has undeniable advantages among all the reviewed provenances in terms of growth rate and accumulation of trunk wood reserves, which is a strong argument in the issue of its expanded introduction as a promising conifer for target reforestation. European larch from Scotland has the worst growth and productivity. On the whole, all climatypes of European larch successfully adapt to the conditions of the center of the Russian Plain and are superior to all local coniferous forest-forming species in terms of inventory characteristics.

CREATION OF DECORATIVE FORMS OF SCOTS PINE FOR THE GREENING OF URBANIZED ENVIRONMENT

The features of creating decorative forms from Scots pine trees are considered. It has been established that, as a result of mechanical damage (death of an apical bud or an apical shoot) and subsequent regeneration processes in pine trunks, two main directions of post-traumatic deformations of young pine trunks stand out - violation of monopodial branching and occurrence of multi-stemming. In the case of the death of an apical bud or apical shoot, in early spring, the growth of shoots from whorl buds is activated and their vertical reorientation occurs. After a short period of relative multi-stemming, one of the shoots from whorl buds takes the place of the central shoot. Formation of multi-stemming occurs in the case of the death of an apical shoot, mainly in late spring-summer period. There is also an increased growth of shoots from whorl buds and their vertical reorientation. All shoots formed from whorl buds retain their vertical orientation in the future with subsequent formation of several separate stems. It is shown that the processes of mechanical damage-regeneration are also reflected in the condition of trunk wood in the places of damage. In trunk areas where mechanical damage and subsequent regeneration took place, a noticeable increase in the basic density of wood is observed - by 15-20 % in case of shoot replacement and by 25-45 % in case of multi-stemming. The content of late wood also increases - by 10-30 % in case of shoot replacement and by 15-35 % in case of multi-stemming. It is recommended, to create decorative forms, to select pine trees no older than 8-10 years old, with an average growth rate in height. Decorative forms of Scots pine require annual adjustments.

ОЦЕНКА СОСТОЯНИЯ И ПРОДУКТИВНОСТИ ВЫСОКОПОЛНОТНЫХ СОСНОВЫХ НАСАЖДЕНИЙ ПОДТАЕЖНО-ЛЕСОСТЕПНОГО РАЙОНА СРЕДНЕЙ СИБИРИ)

Forest ecosystems, in particular pine plantations, are currently experiencing a complex of negative factors that
 affect both the condition of plantations and their growth indicators. The purpose of the study was to determine the condition and productivity of suburban pine forests of Krasnoyarsk, as well as statistical regression assessment of carbon
 concentration in the growing, dying and dried part of the forest stands. The object of research is pine forests of natural
 origin of Karaulnoe area forestry of experimental forestry of M.F. Reshetnev Siberian State University, located in the
 suburban area of Krasnoyarsk. Evaluation of sanitary category of pine forests allowed to state mainly "weakened" their
 condition. Regression analysis ascertained a reliable one-coefficient linear relationship between the carbon of different
 parts of pine forests and the supply of trunk wood and the completeness of forest stands. In this case, when predicting
 the carbon of the deadwood part of the stand, it must be divided into two parts: caused by external influences (forest
 fires, the stage of obsolescence, phyto-pathological conditions) more than 20 tS*ha-1 and caused by natural fall-off to 20
 tS*ha-1. As a result, it was found that in high-density, dense pine forests of the subtaiga forest-steppe region of Middle
 Siberia, the stability of pine forests is due to a complex of factors: age structure (when the active phase of growth in
 plantations is terminated, indicators of vitality decrease); completeness (high density worsens the condition of trees);
 stock (growth of the number of trunk wood per unit area contributes to an increase in the drying part of the pine stand);
 climatic conditions (an increase in temperature during the growing season and a decrease in the amount of precipitation).

СВЯЗЬ АБСОЛЮТНО СУХОЙ ФИТОМАССЫ ФРАКЦИЙ ДЕРЕВЬЕВ ALNUS INCANA (L.) MOENCH С ТАКСАЦИОННЫМ ДИАМЕТРОМ В СЕВЕРО-ТАЕЖНОМ РАЙОНЕ АРХАНГЕЛЬСКОЙ ОБЛАСТИ

The relationship between the absolutely dry aboveground phytomass of fractions of gray alder (Alnus incana (L.)
 Moench) trees and a diameter at a height of 1.3 m was researched in tall grass gray alder stands in the Arkhangelsk forestry, which belongs to the North-taiga forest region of the Arkhangelsk region and to the land territory of the Arctic. In
 the field season of 2020, 4 trial areas were laid, and 5-6 model trees were selected and measured on them, falling on 2-
 centimeter thick steps. A total of 21 model trees were studied. The weight of freshly cut and absolutely dry phytomass
 of 4 fractions of trunk wood, trunk bark, branches and foliage was determined from model trees. Based on the collected
 data, graphically obtained allometric equations of bonds by fractions for each sample area. Allometric equations are
 chosen for this purpose in both Russian and foreign studies. Based on the fact that the obtained determination coefficients in most cases exceed 0.8 and in two cases are in the range from 0.7 to 0.8, general allometric equations were derived using all model trees. Comparison of the results of the calculation of photometric indicators in t/ha by general
 equations with the equations obtained separately for each forest stand shows that the general allometric equations mostly underestimate the phytometric indicators. The best calculation results were obtained for wood and trunk bark fractions. These fractions are of the greatest importance when harvesting wood. Based on general equations, for the first
 time for the Arkhangelsk region, a table has been created that characterizes the wood fractions of gray alder by weight
 on each of the 2-centimeter steps of thickness from 4 to 16 cm. The equations are practically applicable for predicting
 the average absolutely dry phytomass of various fractions at various harvesting operations.

Using deciduous branch wood and conifer spindle wood to manufacture panels with transverse structure

The increasing demand on the wood market makes it necessary to use all secondary resources, including the wood branches and spindles. The properties of deciduous branches and softwood spindles were evaluated in order to create wood panels, highlighting the transverse texture with high value added. The research analyzed the properties of the wood from deciduous (beech, maple) branches and from conifer (spruce, fir) spindles. The methodology of obtaining panels with transversal structure was also presented. The production of minor wood (branches or spindles) was 254 m3/ha/year in the case of beech (branches) and 109 m3/ha/year in the case of spruce (spindles). The proportion of compression wood for spruce had an average value of 40.6%. A similar value of tension wood for beech was obtained. The modulus of elasticity for pine spindle wood was 71.7% lower than the modulus of elasticity for bending strength in the trunk. The quality index was 36.7% lower in the case of spindles than in the case of pine trunk, and the value of the quality ratio in branch maple wood was 2.61% lower than in trunk wood. Thus, even if it is not the only efficient solution, wood in the minor portions can be used to make high value-added panels such as those that highlight the transverse structure.

Oxygen Radical-Generating Metabolites Secreted by Eutypa and Esca Fungal Consortia: Understanding the Mechanisms Behind Grapevine Wood Deterioration and Pathogenesis.

Eutypa dieback and Esca complex are fungal diseases of grape that cause large economic losses in vineyards. These diseases require, or are enhanced by, fungal consortia growth which leads to the deterioration of the wood tissue in the grapevine trunk; however, pathogenesis and the underlying mechanisms involved in the woody tissue degradation are not understood. We examined the role that the consortia fungal metabolome have in generating oxygen radicals that could potentially play a role in trunk decay and pathogenesis. Unique metabolites were isolated from the consortia fungi with some metabolites preferentially reducing iron whereas others were involved in redox cycling to generate hydrogen peroxide. Metabolite suites with different functions were produced when fungi were grown separately vs. when grown in consortia. Chelator-mediated Fenton (CMF) chemistry promoted by metabolites from these fungi allowed for the generation of highly reactive hydroxyl radicals. We hypothesize that this mechanism may be involved in pathogenicity in grapevine tissue as a causal mechanism associated with trunk wood deterioration/necrosis in these two diseases of grape.

Estimation of linear and mass attenuation coefficients of soy-lignin bonded Rhizophora spp. particleboard as a potential phantom material using caesium-137 and cobalt-60.

In this study, linear and mass attenuation coefficients of fabricated particleboards intended for use as phantom material were estimated using 137Cs and 60Co radiation sources. Particleboards made of Rhizophora spp. wood trunk bonded with soy flour and lignin were fabricated at a target density of 1.0gcm-3, with and without gloss finish coating. Elemental composition of the particleboards was obtained by means of energy dispersive X-ray (EDX) spectroscopy. Experimental setups were simulated via the GATE Monte Carlo (MC) package, with particle histories of 1 × 106-1 × 107. Linear and mass attenuation coefficients obtained from measurements and GATE simulations were compared and discussed. The percentage differences between the measured and simulated linear and mass attenuation coefficients of the samples were reasonably small (2.05-4.88% for 137Cs and 3.24-5.38% for 60Co). It is shown that all the particleboards have the potential to be used as phantom materials as the attenuation coefficients measured were in good agreement with those of water (calculated with XCOM) and with those simulated with the GATE toolkit. The use of gloss finish coating also did not show any significant effect on the attenuation coefficient of the phantom material. Verification of experimental results via GATE simulations has been shown crucial in providing reliable data for energy transmission studies. Based on the results achieved in this study, it is concluded that the studied material-Rhizophora spp. wood trunk bonded with soy flour and lignin including gloss finish coating-can be used in radiation dosimetry studies.

Factors Controlling Dead Wood Decomposition in an Old-Growth Temperate Forest in Central Europe.

Dead wood represents an important pool of carbon and nitrogen in forest ecosystems. This source of soil organic matter has diverse ecosystem functions that include, among others, carbon and nitrogen cycling. However, information is limited on how deadwood properties such as chemical composition, decomposer abundance, community composition, and age correlate and affect decomposition rate. Here, we targeted coarse dead wood of beech, spruce, and fir, namely snags and tree trunks (logs) in an old-growth temperate forest in central Europe; measured their decomposition rate as CO2 production in situ; and analyzed their relationships with other measured variables. Respiration rate of dead wood showed strong positive correlation with acid phosphatase activity and negative correlation with lignin content. Fungal biomass (ergosterol content) and moisture content were additional predictors. Our results indicate that dead wood traits, including tree species, age, and position (downed/standing), affected dead wood chemical properties, microbial biomass, moisture condition, and enzyme activity through changes in fungal communities and ultimately influenced the decomposition rate of dead wood.

ИХНОФОССИЛИИ И ПАЛЕОПОЧВЫ ПАЛЕОЦЕНА РАЗРЕЗОВ «ПРИВОЛЬСК» И «ШИХАНЫ» САРАТОВСКОГО ПОВОЛЖЬЯ

The article discusses the results of preliminary studies of the Paleocene sections “Privolsk” and “Shikhany” from the Saratov Volga region. A complete description of the geological structure of the sections is given for the first time. Ichnoassemblages, ichnofacies and paleosols are identified. There is an alternation of sands and sandstones of glauconite-quartz, and quartz of various degrees of density (up to quartzite), mainly light dirty gray, micaceous, fine-grained, sometimes obliquely layered. Some of the layers are strongly bioturbated, others are less bioturbated, occasionally there are thin (up to 1 cm) extended interlayers of clays in the studied sections. Fragments of the wood trunks in a sandstone crust, sometimes with elements of the root system, as well as leaf imprints and plant debris, frequent remains of invertebrates are found in many layers. There are at least one well-defined paleosol profile and several undeveloped FPS profiles (fossil paleosols). In total, there are 12 layers or beds from 1 to 5 m each in the summary section, with a total thickness of 25-28.5 m. The entire section is permeated with a variety of ichnofossils that stand out on the weathered surface. According to their morphology, the ichnofossils are divided into several groups that characterize the certain ichnofacies and reflect specific sedimentation environments

Chlordecone in basal trunk wood of native trees growing in abandoned banana plantations in Guadeloupe, France

Chlordecone (CLD), used to control the Cosmopolites sordidus banana weevil and released from polluted banana plantations, continues to contaminate ecosystems in the French Caribbean. Edible plants have been actively studied for risk prevention, but trees have not, even though they could play a significant role in future remediation strategies. CLD contents were analysed in 24 pioneer trees belonging to 13 species found in abandoned banana plantations in Guadeloupe, at three contaminated sites on Nitisols (Site 1) and Andosols (Sites 2 and 3). Wood samples were taken from each tree in the basal part of the trunk and the soil at its foot and their CLD content was measured by the analytical laboratory for the Drôme département (26) in Valence, France. Mean CLD contents in the top 30-centimetre soil layer from sites 1, 2 and 3 were 2,543 ± 702, 5,251 ± 1,102 and 875 ± 865 µg/kg dry soil respectively. Of the trees, 96% were contaminated. The CLD content in trees growing on Nitisols (3,406 ± 1,658 µg/kg dry wood) was at least 5 times higher than in trees growing on Andosols (299 ± 314 and 226 ± 378 µg/kg), but no clear relationships were found with soil CLD contents. Calculations of available CLD dissolved in the soil liquid phase using equations and soil datasets in the literature showed higher available CLD contents in Nitisols than in Andosols and a linear relationship between CLD available in soil and concentrations of CLD in wood, regardless of the type of soil. Trees growing on Nitisols are the plants most highly contaminated by CLD of all the plants in which this compound has been studied so far. With a plant-to-soil bioconcentration ratio around 150 l/kg, the consistent CLD uptake efficiency of the trees needs to be taken into account in further research for CLD remediation.

Subfossil Scots Pine (Pinus sylvestris L.) Wood from Northern Finland—Physical, Mechanical, and Chemical Properties and Suitability for Specialty Products

The physical, mechanical, and chemical properties of both stem wood and knot wood were investigated from two subfossil Scots pine (Pinus sylvestris L.) trunks retrieved from a lake in Finnish Lapland, dated to 404–486 CE and to 1318–1444 CE. Both the stem wood and the knot wood of the younger trunk had higher moisture content, lower density, and lower strength properties in comparison to the older trunk. The ash content of the stem wood of the younger trunk was lower, but the ash content of the knot wood was higher than that of the older trunk. Due to the degradation that occurred over time, all the values of physical and mechanical properties were lower compared to typical values of recently grown Scots pine wood. The chemical composition of both stem wood samples was close to the composition of the recently grown wood, and the only exception was the small decrease of the cellulose and hemicellulose in the subfossil samples. The bulk extractives were well-preserved, but terpenes and fatty acids underwent transformation, resulting in more stable compounds. The SWOT analysis (strengths, weaknesses, opportunities, and threats) showed pros and cons for the productization of subfossil wood, with the branding value of an ancient material being the potential enabler in developing commercial niche uses.

First Report of Grapevine Virus L Infecting Grapevine in Southeast France.

Grapevine virus L (GVL) is a recently described vitivirus (family Betaflexiviridae) with a positive-sense single-stranded RNA genome. It has so far been reported from China, Croatia, New-Zealand, the United States and Tunisia (Debat et al. 2019; Diaz-Lara et al. 2019; Alabi et al. 2020; Ben Amar et al. 2020). It has significant genetic variability (up to 26% of nucleotide divergence between isolates) and the existence of four phylogroups has been proposed (Alabi et al. 2020). In the frame of a project investigating the possible links between grapevine trunk diseases and grapevine virome, viral high throughput sequencing (HTS)-based testing was performed on symptomatic and asymptomatic grapevines collected in July 2019 in vineyards of four areas in France (Bourgogne, Charentes, Gard, Gironde) corresponding to five cultivars of Vitis vinifera (Cabernet franc, Cabernet Sauvignon, Chardonnay, Sauvignon, Ugni blanc). Total RNAs were purified from powder of 105 trunk wood samples using the Spectrum™ Plant Total RNA Kit (Sigma-Aldrich, Saint-Quentin-Fallavier, France) and RNA-seq libraries were prepared using Zymo-Seq RiboFree Total RNA Library Prep Kit (Ozyme, Saint Cyr l'Ecole, France). HTS was performed on a S4 lane of Illumina NovaSeq 6000 using a paired-end read length of 2x150 bp. The trimmed sequence reads obtained from Chardonnay plants CH30-75M (99.9 M) and CH37-19S (114 M) from a vineyard in Gard were analyzed using CLC Genomics Workbench v21 (Qiagen, Courtaboeuf, France) and revealed complex mixed infections. Besides contigs representing a complete GVL genome (average scaffold coverage: 6,197x and 2,970x, respectively), contigs from grapevine rupestris stem pitting virus (1,697x ; 1,124x), grapevine virus A (82x ; 95x), grapevine pinot gris virus (1,475x ; 866x), grapevine leafroll-associated virus 3 (5,122x ; 1,042x), hop stunt viroid (13,783x ; 29,514x) and grapevine yellow speckle viroid 1 (690x ; 1158x) were also identified. Plant CH37-19S was also co-infected by grapevine rupestris vein feathering virus (164x). The GVL contigs integrated respectively 320,000 and 152,000 reads (corresponding to 0.32% and 0.11% of filtered/trimmed reads, respectively). The GVL genomic sequences from each sample (7,616 nt) have been deposited in GenBank (Accession nos. OK042110 and OK042111, respectively). The two contigs are nearly identical (99.9% nt identity) and share respectively 97.5% and 95.9% with GVL-KA from the USA (MH643739) and GVL-RS from China (MH248020), the closest isolates present in GenBank. To confirm the presence of GVL, the original grapevines were resampled in the field and total RNAs were extracted as described above from cambial scrappings and leaves. Total RNAs were used for RT-PCR tests using primers targeting a 279-bp fragment corresponding to the 3' end of the coat protein gene and part of the nucleic acid binding protein gene (Debat et al. 2019). The Sanger-derived sequences from the amplicons shared 100% nt identities with the corresponding sequences of the HTS assembled genomes, confirming the presence of GVL in both tissues of both grapevine samples. To our knowledge, this represents the first report of the occurrence of GVL in vineyards in France. Given the complex mixed infection present in the two analyzed grapevines, no conclusions can be drawn on the pathogenicity of GVL. Further efforts are needed to better understand GVL distribution and its potential pathogenicity to grapevine. References Alabi, O J., et al. 2020. Arch. of Virol. 165:1905-1909. Ben Amar, A., et al. 2020. Plant disease 104:3274. Debat, H., et al. 2019. Eur J Plant Pathol. 155:319. Diaz-Lara, A., et al. 2019. Arch. of Virol. 164:2573. Acknowledgments The authors are grateful to the "Plan National Dépérissement du Vignoble" (Mycovir project) for the financial support.

Experimental Modal Analysis of a Palm Tree Log under Radial Vibrational Excitation

Trees may be subject to rot-inducing agents that degrade the strength of the material making their trunk, and decrease the quality of their crop. Several techniques, both non-destructive and destructive, are available for assessing the extent of damage caused by rot in a tree trunk. The present work presents the results of a preliminary study conducted on a palm tree trunk for isolating a specific mode from its response to a vibrational excitation, namely the so-called “ovalling” mode. This latter is cross-sectional and in a circular cylinder manifests itself relatively locally, i.e. has little dependence on the lateral extension of the cylinder. An experimental modal analysis is made on a piece of a date palm tree trunk when set into vibration through a radial mechanical excitation, and the response is collected at points along a circumference on the trunk. The value of the resonance frequency of the ovalling mode was found to be somehow variable, probably resulting from some coupling phenomena between various modes of vibration due to the inhomogeneity, anisotropy and fibre-like structure of the trunk wood. As rot usually affects markedly the strength of the trunk wood, the frequency of the ovalling mode, which depends on the strength of the material, can be used for estimating the severity of rot attack in the trunk. A numerical simulation is also made to a cylinder as a simplified representation of a tree trunk.

Leaf photosynthetic capacity, trunk wood structure and stem xylem sap flow in 700-years old Quercus robur L.: a pilot study upon oak ‘Bartek’, a natural monument in Poland

Physiological studies of long-lived trees are particularly important at this time, especially in light of the need for trees to adapt to global climate change. The results of the present studies were obtained on an approximately 700-year-old Quercus robur L. – the ‘Bartek’ oak. The tree has to adapt to changing climatic conditions, starting from the transition between the Medieval Warm Period and the Little Ice Age, up to the present time of rapid global climate change. Tomograph imaging showed decay of the tree trunk interior and revealed that undamaged wood forms a thin layer around the trunk perimeter. Two series of experiments were carried out to assess the physiological state of the tree. The first concerned measurements related to photosynthetic capacity: chlorophyll a fluorescence, gas exchange (CO2 assimilation, transpiration), stomatal conductance and leaf water potential. The second series concerned xylem sap flow velocity and anatomical studies of stem wood. Photosynthetic capacity was within the limits reported for young healthy trees. The diurnal pattern of velocity of xylem sap flow was also typical for young vigorous trees and flow velocity correlated positively with solar radiation and negatively with air relative humidity. Anatomical observations of the outermost wood showed relatively narrow annuals rings with large diameter earlywood vessels. The results indicate that the veteran tree does not show signs of water stress probably due to a good balance of water flow and that leaf area of the canopy needs only the current ring of wood to feed transpiration of the canopy.

Radial Growth and Anatomic Structure of the Trunk Wood of Healthy and Stag-Headed Larch Trees on Permafrost

Radial Growth and Anatomic Structure of the Trunk Wood of Healthy and Stag-Headed Larch Trees on Permafrost

Древовидная форма можжевельника (Juniperus communis L.) в лесах Вологодской области

Common juniper (Juniperus communis L.) is one of the most widespread undergrowth species in the forests of Russia. It has not only important silvicultural significance but is also widely used in economic activities. Numerous works of Russian and foreign authors are devoted to its study. The article shows the results of geobotanical and forest inventory studies of a unique area of pine plantation in the Kirillovskiy district of the Vologda region. In the second understorey of which tree-form common juniper grows. The stand was classified as high-density (relative fullness – 0.85) and low quality (quality class – V–IV). The total stock of trunk wood on the site is 280 m3/ha, including the stock of juniper wood – 28 m3/ha. The average diameter of juniper trunks is 14 cm, the average height is 11 m and the age is 180 yrs. This is several times higher than its usual parameters in other forests. A significant number of specimens of juniper (50 pcs/ha) are in the stage of drying out or have already died and represent dead wood of different years. The number of small and medium-sized juniper undergrowth is 1.5 ths pcs/ha or 62.5 % of the growing. Undergrowth of European spruce, downy birch and black alder is also found. The existing undergrowth is assessed as promising, but Scots pine undergrowth is missing. The ground cover is dominated by green and sphagnum mosses as well as shrubs of the Ericaceae and Vacciniaceae families. The study of such objects, extremely rare not only in the north of the European part of Russia, but also everywhere, is of great practical importance. It is also important for understanding the biology of the only representative of the Cupressaceae family that naturally grows here. The tree-form juniper in the pine plantation has survived and reached a size not typical for this species due to the inaccessibility of the site, the lack of fires and forest felling. Such forest areas should be identified, protected, and subjected to stationary research. For citation: Evdokimov I.V., Dobrynin A.P., Armeeva N.A. Tree Form of Juniper (Juniperus communis L.) in the Forests of the Vologda Region. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 201–209. DOI: 10.37482/0536-1036-2021-5-201-209

ВЛИЯНИЕ МАКРОСТРУКТУРЫ НА ПЛОТНОСТЬ ДРЕВЕСИНЫ ДУБА

An individual process of staining of each trunk occurs as a result of the long-term presence of wood in the river soil without oxygen access. It consists in changing the structure and chemical composition of the wood. There are industrial reserves of this wood on the territory of the Russian Federation, in the floodplains of a number of rivers. One of the most important tasks at the extraction stage is the primary individual quality assessment of the trunk. One of the most effective diagnostic indicators for assessing wood quality can be the number of annual layers in one centimeter. This indicator correlates well with wood density. The purpose of the research is to establish the influence of the macrostructure of natural wood and stained oak wood, changes in the microstructure on its density. It was found that the density of stained oak wood, depending on the number of annual layers in 1 cm, is about 10% higher than that of natural wood, all other things being equal. The magnitude and nature of the decrease in density along the radius of the trunk is the same as in natural wood. It is about 20%. The performed studies will allow making an express analysis of the quality of each stained wood trunk at the stage of making a decision on the behavior of its extraction. This will significantly reduce the cost of logging and primary processing of stained oak wood

Model of a digital device for assessing the state of xylem in tree trunks

For the development of systems for predicting the state of forests and trees, adequate models of the influence of temperature and humidity environment fluctuations on the kinetics of the wood microstructure are needed. Formalized modeling should be based on monitoring data obtained with controlled accuracy in real time. The aim of the work was to substantiate the layout of a device for measuring the potential difference in tree trunks to study their state. For the first time in the article, the recorder layout with the operating principle based on the phenomenon of thermally stimulated polarization of wood has substantiated. In addition, a formalized model has presented for processing the monitoring data of the studied potential difference in the framework of classical thermodynamics, which makes it possible to determine the parameters of the kinetics of the microstructure of wood in tree trunks at fluctuations of external factors. As a result of the research carried out, a model of a digital device for assessing the state of wood of tree trunks was developed. The proposed device for recording the response of the trunk wood on the fluctuations of external factors practically does not violate the unique microstructure of the biocomposite and has a controlled accuracy in real time.

Immobilization of Providencia stuartii Cells in Papaya Trunk Wood for N-acetylglucosamine Production from Pennaeus vannamei Shrimp Shells

Highlight Research AbstractChitin is a natural compound found abundantly in shrimp shells. Chitin can be degraded to produce N-acetylglucosamine, which has wide applications in the food and pharmaceutical fields. Fermentation using chitinolytic microorganisms can be used to produce N-acetylglucosamine from shrimp shells’ chitin. One of the strong chitinolytic bacteria that was isolated from previous research was Providencia stuartii. To provide better stability and efficiency in fermentation, P. stuartii cells were immobilized using entrapment method in papaya trunk wood. The aims of this research were to determine the optimum papaya trunk wood size, ratio of papaya trunk wood and growth medium, as well as the optimum fermentation cycle to produce N-acetylglucosamine from P. vannamei shrimp shells using submerged fermentation method. The research used experimental method with treatment of different sizes of papaya trunk wood (1 x 1 x 1 cm3, 1.5 x 1.5 x 1.5 cm3, and 2 x 2 x 2 cm3), different ratio of papaya trunk wood and growth medium (1:10, 1:15 and 1:20), and 4 fermentation cycles. Results showed that papaya trunk wood with size of 1 x 1 x 1 cm3 and ratio (w/v) of 1:10 could immobilize 87.08±2.05% of P. stuartii cells and produce the highest N-acetylglucosamine concentration, which was 238177.78±3153.48 ppm. The highest N-acetylglucosamine production was obtained from first fermentation cycle and decreased over the last three cycles, but still produced high concentration of N-acetylglucosamine. Therefore, it is possible to perform continuous N-acetylglucosamine production from shrimp shells using P. stuartii cells immobilized in papaya trunk wood.

Сравнительный анализ биоэнергетической продуктивности культурфитоценозов сосны обыкновенной европейского севера

The bioenergetic productivity of artificial pine stands is considered. It was found that in 30-year-old artificial pine coenoses, the lowest amount of energy associated with the tree layer is observed in the lichen type of growing conditions (443,1 GJ/ha), the highest — in the blueberry (1915,1 GJ/ha). Bioenergetic productivity occupies an intermediate position (1210,7 GJ/ha) in the cranberry-type forest culture phytocenoses. It is shown that the accumulated energy reaches the highest relative value in such a component of aboveground phytomass as trunk wood. For this fraction, the variation is observed from 50.2% in the lichen type of growing conditions to 65.8% in the blueberry type, based on the total stock of phytomass of forest crops. It is established that the secondary position relative to this indicator is occupied by woody greens. The share of the energy productivity of needles in the total aboveground phytomass decreases with the improvement of forest growing conditions. An approximately equal ratio of energy deposition in the studied types of artificial pine forests by the fractions of bark and live branches (7,2...11,7%) was determined, and the smallest share of accumulated energy falls on the fraction of dry branches (5,3...7,0 %).