Trunk Wood Research Articles

Drought-Induced Alterations in Carbon and Water Dynamics of Chinese Fir Plantations at the Trunk Wood Stage.

Over the past three decades, China has implemented extensive reforestation programs, primarily utilizing Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) in southern China, to mitigate greenhouse gas emissions and counter extreme climate events. However, the effects of drought on the carbon sequestration capacity of these forests, particularly during the trunk wood stage, remain unclear. This study, conducted in Huitong, Hunan, China, from 2008 to 2013, employed the eddy covariance method to measure carbon dioxide (CO2) and water fluxes in Chinese fir forests, covering a severe drought year in 2011. The purpose was to elucidate the dynamics of carbon and water fluxes during a drought year and across multi-normal year averages. The results showed that changes in soil water content (-8.00%), precipitation (-18.45%), and relative humidity (-5.10%), decreases in air temperature (-0.09 °C) and soil temperature (-0.79 °C), and increases in vapor pressure deficit (19.18%) and net radiation (8.39%) were found in the drought year compared to the normal years. These changes in environmental factors led to considerable decreases in net ecosystem exchange (-40.00%), ecosystem respiration (-13.09%), and gross ecosystem productivity (-18.52%), evapotranspiration (-12.50%), and water use efficiency (-5.83%) in the studied forests in the drought year. In this study, the occurrence of seasonal drought due to uneven precipitation distribution led to a decrease in gross ecosystem productivity (GEP) and evapotranspiration (ET). However, the impact of drought on GEP was greater than its effect on ET, resulting in a reduced water use efficiency (WUE). This study emphasized the crucial role of water availability in determining forest productivity and suggested the need for adjusting vegetation management strategies under severe drought conditions. Our results contributed to improving management practices for Chinese fir plantations in response to changing climate conditions.

Attenuation coefficients of soy-lignin bonded Rhizophora spp. particleboard as a potential phantom material using Monte Carlo GATE

This work aimed to determine the linear and mass attenuation coefficients of soy-lignin bonded Rhizophora spp. particleboard intended for use as a phantom material using Monte Carlo GATE simulation. At a desired density of 1.0 gcm-3, particleboard constructed of Rhizophora spp. wood trunk bonded with soy flour and lignin was created. The sample’s elemental composition was identified using energy dispersive X-ray spectroscopy. The GATE software was used to simulate the setup with the histories of 1 × 107, and comparison was made between the experimental and simulation data. The disparities between the linear and mass attenuation coefficients of the samples experimentally measured and calculated using GATE at low energy photons were quite small. The result revealed a good agreement between the experimental and simulation data, and the attenuation coefficients were in close proximity with XCOM of water. The outcome revealed GATE adequacy for validation of attenuation coefficient measurement in bioresources phantom material for medical physics application.

Important accumulated mercury pool in a remote alpine forest and dynamic accumulation revealed by tree rings in China's Qilian Mountains

Quantification mercury (Hg) pools in forests is crucial for understanding the Hg assimilation, flux and even biogeochemical cycle in forest ecosystems. While several investigations focused on Hg pools among broad-leaved, coniferous and mixed forests, there was still absent information on alpine forest. We sampled soil, moss and various tissues of the dominant Qinghai spruce (Picea crassifolia Kom.) to investigate Hg concentrations and pools, and assess Hg accumulation dynamics in the Qilian Mountains, northwestern China. The mean Hg concentration increased in the following order: trunk wood (1.8 ± 0.7 ng g−1) < branch (4.6 ± 0.8 ng g−1) < root (12.2 ± 2.9 ng g−1) < needle (19.3 ± 5.6 ng g−1) < bark (28.7 ± 9.0 ng g−1) < soil (34.1 ± 7.7 ng g−1) < litterfall (42.9 ± 2.9 ng g−1) < moss (62.5 ± 5.0 ng g−1). The soil contained Hg pools two orders of magnitude higher than vegetation and accounted for 92.2 % of the total Hg pool in the alpine forest ecosystem. Moss, despite representing only 2.7 % of total vegetation biomass, contained a disproportionate 16.7 % of the Hg pool. Although species-specific, aboveground spruce tissues exhibited higher Hg pools in alpine forests compared to other forests in China and America. The dynamic accumulation indicated that increasing atmospheric Hg concentration and enhancing tree productivity contributed to rising Hg assimilation in remote alpine forests, particularly after the 1960s. Our results highlight the relatively high levels of Hg pools in aboveground tree tissues of alpine forest and reveal a significant increase in Hg accumulation. We recommend that when assessing Hg dynamics in forest ecosystems, it is crucial to consider both the variability in atmospheric Hg exposure levels and the forest productivity.

Prospecting for non-timber forest products by chemical analysis of four species of Lauraceae from the Amazon region of Colombia

Lauraceae is a family of woody plants of economic importance mainly for their commercial exploitation as timber, as well as spices/food. Nonetheless, overexploitation is causing a decline in both the population and the associated ecosystems due to the lack of sustainability strategies and knowledge of alternative ways of utilization. The focus of this research was to determine if the secondary metabolites found/identified in the volatile fractions/ethyl acetate extracts of Aniba panurensis, Nectandra cuspidata, Ocotea cymbarum and O. myriantha from the Amazon region of Colombia (Departamento de Caquetá) would be promising/interesting for industry, so that uses/exploitation other than timber could be recommended. In this work, the chemical compositions by GC–FID/MS of the volatile fractions/total extracts (by HS–SPME/SDE/maceration) of the trunk wood of these trees were determined. The results were: (i) the volatile fractions/extracts of A. panurensis were composed of 88–94% benzenoid-type aromatic esters (benzyl salicylate and benzoate); (ii) N. cuspidata contained 95% sesquiterpenes (α-copaene and α-cubebene/germacrene D) by HS–SPME, 89% oxygenated and hydrocarbonated sesquiterpenes (τ-cadinol and δ-cadinene) by SDE, and 87% sesquiterpenes and aporphine alkaloids (α-copaene/germacrene D/δ-cadinene/α-cubebene and dicentrine/dehydrodicentrine) by solvent extraction; (iii) O. cymbarum contained mainly 63% sesquiterpenes and monoterpene ethers (α-copaene/trans-calamenene and eucalyptol) by HS–SPME, 63–85% of monoterpene alcohols (α-terpineol/borneol)/hydrocarbons (α-/β-pinenes)/ethers (eucalyptol) and phenylpropanoid ethers (methyleugenol) by SDE/solvent extraction; and (iv) for O. myriantha, the constituents per family were 91% sesquiterpenes (bicyclogermacrene/germacrene D)—HS–SPME, 72% sesquiterpene alcohols and sesquiterpenes/monoterpenes (spathulenol and bicyclogermacrene/δ-3-carene)—SDE, and 69% benzenoid-type aromatic esters and sesquiterpene hydrocarbons/alcohols (benzyl salicylate and bicyclogermacrene/α-cadinol)—solvent extraction. In conclusion, the main constituents identified in the woods (volatile fractions/extracts) of the species could be isolated and sustainably used/exploitated due to their bioproperties, as well as for their fragrant properties, some of which could be harnessed by different sectors/types of industries.

Разность потенциалов в стволах березы повислой (Betula pendula ROTH): особенности процессов релаксации при изменении температуры окружающей среды

The daily dynamics of the potential difference arising in the wood of the trunk of the hanging birch (Betula pendula Roth) at ambient temperature changes makes it possible to simulate the dynamics of the processes of redistribution of salt ions in the pores. An analysis of the results of measuring the potential difference in the wood of the model tree trunk showed that its dynamics is of a relaxation nature and tends to a certain stationary value. On the basis of the data of full-scale measurements of the potential difference in the framework of classical electrodynamics, a formalized model of the dynamics of the relative potential difference was constructed, containing three parameters. As a result of a computational experiment using an optimization procedure based on the Nash-Sutcliffe criterion, the parameters of the relaxation process of formation of a stable potential difference along the birch trunk caused by a change in the ambient temperature were calculated. It was revealed that the dynamic balance of the charge redistribution flows is determined by the factors of stimulating and stabilizing processes inside the trunks of woody plants. It is shown that a competent combination of the results of monitoring the potential difference in tree trunks and a computational experiment will make it possible to form an extensive database of parameters for the processes of formation of a stable dynamic equilibrium of salt ion fluxes in them, depending on the characteristics of growth, daily and seasonal changes in ambient temperature and soil composition. The study of changes in the state of trees due to the response to the impact of various environmental factors makes it possible to expand the range of tools for predicting the occurrence of catastrophic situations in forest ecosystems.

Estimation of Carbon Stocks of Birch Forests on Abandoned Arable Lands in the Cis-Ural Using Unmanned Aerial Vehicle-Mounted LiDAR Camera

Currently, studies investigating the carbon balance in forest ecosystems are particularly relevant due to the global increase in CO2 content in the atmosphere. Due to natural reforestation over the past 25–30 years, birch (Betula pendula Roth.) forests were extensively grown and established on abandoned agricultural lands in Bashkir Cis-Ural (Republic of Bashkortostan, Russia). The significant positive aspect of reforestation on fallow lands is the carbon sequestration that takes place in the tree phytomass, especially at the growth stage of stand formation. The aim of this article is to test the approach of using a UAV-mounted LiDAR camera to estimate the phytomass and carbon stocks in different-aged birch forests growing on abandoned arable lands in Bashkir Cis-Ural. The methodology was developed using 28 sample plots, where the LiDAR survey was performed using a DJI Matrice 300 RTK UAV. Simultaneously, the stand characteristics and phytomass of stem wood were also estimated, using traditional methods in the field of forest science. The regression equations of phytomass dependence on stand characteristics at different stages of reforestation were constructed using data obtained from LiDAR imagery. It was shown that the above-ground tree biomass could be precisely estimated using the index obtained by multiplying the number of trees and their average height. A comparison of the data obtained using traditional and LiDAR survey methods found that the accuracy of the latter increased in conjunction with stand density. The accuracy of estimation ranged from 0.2 to 6.8% in birch forests aged 20 years and over. To calculate carbon stocks of the above-ground tree stands, the use of regional conversion coefficients is suggested, which could also be applied for the estimation of carbon content in trunk wood and leaves. An equation for the calculation of above-ground biomass carbon stocks of birch forests on abandoned arable lands is proposed.

Chemical Composition in Juvenile and Mature Wood of Branch and Main Trunk of Leucaena leucocephala (Lam.) de Wit

Secondary growth is the most dynamic developmental aspect during the terrestrialization of plants. The development of secondary xylem tissue composed of thick-walled cells with characteristic changes in its structure and chemistry facilitates the growth and development of woody plants. In the present study, the chemical composition of the secondary xylem of juvenile and mature wood from the branch and main trunk of Leucaena leucocephala, has been investigated and the differences established. The biochemical analysis of different cell wall components in the mature wood of the main trunk revealed high holocellulose and α-cellulose and less lignin content in the juvenile wood while its syringyl/guaiacyl (S/G) ratio was less than for the mature wood. As compared to the branch xylem, concentration of cell wall polysaccharides and lignin content was higher in both juvenile and mature wood collected from the main trunk. Thioacidolysis and GC-MS analysis of wood lignin from juvenile and mature wood showed that an increased concentration in lignin content in mature wood is associated with a corresponding increase in S/G ratio. The structural information of the acetylated lignin was investigated by 1H NMR spectroscopy. Our results indicate that the mature wood from the main trunk is superior in pulp yielding and lignin degradability as compared to the juvenile wood of the branch and trunk.

Запасы углерода в 40-летних культурах сосны обыкновенной

The paper presents an assessment of carbon stocks in components of above-ground phytomass of the tree layer of 40-year Scots pine crops (Pinus sylvestris L.) growing in different forest conditions of the Baltic-Belozersky taiga region of the European North of Russia. The studied pine crops were created on fresh, unsodded clearings with a low degree of litter in lichen, lingonberry and bilberry types of forest growth conditions, which are characterized by significant differences in bioproductive potential. It was found that the smallest carbon pool is formed in the stand of a 40-year pine stand of lichen-type culture-phytocenosis (16.59 t/ha), the largest – in the blueberry type of habitat conditions (69.41 t/ha). In artificially created 40-year lingonberry pine forest, carbon stocks in the above-ground phytomass of the tree layer have an intermediate position (44.40 t/ha). The highest relative value of bound carbon is reached in such component of aboveground phytomass as trunk wood. The share of carbon stocks in this fraction of the total aboveground phytomass of the forest stand of the studied pine cenoses varies from 59.5 % in lichen type of habitat conditions to 75.6 % in blueberry one. Branches and needles have close quantitative values of carbon stocks and similar structure of differentiation along the forest typological gradient, occupying a secondary position in the carbon pool of the forest stand of the studied artificial pine forests after stem wood. The proportion of carbon bound by these fractions of aboveground phytomass of the stand decreases from the least productive lichen pine forest to the more productive blueberry pine forest. The share of carbon accumulated by stem bark in the total carbon pool of aboveground phytomass of the stand of the studied artificial pine forests tends to decrease from lichen pine forest to blueberry pine forest. The fraction of dry branches has the smallest percentage of carbon stocks in the tree stand in all studied forest conditions (2.3–5.9 %). For citation: Klevtsov D.N., Tyukavina O.N. Carbon Stocks in 40-year Scots Pine Crops. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 5, pp. 195–203. (In Russ.). https://doi.org/10.37482/0536-1036-2023-5-195-203

Формирование структурно-функциональной организации молодняков сосны обыкновенной (Pinus sylvestris L.) смешанного искусственно-естественного происхождения в условиях сосняков ягодникового и разнотравного Среднего Урала

Restoration of forests, the study of the processes of formation of their structure and productivity, is currently one of the most urgent tasks. The features of the formation of 12-year-old forest plantations and the concomitant natural regeneration of Scots pine (Pinus sylvestris L.) were studied under the conditions of berry pine forest and forb pine forest of the Middle Urals, on trial plots established in accordance with the existing requirements. For each Scotch pine (Pinus sylvestris L.) tree, the diameter at the middle height and height were measured, and the volume of the trunk in the bark was calculated. The rank distribution of trees was carried out by calculating their reduction numbers, determining the amplitude of the reduction numbers and subsequent distribution into 5 main classes. In the 12th year after planting, the survival rate in the berry pine forest was 47.0%, and in the forb pine forest - 35.3%. In the berry pine forest, taking into account the concomitant natural regeneration of Scots pine (Pinus sylvestris L.), a pine forest of artificial and natural origin is being formed, and in the forb pine forest, a pine forest of natural and artificial origin is being formed. The process of natural renewal of Scotch pine (Pinus sylvestris L.) took place over several years. Scots pine (Pinus sylvestris L.) trees of natural origin are 2-7 years younger in biological age than trees of artificial origin. Pine trees of artificial origin in the berry pine forest significantly exceed the average diameter at the middle of the height, height and trunk volume of the same trees in the forb pine forest. Pine trees of natural origin in the berry pine forest are significantly superior in average diameter at the middle of the height to trees in the forb pine forest, but they are significantly inferior to them in the average trunk height and practically do not differ in the average volume of the tree trunk. Trees of artificial origin in terms of diameter at the middle of the height, height and volume of the trunk significantly exceed trees of natural origin both in the berry pine forest and in the mixed grass pine forest. The distribution of trees by diameter and height in young forests of artificial and natural origin, both in the berry pine forest and in the forb pine forest, is characterized by a distribution close to normal. The distribution of trees of artificial and natural origin in the berry pine forest and the forb pine forest in terms of trunk volume is distinguished by left-sided asymmetry and sharpness. When distributed by rank height classes, a significant reduction in the level of variability of biometric indicators is provided. However, in natural young stands, a very high level of variability in stem volume in the bark remains. Both in artificial and natural young stands, the main (86.3-97.5%) stock of trunk wood in the bark falls on trees of I-III height classes. In the forb pine forest, artificial and natural young stands had almost the same reserve values, which confirms the formation of young pine stands of natural artificial origin. In the berry pine forest, birch renewal does not represent significant competition to pine. In the forb pine forest, birch creates serious competition for pine and, probably, the formation of deciduous-coniferous plantations and oppression of pine.

Dead Wood Elements Composition in Different Tree Species and Stages of Decay in the Broad-Leaved Forests of the Kaluzhskie Zaseki Reserve

The content and mass concentration of eight chemical elements Al, Ca, Cu, K, Mg, Mn, P, and Zn were analysed in dead wood of eight tree species at five stages of decomposition. Wood samples were taken at the site of the mass windfall of 2006 in a multispecies broadleaved forest in the Kaluzhskie Zaseki nature reserve. Deadwood of seven deciduous trees species was studied: maple (Acer platanoides), birch (Betula pendula), common ash (Fraxinus excelsior), common aspen (Populus tremula), English oak (Quercus robur), linden (Tilia cordata), rough elm (Ulmus glabra), as well as one coniferous tree species – Norway spruce (Picea abies). A series of one-way analyses of variance was carried out to assess the influence of the species and the stage of deadwood decomposition (including the zero stage for control samples) on the density, content of elements and their mass concentration. Tree species most clearly differed in the content and mass concentration of Mn, Zn, Mg, Ca, and K: R2 varied from 50 to 23% for the content and from 53 to 19% for the mass concentration of elements of the indicated series. The leaders in the content of these elements were the following species: Mn – maple, birch, spruce, linden; Zn – birch and aspen; Mg – maple, elm; Ca – elm; K – linden, elm. The stages of wood decomposition turned out to be a significant factor of variation for the content of Mn, P, Cu, Zn and Ca: R2 varied from 22 to 16%. During the destruction of wood trunks, a significant increase in the content of these elements occurred. Maintenance of cycles of biophilic elements is more successfully implemented in the presence of deadwood of different species at different stages of decomposition.

Variability of activity concentrations and radial distributions of 137Cs and 90Sr in trunk wood of Scots pine and Silver birch

This study analyzes the variability of 137Cs and 90Sr concentrations in wood and their radial distributions in the trunks of Scots pine and Silver birch trees in the small uniformly contaminated forest stands in the Chornobyl Exclusion Zone. Concentrations of both radionuclides follow a lognormal distribution with a large scatter of values measured in the trees within the stands (GSD ranges from 1.6 to 2.0). No correlation was found between the concentrations of the two radionuclides measured in individual trees, or between their concentrations and tree diameter. The average 137Cs and 90Sr Tag were 8.4 × 10−4 m2 kg−1 and 8.8 × 10−3 m2 kg−1 for pine, respectively, and 9.3 × 10−4 m2 kg−1 and 1.1 × 10−2 m2 kg−1 for birch, indicating a much higher availability of 90Sr for uptake by the studied species. For 137Cs, the Tag values are within the range recommended by the IAEA Handbook (IAEA, 2010), while the values for 90Sr exceed the recommended range for birch and are close to its upper value for pine.The highest concentrations of 137Cs in pine at the height of 1.3 m were measured in the youngest sapwood rings; they were lower in the rest of the sapwood and decreased further in the heartwood, but remained relatively high even in annual rings that were the heartwood at the time of deposition, suggesting sapwood-to-heartwood translocation of the radionuclide by diffusion and/or ray transport. In contrast, 90Sr concentrations increased through the sapwood from the trunk periphery in pine trees up to 80 years old and remained stable through the sapwood in older trees (except for higher concentrations in the young annual rings), but dropped to zero in physiologically inactive heartwood tissues. In most birch trees, regardless of age, 137Cs concentrations demonstrated an increasing trend from the trunk periphery towards the pith, while concentrations of 90Sr were relatively stable in the whole trunk except in the oldest annual rings, where they increased sharply, likely indicating active transport of the radionuclide to senescing tissues.

Особенности интерпретации результатов резистограмм при оценке качества стволовой древесины сосны

The article presents the resistogram analysis results of the healthy and damaged pine trunks with the systematic resistance error identification to drilling of pine wood when using the resistograph. The influence of the bore drilling channel length on the amount of resistance to drilling of pine wood has been established. It is indicated that when using resistograms as an express method for assessing the quality of wood trunks, it is necessary to adjust its dataset. A method of modeling the effect of the trunk drilling depth on the amount of resistance to wood drilling is proposed. The influence of the bore drilling channel length on the value of the systematic error of the resistance to pine wood drilling was revealed. The systematic error of pine wood drilling resistance depends on the number of the drill bit working cycles. When the number of work cycles is up to 100, the systematic error is up to 20 Resi; from 100 to 200 — from 20 to 60 Resi; more than 200 — from 60 to 200 Resi. When using a drill bit after 100 working cycles, a linear dependence of systematic errors of resistance to pine wood drilling on the length of the bore drilling channel is noted.

Comparative Assessment of the Antiplasmodial Activity and Acute Toxicity of Schumanniophyton magnificum Good &amp; Halle (Rubiaceae) Leaves, Trunk and Roots Methanolic Extracts

Background: Despite the various medicinal applications of Schumanniophyton magnificum, no comparative data are available to determine the part with best antiplasmodial activity and to guarantee its safety. This work deals with the evaluation of the antiplasmodial activity of methanolic extracts of S. magnificum organs as well as the study of acute toxicity of the most active part.&#x0D; Materials and methods: The methanolic extracts of the leaves, stem bark, trunk wood, root wood and root bark, were obtained by maceration with 96% methanol. Phytochemical screening, based on precipitation and coloring reactions, to highlight the chemical groups present in the plant. The antiplasmodial test was ran against chloroquine sensitive Plasmodium falciparum 3D7 strains while the study of the in vivo acute toxicity was conducted according to guideline 423 of the OECD protocol at a fixed dose on Wistar rats.&#x0D; Results: Phytochemical screening of the methanol extracts of these plants organs revealed the presence of alkaloids, triterpenoids, saponins, anthraquinones, polyphenols, coumarins anthocyanins and flavonoids. The antiplasmodial activity showed that only the leaves exhibited a moderate antiplasmodial effect with IC50 of 30.77 µg/ml. An oral administration of the methanolic extract of the leaves did not induce an abnormal variation of the physiological parameters in female Wistar laboratory rats, at non-toxic doses of 50, 300 and 2000 mg/kg body weight for 14 days.&#x0D; Conclusion: The leaves of S. magnificum exhibited the best antimalarial activity and were non toxic, thus justifying the use of the plant in the treatment of malaria in traditional pharmacopoeia.&#x0D; Keywords: Phytochemical screening, Antiplasmodial activity, Acute toxicity, Schumanniophyton magnificum, Medicinal plant.

Xylochrysis aquatica sp. nov. (Woswasiaceae) from freshwater habitats in Sichuan Province, China

During surveys of ascomycetous fungi in Sichuan province, China, a new aquicolous taxon, Xylochrysis aquatica, isolated from a decaying trunk of an undetermined wood is described. Xylochrysis aquatica differs from the type species X. lucida in having solitary, smaller ascomata with a short papillate ostiole, without a golden yellow layer of surrounded cells and larger asci with rounded ascospores. The phylogenetic analysis of the combined ITS-LSU-SSU-rpb2-tef1-α sequence data matrix showed that X. aquatica clustered together with X. lucida and formed as different lineages, it can be recognized as a distinct species. A detailed description and an illustration of the novel species are given while a nucleotide comparison of related species is provided.

Mechanical behaviour of grapevine wood affected by Xylotrechus arvicola

The cerambycid insect Xylotrechus arvicola is considered a pest that affects the wood of the grapevine (Vitis vinifera) in the major wine areas of the Iberian Peninsula. The larva of this insect perforates the grapevine wood, resulting in structural and biomechanical failure of the vine plants. Vine samples from wood damaged by X. arvicola larvae were picked up from different vineyards and grape varieties. Compressive and flexural tests were performed in order to assess the mechanical behaviour of the wood samples. Total length of the cracks in wood samples (TLCWS) that appeared on the surface of the grapevine wood samples after the mechanical tests was measured. Compressive strength (CS) and flexural strength (FS) decreased with the increase of the cross-sectional area (CSA) of both branches and trunks, regardless of damage condition or water content. Moreover, the resistance was lower in damaged wood. In addition, this was verified through the linear regression coefficients of the interaction CS x CSA and FS x CSA. TLCWS in branches and trunks of damaged samples was greater that in undamaged samples. Also, TLCWS within the same damage condition and part of the plant was higher in dry samples than in fresh samples. The damaged wood would show a higher vulnerability to common mechanical stress suffered by the grapevines in the field including heavy winds, fruit overweight or harvesting machines shaking (when mechanically collected). Larvae of this insect altered the mechanical behaviour of the trunk and branches of grapevine wood. The mechanical strength of wood was more negatively affected when the CSA of the branches and trunks increased. Longer TLCWS was found in affected wood.

The Effect of the Use of Type of Wood on the Appearance and Flavor of Smoked Skipjack

This study aimed to analyze the influence of different types of wood on the appearance and taste of smoked fish. This study used four types of firewood: coconut tranks, driftwood, coconut husks, and sawdust. Fish that have been smoked are then carried out an organoleptic assessment of appearance and taste by 30 consumer panelists. The results showed that using different firewood types affects the appearance and taste of smoked skipjack fish. Smoking using coconut trunk wood provides an organoleptic value of appearance (8.07) and taste (8.40), according to Indonesian National Standard (&gt;7). In contrast, the other three types of the wood show an organoleptic value of appearance and tasteless than 7.

A Wireless Acoustic Emission Sensor System with ACMD-IGWO-XGBoost Algorithm for Living Tree Moisture Content Diagnosis.

Trunk water has an important influence on the metabolism and ecological balance of living trees, which affects the vegetation growth and moisture cycle of the whole forest ecosystem. The accurate and real-time measurement of moisture content (MC) is of vital guiding meaning to living tree cultivation and forest management. In this paper, a water content diagnosis system based on a wireless acoustic emission sensor network (WASN) was designed and implemented with the aim of the nondestructive detection of water content in living wood trunks. Firstly, the acoustic emission (AE) signal of the trunk epidermis was sampled at high speed; then, its characteristic parameters were calculated and transmitted wirelessly to the gateway. Furthermore, the optimal characteristic wavelet sequence was decomposed by the adaptive chirp mode decomposition (ACMD), and the improved grey wolf optimizer (IGWO) optimization XGBoost established the MC prediction model, which was improved by the multi-strategy joint optimization. Finally, field monitoring was carried out on Robinia Pseudoacacia, Photinia serrulata, Pinus massoniana and Toona sinensis. The average diagnostic accuracy reached 96.75%, which shows that the diagnosis system has excellent applicability in different working conditions.

Selection justification of the wood pulp and crown combustion parameters for the calculation of the crown forest fires impact on Vietnamese energy facilities

The selection of specific carbon monoxide generation rate and specific mass gasification rate values is necessary for mathematical modeling of crown forest fires and their thermal effects on Vietnamese energy facilities. The study presents results from experiments on burning trunk wood pulp and crown samples of the most common deciduous and coniferous trees in Vietnam. Specific carbon monoxide generation rate and specific mass gasification rate were measured for wood and crown samples under flame combustion mode. The experimental results were compared with literature values, and it was found that the time-average experimental values of specific mass gasification rate fell within the range specified in the fire load database by Koshmarov 2000 for both coniferous and deciduous trees.

Wood quality of residual branches of Hymenaea courbaril L. from logging in the Amazon rainforest

Abstract Branches remain in the forest environment as logging activity residue. Considering the large size of many Amazonian trees, their branches have considerable dimensions and can contribute to a sustainable wood alternative for various applications. Due to the formation of reaction wood in the branches, relevant macro and ultrastructural changes can occur in its characteristics in relation to the trunk wood. However, the woods of the branches are not technologically well known. Therefore, this work aimed to evaluate the wood quality of branches of Hymenaea courbaril L., comparing it with wood of trunks. The extractives and lignin contents, basic density, shrinkage, fiber biometry, microfibril angle and mechanical resistance to compression parallel to the fibers were analyzed. The branch wood had smaller fiber dimensions and a higher microfibril angle than the trunk wood. The basic density was similar between these materials. The linear and volumetric shrinkages were smaller in the branch wood than in the trunk, while the axial shrinkage was higher in the branch. The parallel compressive strength was also lower in the branch wood than in the trunk. The branch wood has properties suitable for products with higher added value such as furniture, decorative objects, floors and utensils in general.

Моделирование критических локальных деформаций коры растущего дерева при ветровой нагрузке

The interaction between wind loads and forest plantations has been fairly well understood. A large amount of valuable scientific and practical information has been obtained and published so far in this field. There are some known data on wind load damage to plantations, its effect on their growth, and the ability of forest plantations to reduce wind speed and force. Nevertheless, the issues of wind impact on both individual trees and forested areas remain relevant. Analysis of the literature and Internet resources showed that the research has left out the issue of the wind load impact on the grown wood quality. Multi-year observations and a wind rose created using these observations enable the determination of the prevailing wind strength and direction for each area. Knowing the features of the wind load impact on the quality of timber after logging, it is possible to predict the percentage of the yield of commercial and low-quality wood, and to purposefully influence this parameter in plantation forest growing by setting out the planting material in accordance with these data. The article shows the developed method for theoretical estimation of the probability of occurrence of critical bark deformations in the compressed zone, which appears when bending a growing tree due to wind load. Classical studies of the critical state of compressed rods on an elastic base were used as the theoretical basis of the method. A part of growing tree bark plays the role of a rod, while cambium and other living cells between the bark and the trunk wood play the role of the elastic base. A correlation simple enough for practical application is proposed in order to obtain quantitative estimates. Adequacy of the modeling results is confirmed by their consistency with the experimental data. The application of the developed methodology is shown on the examples.