Dry Wood Research Articles

Thermal performance and environmental assessment of a hybrid solar-electrical wood dryer integrated with Photovoltaic/Thermal air collector and heat recovery system

Improving the energy efficiency of the drying industry is considered as one of the most efficient and promising ways for reducing carbon emissions from the industrial sector. In this context, the present work is aimed at investigating numerically the thermal performance and the environmental impact of a novel forced-air convection hybrid dryer for wood drying industry under realistic environmental conditions. The proposed dryer system consists mainly of a Photovoltaic/Thermal (PVT) solar air collector for thermal and electrical energy production, an insulated drying chamber, an air-to-air heat recovery system and fans. To simulate the functioning of the dryer system, a transient model based on energy and mass equations is developed and validated with experimental data. Annual dynamic simulations were carried out under weather conditions of the Ajaccio city and the effect of recovering waste heat from the dryer unit during both solar drying and hybrid drying processes was presented and analyzed. Results show that using the heat recovery system with an effectiveness of 0.8 leads to reduce the solar drying time by about 40% in summer and up to 32% in winter. For hybrid drying functioning, integrating of both heat recovery system and PVT air collector reduces the energy consumption of conventional dryer up to 86.5% during summer and up to 73.5% during winter. Finally, it was shown that the proposed hybrid wood dryer with PVT air collector and heat recovery system is suitable for wood drying industry and leads to improve the energy efficiency of conventional dryers and to reduce annually the amount of CO2 emissions up to 78.5%.

Cross-Flow Flat-Plate Heat Exchanger Using Computational Fluid Dynamics Simulation on Wood Drying Chamber

Engineered wood must undergo a long period of drying process before it is ready to be used. Therefore, a new heat exchanger technology must be invented to dry the engineered wood more effectively. The quality of the engineered wood is one of the factors influencing the production process. This research was conducted to identify the optimal temperature for drying engineered wood using a cross-flow flat-plate heat exchanger with unmixed fluid arrangement and to determine the heat exchanger’s most efficient number of passes.
 This research was conducted using the numerical method (CFD simulation) and the Ansys Fluent software. In this research, the viscosity, density, and pressure constant were determined to be at 1 atm. We used air as fluid medium with a mass density of 1,228 kg/m3, air thermal conductivity of 0.0286 W/m.K, fluid viscosity of 2,0349.10-5 N.s/m2, steam mass density of 0.689 kg/m3, and thermal conductivity of 0.0370 W/m.K.
 Results showed that, in order to increase the air temperature in the drying chamber, heat energy of 69566.01 kJ/s must flow into the flat-plate heat exchanger. Further calculations show that the heat exchanger’s effectiveness (ϵ) was 25% and that the average temperature in the heat exchanger on the air side and the gas side was 68.63 oC and 172.5 oC, respectively.

Green and Efficient Processing of Wood with Supercritical CO2: A Review

Wood processing is a crucial step of wood utilization, but the adding of environmentally hazardous feedstocks and the use of unreasonable technology allow it to harm the environment and human health. Supercritical CO2 (scCO2) is a non-toxic, odorless, and safe solvent, which is widely used in studies and industrial production, but there is no review summarizing wood processing with scCO2. The unique structure and chemical properties of wood combined with scCO2 technology produce positive results. In this paper, wood processing with scCO2 is summarized, including wood impregnation, wood drying, wood thermochemical conversion, and wood extraction. The green and efficient characteristics of wood processing with scCO2 are explained in detail for researchers, engineers, and investors to provide a clean wood processing method. Further study is needed to reduce its energy consumption and commercialize it eventually.

Effective changes in softwood cell walls, gas permeability and sound absorption capability of Larix kaempferi (larch) by steam explosion

ABSTRACT More interest in larch (Larix kaempferi) has been taken because of a greater focus on environmental properties. Steam explosion is an inexpensive and facile approach for the increasing rate of drying and durability of wood. A significant improvement in gas permeability and sound absorption coefficient of steam-exploded larch wood relative to the control wood is observed. It is due to structural changes in the cell wall that is proved by Fourier transform infrared spectroscopy, field emission scanning electron microscope, X-ray diffraction, and Energy-dispersive X-ray spectroscopy. The average increase in SAC of steam-exploded samples is 33.33% higher than the control samples at a wide range of frequency 250-6400 Hz due to the increasing air permeability (190.1%). Color of treated larch wood changed to black due to several chemical reactions in the cell wall and reduced of –OH functionality during the steam explosion. These findings summarized that steam explosion affects softwood cellulose cell walls, and the cross-section surface of larch wood could be considered for improving acoustic comfort in the building.

Effect of Rice Husks and Wood Grain as Electrolyte Adsorbers on Battery

The purpose of this study was to find out the carbon influence of rice husks and wood grain as electrolyte absorbers on large voltage and battery life. The battery fabrication procedure is as follows: (1) Preparing sixteen used batteries with a 1.5 Volt voltage, (2) Making NaCl solution with percentages of 10; 20; 30; and 40%, (3) Drying rice husks and wood grain until drying, (4) Carbonizing rice husks and wood grain, (5) Smoothing rice husks and carbonated wood grain, (6) Mixing rice husk, wood grain, and electrolyte solution, (7) Remove the contents of the used battery and wash it thoroughly, (8) Insert carbon from rice husks and wood grain. (9) Perform the process of closing the battery with the battery cover, (10) Measuring the battery voltage using an avometer. This research shows that carbon derived from rice husks and wood grain can generate electrical voltage, but the resulting voltage is still low compared to commercial batteries. In addition, batteries with electrolyte solutions that have a salt percentage of 10% provide the most voltage.

Eco-Friendly Batteries from Rice Husks and Wood Grain

The purpose of this study was to find out the carbon influence of rice husks and wood grain as electrolyte absorbers on large voltage and battery life. The battery fabrication procedure is as follows: (1) Preparing sixteen used batteries with a 1.5 Volt voltage, (2) Making NaCl solution with percentages of 10, 20, 30, and 40%, (3) Drying rice husks and wood grain until drying, (4) Carbonizing rice husks and wood grain, (5) Smoothing rice husks and carbonated wood grain, (6) Mixing rice husk, wood grain, and electrolyte solution, (7) Remove the contents of the used battery and wash it thoroughly, (8) Insert carbon from rice husks and wood grain. (9) Perform the process of closing the battery with the battery cover, (10) Measuring the battery voltage using an Avometer. This research shows that carbon derived from rice husks and wood grain can generate electrical voltage, but the resulting voltage is still low compared to commercial batteries. In addition, batteries with electrolyte solutions that have a salt percentage of 10% provide the most voltage.

Drying a Standing Teak Tree using a Solar Kiln Drying Method

Understanding the rate of drying of standing trees dried by using a solar kiln drying method could help in predicting the change of moisture content in the tree over a period of drying time. The purpose of this study was to observe the change of moisture content profile in a standing tree during drying. A standing Tectona grandis tree was selected for the experiment with a diameter at breast height of 29 cm in a mixed-species plantation. The tree was girdled with 20 cm width at 20cm above ground. For the experiment, the tree was wrapped in a transparent plastic sheet and a black plastic sheet was installed at the bottom with an angle of 39 °C facing Southwest to maximize solar radiation, with the method being modified from the solar kiln method, which is known as a greenhouse type, with 2 layers of plastic cover. The black and white sheets were placed on the inner side for insulation and for collecting heat from the sun’s radiation, while the outer layer was transparent, which allowed radiation to propagate unhindered in the black sheet. In this study, a sensor for temperature and relative humidity (DHT22) was attached inside the wrapped plastic and the data recorded every 6 min. The results showed that drying a standing teak tree from an initial average moisture content of 105 % to a constant point of 60 % took 80 days under the maximum of the collected temperature of 46 °C inside the wrapped plastic; this finding confirmed that the predicted model of recharge and discharge curve was likely accurate.

Energy analysis and economic feasibility of wood dryers integrated with heat recovery unit and solar air heaters in cold and hot climates

In this paper, the energy performance and economic feasibility of conventional wood dryer systems integrated with a heat recovery unit and solar air heaters are numerically investigated. Four different designs of wood dryers, composed of an insulated drying chamber, a heat recovery unit (HRU), a flat plate air collector (FPC), a photovoltaic/thermal air collector (PVT) and an auxiliary heater, are presented and compared. Annual dynamic simulations were carried out using a heat and mass transfer model with realistic meteorological data from two different climatic zones as boundary conditions. The effect of recovering waste heat and integrating each type of solar air heaters on the wood dryer energy consumption are presented and analyzed. Results show that recovering waste heat from conventional wood dryers in cold climate is more beneficial than in hot climate with an annual energy consumption reduction up to 41%. It is also shown that using a combined heat recovery unit and PVT collector improved significantly the energy efficiency of conventional dryers and reduced by about 67.5% and 49.5% the yearly energy consumption in hot and cold climates, respectively. Based on the economic analysis, the use of the HRU is beneficial in both climatic zones with a maximum payback period of 2 years. However, the use of the PVT collector is recommended only for wood dryers in hot climates where the payback period is about 3.5 years.

Publication de descriptifs techniques extraits de l’Atlas des bois tropicaux

L’Atlas des bois tropicaux publié en 2016 par les Éditions Quæ en version française (aux formats papier, epub et pdf) puis en 2017 en version anglaise (aux formats epub et pdf) présente des informations technologiques sur les bois destinées à tous les professionnels qui transforment et mettent en œuvre des bois tempérés ou tropicaux. Il réunit les principales caractéristiques technologiques de 283 essences tropicales et 17 essences de régions tempérées les plus employées en Europe, associées à leurs principales utilisations. Sa réalisation a bénéficié du soutien financier de l’Organisation internationale des bois tropicaux (OIBT), et d’Agropolis Fondation pour la version anglaise. Les descriptifs techniques d’une sélection d’essences tropicales seront régulièrement publiés dans la revue Bois et Forêts des Tropiques.
 Cet ouvrage est le fruit d’un travail collectif de l’Équipe Bois tropicaux du Cirad qui, depuis des décennies, a étudié dans ses laboratoires les caractéristiques technologiques de plus de 1 200 espèces tropicales en réalisant plusieurs centaines de milliers d’essais. La collecte récurrente d’informations sur le terrain est venue compléter ces données pour constituer une base de connaissances qui se décline aujourd’hui sous différents types d’applications.
 Outre sa fonction de mémoire collective et de réservoir d’informations pour alimenter des produits documentaires de vulgarisation sur la qualité des bois tropicaux (fiches ou guides techniques, atlas, logiciels, etc.), cette base de connaissances constitue un outil d’étude des relations entre les propriétés des bois et les usages des produits forestiers.
 Aujourd’hui, les recherches et les études conduites par les chercheurs et les techniciens de l’Unité de recherche BioWooEB du Cirad continuent à alimenter cette base de connaissances sur le comportement technologique et les potentialités d’utilisations d’un nombre toujours plus important d’espèces forestières issues des régions tropicales des quatre continents.
 L’Atlas des bois tropicaux décrit les caractéristiques de 300 essences. C’est un outil de référence pour les opérateurs de la filière bois en France et à l’étranger, ainsi que pour les établissements de recherche et d’enseignement, les institutionnels, les donneurs d’ordre, les architectes, les maîtres d’œuvre, les maîtres d’ouvrage et, de façon générale, pour tous les professionnels qui transforment et mettent en œuvre des bois tempérés ou tropicaux, ou qui projettent de le faire.
 Pour chaque essence, le descriptif technique reprend les informations suivantes : famille et appellation(s) botanique(s), origine géographique, éventuelle restriction commerciale selon la convention de Washington (CITES), description de la grume, description du bois, principales propriétés physiques et mécaniques, durabilité naturelle et imprégnabilité du bois, traitement de préservation, séchage, sciage et affûtage, assemblage, classements commerciaux, réaction au feu, principales utilisations, principales appellations vernaculaires. Chaque descriptif est illustré par deux photos de débit sur dosse et sur quartier (ou faux quartier), par deux macrophotographies aux grossissements 20 et 115 et par une photo d’un ouvrage construit avec le bois décrit.
 Les détails sur le contenu de ces descriptifs techniques, sur la nature et l’intérêt des informations, des caractéristiques et des données qu’elles contiennent sont disponibles dans une notice d’informations générales sur le site web de Bois et Forêts des Tropiques, annexée uniquement à la version web de cet article.
 Jean Gérard
 Rédacteur scientifique de la revue Bois et Forêts des Tropiques et chercheur de l’unité de recherche BioWooEB

Study of dugout canoes from the coast of La Plata River and the islands of the Paraná Delta, Argentina

In the La Plata Basin, indigenous populations used canoes for colonizing islands, moving people, fishing, transporting loads, and warfare. According to sixteenth century chronicles, dugout canoes were large, up to 24 m in length, and had a capacity for 40 people. In this paper, four dugout canoes recovered in La Plata River, and in the Paraná Delta, are studied. Their context of discovery, dimensions, radiocarbon dating, and the wood taxonomic identification are presented. Canoes were vital for the riverine populations that inhabited the study area since at least two thousand years ago but constitute a rare record given the low likelihood of preservation. The studied canoes measure between 10–8 m in length and 0.9–0.7 m beam. Two of the canoes were dated between 1509–1647 and 1414–1465 cal AD, 1σ. The diagnostic characters identified in the wood link all the samples to Enterolobium contortisiliquum. The use for centuries of the same species in different areas shows the importance of the type of raw material selected and reflects a shared knowledge of the properties of the dry wood: light and porous that contributes to buoyancy, easy to work, and with mechanical resistance. This, in addition to the size of the tree, up to 30 m high and 2.5 m in diameter, has favored its preference for the manufacture of hulls. These watercrafts constitute a unique cultural heritage on the pre-Hispanic naval engineering of the skilled navigators of the La Plata Basin.

Rendimento gravimétrico da carbonização e caracterização qualitativa do carvão vegetal em clones de híbridos de <i>Corymbia</i> spp para uso industrial

Na presente pesquisa, objetivou-se avaliar os rendimentos gravimétricos da carbonização e as características qualitativas do carvão vegetal de clones de híbridos obtidos dos cruzamentos de espécies de Corymbia, e identificar os mais adequados para uso siderúrgico. Seis clones, aos 6 anos e 5 meses de idade, foram utilizados na pesquisa e amostradas cinco árvores de cada material genético. As carbonizações laboratoriais foram realizadas à temperatura final de 450°C, taxa de aquecimento de 100°C.h-1 e tempo de residência de 30 minutos. Os rendimentos gravimétricos da carbonização foram determinados em relação à madeira seca. O carvão produzido foi qualificado, considerando-se a análise química imediata, poder calorífico superior, densidade energética, consumo específico de madeira e a eficiência energética. Na avaliação do experimento, foi utilizado o delineamento inteiramente casualizado com cinco repetições (árvores). A análise multivariada de componentes principais foi empregada para obter a variância dos vetores normalizados, considerando as características avaliadas nos carvões. Os resultados obtidos indicaram o elevado potencial para a utilização dos materiais genéticos de Corymbia, para fins energéticos, sobretudo para a produção de carvão vegetal siderúrgico. O clone 1 foi o destaque para a produção de carvão vegetal e lenha, pois apresenta maiores densidades aparentes e energéticas, maior teor e rendimento em carbono fixo, além de possuir menor consumo específico de madeira por tonelada de carvão vegetal produzido. Os clones 2 e 4 foram os que mais se distinguiram dos demais, respectivamente, em decorrência de seu maior teor de cinzas e por apresentar maior consumo específico de madeira na produção de carvão. O uso de clones híbridos de Corymbia, para a produção de carvão vegetal, pode ser uma boa alternativa, em razão de seu rápido crescimento e qualidades semelhantes de madeira e carvão vegetal a outras espécies que já são usadas para a finalidade energética.

Modeling unsteady heat and mass transfer with prediction of mechanical stresses in wood drying

This work presents a predictive transient two-dimensional model describing the evolution of heat, mass and mechanical stresses during wood dehydration inside an experimental drying chamber. The history of the distributions of moisture content and temperature and the effects produced by its gradients on the stresses were simultaneously modeled. The non-linear coupled differential equations of heat, mass and stresses were integrated by the Control Volume Finite Element method using triangular elements with linear interpolation functions for the dependent variables. Variation of the physical and mechanical properties with the moisture content and temperature in the wet wood were included in the analysis. Experimental results of Pinus radiata being dried inside a conditioned chamber at constant air velocity equal to 1.6 m/s, 44 °C dry-bulb and 36 °C wet-bulb temperatures were used for validation purposes. The mathematical model allows an accurate prediction of the relevant industrial information, such as: drying curves, evolution of temperature distribution, history of moisture content distribution and mass/thermal stresses.

Effect of site conditions on the properties of hawthorn (Crataegus azarolus L.) wood

This study investigated the influence of site conditions on the physical and morphological properties of hawthorn (Crataegus azarolus L.) wood grown in Zagros forests of Iran. Hawthorn is a valuable woody species in Iran’s Zagros forests with data deficiency in its wood properties. To our best knowledge, there is no study on the properties of hawthorn wood. Twenty-seven mature trees were randomly chosen and sampled at three altitude levels (1 800–2 000, 2 000–2 200, and 2 200–2 400 m) in the Bazoft region of Chaharmahal Va Bakhtiari, Iran. Dry wood density, volumetric shrinkage, fibre length, fibre diameter, cell wall thickness were then determined. Multivariate analysis of variance (MANOVA) was conducted to evaluate significant differences between the mean values of studied wood properties at different altitude levels and slope classes. Moreover, the relationships between the above-mentioned properties and some site conditions (temperature, precipitation, altitude, and slope) as well as growth parameters of trees (tree height, DBH, age, crown dimensions, volume, etc.) were studied by principal component analysis (PCA). The results indicated that trees growing at the second altitude level had the highest oven-dry density values, and those at the third altitude level had the lowest ones. Results also indicated a significant effect of altitude levels on fibre length, fibre diameter, and cell wall thickness. In contrast, a significant difference was found between the mean values of fibre diameter at different slope classes. PCA indicated that altitude, precipitation, and temperature are the most important environmental site variables affecting the wood characteristics.

Comparative content of biologically active substances in wood species of the north of the forest steppe on the example of Lipetsk region

The wood of 22 of the most common low resinous tree species were studied. The number of polyphenols in the wood of the studied species ranges from 23.6 to 1433.1 mg% (0.02-1.43%). The maximum number is noted in the wood of thorny blackthorn. As the wood of fruit species ages (over 3 years old), the content of polyphenols decreases. The content of organic acids in wood of tree species varied in the range of 0.21-1.08%. The leader in terms of their content was the common rowan tree. The amount of tannins and dyes in wood species ranged from 1.45 to 26.5% and was maximum in the tissues of thorny blackthorn. The tannin level in the tissues of the tree species was 0.83-20.8%. The highest tannin content was in the wood of the rowan tree. With the natural drying of wood of 20 species within 8 months in a ventilated room at an air temperature of 25° C, the moisture content of the wood decreases 1.4-3.83 times and is set at the level of hygroscopicity (11.47-35.6%). In the process of slow drying of wood species, organic acids are not destroyed in them, but are concentrated. The least hygroscopic is the wood of the walnut and pedunculate oak, the most hygroscopic is the wood of the heart-shaped linden.

Kiln Drying Operations Scheduling with Dynamic Composition of Loading Patterns

Abstract Planning and scheduling wood lumber drying operations is a very difficult problem. The literature proposes different methods aiming to minimize order lateness. They all make use of pre-established kiln loading patterns that are known to offer good physical stability in the kiln and allow full kiln space utilization. Instead, we propose a mixed integer programming (MIP) model, which can be used to generate loading patterns “on the fly.” This MIP model can be integrated into existing kiln drying operation planning/scheduling systems in order to improve their solutions. We show how this integration can be done by adapting a state of the art drying operations planning and scheduling methodology from the literature. We compare the solutions obtained by this system using the predefined loading patterns versus the solutions it generates if it is connected to our loading patterns generator MIP model. The study shows it is much better to dynamically create loading patterns than to use predefined ones, as most North American sawmills do.

Particulate emissions from a modern wood stove – Influence of KCl

Particulate matter (PM) generated by residential wood combustion is a major environmental concern in Europe. This study focuses on the influence of potassium chloride (KCl) on fine particle emissions from a modern wood stove. Wood logs with and without KCl impregnation were subjected to batch combustion and emission measurements. A bi-modal particle number-size distribution characterized by a nucleation mode and an accumulation mode was identified for all types of wood fuel. However, in the presence of KCl, a lower number emission of ultrafine particles and a higher number emission of larger particles (size ∼200–500 nm) were observed. In addition, the emission factor of condensed organic compounds (COC) increased with increasing KCl content, from 0.16 g/kg dry wood for normal wood (NW) to 0.48 g/kg dry wood for wood impregnated with the 2 mol/L KCl solution (HKW), most likely due to the facilitated heterogeneous condensation of semi-volatile hydrocarbons on pre-existing ash particles. In addition, the emission factor of soot particles also increased slightly when the KCl content was high, from 1.47 g/kg dry wood for NW to 2.23 g/kg dry wood for HKW.

Bending Strength of Wood Treated with Propolis Extract and Silicon Compounds.

The modification of wood and its treatment with various preservatives may affect its mechanical properties, hence the knowledge of the character changes in wood caused by impregnation is of great importance. Therefore, the aim of the research was to determine the effect of impregnation, with the propolis-silane preparation (EEP-MPTMOS/TEOS) consisting of the propolis extract (EEP) and silicon compounds: 3-(trimethoxysilyl)propyl methacrylate (MPTMOS) and tetraethoxysilane (TEOS), on the bending strength of treated wood. Moreover, in the study wood treated with components of the propolis-silane formulation was used, namely 70% ethanol, the propolis extract, and silanes (MPTMOS/TEOS). In order to determine whether the impregnation of wood affects its long-term bending, creep tests were performed depending on the humidity. The impregnation of wood with the propolis extract and the propolis-silane preparation (EEP-MPTMOS/TEOS) contributed to the increase in modulus of rapture and work to maximum load values compared to the untreated wood. In dry wood condition, the wood treated with EEP and EEP-MPTMOS/TEOS was characterized by lower modulus of elasticity values than the control samples. In turn, in wet wood condition, wood treated with the propolis-silane preparation showed an increase in the MOE value. Moreover, the impregnation of wood had an influence on the wood creep process under bending loads. The treated wood was characterized by higher relative creep compliance than the untreated wood. The exception was the wood impregnated with EEP-MPTMOS/TEOS, which showed comparable relative creep compliance to the control samples. The presented results indicate that wood treated with a bio-friendly preparation based on propolis and silicon compounds can be used in various application and also in variable humidity conditions.

Molecular identification of timber species from sawn timber and roundwood

Illegal and unsustainable logging of forests have contributed to deforestation and a massive loss of biodiversity, and despite the efforts to regulate the trade of plants and combat the commercialization of illegal logging, the problem continues. DNA analysis of plant tissues is an effective method in species identification, and it is important to dedicate efforts to obtain and amplify DNA from dry wood or exposed to a sawmill process in which its origin is not clear. The aim of this research was to present a strategy to identify tree species from sawn timber and roundwood, based on the use of molecular identification tools. Wood samples of standing trees of Pinus pseudostrobus (PFCap1), round core samples (Ro) and plank wood (SaT) of Pinus pseudostrobus and Pinus devoniana were used. All the samples underwent a DNA extraction protocol, amplification, sequencing, and analysis in the NCBI database. The results showed an efficient extraction of the genetic material, revealing high purity ratios ​​for the three sample groups (PFCap1, Ro and SaT) and quantitative data of the amplified DNA. The information obtained through sequencing showed identities of up to 100% homology (NCBI database). We can conclude that the standardized method developed was successful using the trnL and trnLF primers, managing to isolate, amplify, and sequence the DNA from sawn timber and roundwood, and to identify the age of the tree and the time elapsed between the felling of the tree and the sampling, which are directly related to the success of this method.

Spear study misses the point: a critique of the Ennos and Chan fire-hardening study, concerning wood material representation in archaeological finds and generalized conclusions.

Spear study misses the point: a critique of the Ennos and Chan fire-hardening study, concerning wood material representation in archaeological finds and generalized conclusions.

Evapotranspiration—Tool for seasoning wood of hybrid poplar (Populus maximowiczii A. Henry × Populus nigra L. ‘Max 4-5’) and Salix × smithiana Willd. (Salix caprea L. and S. viminalis L.)

This study deals with the use of evapotranspiration and covering as a means of drying wood. The principle is based on the fact that tree species with outstanding sprouting capacities are able to leaf after being felled and are physiologically active as long as they have enough water. The course of wood drying (the stems) was examined in relation to their subsequent foliage creation and ongoing evapotranspiration, and how those factors related to other factors (climatic factors, storage). The experiment was realized with two fast-growing tree species (special clones): Hybrid poplar (Populus maximowiczii A. Henry × Populus nigra L. ‘Max 4-5’) and Salix × smithiana Willd. (Salix caprea L. and Salix viminalis L.). In the case of poplar wood samples, the presence of roof cover significantly affects the rate of moisture content decrease in wood samples. Wood samples dried slower under the roof. The buds left on the stems probably accelerate the drying process in case of poplar samples. Willow wood samples were in terms of rate of moisture content decrease in four experimental variants indifferent. Presence of roof or buds had no significant effect on the rate of sample moisture content decrease. These findings may help achieve more efficient handling of the timber from fast-growing species in relation to their processing and storage.