Search Results (35)

Recycled wood fiber (RWF) obtained through the multi-stage processing of waste wood serves as an eco-friendly green construction material, exhibiting lightweight, porous, and high toughness characteristics that demonstrate significant potential as a cementitious reinforcement, offering strategic advantages for environmental protection and resource recycling. In this study, high-performance sulfoaluminate cement (SAC)-RWF composites prepared by modifying RWFs with nano-silica (NS) and a silane coupling agent (KH560) were developed and their effects on mechanical properties, shrinkage behavior, hydration characteristics, and microstructure of SAC-RWF composites were systematically investigated. Optimal performance was achieved at water–cement ratio of 0.5 with 20% RWF content, where the KH560-modified samples showed superior improvement, with 8.5% and 14.3% increases in 28 d flexural and compressive strength, respectively, compared to the control groups, outperforming the NS-modified samples (3.6% and 8.6% enhancements). Both modifiers improved durability, reducing water absorption by 6.72% (NS) and 7.1% (KH560) while decreasing drying shrinkage by 4.3% and 27.2%, respectively. The modified SAC composites maintained favorable thermal properties, with NS reducing thermal conductivity by 6.8% through density optimization, whereas the KH560-treated specimens retained low conductivity despite slight density increases. Micro-structural tests revealed accelerated hydration without new hydration product formation, with both modifiers enhancing cementitious matrix hydration product generation by distinct mechanisms—with NS acting through physical pore-filling, while KH560 established Si-O-C chemical bonds at paste interfaces. Although both modifications improved mechanical properties and durability, the KH560-modified SAC composite group demonstrated superior overall performance than the NS-modified group, providing a technical pathway for developing sustainable, high-performance recycled wood fiber cement-based materials with balanced functional properties for low-carbon construction applications. Full article

The main objective of energy balance analysis is to guide farmers in making informed decisions that promote the efficient management of natural resources, optimise the use of agricultural inputs, and improve the overall economic performance of their farms. In addition, it supports the adoption of sustainable agricultural practices, such as crop diversification, the use of renewable energy sources, and the recycling of agricultural by-products and residues into natural energy sources or fertilisers. This paper analyses the variation in energy efficiency between 2019 and 2022 of the main crops in Angola: maize, soybean, and rice, and the forest production of eucalyptus biomass in agroforestry farms. The research was based on the responses to interviews conducted with the managers of the farms regarding the machinery used, fuels and lubricants, labour, seeds, phytopharmaceuticals, and fertilisers. The quantities are gathered by converting data into Megajoules (MJ). The results show variations in efficiency and energy balance. In corn, efficiency fluctuated between 1.32 MJ in 2019 and 1.41 MJ in 2020, falling to 0.94 MJ in 2021 due to the COVID-19 pandemic before rising to 1.31 MJ in 2022. For soybeans, the energy balance went from a deficit of −8223.48 MJ in 2019 to a positive 11,974.62 MJ in 2022, indicating better use of resources. Rice stood out for its high efficiency, reaching 81,541.33 MJ in 2021, while wood production showed negative balances, evidencing the need for more effective strategies. This research concludes that understanding the energy balance of agricultural operations in Angola is essential not only to achieve greater sustainability and profitability but also to strengthen the resilience of agricultural systems against external factors such as climate change, fluctuations in input prices, and economic crises. A comprehensive understanding of the energy balance allows farmers to assess the true cost-effectiveness of their operations, identify energy inefficiencies, and implement more effective strategies to maximise productivity while minimising environmental impacts. Full article

Saline-alkaline and alkaline land is an important potential cultivated land resource in the world. With the destruction of the ecological environment, the cultivated land area is less and less. As a potential soil conditioner, wood vinegar can adjust soil pH, increase root activity, and promote seed germination and root growth, showing its potential in improving saline-alkaline soil. This review summarizes the present situation of saline-alkaline and alkaline land, and its application to China’s cultivated land policy. The traditional saline-alkaline and alkaline land management measures, and analyzes the advantages and disadvantages. Some new methods of treating saline-alkaline soil were enumerated, and the methods of treating saline-alkaline soil with wood vinegar were emphatically introduced, and the molecular mechanism of action of wood vinegar was discussed, the effects of long-term application of wood vinegar on the stability of soil ecosystem were analyzed. The prospect of comprehensive management of saline-alkaline land and how to balance economic development were proposed. Full article

Particleboard is an important forest product that can be reprocessed using wood processing by-products. This approach has the potential to achieve significant conservation of forest resources and contribute to the protection of forest ecology. Most current detection models require a significant number of tagged samples for training. However, with the advancement of industrial technology, the prevalence of surface defects in particleboard is decreasing, making the acquisition of sample data difficult and significantly limiting the effectiveness of model training. Deep reinforcement learning-based detection methods have been shown to exhibit strong generalization ability and sample utilization efficiency when the number of samples is limited. This paper focuses on the potential application of deep reinforcement learning in particleboard defect detection and proposes a novel detection method, PPOBoardNet, for the identification of five typical defects: dust spot, glue spot, scratch, sand leak and indentation. The proposed method is based on the proximal policy optimization (PPO) algorithm of the Actor-Critic framework, and defect detection is achieved by performing a series of scaling and translation operations on the mask. The method integrates the variable action space and the composite reward function and achieves the balanced optimization of different types of defect detection performance by adjusting the scaling and translation amplitude of the detection region. In addition, this paper proposes a state characterization strategy of multi-scale feature fusion, which integrates global features, local features and historical action sequences of the defect image and provides reliable guidance for action selection. On the particleboard defect dataset with limited images, PPOBoardNet achieves a mean average precision (mAP) of 79.0%, representing a 5.3% performance improvement over the YOLO series of optimal detection models. This result provides a novel technical approach to the challenge of defect detection with limited samples in the particleboard domain, with significant practical application value. Full article

This study aims to evaluate the growth characteristics of six Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) provenances (S1–S6) from different climatic regions in subtropical China in order to select superior provenances with strong adaptability, fast growth, and reasonable biomass allocation. These results will provide references for genetic improvement and resource utilization of Chinese fir plantations. A total of 385 trees, aged 26 to 48 years, were selected from the Chinese fir gene bank in Anhui. Wood core sampling was used to obtain tree ring width and early/latewood width data. Growth rate, fast-growth period, and biomass allocation of each provenance were analyzed using methods such as the logistic growth equation, BAI (basal area increment), latewood percentage, and biomass estimation. The fast-growth period of Chinese fir starts from the 2nd to the 4th year, with significant growth occurring around the 14th year and growth stabilizing between 30 and 50 years. Provenance S2 showed clear advantages in growth rate and biomass, while S6 was relatively weak. BAI analysis revealed that the provenances reached their growth peak around 10 years of age, with a gradual decline afterward, but S2 maintained higher growth levels for a longer period. Root-shoot ratio analysis showed that S2 had the most balanced ratio, promoting stable growth and efficient water and nutrient absorption, while S6 had a higher root-shoot ratio, indicating growth limitations. Furthermore, S2 demonstrated continuous biomass increase after 30 years, indicating excellent growth potential. This study provides quantitative analysis of the growth characteristics and adaptability of different Chinese fir provenances, offering scientific support for the construction and breeding of Chinese fir plantations, and contributing to enhancing the productivity and ecological adaptability of Chinese fir plantations for sustainable resource utilization. Full article

Recycling wood-based panels is essential for promoting the cascading use of wood, advancing the transition to a circular economy, and maximizing the efficient use of natural resources. While recycling particleboard has become a well-established industrial practice, recycling medium density fiberboard (MDF) panels presents challenges, particularly in preserving material quality. The aim of this research work was to investigate and evaluate the combined effect of recycled MDF fibers and urea–formaldehyde (UF) resin content on the performance characteristics of the panels. MDF recycling was conducted using hydrothermal hydrolysis and hammer mill refinement. Preliminary experiments revealed that the degradation of properties in recycled MDF panels is not uniform with the addition of recycled fibers. The panels retained their properties significantly with up to 20% recycled fiber content, while formaldehyde emissions decreased by 1.2%. Based on these findings, the optimization of recycled fiber and UF resin content was performed, revealing that the maximum allowable recycled fiber content through hydrothermal hydrolysis and hammer mill refinement is 24%, with a minimum UF resin content of 12%. This study highlights the potential for integrating recycled MDF fibers into new panels, contributing to more sustainable production practices. By optimizing the balance between recycled fiber content and UF resin, it is possible to produce MDF panels that meet industry standards while reducing the environmental impact. Full article

The amended European Union (EU) Renewable Energy Directive—in aiming to increase the share of renewable energy in overall energy consumption—promotes an increased demand for wood, while the EU’s updated Land Use, Land-Use Change, and Forestry (LULUCF) Regulation sets ambitious, binding national targets for the increase in net greenhouse gas removals that could restrict the supply of wood. Additionally, the ongoing war in Ukraine has directly affected the availability of woody biomass in Europe through the EU’s import ban on timber and timber products from Russia and Belarus. This paper provides an in-depth comparative analysis of sources and uses of woody biomass in four European regions in light of these recent climate and energy policies and geopolitical developments. The analysis indicates significantly underestimated reported removals in three of the four European regions studied. Further, projections suggest policy incoherence between current climate and energy objectives until 2030 in all four regions, as fellings increase at a faster rate than net annual increment in all four regions, decreasing the forest carbon sink and thus making it all but impossible to reach the 2030 target of the LULUCF regulation. However, between 2030 and 2040, energy-related fellings could decrease in regions north and west, while they could continue to grow in regions east and south, albeit at a lower rate. Full article

Understanding the influence of heat transfer on the pyrolysis process is crucial for optimizing industrial biofuel production processes. While numerous scientific studies focus on experimental investigations of pyrolysis using laboratory-scale devices, many neglect the essential role of thermal energy in initiating and controlling thermal decomposition processes. This study presents a transient two-dimensional numerical model of biomass single-particle pyrolysis, which includes the energy balance, mass conservation equations and pyrolysis gas pressure and velocity equations. The model employs explicit numerical methods to manage the high computational demands of 2D transient simulations, but is successfully validated with the use of experimental data found in the literature. The model reflects the heterogeneous structure of wood by using different thermal conductivity coefficients depending on the wooden fibers’ orientation. The results demonstrate the impact of fiber orientation on the heat transfer and thermal decomposition processes. The anisotropic properties of wood led to varied temperature fields and pyrolysis decomposition stages, aligning well with experimental data, thus validating the model’s accuracy. The proposed approach can provide a better understanding and lead to improvement in biofuel production processes, enabling more efficient and controlled conversion of biomass into fuel. By optimizing the pyrolysis process, it contributes to the development of sustainable energy preservation and regeneration methods, supporting a shift towards more sustainable fuel production patterns using renewable biomass resources like wood. Full article

This paper characterizes the carbonization process of biomass wastes, including sunflower husk pellets and sunflower sponge stalk pellets, at carbonization temperatures of 450 and 550 °C. These studies are important because of the reductions in wood resources for the preparation of barbecue charcoal, as well as agricultural benefits in terms of soil additives. In terms of energy balance, the obtained pyrolysis ensures the autothermal process. The heating characteristics of fixed bed showed that, due to the difference in bulk density, the bed temperature of the sunflower husk pellets reached 450 °C in 110 min, whereas the bed temperature of the sunflower stalk sponge reached the same temperature in 200 min. Additionally, the energy used for the sunflower husk carbonization increased from 2.9 kWh at 450 °C to 3.3 kWh at 550 °C, while the sunflower stalk sponge increased from 3.5 to 3.9 kWh. The combustion characteristics assessed using TGA showed that the carbonization of sunflower husk leads to obtained biochar with a higher combustion activity than biochar derived from sunflower stalk sponge. According to the experimental results, biochar from sunflower husk pellets has a higher water content capacity and water absorption rate than biochar from sunflower stalk sponge pellets. Full article

The global demand for sustainable building materials has fuelled research into composite panels from wood waste. Despite their potential, the widespread adoption of this practice is hindered by the absence of quality standards, inconsistent material properties, and uncertainties about durability and strength. This paper critically reviews existing standards, manufacturing processes, and the suitability of panels from wood waste. A systematic review is conducted to identify the influencing processes and parameters affecting panel performance, from waste collection to the finishing stages. The findings indicate that incorporating 10–30% of wood waste can enhance the mechanical and physical properties, with particularly improved hygroscopic properties and greater dimensional stability. By establishing comprehensive standards and optimizing manufacturing processes, wood waste-based panels can emerge as a viable and eco-friendly alternative. Furthermore, the potential for repeated recycling in a closed-loop process offers promising environmental benefits, though it necessitates balancing resource conservation with product quality. By addressing these challenges, wood waste-based panels can significantly contribute to environmental conservation and resource management. Full article

Humans have relied on forest resources for their basic needs, including fuel, food, and shelter. The high demand for these resources has led to the implementation of forest protection and management measures, including the establishment of by-laws. These regulations aim to control community access and use of forest products, which significantly affect the availability of non-timber forest products (NTFPs) and, in turn, food security in the study area. Our study employs a combination of probability and non-probability household sampling methods and a cross-sectional survey to collect data from respondents in Mnenia and Kolo villages. Our findings reveal that 74% of respondents in the study area experience food shortages. To address food security, 81% resort to selling household assets, 63% rely on food aid from institutions and the government, and 36.31% supplement their food supply by consuming edible NTFPs. The NTFPs available for gathering in the area encompass dead wood, wild vegetables, fruits, mushrooms, and medicinal plants, which are essential to the local communities. However, the perception of the people regarding forest management and food security indicates that 85.2% of respondents favor reducing the strictness of forest access, while 74.07% advocate for an increase in NTFP collection, recognizing potential side effects on forest management. In light of these findings, it is imperative to strike a balance between by-laws and the sustainable management of forest resources to strengthen the region’s forest management and food security. Full article

Forest wood biomass is one of the basic renewable resources used in the bioeconomy as a raw material for industrial products and fuel. The forest also plays an important role in the global carbon cycle. The increasing demand for wood biomass due to the growing population, as well as the required strategies to face climate change, force us to look at the use of forest wood biomass from a different angle. The European Commission has made a decision about the European Green Deal strategy. The new EU Forestry Strategy, as an element of the European Green Deal, promotes the sustainable use of wood-based resources. Therefore, it is important to know what is the sustainable potential of forest wood biomass and how it can be assessed. This study aimed to assess the potential of forest wood biomass in terms of sustainable development in the European Union. Five estimates were applied, the self-sufficiency ratio, imports-dependence ratio, logging residues rate, recovery rate, and the ratio between annual fellings and the net annual increment of forest wood biomass. The findings indicate that the self-sufficiency in primary wood biomass is quite high, and the ratio between annual fellings and net annual increment of wood biomass is sustainable in total in the EU. However, in separate countries, there are opportunities to increase domestic fuelwood potential and reduce fuelwood imports by using logging residues. The basic idea is that the biomass potential of forest wood has more sustainable use opportunities. This study can provide insight for political direction into how to increase self-sufficiency in wood biomass and maintain a balance between harvesting and the increment of wood biomass at the same time. Future research on the potential of forest wood biomass should consider the distribution potential by countries and counties. The principal conclusions of this study are important for the development of a sustainable bioeconomy and the need to sustainably use the potential of forest wood biomass. Full article

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) is an important timber species native to southern China. While the single, unstructured breeding strategy was employed in the past three cycles of breeding, it is no longer adequate for managing a more advanced breeding population. In this study, we utilized restriction-site-associated DNA-sequencing (RAD-seq) to estimate the genetic diversity of breeding populations and phenotypic values or breeding values to estimate the genetic gain of hundred-grain weight, diameter at breast height, and wood basic density. To achieve a balance between genetic gain and genetic diversity, we combined the multiple populations and core-main populations methods to construct the fourth cycle breeding population. Finally, the fourth cycle breeding population was made up of a core population of 50 individuals with an inbreeding coefficient of ~0, and an additional main population of 183 individuals, with an effective population size of 108. Crossings made within and/or between different trait-targeted subpopulations could facilitate bidirectional gene flow between the core and main populations, depending on the breeding objectives. This structured breeding population of Chinese fir could aim for both short- and long-term genetic gains and has the potential to support the preservation of germplasm resources for future climate change. Full article

Community forestry is a strategy in which communities are, to some degree, responsible for managing the forests, using a more participatory approach to replace the traditional top-down model. Various forms of policies and governance have been developed to balance goals to ensure the community’s socioeconomic resilience and the landscape’s biological sustainability. The reinvestment of community forest (CF) income back into forest regeneration is not well documented, and there is a lack of research comparing forest income to the costs associated with forest regeneration. This research examines how changes in timber income and forest-regeneration costs affected CF social and ecological viability. We conducted expert elicitation interviews for CFs (n = 33) under three zones of management in Chitwan, Nepal (Zone 1: buffer zone, Zone 2: forest corridor, and Zone 3: community forest). To examine how CFs differ financially, we asked questions regarding timber income and forest-regeneration expenditures and then posed 22 questions regarding socioeconomic and biological aspects of the CF. Finally, a Kruskal–Wallis rank-sum test was performed to determine whether there were statistically significant differences in perceptions between groups, including zone, timber income (high, medium, low), and forest-regeneration expenditures (high, medium, low). The amount of income from timber had a substantial impact on the communities’ biological benefits and financial stability. Lower timber-income areas were thought to be less economically stable, lack the resources to enforce rules and regulations necessary to meet the CF’s socioeconomic or biological goals, and place more significant restrictions on the amount of wood members can harvest from the forest. Communities that spent less money on forest regeneration reported poorer levels of forest regeneration, economic sustainability, and community rights. Our research shows that community-forest user groups in the Chitwan district have a significant income and expenditure gap between their forests’ biological and socioeconomic advantages and resilience. Full article

Low-carbon energy requires more land than the non-renewable resources. This paper balances holistic assessments of the land demands for biomass heating and their ecosystem services. It is predicted that biomass will continue to play an important role in the heating sector in Germany by 2050, as it is one way to increase the use of renewable energy and reduce CO₂ emissions. To balance this out, it is important to ensure that the substitution of fossil fuels with fuelwood does not result in losses in biodiversity, natural forest, and agricultural land. Based on the observed types of fuel demand, the need for space in terms of the growing area is characterized as the corresponding land under the consideration of a given land-use type. Formulas have been applied at the federal level in Germany. The area required to supply an average German household is 0.64 ha if all the wood harvested is used for energy purposes, but this is in competition with all other types of timber use. Fuelwood from thinning alone cannot meet the domestic demand. However, a sustainable supply of woody biomass is possible if residues mainly from forestry and the wood processing industry are used, causing a land demand of 2.69 ha per house, possibly in combination with smaller shares of the above-mentioned types of use. Thus, the shares of pellets and wood chips for heating purposes should be expanded, which would also bring ecological advantages. The qualitative consideration of forest ecosystem services shows that changing the forest composition or management may increase the fuelwood supply but does not necessarily decrease forest ecological services. Full article