Search Results (52)

The identification of standing tree species, timber logs, and on-site assessment of their quality and value using images holds significant potential for forestry applications, including inventory management, traceability under EU regulations like the Deforestation Regulation, and market valuation amid growing demands for sustainable practices. This study addresses this by classifying images of timber logs by tree species and market value using the Orange data mining software, which leverages pre-trained convolutional neural networks (Inception v3 and SqueezeNet) to generate embeddings from a dataset of 5549 images collected at a real timber auction in Slovenia, followed by logistic regression image classification. Results show high accuracy for tree species classification (up to 92.6%), but substantially lower accuracy for market value classification (40%–55%), reflecting the greater complexity of value determination from visual features. These findings underscore the promise of deep learning for species identification while indicating the need for further methodological advancements to enhance value classification reliability, which offers the practical impact for operational forestry and bioeconomy value chains. Full article

This study investigates how key planning variables—the number of wood assortments, the geometric shape of clear-cut areas, and the extraction (forwarding) distance—influence greenhouse gas (GHG) emissions. Twelve plots formed a heterogeneous sample with similar site type and soil moisture conditions. A Komatsu 931 harvester and a 855 forwarder, driven by the experienced operators, were used to ensure consistency in operator skill. For each plot, the isoperimetric quotient was computed to quantify how plot shape correlated with labor hours, fuel consumption, and the resulting volume of GHG emitted. The number of assortments extracted per plot ranged from three to fourteen product groups. The results show that plots with more complex shapes require significantly more operator time and fuel. Increasing the number of assortments amplifies handling time and fuel use. Longer extraction distances further exacerbate the emissions. These findings underscore the importance of integrating spatial geometry and wood assortment planning into harvest scheduling to enhance productivity and reduce the carbon footprint of forest operations. Recommendations for practitioners include prioritizing more compact treatment units, optimizing assortment grouping, and minimizing extraction distances as key strategies for precision forestry. Full article

Pedunculate oak (Quercus robur L.), an ecologically and economically important tree species has been significantly affected by oak dieback in recent years. Since one of the symptoms of oak dieback is crown defoliation, this research aimed to determine the quantity, quality, average tree value, and wood defects that influence grading in different stages of oak dieback indicated by tree crown defoliation degree. The research was conducted in a 62- and 116-year-old stand of the lowland Croatian forest. In total, 115 pedunculate oak trees were sampled and processed in 983 logs that were analyzed. The prescribed single-entry volume tables underestimate harvesting volume by 5.45% on site A and 6.16% on site B, while the calculation of net harvesting volume underestimates net volume by 0.26% on site A and overestimates net volume on site B by 4.59%. The analysis of wood defect presence showed that insect holes, rot, and covered knots were the main reasons for the degradation of quality class. Dead trees showed a decreased average tree value in DBH classes 32.5–42.5 cm compared to the healthy trees. Based on the findings of this research, tree crown defoliation degree could be used as a timber quality and average tree value indicator. Full article

This work aimed to compare the qualitative assessment of valuable oak logs using the conventional method employed in forestry operations with the evaluation based on image outputs from a CT scanning line. A total of 125 oak logs from southwestern Slovakia were analyzed. Quantitative and qualitative features were measured using both approaches, and the logs were classified into quality classes according to the technical conditions of the STN 48 0056 standard, based on their dimensions. The qualitative assessment of logs using CT images revealed additional internal features that often resulted in the downgrading of logs to lower-quality classes. This method of evaluation increased the frequency of logs classified into lower-quality classes. Nearly half of all evaluated logs were classified into the same quality class by both assessment methods. However, 33% of the logs were classified as one quality class lower when assessed using CT images. This discrepancy can be tentatively attributed to the detection of hidden internal features, as well as the enhanced precision in measurement and feature evaluation enabled by 3D models and cross-sectional images from CT scans. Notably, more than 10% of the logs were classified into a higher quality class based on CT images compared to visual assessment. The economic evaluation based on CT classification was 3769 EUR lower than that based on the conventional method. Full article

In the years 2022 to 2023, the harvesting of medium-sized round wood by the State Forests Service in Poland was estimated at between 22.2 and 23.6 million solid cubic meters per year. This is a significant amount of timber to be transported by road. It is a challenge for both transport companies and round wood buyers. The high variability of wood density depending on the species in combination with its moisture content is a significant issue in logistics operations. This study focuses on the influence of the absolute moisture content on selected parameters of wood deliveries, taking into account the differences in the seasons. The total weight of a transport set (GVW) and empty set (Tare) and the weight of the load (Net) were determined on the basis of weighing the transports on stationary scales at the recipient. The moisture content of each wood load was determined using the dryer-weigher method for sawdust taken from the cutting of several logs from the delivery. This study analyzed a total of 13,602 transports of ten tree species and two wood assortments of pulpwood (S2a) and industrial wood (S2ap) in four seasons in the years 2020–2022. Pine was the dominant species in 5352 deliveries, and spruce was the dominant species in 3161. In terms of seasons, 3983 transports were recorded in the summer, 3650 were recorded in the spring, and 3492 were recorded in the autumn. The lowest number of 2475 was in winter. The mean volume of delivered wood (from 13,602 transports) was 28.18 m³, with a range of results from 19.00 to 51.29 m³ and SD = 2.40. The mean weight of the shipment was 24.95 Mg, with SD = 3.36. The range was from 13.92 Mg to 38.20 Mg. The mean absolute moisture content (AMC) of all wood loads (regardless of species and quality) was 42.91%. The results varied significantly (SD = 6.41). The minimum value was 15.64%, and the maximum value was 66.79%. The absolute moisture content of round wood is related to the season, species and assortment of transported wood. Loads of hardwood have lower average solid cubic meter values than softwood. Full article

Integrating different ecosystem services (ES) to determine when to harvest a forest stand is still challenging. This is due to the difficulty of obtaining information, models, and methods to quantify those ES and achieving an adequate valuation of these services. In this study, we propose a methodology comprising two different models that could allow for different ES integration with the optimal silviculture to calculate the optimal economic rotation. We have applied both models to eucalyptus plantations in Brazil considering two ES: wood with four different assortments and carbon sequestration. For both models, we calculated a ranking with previously defined management alternatives, with decreasing trees-per-hectare compared to traditional plantations. For the first model, when the ES are measured in monetary units, the optimal rotation corresponds to fewer trees per hectare than the traditional plantations and greater associated profitability. The second model incorporates the ES in physical units through a multi-criteria decision-making model and results in a longer rotation with again fewer trees per hectare. This study suggests that optimum forest rotation analysis should consider ES other than timber production integrated with silvicultural alternatives, such as spacing. Full article

Forest stands are developing in changeable climate conditions that influence stand health and consequently assortment quality. Narrow-leaved ash is strongly affected by dieback because of new fungal diseases. The main aim of this study was to determine the quantity and quality of produced wood assortments in dieback-affected narrow-leaved ash stands. Based on the study results, the average tree value increased with tree diameter and partially decreased with tree crown defoliation degree. The healthy (crown defoliated up to 25%) and 3A (crown defoliated from 61 to 80%) trees had significantly higher average tree values (EUR/m³) compared to the significantly defoliated 3B trees (crown defoliated from 81 to 99%) and dead trees (100% defoliated crown). The influence of stand age and share of narrow-leaved ash in stand volume were confirmed as factors influencing the average tree value. Wood chips quality remained the same regardless of tree crown defoliation degree. Based on the significance influence of the tree crown defoliation degree on the average tree value, current assortment tables should be expanded in order to achieve more accurate expected values. Full article

In general, bark serves a protective role for trees and is genetically determined. The quantification of bark based on biometric characteristics is linked to studies on the distribution of forest species across the globe and vegetation fires. In Romania, on the other hand, the improvement of the wood traceability system requires an increase in the accuracy of the estimation of the biometric characteristics of bark and, implicitly, of the volume of wood under the bark. The aim of this study was to develop more precise models for predicting bark thickness along the stem of three key Romanian species, taking into account a comprehensive range of models and stem sections, including those with a diameter over bark smaller than 8 cm, which have been excluded in previous studies. The study is based on two datasets, one containing the national measurements of three commercially valuable forest species, i.e., Norway spruce (Picea abies (L.) Karst), European beech (Fagus sylvatica L.), and pedunculate oak (Quercus robur L.) from 12,186 trees, and a second dataset containing the measurements from 61 logs of the same species at a specific forest site. A set of seven double bark thickness (DBT) estimation models with stem diameter over bark (DOB), DOB and total tree height (H), DOB and relative height along the stem (h/H), and diameter over bark at breast height (DBH) and DOB as predictors were used. The DBT models were evaluated using the coefficient of determination (R²), mean absolute error (MAE), root mean squared error (RMSE), the Akaike information criterion (AIC), and the Bayesian information criterion (BIC). This led to the selection of two more accurate models, Model 2 (based on a third-degree polynomial) and Model 3 (based on a logarithmic function), with DOB as the predictor. Relative double bark thickness (RDBT) and proportion of bark area (PBA) were also estimated using a sixth-degree polynomial and relative height as a predictor variable after stratifying the data by DBH classes to reduce variability. The results of this study indicate that there is a need to complete the database, for all three forest species of commercial value in Romania especially for large trees with DBH greater than 60–70 cm. The models obtained for PBA are of great use to the industry and the economy, in particular in the context of the traceability of wood. This is due to the fact that PBA can be equated with the proportion of bark volume (PBV), which describes the variation in the proportion of bark in the volume of the wood assortments along the stem. For a given DBH, PBA and PBV demonstrate minimal variability in sections from the tree’s base to a relative height of 0.6; however, a pronounced increase is observed at crown level in sections above relative heights of 0.8. Full article

Coppicing has been neglected in recent decades, leaving gaps in knowledge on silvicultural interventions, especially the long-term effects on coppices of Southeast Europe. The recent economic crisis, the sudden increase in energy prices, and the increased demand for assorted wood products have initiated higher interest in coppices in Croatia. Thus, our work aims to define the long-term effects of thinning in sessile oak (Quercus petraea (Matt.) Liebl.) and European beech (Fagus sylvatica L.) sub-mountainous thermophilic low coppices in the Croatian Dinarides. The experiment includes two localities with thinning and control plots. Thinning was performed in 2002, with 17.71% of wood volume removed in the European beech coppice and 26.09% in the sessile oak coppice. In 2020, 1276 trees were marked, measured (DBH, tree height, number of stems per stump), and assessed for vitality, origin, and six silvicultural features revealing tree quality. In 2022, trees were again measured (DBH, tree height) to gain data on tree growth. Conventional data analysis methods were used. The results show a statistically significant positive long-term effect of thinning on tree growth, stem, and crown features and support findings that thinning, by increasing growth and quality, is a necessary intervention in European beech and sessile oak low coppices. Thinning promoted the healthiest and best quality trees/stems, resulting in a more valuable range of wood products and the potential for higher income. It had a positive impact on tree growth regardless of the tree’s origin (seed or stump) and improved the growth and quality of trees among the supporting tree species. Short-term effects of thinning in trial plots suggested that thinning supported tree species diversity, but this effect diminished over time, showing no positive effect after twenty years. The study points to the need for more frequent thinning in coppices to support tree species diversity (i.e., to allow growth to less competitive tree species) but underlines the need for further research. Full article

According to most energy demand forecasts, woody biomass has the potential to become an important source of renewable energy, especially during the transitional period of energy transition. The aim of this article was to estimate the energy potential of the biomass from the forest and the biomass generated by the mechanical processing of wood raw material and also to show the spectrum of possibilities for the potential use of the biomass for energy production in Poland. This research used available statistical and literature data on the species structure of harvested wood and the qualitative and assortment structures of woody biomass. The basic parameters of the raw material were evaluated in accordance with the EU classification of energy wood. This study confirmed the relationship between the energy potential of woody biomass and energy demand in Poland. The correlation coefficient for these variables was r = 0.984. This correlation was reflected in the significant shares of biomass in the production of electricity (more than 9%) or heat (almost 14%). Energy wood resources in Poland are smaller than in other European Union countries, which affects the scale of the potential use of woody biomass for energy purposes. Nevertheless, the use of such a biomass is fully justified from the point of view of possible development. Full article

Wood, as the main product of the forest, must be brought from the forest to various beneficiaries by various vehicles. The choice of a particular type of vehicle should consider the characteristics of the area from which the wood is loaded, the wood-storage yard, and the availability of a certain model. Besides this, the assortments and quantities of wood to be transported influence, to a large extent, the type of vehicle, which has consequences for transport efficiency and productivity. The aim of the paper was to evaluate the wood-loading process in various types of transport vehicles in terms of time consumption for each working phase and the factors that can affect productivity. The research was carried out in four counties of Romania and addressed the loading of wood in different forestry trucks and platforms, with or without trailers. Transport distances were documented in Brasov County based on 200 transport documents. To evaluate the transport distances in the case of wood intended for contractors, field measurements were carried out in three different are as managed by the private Lignum Forest District (Bacău County). The study of the loading process and productivity estimation at loading was carried out in three locations, namely Bacău County, Sibiu County, and Caraș-Sever in County. To observe whether there are differences in the loading of tree lengths from the harvesting area in various types of vehicles (forestry trucks—ATF—and forestry platforms—APF), research was carried out in Caraș-Sever in County. After processing the data, it was found that in the forests managed by the state and in the forests owned by the local public administrations, the fuelwood reaches mainly locals, and the working wood reaches some wood processing companies. For forestry trucks (ATFs), the loading time was somewhat constant, while for forestry platforms (APF), it varied, with differences observed from the first to the last loading. Following the evaluation of the work-element phases specific to the operation of loading round wood into vehicles, it was found that, sometimes, significant importance is given to the working elements as phases of preparation of the wooden material that can be carried out before the loading process, in order to load it. To eliminate delays in the loading process, it is recommended that logs are prepared before loading, which will increase productivity and it will decrease the risk of accidents for workers who perform these tasks during the loading process. Full article

Subfossil oak (SO) wood material, originating from three different buried trunks discovered in recent years by excavations in riverbanks on Romanian territory, was analysed in this research. Aged oak recovered from constructions (AO_C) and recent/new oak wood material (NO) were also investigated to provide comparative data for the SO. The oven-dry density and the basic density, the total volumetric and linear swelling and shrinkage coefficients and the compression strength parallel to the grain were the selected physical and mechanical properties considered. The experimental results showed a lower density of SO compared to NO and AO_C tested by up to about 19–20%, alongside a trend of increased dimensional instability, with variability among the tested assortments. The compression strength parallel to the grain was reduced by 19–31% compared to NO. The properties of AO-C were closer to those of NO, but differences between wood materials from different sources and of different ages were registered. A positive linear correlation was found between compression strength parallel to grain and the basic density for all types of material and assortments tested. These comparative results have to be considered by designers and engineers in the valorisation of SO in furniture design and other applications. Full article

As forest-based climate change mitigation has become a crucial element of international climate policy it is of increasing importance to understand the processes leading to the carbon offsetting capacity of the sector. In our study, we assessed the climate benefits of contrasting forest management strategies: decreasing harvest and enlarging the forest carbon stock, or increasing harvest to increase carbon uptake, wood product carbon pools, and substitution effects. We developed the Forest Industry Carbon Model (FICM) which is a new carbon accounting tool covering forest biomass, dead organic matter, soil, and harvested wood product pools, as well as avoided emissions through product and energy substitution. We modeled the carbon balance of the Hungarian forest industry under three different scenarios. In the business as usual (BAU) scenario, we assumed no changes in the current harvest and afforestation levels. In the extensification scenario, we assumed that the harvest and afforestation levels drop to half, while in the intensification scenario, we assumed an increase in afforestation, improved industrial wood assortments, and a gradual increase in logging, reaching the highest level as per sustainability criteria by 2050. Our results show that the intensification scenario is characterized by the largest net removals and the maximized product and energy substitution effects. By 2050, the net forest industry carbon balance reaches −8447 kt CO₂ eq under the BAU scenario, while −7011 kt CO₂ eq is reached under the extensification scenario and −22,135 kt CO₂ eq is reached under the intensification scenario. Although substitution effects are not accounted for under the land-based (LULUCF) sector in the greenhouse gas inventory, the emission reductions in the industry and energy sectors have beneficial effects on the national carbon balance. Modeling results show that the 2030 LULUCF greenhouse gas removal target set by EU legislation for Hungary is reached under the intensification scenario. To achieve this outcome, widespread innovation is needed in the wood sector. The modeling results show that nonutilization of forests can only be a very short-term solution; however, its favorable effects will be reversed by 2050 resulting in additional emissions compared to the BAU scenario. Full article

In any forest stand, the theoretically modelled output of sawlogs (the most valuable roundwood assortments) will differ from what is actually obtained. The aim of this study was to assess whether it is possible to characterise this difference by site properties or forest inventory parameters for birch, black alder, and aspen. We compared theoretically modelled sawlog recovery with actual recovery according to harvester data from final fellings. The difference between the theoretically modelled and actually recovered sawlog outcomes varied from −24.32 to −60.96 percentage points, with overestimations reaching up to three times for aspen. The differences in yield of sawlogs varied among soil types and increased with age and the average diameter of a tree. The sawlog recovery was underestimated up to the mean diameter at breast height of 16 cm and age of 20 years while being overestimated for larger and older trees. The results highlight the necessity to consider decreasing wood quality with increasing age to account for decay, such as stem rot, in assortment tables. Full article

In Europe, forest fires are a serious and constant threat. They destroy forests and forest land, causing damage, financial loss, and long-lasting impacts on forest ecosystem services. There are several ways to decrease the number of forest fires, including continuous investment in fire prevention measures and the intensive implementation of adaptive sustainable forest management measures, which need additional financial resources. In many cases, forest management activities in karst forests are not implemented in a timely manner and in coordination with other stakeholders. A comprehensive study about the impact of forest fires on different economic activities (tourism and protected areas) is not currently available. In this study, the legislative framework in Croatia was analysed in relation to the fire protection activities and jurisdictions of different institutions. From data collected in the period 2013–2020, the first-age class afforestation costs and growing stock assortment value were calculated, and the non-wood forest functions were estimated. The aforementioned data were further compared to the Fire Weather Index (FWI) and Seasonal Severity Rating (SSR) of fire seasons. The total estimated damage is EUR 326,810,724.72. The research emphasises the need for the implementation of cross-sectoral forest policy measures. The state forest company should allocate more financial resources for biological forest restoration in the future. Forest management practices should implement climate-adaptable silviculture measures to preserve forest and forest land. Full article