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Sandy soils represent an extreme environment for tree growth. Traditionally, site preparation before planting involves removing logging residues (LRR) and ploughing. An alternative method is incorporating logging residues (LRI) into the topsoil which may enhance tree regeneration and seedling growth. The aim of this study was to assess whether and how different site preparation techniques affect soil physico-chemical and microbial properties over the long term. The study was performed in the Záhorská nížina lowland (Slovakia) in September 2020. Soil samples were taken in two 25-year-old Pinus sylvestris (L.) plantations along five soil profiles in each stand, down to a depth of 30 cm. Results showed a significant increase in carbon and nitrogen concentration and soil moisture in the LRI plot. However, soil pH and phosphorus content significantly decreased. No significant differences were observed in calcium, magnesium, and potassium concentrations between the differently treated plots. The LRI plot also exhibited a significant increase in microbial biomass carbon, N-mineralisation, and catalase activity. The results indicate that different mechanical site preparation methods may impact soil properties over the long term, likely through improved seedling survival and tree growth.

In 2023, branches of European beech (Fagus sylvatica L.) were placed on 24 different study sites within beech stands in the Czech Republic to study the distribution of the beech bark beetle (Taphrorychus bicolor Her.). After infestation, the branches were placed in emergence traps to capture adults of the offspring generation. In total, 2167 adults of T. bicolor were captured across the 24 study sites. The average capture (mean ± SE) was 90.3 ± 24.4 adults per site. Statistical analyses, including GLMM and GLM, were employed to assess the influence of elevation and stand age on the abundance of T. bicolor. The results indicate that the distribution of T. bicolor is mainly influenced by the elevation and age of the beech stand. The number of captured adults decreased with elevation and increased with stand age. Climatic region, volumes of beech, and volumes of felled beech wood from principal felling and thinning felling had no significant effect on the number of T. bicolor adults captured. We found that, overall, 73.37% of Czech beech stands (at elevations 300–650 m a.s.l.) are possibly threatened (either highly or slightly) by the large occurrence of T. bicolor, because they are present at elevations where T. bicolor is widespread. No outbreaks of T. bicolor have yet been reported in the Czech Republic, but with the increasing amount of beech planted, combined with global climate change, the possibility of outbreaks in the future cannot be excluded. [ABSTRACT FROM AUTHOR]

The reduction of greenhouse gas (GHG) emissions demands a significant increase in the use of wood as a renewable energy source. However, environmental restrictions determine limits on the further growth of harvesting volume. Therefore, a viable solution to enhance the share of energy wood in Estonia’s energy balance involves focusing on less exploited assortments of raw material and implementing precise logistics planning. In recent years, mild winters have posed challenges to the extraction of residues and local transport of wood fuels, taking place on soft and unfrozen soils. In such conditions, ensuring a reliable supply of wood fuels becomes rather complicated. When piles of logging residues on unfrozen soils are inaccessible, there is a need to process older piles. The quality of wood chips from such piles is lower compared to the norm. To investigate the impact of extra long-term storage of residues in piles, a study was conducted at the Järvselja Training and Experimental Forest Centre. In 2010, sample piles were created in birch and spruce final felling areas. Over an eight-year period, samples were regularly taken from the piles to analyse the properties of woody biomass during storage. The study results indicate that the quality of fuel from covered piles changes slowly during the first two years of storage. Subsequently, the degradation speed equalizes in both uncovered and covered piles. Despite extensive degradation and loss of dry matter during long-term storage (approximately 29% for Norway spruce and 55% for silver birch after eight years), the quality of dry fuels still meets standard requirements and remains acceptable for boiler houses.

Torrefaction and combustion have been applied to naturally decomposed red oak logging residues. The results indicated that four-year natural decomposition would lower the energy density of red oak from 20.14 to 18.85 MJ/kg. Torrefaction reduced the O/C and H/C ratios but improved the energy yield values. Two combustion stages were observed for all samples, and no hemicellulose derivative thermogravimetric peak appeared for torrefied samples. The differential scanning calorimetry exothermic heat flow increased after torrefaction. In addition, the Kissinger–Akahira–Sunose average activation energy of untorrefied samples decreased in the first stage (from 157.77 to 149.52 KJ/mol), while it increased in the second stage (from 131.32 to 181.83 KJ/mol). The ∆H, ∆G, and ∆S values of all samples decreased in the first stage, while they increased when the conversion rate was greater than 0.5 for torrefied samples. These findings can aid in a better understanding of the fuel performance of torrefied and untorrefied naturally decomposed red oak logging residues. [ABSTRACT FROM AUTHOR]

Tropical forest management has a potential role in forest conservation if it is sustainable. This study of a forest under management in Bolivian Amazonia strongly suggests that the management project is not sustainable and that no potential changes in management would be likely to make it so. In a 216.41 ha harvested area, 278 commercial trees from 10 families, 15 genera, and 15 species were measured. The density of commercial species with diameter at breast height (DBH) ≥ 50 cm was 1.28 trees ha−1, and the harvestable commercial volume was 12.40 m3 ha−1. Due to market restrictions, the actual amounts harvested were much lower: 96 trees were harvested with commercial boles totaling 2.7 m3 ha−1. Of the total impact on biomass and carbon (above- and belowground), the logs removed from the area represented only 13.4%, while 86.6% was from losses in the forest as follows: 14.5% from the stumps, crowns, and roots of harvested trees (DBH ≥ 50 cm) plus 72.1% from the trees (DBH ≥ 10 cm) in the forest lost to roads, log landings, and skid tracks and the gap openings caused by felling the harvested trees. The estimated expenses exceeded the gross revenue of the management company (USD 519.15 ha−1), a fact confirmed by the company's subsequent bankruptcy. The project's low harvest intensity reduces the environmental impact per hectare but increases the impact per cubic meter of wood harvested because producing a given volume of wood requires disturbing a larger area and because more kilometers of access roads and skid tracks have to be installed to extract a given volume of wood. Because many costs are fixed regardless of harvest intensity, small harvest volume can render such projects financially unfeasible, increasing the likelihood that they will be abandoned and not provide long-term "sustainable" forest protection. However, this does not mean that higher harvest intensity results in sustainability, as other constraints apply to high-intensity projects. We conclude that conservation alternatives to maintain the forest would be more beneficial than management for timber. [ABSTRACT FROM AUTHOR]

The transition from fossil jet fuel to biojet fuel is an important step towards reducing greenhouse gas (GHG) emissions from aviation. To enable such a fuel shift, the Swedish Government introduced a GHG emission reduction mandate of 27% by 2030 for aviation fuel sold in Sweden, forcing fuel suppliers to blend in biojet fuel in fossil jet fuel. A similar policy instrument is being discussed within the EU. Biojet fuels with life cycle GHG emissions 90% lower than those for fossil jet fuel are projected to be available by 2025, which by far exceeds the requirement of 65% lower emissions in the EU Renewable Energy Directive. The purpose of this study was to carry out life cycle assessments for a number of wood-fuel-based production chains near commercialization and to determine whether they meet the Swedish projection and the EU requirement. The study illustrates what can be achieved in a region with high availability of wood fuels and access to heat and power with low GHG emissions. The production chains studied include the production of hydrocarbon intermediates via (i) fast pyrolysis, (ii) hydrothermal liquefaction, (iii) thermal gasification followed by Fischer–Tropsch-synthesis, and (iv) cellulosic ethanol fermentation followed by upgrading of these four intermediates to biojet fuel and other liquid biofuels. The results show that all the production chains studied can deliver biojet fuels with 89–91% lower GHG emissions than fossil jet fuels. Non-fossil hydrogen is required to achieve low emissions in the upgrading of intermediates from fast pyrolysis and hydrothermal liquefaction. [ABSTRACT FROM AUTHOR]

A significant amount of logging residue is produced during roundwood harvesting. Logs are often left in forest sites due to, for example, ecological or logistical aspects. Taking into account the fact that the number of studies focused on changes in the properties of the residue is very low, it was decided to conduct research on the effect of a three-year storage period in forest stands on the chemical properties and energy potential of the wood. The research design allowed for the determination of changes during up to three years of storage. The performed analysis showed a highly negative impact on the characteristics of the material. These adverse effects were probably caused by the activity of microorganisms such as fungi and bacteria, as evidenced by the increased concentrations of ergosterol and low-molecular-weight organic acids. Moreover, it was found that wood stored for three years was characterized by a lower cellulose content; an increased percentage of lignin; a reduced content of sterols (desmosterol, stigmasterol, lanosterol and β-sitosterol) and phenolic acids; and reduced antioxidant activity, as determined with the ABTS+ method. Storing logs also led to a reduction in the energy potential of the residues, as shown by a reduction in net and gross calorific value and an increased ash content. [ABSTRACT FROM AUTHOR]

Expanding markets for renewable energy feedstocks have increased demand for woody biomass. Concerns associated with forest biomass harvesting include increased erosion, the applicability of conventional forestry Best Management Practices (BMPs) for protecting water quality, and reduced woody debris retention for soil nutrients and cover. We regionally compared the data and results from three prior independent studies that estimated erosion, BMP implementation, and residual woody debris following biomass and conventional forest harvests in the Mountains, Piedmont, and Coastal Plain of Virginia. Estimated erosion was higher in the Mountains due to steep slopes and operational challenges. Mountain skid trails were particularly concerning, comprising only 8.47% of the total area but from 37.9 to 81.1% of the total site-wide estimated erosion. BMP implementation varied by region and harvest type, with biomass sites having better implementation than conventional sites, and conventional Mountain sites having lower implementation than other regions. Sufficient woody debris remained for BMPs on both harvest types in all regions, with conventional Mountain sites retaining twice that of Coastal Plain sites. BMPs reduced the estimated erosion on both site types suggesting increased implementation could reduce potential erosion in problematic areas. Therefore, proper BMP implementation should be ensured, particularly in Mountainous terrain, regardless of harvest type.

Expanding markets for renewable energy feedstocks have increased demand for woody biomass. Concerns associated with forest biomass harvesting include increased erosion, the applicability of conventional forestry Best Management Practices (BMPs) for protecting water quality, and reduced woody debris retention for soil nutrients and cover. We regionally compared the data and results from three prior independent studies that estimated erosion, BMP implementation, and residual woody debris following biomass and conventional forest harvests in the Mountains, Piedmont, and Coastal Plain of Virginia. Estimated erosion was higher in the Mountains due to steep slopes and operational challenges. Mountain skid trails were particularly concerning, comprising only 8.47% of the total area but from 37.9 to 81.1% of the total site-wide estimated erosion. BMP implementation varied by region and harvest type, with biomass sites having better implementation than conventional sites, and conventional Mountain sites having lower implementation than other regions. Sufficient woody debris remained for BMPs on both harvest types in all regions, with conventional Mountain sites retaining twice that of Coastal Plain sites. BMPs reduced the estimated erosion on both site types suggesting increased implementation could reduce potential erosion in problematic areas. Therefore, proper BMP implementation should be ensured, particularly in Mountainous terrain, regardless of harvest type. [ABSTRACT FROM AUTHOR]

The reduction of greenhouse gas (GHG) emissions demands a significant increase in the use of wood as a renewable energy source. However, environmental restrictions determine limits on the further growth of harvesting volume. Therefore, a viable solution to enhance the share of energy wood in Estonia's energy balance involves focusing on less exploited assortments of raw material and implementing precise logistics planning. In recent years, mild winters have posed challenges to the extraction of residues and local transport of wood fuels, taking place on soft and unfrozen soils. In such conditions, ensuring a reliable supply of wood fuels becomes rather complicated. When piles of logging residues on unfrozen soils are inaccessible, there is a need to process older piles. The quality of wood chips from such piles is lower compared to the norm. To investigate the impact of extra long-term storage of residues in piles, a study was conducted at the Järvselja Training and Experimental Forest Centre. In 2010, sample piles were created in birch and spruce final felling areas. Over an eight-year period, samples were regularly taken from the piles to analyse the properties of woody biomass during storage. The study results indicate that the quality of fuel from covered piles changes slowly during the first two years of storage. Subsequently, the degradation speed equalizes in both uncovered and covered piles. Despite extensive degradation and loss of dry matter during long-term storage (approximately 29% for Norway spruce and 55% for silver birch after eight years), the quality of dry fuels still meets standard requirements and remains acceptable for boiler houses. [ABSTRACT FROM AUTHOR]

The European Union's current pressure on the Member States to adopt both the Green Deal and the Fit for 55 package is leading to an accelerated drive to put in place measures to meet the 2030 climate targets. At the same time, many discussions at the international bilateral meetings of EU country representatives raise the question of the realism of setting climate targets, and therefore, the ability to meet these commitments. The results elaborated in this analytical study offer a realistic picture of the possibilities of meeting strategic climate targets using the example of the use of forest dendromass. The data assess the possibility of achieving a 22% share of renewable energy sources (RES) in gross final energy consumption by 2030 in the Czech Republic. The study points out that at present, the use of forest dendromass from primary production is at its maximum and meeting the climate targets for increasing the share of RES in the energy mix represents a major problem in the long term. The findings published in this study also point to the objective threat of the increased use of dendromass in the energy sector to the maintenance of sustainable forest management and the preservation of forest quality. [ABSTRACT FROM AUTHOR]

Torrefaction and combustion have been applied to naturally decomposed red oak logging residues. The results indicated that four-year natural decomposition would lower the energy density of red oak from 20.14 to 18.85 MJ/kg. Torrefaction reduced the O/C and H/C ratios but improved the energy yield values. Two combustion stages were observed for all samples, and no hemicellulose derivative thermogravimetric peak appeared for torrefied samples. The differential scanning calorimetry exothermic heat flow increased after torrefaction. In addition, the Kissinger–Akahira–Sunose average activation energy of untorrefied samples decreased in the first stage (from 157.77 to 149.52 KJ/mol), while it increased in the second stage (from 131.32 to 181.83 KJ/mol). The ∆H, ∆G, and ∆S values of all samples decreased in the first stage, while they increased when the conversion rate was greater than 0.5 for torrefied samples. These findings can aid in a better understanding of the fuel performance of torrefied and untorrefied naturally decomposed red oak logging residues.

A significant amount of logging residue is produced during roundwood harvesting. Logs are often left in forest sites due to, for example, ecological or logistical aspects. Taking into account the fact that the number of studies focused on changes in the properties of the residue is very low, it was decided to conduct research on the effect of a three-year storage period in forest stands on the chemical properties and energy potential of the wood. The research design allowed for the determination of changes during up to three years of storage. The performed analysis showed a highly negative impact on the characteristics of the material. These adverse effects were probably caused by the activity of microorganisms such as fungi and bacteria, as evidenced by the increased concentrations of ergosterol and low-molecular-weight organic acids. Moreover, it was found that wood stored for three years was characterized by a lower cellulose content; an increased percentage of lignin; a reduced content of sterols (desmosterol, stigmasterol, lanosterol and β-sitosterol) and phenolic acids; and reduced antioxidant activity, as determined with the ABTS+ method. Storing logs also led to a reduction in the energy potential of the residues, as shown by a reduction in net and gross calorific value and an increased ash content.

Woody logging residues produced by logging activities are currently an underutilised resource that is mainly burned for energy production or left in the forest to decay, thus releasing CO2 into the atmosphere. This resource could be used to manufacture long-lasting products and store a significant amount of CO2, promoting CO2 valorisation in rural areas. In this study, potential use for logging residues is proposed – the production of low-density wood fibreboard insulation panels. The new material’s potential properties, manufacturing method and combined heat and power (CHP) plant parameters were proposed. The potential climate benefits of the new product were analysed using various biogenic carbon accounting methods. As energy production for manufacturing can be a significant source of emissions, possible energy production scenarios were analysed for manufacturing the product. However, an economically and environmentally viable energy production scenario should be chosen. By conducting a multi-criteria analysis, three possible energy production scenarios were analysed – wood biomass CHP plant, a natural gas CHP plant and a standalone wood biomass combustion plant combined with Solar photo-voltaic (PV) panels. The scenarios were analysed in terms of technological, economic, and environmental performance to determine the best strategy in this case.

Woody biomass is an important feedstock for renewable energy production in the United States. Residues are produced by forest harvests, and some operations utilize this material for energywood. Energywood requires additional processing and is often the lowest value product generated. Additional research quantifying the productivity and costs of energywood operations could allow stakeholders to evaluate the efficiency of those operations and identify areas for improvement. This study evaluated five energywood harvesting operations in the Lower Mid-Atlantic region of the United States (two Appalachian Mountain harvests and three Coastal Plain harvests). Each harvesting operation was observed for 4–7 days, and productivity data were collected on each harvesting function using time study and activity sampling methods. Productivity and costs of each operation were estimated, and equipment mixes and harvesting methods were evaluated to determine efficiency. Interviews were also conducted with each logging contractor to understand operating strategies and decision making. Cut and haul costs averaged (USD) $32.07/tonne and ranged from $26.19 to $38.28/tonne. Hauling consistently comprised the largest function cost at an average of $12.24/tonne. Machines handling energywood were less productive than those harvesting roundwood because of the large effect average stem size had on productivity levels. Harvesting system analysis also highlighted the importance of ensuring a balanced equipment mix to lower costs and ensure efficiency. This research provides stakeholders with a valuable comparison of energywood harvesting operations in the Lower Mid-Atlantic region of the United States that can be used to make better-informed decisions regarding the efficient and economical harvest of energywood. [ABSTRACT FROM AUTHOR]

The aim of the work was to quantify the mass of logging residues (branches and tops; t yr−1 dry matter, DM) for energy generation starting from Forest Management Plans (FMP) data. The methodology was applied to public stands of an Italian district (area: 3.60 × 104 ha; period: 2009–2018). Compared to the previous preliminary analysis, the potentially available residues were computed considering forest accessibility and road traversability, by combining FMPs data with a geographic information system (GIS). New issues that were assessed here were: (i) representation of stands consisting of multiple disconnected parts; (ii) calculation of producible residues by using different values of biomass expansion factors (Scenario 1, S1; Scenario 2, S2). The potentially available residues computed for the analyzed period were used to quantify the current sustainable supply. Then, the potentially generated heat (thermal energy, TE; GJ yr−1) and electricity (EE; GJ yr−1), and the potentially avoided CO2 emissions into the atmosphere (EM; t yr−1 CO2) related to the final combustion process were computed by assuming that the current supply of residues was used as woodchips in a local centralized heating plant currently operating. For both S1 and S2, the large difference between the potentially producible and the potentially available residues demonstrated that geodata are essential for reliable estimations. Moreover, as the required information for the GIS analysis can be easily found in databases made available by forestry authorities, the proposed approach can be applied also to other areas; this could be helpful to support local decision-makers in defining sustainable practices for residues recovery. [ABSTRACT FROM AUTHOR]

The paper deals with the determination of the amount of logging residues including merchantable timber volume (brush) left in the beech stands for further use. Logging residues were recorded in all types of intentional felling starting with intentional improvement felling up to 50 years and ending with intentional regeneration felling. The potential amount of biomass left was divided into the share of brush and the share of small wood. The parameter was monitored for 3 years and all measured values were then statistically evaluated and related to 1 m3 of intentional felling in beech stands. A partial goal of this publication is characterization of economic impacts of the proposal for processing the recorded volume of logging residues left in the beech stands on the forest branch in Smolenice. The economic impacts are characterized in two proposed and mutually compared scenarios. The first scenario considers framework contractors for logging works with their own machines, i.e. by assignments, as a mediation of service invoiced for the assumed amount (m3) forwarded to the roadside landing, with the ownership of the forwarded dendromass belonging to Lesy SR (Forests of the Slovak Republic). Then, the dendromass is sold from the roadside landing to customers who are going to transport and process it at their own expense. The second scenario considers sales of assumed amounts of left dendromass including brush to customers who will provide for its transport and processing on the identified roadside landing within a set deadline under obligation to return the site to its original condition if there is possible damage. In this case, Lesy SR would be only a control body supervising labour quality and set-up technological procedures.

Due to a continuous abandonment of marginal agricultural land, Mediterranean pine forests are growing both in biomass stock and area but remain mainly unmanaged. Pinus halepensis is one of the main pioneer species with strong expansion throughout the Mediterranean basin. In mature forests and pole stands, selective thinnings aimed to eliminate dominated and dead trees are necessary to improve the resilience and persistence of these forest ecosystems. Bioenergy market provides an opportunity to mobilise this woody material, helping to prevent and reduce wildfires in a context of climate change and energy transition. Despite the existing expertise on wood harvesting, there is a lack of practical knowledge about cost-effective methods for bioenergy use of selective thinnings in such forests. The objective of this study was to compare thinning harvesting methods in representative 63-year-old Pinus halepensis afforestation in pole stage for bioenergy uses, following the silvicultural treatments defined in the Spanish forest management plan. Time studies were performed over six representative plots in Navalón (Spain). Treatments included three plots with the traditional stem wood method combined with the logging of forest residues (integrated system), and three plots with the whole tree chipping (whole tree system). Time, productivity and fuel consumption were recorded for both systems. A woodchip quality assessment of each assortment was performed in the laboratory according to European standards. The results obtained demonstrated that time consumption and productivity were similar between the integrated harvesting system and the whole tree system. Regarding the total energy balance, it should be noted that both systems produce woodchips that contain over ten times more energy than that required to mobilise and process the obtained biomass. Fuel consumption, costs and degree of damage were slightly higher in the whole tree system due to the more intensive forwarding operation. The two assortments of woodchips in the integrated system had a higher (chipped log material) and lower quality (chipped crown material) than whole tree woodchips. In conclusion, integrated harvesting is a better option to diminish fuel consumption, cost and environmental impact, and also to obtain better quality woodchips for the production of added value biofuels (pellets).

In this report, we describe a local outbreak of small bark beetles on 4-year-old seedlings of Picea abies in a forest nursery in Central Europe in 2021. In March 2022, 10–50% of the seedlings were "dry" (i.e., with dry and easily broken twigs and with easily peeled bark) in each 4-row bed in the nursery. Half of the dry plants were completely covered by galleries of bark beetles and another 35% of the seedlings were with one or two bark beetle galleries. Almost 90% of the beetles found on the affected seedlings were Pityogenes chalcographus, and only 10% were Pityophthorus pityographus (we studied 100 seedlings in the second bed). The chipping of Picea pungens in previous years had left many felled trunks, branches, and other logging residues in the area. These residues are covered by galleries of both bark beetles. We suggest that, after multiplying on the logging residues, the beetles could not find suitable material for reproduction and were lured to the nursery seedlings, which had been weakened by location (a location that provided inadequate shade and no wind protection) and by repeated replanting. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the impacts of piling up Norway spruce logging residues on the dynamics of forest soil organic matter composition in the years following final felling and to discuss possible consequences for soil C and N cycling. We focused on the content of dissolved organic carbon (DOC), phenolic compounds, and terpenes in the humus layer to determine whether they controlled changes in C- and N-cycling, as residue piles have previously been observed to be a hot spot for N-cycling and losses. We monitored the dynamics for four years in a logging residue experiment that included plots with residue piles (40 kg/m2) and control plots without residues (0 kg/m2). We also sampled two other field experiments six years after additions of different residue amounts (0, 10, 40 kg/m2). Overall, logging residues strongly affected humus layer properties, with the temporal variation depending on the compound group. Within months logging residues increased the concentrations of K 2 SO 4 -extractable DOC and condensed tannins, and both effects endured for years. There was a sharp increase in the concentration of volatile monoterpenes due to residues, but it lasted only for a year. The increase in di- and triterpenes occurred later, showing that diterpenes and triterpenes were enriched in time in the humus layer. The amount of microbial biomass C and rates of C and net N mineralization and nitrification were positively correlated with DOC concentration. There were also some strong and positive correlations of microbial biomass C and N and C mineralization with higher terpenes, especially with triterpenes. While, in the residue treatment net N mineralization and nitrification rates were negatively correlated with monoterpenes, indicating their important role in controlling N-cycling in situations with N excess as well. Logging residues caused similar changes in the two other field experiments, but the responses were not always proportional to the residue amounts added. In conclusion, piling up Norway spruce logging residues changes the dynamics of forest soil organic matter composition for years and creates hotspots for soil C- and N-cycling. The overall result of the uneven residue distribution is a strong spatial variation in soil, evident from the beginning to several years. • Soil organic matter composition is continuously changing under spruce logging residues. • Residues result in increased DOC and condensed tannins in humus layer. • First a sharp increase in volatile monoterpenes, later di- and triterpenes were enriched. • Dynamics in organic matter composition partly explain changes in C and N cycling. • Uneven residue distribution in clear cuts results in strong spatial variation in soil. [ABSTRACT FROM AUTHOR]

As demand for wood energy rises, it's vital to understand the environmental impact of various harvest types, considering different best management practices (BMPs) and site conditions, for sustainable forest management. This study provides a comparative analysis of postharvest site characteristics between biomass and conventional harvest sites located in the Coastal Plain region of the southeastern US. A total of 30 recently harvest sites (15 each for biomass and conventional) were selected from the Coastal regions of Alabama, Georgia, and Florida. Erosion rates were estimated using the USLE-Forest method and ground cover was assessed as a percentage of the area covered by bare soil, litter, light slash, heavy slash, and piles. BMP implementation (%) was based on state-specific BMP surveys. The findings show that stream management zones (SMZs) and harvest areas were less prone to soil erosion, while forest roads, skid trails, and stream crossings were more prone to erosion, regardless of the harvest type. Conventional harvest sites had an overall weighted average erosion rate of 0.35 Mg/ha/year, with an average BMP implementation of 92.70 %, while biomass harvest sites had an overall weighted average erosion rate of 0.22 Mg/ha/year, with an average BMP implementation rate of 97.91 %. Average erosion rate (Mg/ha/year) from the harvest area (biomass=0.11, conventional=0.06) and SMZs (biomass=0.05, conventional=0.02) were not significantly different (p >0.05). Conversely, average erosion rate from roads (biomass=4.17, conventional=6.44), skid trails (biomass=2.15, conventional=3.73), decks (biomass=0.39, conventional=0.72), and stream crossings (biomass=1.53, conventional=5.31) were significantly higher in conventional harvest sites (p <0.05). BMP implementation rates for roads (biomass=98.09 %, conventional=93.71 %), stream crossings (biomass=95 %, conventional=71 %), and timber harvest (biomass=96.44 %, conventional=93.33 %) were significantly higher in biomass harvest sites, while waste management BMP (biomass=89.91 %, conventional=100 %) was significantly higher in conventional harvest sites. Regarding ground cover, conventional harvest sites had significantly larger areas covered by light slash, heavy slash, and piles than biomass harvest sites, while biomass harvest sites had significantly larger areas covered by green growth. Our research shows a significant negative correlation between overall BMP implementation and erosion rates (r=-0.67, p =0.0002), as well as site size (r=-0.38 p =0.0400), indicating that larger sites tend to have lower BMP implementation and increased erosion risk. In conclusion, biomass harvest sites in our study did not yield higher erosion rates in comparison to conventional harvest sites, provided that the current BMP recommendations were implemented properly and in adequate amounts. This study emphasizes the importance of site-specific management strategies to mitigate erosion in all harvest sites, irrespective of harvest type used. • There is no significant difference in erosion rate between biomass and conventional harvest sites. • Conventional harvest sites exhibit a greater coverage of woody debris than biomass harvest sites. • Proper implementation of BMPs at both conventional and biomass harvest sites underscores water quality protection efforts. • A significant negative correlation exists between BMP implementation and erosion rate. [ABSTRACT FROM AUTHOR]

Water quality best management practices (BMPs) developed for conventional forest harvests may be adequate for biomass harvests, yet quantitative data is lacking. This study compared estimated erosion, operational feature areas, BMP implementation rates, ground cover characteristics, and downed woody debris quantities following biomass and conventional harvests in the mountains of Virginia. Haul roads on biomass harvests had significantly higher estimated erosion rates (P  = 0.064) and masses (P  = 0.045) than conventional harvests, but conventional harvests had higher erosion contributions from skid trails (P  = 0.089) and averaged more estimated erosion mass overall, despite being significantly smaller in size (P  = 0.054). There was significantly less area in heavy slash (P  = 0.076) and lower estimated mass of residual downed woody debris (P  = 0.001) on biomass sites than conventional sites (10.98 and 27.95 tons/ac, respectively). Site-wide BMP implementation scores (P  = 0.041), streamside management zones (SMZs) (P  = 0.024), and skidding (P  = 0.063) were significantly higher on biomass sites than conventional sites. BMP implementation scores were significant predictors of estimated erosion rates (P  < 0.001, R 2  = 59%), indicating that adequate levels of existing water quality BMPs are effective for erosion control on both conventional and biomass harvests. [ABSTRACT FROM AUTHOR]

Forest management practices can increase climate change mitigation potential through applications focused on carbon budgets. One such application involves utilizing non-merchantable material (i.e., logging residues typically piled and burned) for bio-energy. However, limited remote sensing data is available for estimating wood residues until after timber has been harvested, at which point recovery of residual wood is of little financial interest. This research utilizes a hybrid method to develop models that provide pre-harvest estimates of the amount of merchantable and non-merchantable material that would result from harvesting and investigates the scalability and transferability of such measures to the harvest block level. Models were trained using 38 plots across two sites dominated by Douglas-fir, then expanded to ten harvest blocks, and transferred to eight blocks from two sites without training data before being compared against multiple independent block-level estimates. Model results showed root mean square errors of 35% and 38% for merchantable and non-merchantable volumes, respectively. Merchantable volume estimates in blocks with training had average absolute differences from the harvest scale (9–34%) similar to transferred blocks without training (15–20%). Non-merchantable model results were also similar in both trained and transferred harvest blocks, with the pre-harvest model results having lower differences from the post-harvest geospatial versus field surveys. The results from this study show promise for hybrid methods to improve estimates of merchantable wood volume compared to conventional forest cover data approaches, and provide the ability to predict non-merchantable volumes within the range of accuracy of post-harvest residue survey methods. [ABSTRACT FROM AUTHOR]

Using timber from multifunctional forests for energy production can be economically viable and environmentally friendly when it is consistent with the principles of sustainable management; otherwise, it could be harmful from both an ecological and commercial point of view. The objective of this paper was to present the overall balance of timber biomass from felled trees in multifunctional forests and assess what kind and how much of this biomass can be used for energy purposes. The research material consisted of data on forest resources and the volume of timber removal in Polish State Forests in 2016–2020. The biomass of branches and stumps of felled trees was determined using biomass expansion factors (BEFs). The results obtained in this study indicated that industrial timber, energy wood, and biomass left in the forest as a source of deadwood are 67%, 20%, and 13% of the total woody biomass, respectively. The Polish State Forest's potential for energy wood is estimated at 6.18 million tonnes of biomass annually. Total available energy produced from woody biomass amounted to 104.8 PJ y−1. [ABSTRACT FROM AUTHOR]

The study evaluates the development of national supply security. The aim of the paper was to examine the supply security of solid domestic fuels for Finnish combined heat and power plants (CHP) in a domestic fuel disruption. The consumption of wood fuels has increased in recent decades and discussion of supply security has become important nationally. On the other hand, the consumption of peat and coal has been replaced by biomass, which has created questions over its sustainable availability regionally and nationally. The study utilised a questionnaire targeting major combined heat and power plants utilising domestic fuels located around Finland. The response rate of questionnaire was as high as 88%, which reflected the importance attached to the subject. The most significant concern was that economical operating conditions for peat should be ensured, or wood fuels will face difficulties in securing the energy supply by itself. However, the CHP plants were prepared to increase the use of wood fuels, for example by developing logistical systems, investing in fuel terminals and intensifying cooperation with fuel suppliers. Topic of the study is also important internationally. [ABSTRACT FROM AUTHOR]

The first aim of the study was to present the methodology applied by the model WOody biomass and Carbon ASsessment to compute the past potentially available residues (RA; branches and tops only; t·yr−1 of dry matter, DM), potentially generated heat and electricity (TE, EE, respectively; GJ·yr−1) and potentially avoided CO2 emissions into the atmosphere (EM; t·yr−1 CO2) for the final combustion process. The available residues are computed at the forest stand level through a recovery rate based on six technical parameters. The methodology was applied to the public stands of Valle Camonica district (Italy) (total area: 3.67·104 ha; period: 1984–2016). The mass of residues calculated for that period was used to estimate the current supply, i.e. 2.15·103 ± 6.04·102 t·yr−1 DM. By assuming that this mass was used in an Organic Rankine Cycle (ORC) unit of a local centralized heating plant, TE = 2.06·104 ÷ 2.41·104 GJ·yr−1 and EE = 5.08·103 ÷ 5.95·103 GJ·yr−1. By assuming that: (i) heat generated by the ORC replaced heat produced by conventional natural gas-based plants; (ii) electricity generated by the ORC replaced electricity generated by Italian natural gas-based plants-mix (combined heat and electricity production) EM = 1.85·103 ÷ 2.17·103 t·yr−1 CO2. [ABSTRACT FROM AUTHOR]

Maximum energy demand (winter) and logging residue availability (spring and summer) occur at different times promnting the necessity of storage. Our aim was to analyse the effects of storage on baled logging residues from Eucalyptus globulus over a period of storage (TS t) by measuring the moisture content (MC), net calorific value (NCV), and ash content, and by determining dry matter losses (DML) and the usable energy content of the residues. These analyses were performed six out 6 times over the course of 18 months for each component of the residues (leaves, branches and bark). The analysed samples were placed in different positions within stacks of cylindrical bales: 1) centrally placed and 2) surface (open-air). MC decreased during the first 3 months of storage in all samples. From this point onwards, the surface samples' MC varied significantly throughout the storage time (TS t) because of precipitation influence, whereas it remained stable in the centrally placed samples. Significant differences in NCV (wet basis) were observed in the surface samples with respect to storage time, whereas in the centrally placed samples, these differences were not significant after 3 months of storage. Differences between surface and centrally placed samples for a given TS t were more pronounced during periods of higher precipitation, reaching a value of 4.52 MJ kg−1 after 6 months of storage. The influence of extractive content in the residues was reflected in the NCV (on a dry basis), which varied slightly with TS t , peaking at 3 months with values of 17.60 and 18.34 MJ kg−1, for the surface and centrally placed samples, respectively. The ash content of the surface samples increased significantly (p < 0.05) with storage time, whereas the centrally placed samples did not exhibit this trend. The highest values were recorded in the following order: bark > leaves > branches. The maximum values obtained were 4.2% and 3.7% for the surface and centrally placed samples after 18 months of storage respectively. DMLs increased with storage time, reaching 16.5% and 4.9% for the surface and centrally placed samples after 18 months of storage, respectively. The usable energy content increased during the first 3 months, indicating a positive influence of storage time on the fuel quality. The shape of the top row of bales in a stack could help reduce rainwater penetration, resulting in a higher proportion of internal residues and therefore improving usable energy content. • The bark fraction had the lowest fuel quality in the biomass. • Lower dry matter losses in baled than chipped residues. • Usable energy content was maximum after 3 months of storage in bale stacks. [ABSTRACT FROM AUTHOR]

The paper deals with the determination of the amount of logging residues including merchantable timber volume (brush) left in the beech stands for further use. Logging residues were recorded in all types of intentional felling starting with intentional improvement felling up to 50 years and ending with intentional regeneration felling. The potential amount of biomass left was divided into the share of brush and the share of small wood. The parameter was monitored for 3 years and all measured values were then statistically evaluated and related to 1 m³ of intentional felling in beech stands. A partial goal of this publication is characterization of economic impacts of the proposal for processing the recorded volume of logging residues left in the beech stands on the forest branch in Smolenice. The economic impacts are characterized in two proposed and mutually compared scenarios. The first scenario considers framework contractors for logging works with their own machines, i.e. by assignments, as a mediation of service invoiced for the assumed amount (m³) forwarded to the roadside landing, with the ownership of the forwarded dendromass belonging to Lesy SR (Forests of the Slovak Republic). Then, the dendromass is sold from the roadside landing to customers who are going to transport and process it at their own expense. The second scenario considers sales of assumed amounts of left dendromass including brush to customers who will provide for its transport and processing on the identified roadside landing within a set deadline under obligation to return the site to its original condition if there is possible damage. In this case, Lesy SR would be only a control body supervising labour quality and set-up technological procedures. [ABSTRACT FROM AUTHOR]

Abstract Eucalyptus plantations have replaced other (agro)ecosystems over 5.6 Mha in Brazil. While these plantations rapidly accumulate carbon (C) in their biomass, the C storage in living forest biomass is transient, and thus, longer‐term sustainability relies on sustaining soil organic matter (SOM) stocks. A significant amount of harvest residues (HR) is generated every rotation and can yield SOM if retained in the field. Yet, there is little information on how managing eucalyptus HR changes SOM dynamics. We used isotopic and molecular approaches in a 3‐yr field decomposition experiment where a native grassland has been replaced by eucalyptus plantations to assess how HR management practices influence content and chemistry of two distinct SOM fractions [particulate (POM) and mineral‐associated organic matter (MAOM)] at two soil depths (0–1 and 1–5 cm). The management practices investigated were HR removal (−R), only bark removal (−B), and retention of all HR (including bark, +B), combined with two levels of nitrogen (N) fertilization [0 (−N) and 200 (+N) kg/ha]. N fertilization inhibited HR decomposition (P = 0.0409), while bark retention had little effect (P = 0.1164). Retaining HR, especially with bark, increased POM‐C and MAOM‐C content (2.1‐ and 1.2‐fold, respectively), decreased POM‐δ13C (1.2‐fold), and increased inorganic N retention (1.7‐fold) compared with plots where HR had been removed. Inorganic N applications, however, diminished the positive impacts of bark retention. Although the influence of HR management was most pronounced in POM, retaining HR reduced potential soil C mineralization by up to 20%. POM and MAOM chemistry shifted over time and revealed distinct influence of HR on the formation of these fractions. We demonstrate that HR management alters SOM dynamics and that retaining HR, particularly including bark, enhances SOM retention. With continuing conversion of native grassland ecosystems to eucalyptus, long‐term sustainability will require careful HR and fertilizer management to balance total biomass harvest with sustaining belowground SOM concentrations.

Eucalyptus plantations have replaced other (agro)ecosystems over 5.6 Mha in Brazil. While these plantations rapidly accumulate carbon (C) in their biomass, the C storage in living forest biomass is transient, and thus, longer‐term sustainability relies on sustaining soil organic matter (SOM) stocks. A significant amount of harvest residues (HR) is generated every rotation and can yield SOM if retained in the field. Yet, there is little information on how managing eucalyptus HR changes SOM dynamics. We used isotopic and molecular approaches in a 3‐yr field decomposition experiment where a native grassland has been replaced by eucalyptus plantations to assess how HR management practices influence content and chemistry of two distinct SOM fractions [particulate (POM) and mineral‐associated organic matter (MAOM)] at two soil depths (0–1 and 1–5 cm). The management practices investigated were HR removal (−R), only bark removal (−B), and retention of all HR (including bark, +B), combined with two levels of nitrogen (N) fertilization [0 (−N) and 200 (+N) kg/ha]. N fertilization inhibited HR decomposition (P = 0.0409), while bark retention had little effect (P = 0.1164). Retaining HR, especially with bark, increased POM‐C and MAOM‐C content (2.1‐ and 1.2‐fold, respectively), decreased POM‐δ13C (1.2‐fold), and increased inorganic N retention (1.7‐fold) compared with plots where HR had been removed. Inorganic N applications, however, diminished the positive impacts of bark retention. Although the influence of HR management was most pronounced in POM, retaining HR reduced potential soil C mineralization by up to 20%. POM and MAOM chemistry shifted over time and revealed distinct influence of HR on the formation of these fractions. We demonstrate that HR management alters SOM dynamics and that retaining HR, particularly including bark, enhances SOM retention. With continuing conversion of native grassland ecosystems to eucalyptus, long‐term sustainability will require careful HR and fertilizer management to balance total biomass harvest with sustaining belowground SOM concentrations. [ABSTRACT FROM AUTHOR]

Using timber from multifunctional forests for energy production can be economically viable and environmentally friendly when it is consistent with the principles of sustainable management; otherwise, it could be harmful from both an ecological and commercial point of view. The objective of this paper was to present the overall balance of timber biomass from felled trees in multifunctional forests and assess what kind and how much of this biomass can be used for energy purposes. The research material consisted of data on forest resources and the volume of timber removal in Polish State Forests in 2016–2020. The biomass of branches and stumps of felled trees was determined using biomass expansion factors (BEFs). The results obtained in this study indicated that industrial timber, energy wood, and biomass left in the forest as a source of deadwood are 67%, 20%, and 13% of the total woody biomass, respectively. The Polish State Forest’s potential for energy wood is estimated at 6.18 million tonnes of biomass annually. Total available energy produced from woody biomass amounted to 104.8 PJ y−1.

Bu çalışmada, endüstriyel odun hammaddesinin tarım traktörleriyle sürütme şeritleri üzerinde sürütülerek bölmeden çıkarılması sonucunda toprak üstünde bulunan ölü ve diri örtünün uzaklaşmasının ve sürütme şeritlerine kesim artıklarının serilmesinin toprağın besin durumuna etkisi araştırılmıştır. Çalışmaya konu belirlenen sürütme şeritlerinde toplam 4 adet bloklar oluşturuldu. Her bir bloğa 3 adet yüzeysel akış parseli yerleştirildi. Yüzeysel akış parsellerinden bir tanesi kontrol (K) için boş bırakıldı, diğerlerinde ise yonga (Y) ve dal-yaprak (DY) gibi kesim artıkları (slash) yerleştirildi. Parsellerdeki bitki besin elementleri miktarının belirlenmesinde; yağmurla çözülen ve akışa geçen katyonların ve anyonların miktarları, araziye gidilerek ölçülmüş ve analiz için su örnekleri alınmıştır. Deneme alanlarından toplamda kontrol, yonga ve dal-yaprak parsellerinin her birinden 28 adet olmak üzere tamamından 84 adet su örneği alınmıştır. Alınan su örnekleri DÜBİT Araştırma Merkezi laboratuvarında iyon kromatografi (IC) cihazı ile bazı bitki besin elementleri miktarına ilişkin analizler yapıldı. Çalışma sonucunda, deneme alanlarındaki parsellerde ortalama yüzeysel akış miktarı birbirlerine yakın değerlerde bulunmuştur. Katyonların ve anyonların her parsel için ortalama miktarları karşılaştırıldığında Lityum ve Bromür hariç genel olarak yonga parsellerinde kontrol parsellerine göre 1,11-4,5 kat arasında, dal-yaprak parsellerinde ise 1,08-3,46 kat arasında daha fazla olduğu bulunmuştur. Bitki besin maddelerine ilişkin yapılan varyans analizi sonuçlarına göre; parsellerdeki yüzeysel akış sularında bulunan Magnezyum ve Florür miktarları arasında istatistiksel olarak anlamlı bir farklılık (p lt;0.05) belirlenmiştir. Ancak diğerlerinde istatistiksel olarak anlamlı bir farklılık (p gt;0.05) bulunmamıştır. Ayrıca ibre yapraklı meşcerelere kurulan parsellerdeki bitki besin elementleri miktarları yapraklıya göre daha büyük çıkmıştır.

The potential for harvestable forest fuel (logging residues and stumps from regeneration fellings and small diameter trees from early thinnings) in Sweden, divided in five regions, is provided. Marginal cost curves for logging residues and stumps are calculated through a GIS-based method based on forest inventory plots and locations of selected terminals, and heat and combined heat and power facilities. Four supply chains for logging residues and two for stumpwood were compared. Fixed and variable costs of harvesting equipment and transport vehicles were used for determining the costs of each of the supply systems under consideration. A list with the GPS coordinates of all facilities and terminals was made based on their geographical location. The distance from the center of each forest inventory plot to the nearest receiving point within the region, either facility or terminal, was estimated. There were large differences in the estimated potential of harvestable forest fuel between the regions. The overall annual potential for each of the five regions ranged from 0.97 to 2.73 million oven dry tonnes and the total potential amounted to 9.39 Mt (oven dry). One of the northernmost regions (R1) had the steepest slope in its marginal cost curve. For the other regions, the slope of their cost curves was less dramatic. Information on the economic availability of logging residues and stumps in each region is important for forest fuel suppliers and receiving facilities.

Abstract A stable and affordable energy supply is the indispensable basis for the successful development of countries in West Africa. Ghana currently suffers from an energy crisis. The country is no longer able to meet the rising demand for electricity. At the same time, the energy supply needs to be switched to renewables to protect the climate and increase local added value. Therefore, local biomass utilization is crucial for the future Ghanaian Energy Mix. In this case study for Sunyani, suitable biomass residue sources were identified. The residues are divided into forest biomass, namely logging and sawmill residues from production zones of a forest reserve and residues from Tetrapleura tetraptera and food waste, consisting of residues from Manihot esculenta (cassava), Musa×paradisiaca (plantain) and kitchen waste. Abundance and energetic potentials were calculated and the feedstocks were characterized (elemental analysis, moisture content, ash content, calorific value, ash melt behavior and crude fat content). Sawdust from logging and sawmill residues, remaining from a specific harvested forest area, have an average abundance of 3.18 t/ha and 1.97 t/ha, respectively. This sawdust can be pressed to pellets and converted to 3.4 MWh el /ha in a wood gasifier system. The average theoretical biogas yield from food waste and cassava/plantain peel residues is 823 l/kg with an average methane share of 48.6 vol%. A design of an integrated sustainable energy system consisting of a solar thermal dryer, a biogas plant, a wood gasifier and an absorption cooling machine, was proposed for electricity, heat, cold and cooking gas production in Sunyani. The study showed that utilizing biomass in Ghana in a modern and efficient way is applicable to solve energy problems, affect local markets positively and support the implementation of renewable energies in Ghana. Highlights • Suitable biomass residue sources for energy conversion in Ghana were identified. • A calculation for estimating the quantities of logging residues is presented. • Characterization of the biomass residues in the laboratory was done. • Biogas yields for identified biomass residues were calculated. • A design of an integrated sustainable energy system is presented. [ABSTRACT FROM AUTHOR]

Highlights • Leaf decomposition rates are affected by forest biomass removal. • Conventional logging is more detrimental than the logging residue removal practise. • Fungi:Bacterial ratio, a generally overlooked predictor, is crucial for leaf decomposition. Abstract The complexity and multidimensionality of freshwater processes require multiple metrics to assess their responses to disturbances. However, studies have historically relied on structural attributes, while functional attributes have received much less attention. The relative ease of implementing functional attributes, like leaf decomposition assays, make them an attractive choice to complement structural attributes (e.g. species diversity and community composition). However, the congruence of these disparate attributes is still debatable, as studies have reported results to be strongly context-dependent. The concept of using forest biomass as a source of alternative energy instead of fossil fuel has led to rapid changes in forestry practices. One of these practices involves removal of logging residues that would have otherwise been left on site (logging residue removal, LRR), potentially leaving the landscape prone to high erosion, run-off and sedimentation. This study investigated the decomposition rates of alder leaves in sites affected by LRR compared with conventionally logged (CL) and near-natural, non-harvested sites. Our results revealed CL as having the strongest effects, while LRR had an intermediate response, both in terms of decomposition rates (k total , k microbial and k shredders) and microbial biomass. These results match those for structural attributes reported previously at the same sites, thus providing multiple lines of evidence for the ecosystem-level impacts of forestry activities. Bacterial biomass on decomposing leaves was consistently several orders of magnitude greater than that of fungi in all study streams and treatments. Most previous research on the relative contributions of shredders, fungi and bacteria to leaf decomposition has focused on fast-flowing riffles and more research is needed to clarify their relative roles in other types of running waters, such as the slow-flowing, strongly allochthonous and humic forest streams studied by here. In conclusion, this study points to further need to revise the current practice of forestry activities in light of its negative impact on biodiversity. [ABSTRACT FROM AUTHOR]

Highlights • The impact of shelterwood (SW) cutting on understorey diversity was studied. • SW increases the species richness of vascular plants and bryophytes in pine forests. • The responses to different management practices were species group specific. • SW may be a suitable method to sustain the keystone forest floor species bilberry. Abstract Shelterwood (SW) cutting is considered a sustainable harvest method but its impact on understorey diversity of Scots pine (Pinus sylvestris) forests has not been thoroughly studied. Our aim was to clarify how uniform SW cutting in interactions with soil scarification, deposition of logging residues and altered light conditions affects the species richness and composition of vascular plants and bryophytes and how different species groups and individual species vary in their responses to SW practices. We monitored permanent vegetation plots in nine mature pine forests of hemiboreal Estonia before, shortly after and 3–4 years after SW harvesting. The results indicated that the effect of uniform SW harvesting was species group specific as the majority of vascular plant species groups as well as mosses and epigeic bryophytes increased in richness, however, the species richness of epiphytic and epixylic bryophytes decreased. Late-successional species showed two types of responses to SW harvesting: either reduction of cover or reduction followed by a recovery. Soil scarification favoured early-successional bryophyte species as well as the richness of tree seedlings and dwarf-shrubs but diminished the cover of Vaccinium myrtillus , Vaccinium vitis-idaea and Hylocomium splendens. The harvest-induced changes in the species composition were more pronounced for bryophyte communities than for vascular plants. Retention of green trees and dead-wood is important in SW harvesting for sustaining the vulnerable epixylic and epiphytic bryophyte species. To summarise, uniform SW harvesting increases the species richness of vascular plant and bryophyte communities in pine forests - at least in the short term. [ABSTRACT FROM AUTHOR]

Using a partial market equilibrium framework, this study evaluated the US regional timber and wood products market impacts of a projected national level expansion in wood biomass consumption for energy. By restricting logging residue use, we focus on the impacts on timber harvests and paper production from increased pulpwood consumption and focus on the impacts on lumber production from increased mill residue consumption. Analyses showed that increased consumption of wood for energy led to diversion of about 37 million m3 of pulpwood away from pulpwood-using traditional products (e.g., panels and paper), reducing production and net exports of paper and paperboard by up to 3 million tonnes. Increased wood energy consumption also led to increased timber harvests (up to 40 million m³ or 8 percent), increased prices (up to 31 percent), and increased lumber production and net exports by up to 9 million m3. The South was projected to supply the majority of the energy feedstock (47 m³ or 77 percent) and to experience the resultant effects on forests and wood products sectors. The findings highlight the importance of market linkages at local, national, and global levels in evaluating the impacts of increased wood energy consumption and the importance of identifying feedstock sources. [ABSTRACT FROM AUTHOR]

This case study investigates the potentials, greenhouse gas (GHG), and energy performance of forest residue biofuels produced by new and emerging production technologies, which are commercially implemented in Sweden for heavy transport. The biofuel options included are ethanol (ED 95), hydro-processed vegetable oil (HVO), and liquefied biogas (LBG) produced from logging residues in forestry and sawdust generated in sawmills. The calculated life cycle GHG emissions, based on the EU Renewable Energy Directive calculation methodology, for all three pathways are in the range of 6–11 g CO2eq./MJ, corresponding to 88–94% GHG emission reductions as compared to fossil fuel. Critical parameters are the enzyme configuration for ethanol, hydrogen supply systems and bio-oil technology for HVO, and gasifier size for LBG. The energy input is ranging from 0.16 to 0.43 MJ/MJ biofuel and the total conversion efficiency from the feedstock to biofuel, including high-value by-products (excluding heat), varies between 61 and 65%. The study concludes that the domestic biofuel potential from estimated accessible logging residues and sawdust is equivalent to 50–100% of the current use of fossil diesel in heavy-duty road transport in Sweden, depending on the biofuel production technology selected and excluding energy by-products. Thus, an expansion of forest-based biofuels is a promising strategy to meet the ambitious climate goals in the transport sector in Sweden.

Two ground-based timber harvesting methods have been commonly used for beetle-kill salvage treatments after a bark beetle epidemic in northern Colorado. A "lop and scatter" method uses a mobilized stroke delimber to delimb and buck trees at the stump, leaving tree tops and limbs on the forest floor, while a whole-tree harvesting method brings the entire tree to the landing where it is delimbed and bucked, and thus produces logging residue piles at the landing as a byproduct. We conducted a detailed comparative time study of the two harvesting methods to develop productivity and cost models and compared the performance of the two methods under various site conditions. We applied the productivity and cost models to lodgepole pine forest stands totaling 3400 hectares of the Colorado State Forest State Park to estimate salvage harvesting costs for each forest stand and identify the least costly harvesting options. The results show that the estimated stump-to-truck timber production costs were $30.00 per oven dry ton (odt) for lop and scatter and $23.88 odt-1 for the whole-tree method in our study harvest unit. At the forest level, the estimated average stump-to-truck costs were $54.67 odt-1 and $56.95 odt-1 for lop and scatter and whole-tree harvesting, respectively. Skidding distance and downed trees affect the harvesting costs of both methods, but their influence appears to be more significant on the whole-tree method. [ABSTRACT FROM AUTHOR]

Replacing fossil fuels by logging-residue-based bioenergy has been proposed as a way to mitigate climate change. If residues are combusted for energy, their carbon content is released immediately. Residues, that are not combusted, decompose and emit carbon gradually. The relative harmfulness of bioenergy emissions therefore depends on how strongly we prefer the slow release of carbon to an immediate one. Two factors affect this judgment: (1) our time preference and (2) our expectations regarding the relative harmfulness of future carbon emissions. Neither aspect is included in established biomass emission factors. The Effective Emission Factor (EEF), outlined in this study, includes both aspects in a transparent and tractable way. We demonstrate the concept by deriving the EEFs for the logging residues of three Nordic tree species: Norway spruce (Picea abies), Scots pine (Pinus sylvestris) and silver birch (Betula pendula). We also examine the sensitivity of the results to variation in time preference and damage expectations. The derived factors can be used to compare the harmfulness of carbon emissions from residue-based bioenergy and fossil fuel combustion and to organize bioenergy carbon taxation consistently with the taxation of fossil fuels. [ABSTRACT FROM AUTHOR]