Logging Residues Research Articles

Bark beetles on logging residues of European larch: Effects of shading and diameter of logging residues on infestation density

Abstract Ips cembrae, an important pest of European larch (Larix decidua), has caused local outbreaks in the last two decades and is becoming increasingly important as the proportion of European larch in forests increases. In 2021–2023, larch logs and piles of branches were placed into shaded forest and sunlit areas every month to study bark beetle species on logging residues. After adult emergence, the logs and branches were debarked, and the infestation density of bark beetles was analysed. The results indicate that shading, log diameter and top/bottom parts of log had a significant effect on infestation density of I. cembrae on logs. The infestation density of I. cembrae was higher on logs felled between December and June than on logs felled between July and November. Shading of branches was the most significant variable affecting the bark beetle species composition on branches. All four of the bark beetle species recorded were affected by diameter of the branches. Ips cembrae primarily infested sunlit branches while Cryphalus intermedius preferred shaded branches. In contrast, the infestation densities of Pityogenes chalcographus and Pityophthorus pityographus seemed to be affected primarily by moisture content of the branches.

Analyzing Potential Failures and Effects in a Pilot-Scale Biomass Preprocessing Facility for Improved Reliability

This study demonstrates a failure identification methodology applied to a preprocessing facility generating conversion-ready feedstocks from biomass meeting conversion process critical quality attribute (CQA) specifications. Failure Modes and Effects Analysis (FMEA) was used as an industrially relevant risk analysis approach to evaluate a logging residue preprocessing system to prepare feedstock for pyrolysis conversion. Risk evaluations considered both system-level and operation unit-level assessments considering process efficiency, product quality, cost, sustainability, and safety. Key outputs included estimations of semi-quantitative risk scores for each failure, identification of the failure impacts, identification of failure causes associated with material attributes and process parameters, ranking success rates of failure detection methods, and speculation of potential mitigation strategies for decreasing failure risk scores. Results showed that deviations from moisture specifications had cascading consequences for other CQAs along with process safety implications. Failures linked to fixed carbon specifications carried the highest risk scores for product quality and process efficiency impacts. As increased throughput can be inversely related to meeting product quality specifications; achieving throughput and other material-based CQAs simultaneously will likely require system optimization or prioritization based on system economics. Ultimately, this work successfully demonstrates FMEA as a risk analysis approach for other bioenergy process systems.

Life cycle emissions and unit production cost of sustainable aviation fuel from logging residues in Georgia, United States

Production of Sustainable Aviation Fuel (SAF) has gained popularity for reducing carbon emissions from the aviation sector. To evaluate the environmental and economic tradeoffs related to SAF production and its potential use, this study estimates the life cycle carbon emissions and unit production cost of SAF produced from logging residues generated during harvest and thinning operations in Georgia, a major roundwood producing state in the Southern United States. We considered two production pathways, i.e., Ethanol-to-Jet (ETJ) and Iso-Butanol-to-Jet (Iso-BTJ), to compute the carbon savings and unit production costs. A sensitivity analysis was performed to identify significant factors contributing to the overall carbon savings and unit production costs for the selected pathways. After considering revenues generated from co-products, the minimum aviation fuel selling price (MASP) was $2.71 L-1 and $2.44 L-1 for ETJ and Iso-BTJ pathways, respectively. Capital investment cost at biorefinery accounted for most of the MASP, followed by the minimum haul rate for transporting biomass and variable cost for alcohol intermediate production. Finally, after considering tax credit from the Inflation Reduction Act of 2022 and RIN (Renewable Identification Number) credit along with co-product revenue, the MASP ranged between $2.29 L-1 and 0.83 L-1 for the ETJ pathway and between $2.04 L-1 and $0.59 L-1 for the Iso-BTJ pathway. In addition, the carbon intensity of both the ETJ and Iso-BTJ pathways were 758 g CO2e L−1 and 976 g CO2e L−1, with relative carbon savings of 70.6 % and 62.1 % compared to conventional aviation fuel. The production cost suggests a minimum abatement cost of $59 t CO2e−1 for the ETJ and -$59.3 t CO2e−1 for the Iso-BTJ pathways in the presence of federal incentives. Our study shows that logging residues-based SAF could reduce the overall carbon footprint of the aviation sector; however, policy support is needed to support its production in light of higher production costs.

Production of greenhouse gases by logging residue in boreal clear-cut forests

AbstractForest deadwood is an important carbon reserve, estimated to contain 8% of the total forest carbon. This type of woody debris is recognized as a source of carbon dioxide (CO2), as the carbon is released back into the atmosphere by microbial decomposition. Production of methane (CH4) and nitrous oxide (N2O) has also been reported. In managed forests, logging residues form a major source of fine deadwood, but its role in the greenhouse gas exchange of forest ecosystems is poorly understood. We studied the greenhouse gas production of spruce and birch left-over fine woody debris and estimated the residence time of these residues at 18 spruce-dominated boreal forest sites in Central Finland. The study areas consisted of clear-cut forest stands, totally covering approximately 47 hectares, with logging residue ages varying between 0 and 10 years. The research was carried out over eight months from May to December 2019. We observed that CO2 dominated the greenhouse gas production of the logging residues, with the production being regulated by air temperature, tree species, residue age, and wood moisture. Emission of CO2 continued throughout the research period with a clear seasonal pattern. Production of CH4 and N2O was also observed, but not in climatically-relevant amounts. Deadwood half-life was estimated at 18 years for spruce and 9 years for birch. Our study demonstrates that logging residues form a mid-term carbon reserve and suggests that global warming could reduce the lifetime of the residues as a result of elevated and temperature-dependent CO2 release in the studied Myrtillus type forest stands.

Combustion Behaviors, Kinetics, and Thermodynamics of Naturally Decomposed and Torrefied Northern Red Oak (Quercus rubra) Forest Logging Residue

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.

Efficient Technologies for Harvesting and Reutilizing Logging Residues in Russia: A Sustainable Forestry Approach

Efficient Technologies for Harvesting and Reutilizing Logging Residues in Russia: A Sustainable Forestry Approach

Assessing the Impact of Preprocessing and Conversion Technologies on the Sustainable Aviation Fuel Supply from Forest Residues in the Southeast U.S.A.

Forest residues have been suggested as potential feedstock for sustainable aviation fuel (SAF) production through different pathways. However, the bulky density and scatter distribution require efficient size-reduction processes to enhance the feedstock supply. Thus, this study analyzes the impact of alternative preprocessing and conversion technologies on the SAF supply chains from logging residues (the predominant share of forest residues) using a two-stage mixed-integer linear programming model. The model determines the optimal location of biomass preprocessing depots, conversion facilities, and airports receiving SAF by minimizing the net present value of the total supply chain cost over 10 years. Using high-resolution spatial data in the Southeast U.S.A. as a case study, the results show that the technology and scale of the facilities heavily influenced the SAF’s breakeven cost and maximum supply quantity. The most economically efficient system that adopts a rotary shear milling system and pyrolysis conversion process could generate up to 650 million gallons of SAF from logging residues in the region, with nearly 62% of the SAF being produced from hardwood residues. Also, the most efficient system has an estimated breakeven cost of US$5.51 per gallon of SAF.

Variability in Physical Properties of Logging and Sawmill Residues for Making Wood Pellets

Wood pellets are a versatile ingredient to produce bioenergy and bioproducts. Wood pellet manufacturing in Canada started as a way of using the excess sawdust from sawmilling operations. With the recent dwindling availability of sawdust and the growth in demand for wood pellets, the industry uses more non-sawdust woody biomass as feedstock. In this study, woody biomass materials received from nine wood pellet plants in British Columbia (BC) and Alberta were analyzed for their properties, especially those used for fractionating feedstock to make pellets. Half of the feedstock received at the plants was non-sawdust. Moisture contents varied from 10 to 60% wet basis, with the hog having an average of 50%. Ash contents ranged from 0.3 to 4% dry basis and were highest in the hog fraction. Bulk density varied from 50 to 450 kg/m3, with shavings having the lowest bulk density. Particle density ranged from 359 kg/m3 for infeed mix to 513 kg/m3 for sawdust. In total, 25% of particles received were larger than 25 mm. The extraneous materials (sand, dirt) in the infeed materials ranged from 0.03% to 1.2%, except for one hog sample (8.2%). Plant operators use mechanical fractionation and blending to meet the required ash content. In conclusion, further instrumental techniques to aid in fractionation should be developed.

Investigation of the Process of Obtaining Flour from Wood Greens of Coniferous Species

An analysis of the waste generation process from wood during logging operations is presented in this paper. The authors presented the concept of a device that can produce flour from green coniferous wood. An evaluation was also conducted regarding the quantity of waste derived from logging residues obtained directly from cutting sites, as well as the potential areas for utilization. The use of coniferous wood waste as a potential raw material for the production of various types of products is also noted. The concept of a mobile knife installation has been proposed for the generating flour from the greenery of coniferous trees, directly at the logging site. A multifactorial experiment was planned and implemented in order to determine the optimal design and technological parameters for the proposed installation and design of an industrial device. The investigation was conducted utilizing both analytical and experimental techniques. The use of a mobile installation for the production of flour from green coniferous wood, in conditions of logging operations, will expand the raw material base for the manufacture of products using pine needles, as well as reduce the amount of waste generated during the wood harvesting process. It will have a positive impact not only on the ecological situation of the environment, but also on the likelihood of a forest fire occurring and spreading.

Runoff and soil loss are drastically decreased in a rubber plantation combining the spreading of logging residues with a legume cover

Soil erosion on agricultural land is a major threat for food and raw materials production. It has become a major concern in rubber (Hevea brasiliensis) plantations introduced on sloping ground. Alternative agroecological crop management practices must be investigated. One aim of our study was to assess the ability of logging residues (i.e., trunks, branches, leaves and stumps of a clearcut plantation) and of legume cover (Pueraria phaseoloides) to mitigate N, P and K losses through runoff and soil detachment in a young rubber plantation. The other aim was to investigate the relationships of these nutrient losses with soil structure and soil macrofauna diversity. Runoff and soil loss were monitored for 3 years using 1-m2 plots under different practices as regards the management of logging residues and the use or not of a legume. The monitoring started when rubber trees were one-year-old. The planting row, where soil was bare, was the hotspot of soil erosion, with an average runoff of 832 mm y−1 and soil loss of 3.2 kg m−2 y−1. Sowing a legume in the inter-row reduced runoff and soil loss by 88 % and 98 % respectively, compared to bare soil. Spreading logging residues as well as growing a legume cover almost eliminated runoff and soil detachment (19 mm y−1 and 4 g m−2 y−1 respectively). Nutrient losses were negligible as long as the soil surface was covered by a legume crop, with or without logging residues. Total N loss from soil detachment ranged from 0.02 to 0.2 g m−2 y−1, for example. Spreading logging residues in the inter-rows significantly improved soil structure and soil macrofauna diversity compared to bare soil. Nutrient losses from runoff and soil detachment were negatively correlated with improved soil structure and soil macrofauna diversity. We recommend investigating alternative ways to manage planting rows.

Predicted essential fatty acid intakes for a group of dairy cows also apply at individual animal level

The ruminant requirements for essential fatty acids (EFAs), particularly linoleic acid (LA) and alpha-linolenic acid (ALA), have not been fully determined, although evidence suggests that an adequate supply of polyunsaturated fatty acids (FAs) could improve immunity and reproduction in transition cows. In previous studies, we predicted EFA intake for a group of cows based on animal characteristics and milk EFA secretions. However, to support precision livestock feeding, we need to match the nutrient requirements and intakes of each cow as closely as possible. Our group-level predictions may not be accurate enough to estimate the EFA intake of an individual cow, due to inter-individual variations in EFA digestion and metabolism related to differences in feed intake, intake patterns, and the composition and functioning of the rumen microbiota. To address this issue, here we set out to establish specific equations that predict EFA intake for an individual cow based on the difference (i.e. the residuals) between observed EFA intake and the predicted EFA intake based on our group-level equations. We studied a database of individual dairy cows (26 experiments; 503 datapoints from three research teams) and we predicted the residuals from (1) dietary and animal-related factors (i.e. full predictions) and (2) animal-related factors only (i.e. field predictions), which are considered more field-amenable. The variance of predicted LA and log ALA intake was explained to 68% by observed LA intake and 66% by observed log ALA intake, respectively. The residuals of LA intake were predicted by dietary ALA content, total FA intake, BW, milk yield and fat content in full predictions, and by BW, feeding level, milk yield and fat content, and sum of milk C4:0 to C14:0 FA in field predictions. The log residuals of ALA intake were predicted by dietary NDF and total FA contents, NDF intake, BW, milk protein, LA and ALA contents, and fat yield in full predictions, and by BW, DM intake, milk LA and ALA contents, and fat yield in field predictions. The field predictions showed a moderate loss of accuracy compared to full predictions based on RMSE of prediction (from 38 to 54 g/d for LA and from 0.090 to 0.12 log (g/d) for ALA). This work is the first to predict the EFA intake of an individual cow based on previously established group-level predictions of EFA intake adjusted for dietary and animal-related factors.

Assessment of Potential of Forest Wood Biomass in Terms of Sustainable Development

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

Nutrient pools and loss due to the removal of harvesting residue in cedar plantations (a case study from Türkiye).

Determining the nutrient stocks and revealing the extent to which these stocks will be affected by the interventions in forest ecosystems are crucial for sustainable forest management. This study aimed to determine the nutrient stock of cedar (Cedrus libani A. Rich.) plantations at different stands with various diameter classes and estimate the nutrient stock to be removed from the forest due to harvesting. Soil and plant samples were collected from 40 plots in Eskişehir and Afyonkarahisar provinces in Turkey. The variation in the nutrient concentrations and stocks of different components of the ecosystem were evaluated by analysis of variance and the decrease via harvesting by regression analysis. The results showed that the concentrations of N, P, K, Mg, S, Fe, Zn, and Mn were highest in the needles, Ca in the bark, Cu in the needles, dead branches, and root. In the large-diameter forest (LDF), dbh=20.0-35.9 cm, the highest P stock was found in the trees, Fe stock in the forest floor, and S stock in the soil and trees. As a result, the forest floor should be protected as it is the crucial component of both the nutrient cycle and the Fe stock in the ecosystem. In LDF, 28.4-37.3% of the nutrient stored in the trees would be removed from the ecosystem in the case of moderate thinning with whole-tree harvesting, while only 5.9-14.1% of the nutrient stock in the case of stem-only harvesting. For these reasons, leaving logging residues after harvesting in the forest would minimize nutrient loss. The study results showed that improved nutrient management in a forest ecosystem will make a significant contribution to the sustainability of forests.

Post-harvest energy chipping feasibility in mature pine forests in the Coastal Plain of the US South

ABSTRACT Research indicates that integrated systems, in which roundwood and energy chips are produced simultaneously, produce energy chips at the lowest cost. However, integrated systems may be feasible on a narrow range of sites. Post-harvest chipping, in which roundwood is harvested by one logging crew and energy chipping conducted independently by a second crew, may allow chips to be produced from more harvest sites. The goal of this study was to evaluate the feasibility of recovering logging residues and non-merchantable stems using post-harvest systems. Time-and-motion studies were conducted on both roundwood harvesting and post-harvest chipping on three harvest tracts on the Savannah River Site in the Coastal Plain of South Carolina. Hourly machine costs were estimated using the machine rate method. Harvesting costs per tonne were calculated using a modified Auburn Harvesting Analyzer. Energy chips were produced at an average estimated cost of $22.04 green t−1 (USD, onboard truck) and $31.96 t−1 delivered. Requiring the feller-buncher to fell and bunch non-merchantable stems reduced feller-buncher productivity by an average of 42% but did not reduce system productivity. This study suggests that post-harvest energy chipping can be a cost-effective alternative.

The Effect of Forest Growth Rate on Climate Change Impacts of Logging Residue Utilization

Biofuel is encouraged because of its low impact on climate change. A new framework was developed to accurately assess the climate change impacts (CCI) of biofuel by integrating the atmospheric carbon cycle model and vegetation carbon dynamic models. Forests with different growth rates (fast, medium, slow) and three collection intensities (71%, 52%, 32%) of logging residues were presumed to test the performance of this framework. The CCI of biofuel was analyzed under two functional units: 1 GJ of biofuels and 1 ha of forests to supply biofuels. According to this study, increasing the forest growth rate could decrease the CCI in both functional units. Increasing the collection intensity could decrease the CCI of 1 GJ of biofuel but increase the CCI of 1 ha of forest land (unless the impacts were negative in fast-growth forests with high and medium collection intensities). Producing bioethanol resulted in a lower CCI (−3.1–67.7 kg CO2 eq/GJ) compared to bio-diesel (29.3–94.7 kg CO2 eq/GJ). Hence, collecting all available logging residues (without inhibiting forest regrowth) to produce low CCI biofuels such as bioethanol was found to be the optimal option for achieving high mitigation effects.

Влияние лесоводственных мероприятий на почвенный углерод: обзор

The paper provides a review of Russian and foreign articles that study the impact of silvicultural practices on the soil carbon pool to assess the effectiveness of forest carbon projects. Analyzing the works allowed us to conclude that silvicultural practices affect the content of soil carbon through a change in the rate of influx and decomposition of organic matter and, as a result, the redistribution of carbon in the soil profile. High-intensity felling, including clear felling, removal of logging residues, damage to the ground cover when planting forest crops, and development of monocultures may have a negative impact on the soil carbon pool. On the contrary, selective and low-intensity thinning, leaving logging residues, and planting mixed forest stands, especially on abandoned agricultural lands, proved to be promising forest management practices that contribute to the accumulation and conservation of soil carbon.

Logging Residue Assessment in Salvage Logging Areas

Salvage logging operations often occur after large disturbances and usually leave behind a substantial quantity of residues, which is fundamental for maintaining soil fertility and facilitating ecosystem dynamics. This study aims to estimate the amount of logging residues following salvage operations categorized by two wood harvesting systems: Cut-To-Length (CTL) and Full-Tree System (FT). Logging residues in the harvested areas were sampled using linear transects and the data collected were divided into classes based on diameter. The quantity of residues was estimated using the Brown method for Fine Wood Debris (FWD) and the Van Wagner method for Coarse Wood Debris (CWD). Furthermore, the carbon and nutrient content associated with logging residues were also determined, considering their interaction with the soil organic layer. Overall, a higher quantity of FWD was detected in the sites cleared with the FT system and a higher quantity of CWD in the sites logged with the CTL system. Differences could be observed for all three years and systems considered, but only the third year reported statistically significant results (p<0.01). The soil and residue chemical analysis for carbon and nutrient contents revealed a high amount of carbon stored in a potential layer of 10 cm of soil (up to 85 Mg·C·ha-1), while only up to 15 Mg·C·ha-1 for the woody material.

Обоснование технологических процессов и систем машин для лесосечных работ

The work analyses the forest raw material resources of the Far Eastern Federal District. Corresponding to the conclusions, it is made an evaluation of a promising technology and systems of machinery for logging. It shows the significance of logging development for the rational exploitation of forest resources and the economic progress of the Far Eastern Federal District. It is performed an analysis of different technological procedures for timber harvesting. The study gives a mathematical model for the evaluation of forestry companies by economic efficiency, regarding the resolution “The Strategy for the Development of the Forest Complex of the Russian Federation Until 2030”. The examination of the region’s forest resources reveals that, currently, in coniferous forests, up to 60 % of industrial wood is available from the total volume of timber for harvesting. However, the sawlog of 1–2 classes contains only 30–35 % of this volume. Within the framework of the research conducted in the developed cutting areas are established territorial-technological plots, in which logging residues are produced and collected. In these plots, the types and the volumes of the abandoned wood are determined. It is estimated that approximately 40–50 % of the annual volume of the timber released for logging is left as a trunk lowvalue timber and forest residues at cutting areas and loading points. The article gives a proposal fоr the automation systems and technologies for harvesting in mixed stands with low-valued wood class, which allow to increase the degree of usable wood, reduce risks from littering and provide in the future various regional forestry companies with row materials. The represented mathematical model on determination of economic efficiency and cost-effectiveness of technological process allows to make rational decisions on the implementation of bucking program of forestry company. For citation: Ryabukhin P.B., Kunitskaya O.A., Grigoreva O.I. Substantiation of Technological Processes and Machinery Systems for Logging Operations. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 2, pp. 88–105. (In Russ.). https://doi.org/10.37482/0536-1036-2023-2-88-105

Production of compost from logging residues

The implementation of forest management generates logging residue which can be used in several ways. One of the option is to use of logging residue in the composting process. Therefore, this study determined the possibility of producing compost based on logging residue and the produced fertilizer used to fertilize forest nurseries. Pine chips and sewage sludge were used for carrying out the study. The compost, as well as the leachate produced during composting, were characterized by high NPK content. The leachate collected at the end of the experiment was characterized by nitrogen content of approximately 6500 mg‧dm−3, phosphorus of approximately 450 mg‧dm−3, and potassium of approximately 500–700 mg‧dm−3. In contrast, the compost produced contained approximately 0.57 g‧kg−1 nitrogen, approximately 0.39 g‧kg−1 phosphorus, and approximately 0.24 g‧kg−1 potassium. The disadvantage in terms of the usefulness of the resulting fertilizer in forest nurseries is its pH, which exceeded 9.0.

Thermodegradation of naturally decomposed forest logging residues: Characteristics, kinetics, and thermodynamics

Combustion and pyrolysis characteristics, kinetics, and thermodynamics of naturally decomposed softwood and hardwood forest logging residues (FLR) were investigated using thermogravimetric analysis. Results showed that calorific values of fresh red pine, two-year decomposed, four-years decomposed, fresh red maple, two-year decomposed, and four-years decomposed were 19.78, 19.40, 20.19, 20.35, 19.27, and 19.62 MJ/kg, respectively. Hemicellulose pyrolysis peak only occurred in the hardwood thermodegradation process. Softwood had a higher pyrolysis yield of solid products (16.08–19.30%) than hardwood (11.19–14.67%). The average pyrolysis activation energy (Ea) of hardwood residue increased with the year after harvest, whereas softwood samples decreased. The average combustion Ea of hardwood samples increased first, then decreased, while that of softwood samples decreased continuously. Enthalpy (ΔH), entropy (ΔS), and Gibbs free energy (ΔG) were also investigated. This research will aid in understanding the thermal decomposition properties of naturally decomposed FLR from various years after harvest.