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Recent extreme wildfire seasons in the United States (US) have rekindled policy debates about the underlying drivers and potential role forest management can play in reducing fuels and future wildfire. Most US western national forests face a substantial backlog of treatments and manifold management issues related to wildfire, forest health, and wildfire protection and constitute the major part of the wildfire problem. However, the precise schedule and detailed assessments that map the type and amount of treatments needed, as well as the associated cost are rarely assessed. We simulated restoration trajectories on the US fire prone Umatilla National Forest that faces complex management challenges related to wildfire and forest resiliency. The treatments were targeted to specific ecological conditions based on a decision tree developed in consultation with specialists. Planning areas were then prioritized based on fire protection of the wildland-urban interface (WUI), forest products, and stand resiliency. The results revealed a backlog of 211,893 ha, that when treated would generate $320 million in revenue from forest products, and cover 80% of the forest. The treatment area estimate was more than double prior estimates based on ecological departure from historic condition. Financial sensitivity analysis showed that high priority fuel treatments were revenue positive on 22% of the planning areas. The study established a restoration blueprint in terms of amount, location, and treatment type to support funding requests to the agency and schedule internal and external capacity to complete the work. The work also contributes to ongoing collaborative restoration planning to help stakeholders understand the opportunity cost of specific restoration objectives. The case study and framework can be widely extrapolated to the national forests in the western US to improve financial evaluation of forest and fuel management and estimate future management inputs. This work represents a rare instance of a bottom-up spatially explicit assessment of a restoration backlog, and prioritization of planning areas to reduce that backlog on a US national forest.
Pedro Belavenutti; Woodam Chung; Alan A. Ager. The economic reality of the forest and fuel management deficit on a fire prone western US national forest. Journal of Environmental Management 2021, 293, 112825 .
AMA StylePedro Belavenutti, Woodam Chung, Alan A. Ager. The economic reality of the forest and fuel management deficit on a fire prone western US national forest. Journal of Environmental Management. 2021; 293 ():112825.
Chicago/Turabian StylePedro Belavenutti; Woodam Chung; Alan A. Ager. 2021. "The economic reality of the forest and fuel management deficit on a fire prone western US national forest." Journal of Environmental Management 293, no. : 112825.
Over half of California’s forestland is managed by the US Forest Service, and the agency has identified a need to scale up forest restoration treatments in the state to one million acres per year by 2025. However, the high costs of mechanical fuel reduction and lack of markets for biomass pose significant barriers to accomplishing this target. The objectives of this case study were: (1) to identify costs of forest restoration treatments on federally-managed land in the Northern Sierra under a variety of harvesting scenarios and haul distances to biomass facilities, and (2) to understand what market prices for biomass must be offered to support such efforts. We modeled silvicultural prescription and harvesting options, machine productivity and costs, and transportation costs to assess economic thresholds. Biomass harvest, chip, and haul costs ranged from $55/bone dry ton to $118/bone dry ton, depending on the harvesting system scenario and distance from the biomass disposal site. Results suggest that the cost of forest restoration far exceeds current market prices for biomass, and additional investment is needed to adequately pay for federal forest restoration in California. Additional takeaways include that biomass outlets closer to supply sources can reduce both haul costs and production costs, and local wood utilization campuses can play a key role in supporting forest restoration.
Camille Swezy; John Bailey; Woodam Chung. Linking Federal Forest Restoration with Wood Utilization: Modeling Biomass Prices and Analyzing Forest Restoration Costs in the Northern Sierra Nevada. Energies 2021, 14, 2696 .
AMA StyleCamille Swezy, John Bailey, Woodam Chung. Linking Federal Forest Restoration with Wood Utilization: Modeling Biomass Prices and Analyzing Forest Restoration Costs in the Northern Sierra Nevada. Energies. 2021; 14 (9):2696.
Chicago/Turabian StyleCamille Swezy; John Bailey; Woodam Chung. 2021. "Linking Federal Forest Restoration with Wood Utilization: Modeling Biomass Prices and Analyzing Forest Restoration Costs in the Northern Sierra Nevada." Energies 14, no. 9: 2696.
Purpose of Review Winch-assist systems have seen rapid development, adoption, and implementation in many parts of the world in the past decade and can be considered one of the major recent innovations in steep terrain harvesting. Though a comparatively young topic, the literature around this topic has grown considerably during the last decade. This review summarizes the present body of literature on winch-assist systems and provides a comprehensive introduction to the topic. Recent Findings The analysis showed that work safety in steep terrain harvesting operations has increased through winch-assist systems by removing workers from the many hazards of manual and motor-manual work. The extent of rutting, subsequent erosion, and soil densification after working with winch-assist systems was found to be similar to operations on gentle terrain or cable logging. Winch-assist harvesting is considered more productive than conventional steep terrain harvesting. While case studies provide indicative utilization and productivity values, a robust understanding of economic viability under varied stand and terrain conditions is not yet well established. Summary Winch-assist is proving to be a robust, safe, and high-performance forest harvesting technology that has increased the operating range of ground-based, mechanized harvesting. It can help increase access to forest grounds in steep terrain that are previously considered economically marginal for forest management. Besides steep terrain, the potential benefits of winch-assist in reducing soil disturbance from ground-based equipment indicate that its operating range can also expand to gentle terrain where environmental impacts are of great concern due to wet or unstable soils. As the technology is relatively young and still evolving, there are many unknown social, environmental, and economic challenges and opportunities associated with the winch-assist technology. More research is certainly warranted.
Thomas Holzfeind; Rien Visser; Woodam Chung; Franz Holzleitner; Gernot Erber. Development and Benefits of Winch-Assist Harvesting. Current Forestry Reports 2020, 6, 201 -209.
AMA StyleThomas Holzfeind, Rien Visser, Woodam Chung, Franz Holzleitner, Gernot Erber. Development and Benefits of Winch-Assist Harvesting. Current Forestry Reports. 2020; 6 (3):201-209.
Chicago/Turabian StyleThomas Holzfeind; Rien Visser; Woodam Chung; Franz Holzleitner; Gernot Erber. 2020. "Development and Benefits of Winch-Assist Harvesting." Current Forestry Reports 6, no. 3: 201-209.
Diameter at breast height is a standard method for characterizing trees and ultimately forests over large geographical scales. Expressing the cross-section of a tree stem with a diameter measurement has inherent errors, as stems are not perfect conical frustums. Diameter suffices as an approximation, since methods for the exact cross-sectional area of a stem are infeasible in practice. There are other primary sources of error in diameter at breast height measurements: diameter measurement error and breast height measurement error. This paper addresses the latter in the context of an automated measurement system using 3D photography. We consider breast height estimation a fundamental component in such systems, as errors in measurement height can precipitate significant errors in stand-level attribute estimation as diameter changes along the height of the stem because of taper. We evaluate the efficacy of breast height estimation using stereo photogrammetry by fitting a planar surface to the ground and elevating the plane to breast height. Results from a validation test on 560 observations show that breast height can be estimated with a root mean squared error of 10.20 cm within 10 m from the camera and 13.36 cm within 20 m from the camera on flat terrain in varying levels of stem density. Study Implications Increasing the level of automation in forest operations is one approach to address workforce attrition and safety issues in the industry. Automated tree measurement and mapping systems present an opportunity to reduce operational costs by providing machine operators with necessary information to carry out silvicultural prescriptions and eliminate the need for individual tree marking in certain situations. In order to maintain trust between landowners and harvesting contractors, it is imperative that automatic measurement systems are rigorously tested to determine that measurement accuracy is within acceptable limits. Breast height measurement error is often overlooked as a source of error in estimating diameter at breast height. However, accurate breast height estimation is a necessary prerequisite for reliable, consistent, and precise diameter at breast height measurement. The capacity of machine vision systems to automate forest inventory and monitoring tasks is increasing and can help managers achieve sustainable forestry objectives on more acres in less time.
Lucas A Wells; Woodam Chung. Evaluation of Ground Plane Detection for Estimating Breast Height in Stereo Images. Forest Science 2020, 66, 612 -622.
AMA StyleLucas A Wells, Woodam Chung. Evaluation of Ground Plane Detection for Estimating Breast Height in Stereo Images. Forest Science. 2020; 66 (5):612-622.
Chicago/Turabian StyleLucas A Wells; Woodam Chung. 2020. "Evaluation of Ground Plane Detection for Estimating Breast Height in Stereo Images." Forest Science 66, no. 5: 612-622.
Multiobjective optimization is increasingly used to assist decision‐making in forest management when multiple objectives are considered and conflict with each other. Since forest management problems may deal with combinatorial optimization, as the scale of a problem increases, the computation complexity increases exponentially beyond the practical use of exact methods. We propose a multiple‐objective metaheuristic method, referred to as multiobjective record‐to‐record travel (MRRT), to solve such challenging problems. We examined the performance of MRRT and compared it to a mixed integer programming (MIP) optimizer on a forest supply chain multiobjective optimization problem that simultaneously maximizes net revenues and greenhouse gas emission savings from salvage harvest and utilization of beetle‐killed forest stands. Testing on four cases of different problem sizes showed that MRRT performed satisfactorily in approximating the actual Pareto fronts in terms of convergence and coverage, and the distribution of solutions was approximately uniform. The gap between MRRT and MIP solutions increased as the problem size increased. But MRRT produced all solutions within a reasonable computation time, where the computational advantage over MIP was more apparent for large‐scale test cases. Recommendations for Resource Managers Multiobjective optimization shows trade‐offs among conflicting objectives and assists decision‐making to enhance sustainable forest management. Multiobjective record‐to‐record travel (MRRT) has a simple algorithm structure and easy parameterization process so that it is adaptable to solve various multiobjective optimization problems. MRRT produces high‐quality solutions for large‐scale multiobjective optimization problems within a reasonable computation time, which promotes its applicability in practice.
Ji She; Woodam Chung; Hector Vergara. Multiobjective record‐to‐record travel metaheuristic method for solving forest supply chain management problems with economic and environmental objectives. Natural Resource Modeling 2020, 34, 1 .
AMA StyleJi She, Woodam Chung, Hector Vergara. Multiobjective record‐to‐record travel metaheuristic method for solving forest supply chain management problems with economic and environmental objectives. Natural Resource Modeling. 2020; 34 (1):1.
Chicago/Turabian StyleJi She; Woodam Chung; Hector Vergara. 2020. "Multiobjective record‐to‐record travel metaheuristic method for solving forest supply chain management problems with economic and environmental objectives." Natural Resource Modeling 34, no. 1: 1.
Cable-assisted (or tethered) mechanized harvesting has recently been introduced to the Pacific Northwest of the United States, and is rapidly being adopted by the forest industry. However, potential environmental impacts, productivity and cost of the new harvesting systems have not been well-assessed. This study aims to examine the effects of cable assistance on soil compaction, system productivity and cost through a field-based experiment. A harvester-forwarder system was used to thin a harvest unit on dry soils in western Oregon, with and without cable-assistance. We conducted a detailed time study during operations and collected soil measurements before and after machine passes. Machine productivity ranged from 28.75 to 92.36 m3 per scheduled machine hour, with resulting unit costs for untethered and tethered systems ranging from $13.19 to $18.13/m3. Our results showed reduced soil impacts in both extent and degree of soil compaction when cable assistance was employed. The reduced extent of soil impacts is attributed to a reduction in track wander owing to the operative tensions of the tether cable, and the smaller increase in soil density appears to be attributed to combined effects of initially denser soil conditions and reduced shear displacement as a result of cable-assistance.
Preston Q Green; Woodam Chung; Ben Leshchinsky; Francisca Belart; John Sessions; Stephen A Fitzgerald; Jeffrey A Wimer; Tamara Cushing; John J Garland. Insight into the Productivity, Cost and Soil Impacts of Cable-assisted Harvester-forwarder Thinning in Western Oregon. Forest Science 2019, 66, 82 -96.
AMA StylePreston Q Green, Woodam Chung, Ben Leshchinsky, Francisca Belart, John Sessions, Stephen A Fitzgerald, Jeffrey A Wimer, Tamara Cushing, John J Garland. Insight into the Productivity, Cost and Soil Impacts of Cable-assisted Harvester-forwarder Thinning in Western Oregon. Forest Science. 2019; 66 (1):82-96.
Chicago/Turabian StylePreston Q Green; Woodam Chung; Ben Leshchinsky; Francisca Belart; John Sessions; Stephen A Fitzgerald; Jeffrey A Wimer; Tamara Cushing; John J Garland. 2019. "Insight into the Productivity, Cost and Soil Impacts of Cable-assisted Harvester-forwarder Thinning in Western Oregon." Forest Science 66, no. 1: 82-96.
Forest road aggregate changes due to traffic. The physical processes that cause these aggregate changes need to be understood for more effective road management that can help reduce maintenance costs and efforts, and negative environmental impacts of forest roads. This study modeled three processes that could change the particle size distribution (PSD) of forest road aggregate: crushing (breaking down the surfacing material), subgrade mixing (moving upward of fine-grained, roadbed sediment), and sweeping (migration of loose aggregate particles to the shoulder and roadside by tire action). There are two types of sweeping: sweeping-out (dislodging large-size particles from tire tracks) and sweeping-in (accumulating large-size particles near the roadside and shoulder). Our study modeled the expected traffic-induced processes based on theoretical concepts and literature to examine how these processes change forest road aggregate PSD. Then the modeled results were compared with the observed PSDs from cross-sectional locations where traffic-induced processes likely occurred. Based on these comparisons, we enhanced the modeling and inferred how much the crushing, subgrade mixing, and sweeping-in processes changed the PSDs, but could not infer the sweeping-out process due to the difficulty in separating the sweeping-out from crushing. This study demonstrates that the traffic-induced processes could be modeled and quantified using the following assumptions: crushing was estimated by assuming a half logarithmic normal distribution with a mean of the crushed particle diameter and higher crushing rates for large-size particles; subgrade mixing was estimated by assuming the move-in of fine-grained subgrade soils from the road bed; and sweeping-in was estimated by assuming the move-in of large-size particles with a logarithmic normal distribution. Our modeling approach can offer insights on how traffic-induced processes affect road aggregate under various road and traffic conditions. This information can be useful in developing cost-effective road maintenance strategies and implementation plans.
Hakjun Rhee; James Fridley; Woodam Chung; Deborah Page-Dumroese; Rhee; Page- Dumroese. An Approach for Modeling and Quantifying Traffic-Induced Processes and Changes in Forest Road Aggregate Particle-Size Distributions. Forests 2019, 10, 769 .
AMA StyleHakjun Rhee, James Fridley, Woodam Chung, Deborah Page-Dumroese, Rhee, Page- Dumroese. An Approach for Modeling and Quantifying Traffic-Induced Processes and Changes in Forest Road Aggregate Particle-Size Distributions. Forests. 2019; 10 (9):769.
Chicago/Turabian StyleHakjun Rhee; James Fridley; Woodam Chung; Deborah Page-Dumroese; Rhee; Page- Dumroese. 2019. "An Approach for Modeling and Quantifying Traffic-Induced Processes and Changes in Forest Road Aggregate Particle-Size Distributions." Forests 10, no. 9: 769.
Harvesting mountain pine beetle-infested forest stands in the northern Colorado Rocky Mountains provides an opportunity to utilize otherwise wasted resources, generate net revenues, and minimize greenhouse gas (GHG) emissions. Timber and bioenergy production are commonly managed separately, and their integration is seldom considered. Yet, degraded wood and logging residues can provide a feedstock for bioenergy, while the sound wood from beetle-killed stands can still be used for traditional timber products. In addition, beneficial greenhouse gas emission (GHG) savings are often realized only by compromising net revenues during salvage harvest where beetle-killed wood has a relatively low market value and high harvesting cost. In this study we compared Sequential and Integrated decision-making scenarios for managing the supply chain from beetle-killed forest salvage operations. In the Sequential scenario, timber and bioenergy production was managed sequentially in two separate processes, where salvage harvest was conducted without considering influences on or from bioenergy production. Biomass availability was assessed next as an outcome from timber production managed to produce bioenergy products. In the Integrated scenario, timber and bioenergy production were managed jointly, where collective decisions were made regarding tree salvage harvest, residue treatment, and bioenergy product selection and production. We applied a multi-objective optimization approach to integrate the economic and environmental objectives of producing timber and bioenergy, and measured results by total net revenues and total net GHG emission savings, respectively. The optimization model results show that distinctively different decisions are made in selecting the harvesting system and residue treatment under the two scenarios. When the optimization is fully economic-oriented, 49.6% more forest areas are harvested under the Integrated scenario than the Sequential scenario, generating 12.3% more net revenues and 50.5% more net GHG emission savings. Comparison of modelled Pareto fronts also indicate the Integrated decision scenario provides more efficient trade-offs between the two objectives and performs better than the Sequential scenario in both objectives.
Ji She; Woodam Chung; Hee Han; She; Han. Economic and Environmental Optimization of the Forest Supply Chain for Timber and Bioenergy Production from Beetle-Killed Forests in Northern Colorado. Forests 2019, 10, 689 .
AMA StyleJi She, Woodam Chung, Hee Han, She, Han. Economic and Environmental Optimization of the Forest Supply Chain for Timber and Bioenergy Production from Beetle-Killed Forests in Northern Colorado. Forests. 2019; 10 (8):689.
Chicago/Turabian StyleJi She; Woodam Chung; Hee Han; She; Han. 2019. "Economic and Environmental Optimization of the Forest Supply Chain for Timber and Bioenergy Production from Beetle-Killed Forests in Northern Colorado." Forests 10, no. 8: 689.
The increasing use of cable-assisted steep-slope harvesting has presented different operational, safety, and environmental opportunities and challenges. One of the primary benefits is the increased safety introduced when tethered equipment is used appropriately—notably, “appropriate” use is the use of cable tension for assistance, not stability. However, the stability of such equipment on realistic soils under wet or dry conditions is not well defined, blurring the transition between tethering as a safety measure or as an aid for traction. Therefore, we propose an approach that enables assessment of the stability and required tensions to ensure stable equipment operation under various configurations on steep slopes. A sensitivity analysis was performed, including two equipment track geometric parameters: track width and grouser depth, and soil properties by evaluating two distinctive soil types. Equipment geometry had a role in stability, but less than the influence of soil shear strength. For equipment properties, grouser depth presented the greatest effect on stability, concentrated between slopes of 36–70 percent. Greater soil moisture increases equipment stability in sandy loams and significantly decreases stability in clay loams. When the effects of soil properties are isolated, cohesion and angle of friction are the properties with the greatest effect on equipment stability.
Francisca Belart; Ben Leshchinsky; John Sessions; Woodam Chung; Preston Green; Jeff Wimer; Brett Morrissette. Sliding Stability of Cable-Assisted Tracked Equipment on Steep Slopes. Forest Science 2018, 65, 304 -311.
AMA StyleFrancisca Belart, Ben Leshchinsky, John Sessions, Woodam Chung, Preston Green, Jeff Wimer, Brett Morrissette. Sliding Stability of Cable-Assisted Tracked Equipment on Steep Slopes. Forest Science. 2018; 65 (3):304-311.
Chicago/Turabian StyleFrancisca Belart; Ben Leshchinsky; John Sessions; Woodam Chung; Preston Green; Jeff Wimer; Brett Morrissette. 2018. "Sliding Stability of Cable-Assisted Tracked Equipment on Steep Slopes." Forest Science 65, no. 3: 304-311.
Operational studies are necessary to support production and management decisions of forest industries. A time study (TS) approach is widely used in timber harvesting operations to understand the performance of individual harvesting machines as well as the entire system. However, several limitations of the TS approach include the use of generalized utilization rates, incapability of capturing interactions among equipment, and model extrapolation in sensitivity analysis. In this study, we demonstrated the use of discrete event simulation (DES) techniques in modeling a ground-based timber harvesting system, and compared the DES results with those of the TS model developed with the same observed data. Although both TS and DES models provided similar estimation results for individual machine cycle times and productivities, the estimated machine utilization rates were somewhat different due to the difference in synthesizing machine processes in each approach. Our sensitivity analysis and model expansion to simulate a hypothetical harvesting system suggest that the DES approach may become an appropriate method for analyzing complex systems especially where interactions among different machine processes are unknown.
Ji She; Woodam Chung; David Kim. Discrete-Event Simulation of Ground-Based Timber Harvesting Operations. Forests 2018, 9, 683 .
AMA StyleJi She, Woodam Chung, David Kim. Discrete-Event Simulation of Ground-Based Timber Harvesting Operations. Forests. 2018; 9 (11):683.
Chicago/Turabian StyleJi She; Woodam Chung; David Kim. 2018. "Discrete-Event Simulation of Ground-Based Timber Harvesting Operations." Forests 9, no. 11: 683.
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.
Hee Han; Woodam Chung; Ji She; Nathaniel Anderson; Lucas Wells. Productivity and Costs of Two Beetle-Kill Salvage Harvesting Methods in Northern Colorado. Forests 2018, 9, 572 .
AMA StyleHee Han, Woodam Chung, Ji She, Nathaniel Anderson, Lucas Wells. Productivity and Costs of Two Beetle-Kill Salvage Harvesting Methods in Northern Colorado. Forests. 2018; 9 (9):572.
Chicago/Turabian StyleHee Han; Woodam Chung; Ji She; Nathaniel Anderson; Lucas Wells. 2018. "Productivity and Costs of Two Beetle-Kill Salvage Harvesting Methods in Northern Colorado." Forests 9, no. 9: 572.
Adequate biomass feedstock supply is an important factor in evaluating the financial feasibility of alternative site locations for bioenergy facilities and for maintaining profitability once a facility is built. We used newly developed spatial analysis and logistics software to model the variables influencing feedstock supply and to estimate and map two components of the supply chain for a bioenergy facility: (1) the total biomass stocks available within an economically efficient transportation distance; (2) the cost of logistics to move the required stocks from the forest to the facility. Both biomass stocks and flows have important spatiotemporal dynamics that affect procurement costs and project viability. Though seemingly straightforward, these two components can be difficult to quantify and map accurately in a useful and spatially explicit manner. For an 8 million hectare study area, we used raster-based methods and tools to quantify and visualize these supply metrics at 10 m2 spatial resolution. The methodology and software leverage a novel raster-based least-cost path modeling algorithm that quantifies off-road and on-road transportation and other logistics costs. The results of the case study highlight the efficiency, flexibility, fine resolution, and spatial complexity of model outputs developed for facility siting and procurement planning.
John Hogland; Nathaniel Anderson; Woodam Chung. New Geospatial Approaches for Efficiently Mapping Forest Biomass Logistics at High Resolution over Large Areas. ISPRS International Journal of Geo-Information 2018, 7, 156 .
AMA StyleJohn Hogland, Nathaniel Anderson, Woodam Chung. New Geospatial Approaches for Efficiently Mapping Forest Biomass Logistics at High Resolution over Large Areas. ISPRS International Journal of Geo-Information. 2018; 7 (4):156.
Chicago/Turabian StyleJohn Hogland; Nathaniel Anderson; Woodam Chung. 2018. "New Geospatial Approaches for Efficiently Mapping Forest Biomass Logistics at High Resolution over Large Areas." ISPRS International Journal of Geo-Information 7, no. 4: 156.
The effective implementation of sustainable forest management depends largely on carrying out forest operations in a sustainable manner. Climate change, as well as the increasing demand for forest products, requires a re-thinking of forest operations in terms of sustainability. In this context, it is important to understand the major driving factors for the future development of forest operations that promote economic, environmental and social well-being. The main objective of this paper is to identify important issues concerning forest operations and to propose a new paradigm towards sustainability in a changing climate, work and environmental conditions. Previously developed concepts of forest operations are reviewed, and a newly developed concept – Sustainable Forest Operations (SFO), is presented. Five key performance areas to ensure the sustainability of forest operations include: (i) environment; (ii) ergonomics; (iii) economics; (iv) quality optimization of products and production; and (v) people and society. Practical field examples are presented to demonstrate how these five interconnected principles are relevant to achieving sustainability, namely profit and wood quality maximization, ecological benefits, climate change mitigation, carbon sequestration, and forest workers' health and safety. The new concept of SFO provides integrated perspectives and approaches to effectively address ongoing and foreseeable challenges the global forest communities face, while balancing forest operations performance across economic, environmental and social sustainability. In this new concept, we emphasize the role of wood as a renewable and environmentally friendly material, and forest workers' safety and utilization efficiency and waste management as additional key elements of sustainability.
Enrico Marchi; Woodam Chung; Rien Visser; Dalia Abbas; Tomas Nordfjell; Piotr S. Mederski; Andrew McEwan; Michal Brink; Andrea Laschi. Sustainable Forest Operations (SFO): A new paradigm in a changing world and climate. Science of The Total Environment 2018, 634, 1385 -1397.
AMA StyleEnrico Marchi, Woodam Chung, Rien Visser, Dalia Abbas, Tomas Nordfjell, Piotr S. Mederski, Andrew McEwan, Michal Brink, Andrea Laschi. Sustainable Forest Operations (SFO): A new paradigm in a changing world and climate. Science of The Total Environment. 2018; 634 ():1385-1397.
Chicago/Turabian StyleEnrico Marchi; Woodam Chung; Rien Visser; Dalia Abbas; Tomas Nordfjell; Piotr S. Mederski; Andrew McEwan; Michal Brink; Andrea Laschi. 2018. "Sustainable Forest Operations (SFO): A new paradigm in a changing world and climate." Science of The Total Environment 634, no. : 1385-1397.
An important task in forest residue recovery operations is to select the most cost-efficient feedstock logistics system for a given distribution of residue piles, road access, and available machinery. Notable considerations include inaccessibility of treatment units to large chip vans and frequent, long-distance mobilization of forestry equipment required to process dispersed residues. In this study, we present optimized biomass feedstock logistics on a tree-shaped road network that take into account the following options: (1) grinding residues at the site of treatment and forwarding ground residues either directly to bioenergy facility or to a concentration yard where they are transshipped to large chip vans, (2) forwarding residues to a concentration yard where they are stored and ground directly into chip vans, and (3) forwarding residues to a nearby grinder location and forwarding the ground materials. A mixed-integer programming model coupled with a network algorithm was developed to solve the problem. The model was applied to recovery operations on a study site in Colorado, USA, and the optimal solution reduced the cost of logistics up to 11% compared to the conventional system. This is an important result because this cost reduction propagates downstream through the biomass supply chain, reducing production costs for bioenergy and bioproducts.
Hee Han; Woodam Chung; Lucas Wells; Nathaniel Anderson. Optimizing Biomass Feedstock Logistics for Forest Residue Processing and Transportation on a Tree-Shaped Road Network. Forests 2018, 9, 121 .
AMA StyleHee Han, Woodam Chung, Lucas Wells, Nathaniel Anderson. Optimizing Biomass Feedstock Logistics for Forest Residue Processing and Transportation on a Tree-Shaped Road Network. Forests. 2018; 9 (3):121.
Chicago/Turabian StyleHee Han; Woodam Chung; Lucas Wells; Nathaniel Anderson. 2018. "Optimizing Biomass Feedstock Logistics for Forest Residue Processing and Transportation on a Tree-Shaped Road Network." Forests 9, no. 3: 121.
Risk assessment of forest fires requires an integrated estimation of fire occurrence probability and burn probability because fire spread is largely influenced by ignition locations as well as fuels, weather, topography and other environmental factors. This study aims to assess forest fire risk over a large forested landscape using both fire occurrence and burn probabilities. First, we use a spatial point processing method to generate a fire occurrence probability surface. We then perform a Monte Carlo fire spread simulation using multiple fire ignition points generated from the fire occurrence surface to compute burn probability across the landscape. Potential loss per land parcel due to forest fire is assessed as the combination of burn probability and government-appraised property values. We applied our methodology to the municipal boundary of Gyeongju in the Republic of Korea. The results show that the density of fire occurrence is positively associated with low elevation, moderate slope, coniferous land cover, distance to roads, high density of tombs and interaction among fire ignition locations. A correlation analysis among fire occurrence probability, burn probability, land property value and potential value loss indicates that fire risk in the study landscape is largely associated with the spatial pattern of burn probability.
Hyeyoung Woo; Woodam Chung; Jonathan M. Graham; Byungdoo Lee. Forest fire risk assessment using point process modelling of fire occurrence and Monte Carlo fire simulation. International Journal of Wildland Fire 2017, 26, 789 .
AMA StyleHyeyoung Woo, Woodam Chung, Jonathan M. Graham, Byungdoo Lee. Forest fire risk assessment using point process modelling of fire occurrence and Monte Carlo fire simulation. International Journal of Wildland Fire. 2017; 26 (9):789.
Chicago/Turabian StyleHyeyoung Woo; Woodam Chung; Jonathan M. Graham; Byungdoo Lee. 2017. "Forest fire risk assessment using point process modelling of fire occurrence and Monte Carlo fire simulation." International Journal of Wildland Fire 26, no. 9: 789.
Forests provide wood products and feedstock for bioenergy and bio-based products that can mitigate climate change by reducing carbon emissions. In order to assess the effects of forest products on reducing carbon emissions, we analyzed the carbon balance for individual carbon pools across the forest supply chain over a long period of time. We simulated particular forest supply chain activities pertaining to even-aged management of pine stands in South Korea to demonstrate our methods. Two different rotation scenarios (i.e., 40 and 70 years) were assessed over the 280-year time horizon in terms of temporal changes in carbon stock in each carbon pool along the supply chain, carbon transfer between carbon pools, substitution effects, and delayed carbon release by wood products. We found that the average carbon stock level was higher for the 70-year rotation scenario, but the total amount of gain in carbon was higher for the 40-year rotation at the end of the time horizon. This study confirms that forest products and energy feedstock can both reduce carbon emissions and increase carbon storage. However, the complexity of carbon accounting along the supply chain warrants a thorough evaluation from diverse perspectives when it is used to assess forest carbon management options.
Hee Han; Woodam Chung. Carbon balance of forest stands, wood products and their utilization in South Korea. Journal of Forest Research 2016, 21, 199 -210.
AMA StyleHee Han, Woodam Chung. Carbon balance of forest stands, wood products and their utilization in South Korea. Journal of Forest Research. 2016; 21 (5):199-210.
Chicago/Turabian StyleHee Han; Woodam Chung. 2016. "Carbon balance of forest stands, wood products and their utilization in South Korea." Journal of Forest Research 21, no. 5: 199-210.
Hee Han; Woodam Chung; Jungeun Song; Ara Seol; Joosang Chung. A terrain-based method for selecting potential mountain ridge protection areas in South Korea. Landscape Research 2016, 41, 1 -16.
AMA StyleHee Han, Woodam Chung, Jungeun Song, Ara Seol, Joosang Chung. A terrain-based method for selecting potential mountain ridge protection areas in South Korea. Landscape Research. 2016; 41 (8):1-16.
Chicago/Turabian StyleHee Han; Woodam Chung; Jungeun Song; Ara Seol; Joosang Chung. 2016. "A terrain-based method for selecting potential mountain ridge protection areas in South Korea." Landscape Research 41, no. 8: 1-16.
A substantial proportion of forests in the Republic of Korea are characterized by dense, young-growth pine stands which are prone to burn, particularly in the dry spring and fall seasons. Forest fuel reduction by thinning is needed to reduce the risk of catastrophic forest fire in Korea, but thinning guidelines to effectively reduce crown fire potential are not well established, particularly in areas with steep slopes. We describe an exploration of the interaction of different tree spacings, forest age classes, and slopes using the Wildland–urban interface Fire Dynamics Simulator (WFDS), a physics-based fire behavior model. A total of 36 simulations were performed using two terrain slopes, three stand ages and six tree spacings. Our results suggest that tree spacing significantly affects how fires propagate through forest canopies. We observed large reductions in fire size and intensity when tree spacing approached crown width. Also, most crown fires in our simulation stopped spreading through the canopy in less than 100 m when tree spacing was at least 6 m. We found that a different range of tree spacings was required to limit fire size, intensity, and fire spread distance according to its age class and the terrain slope. Although this exploratory study is only a first step in assessing the potential effectiveness of thinning treatments on fire behavior in steep terrain, this study demonstrates a potential use of WFDS for testing fuel reduction thinning guidelines. Future studies should assess sensitivity to different wind speeds and a broader range of fuel characteristics.
Ng-Wook Kim; Woodam Chung; Byungdoo Lee. Exploring tree crown spacing and slope interaction effects on fire behavior with a physics-based fire model. Forest Science and Technology 2016, 12, 1 -9.
AMA StyleNg-Wook Kim, Woodam Chung, Byungdoo Lee. Exploring tree crown spacing and slope interaction effects on fire behavior with a physics-based fire model. Forest Science and Technology. 2016; 12 (4):1-9.
Chicago/Turabian StyleNg-Wook Kim; Woodam Chung; Byungdoo Lee. 2016. "Exploring tree crown spacing and slope interaction effects on fire behavior with a physics-based fire model." Forest Science and Technology 12, no. 4: 1-9.
Fuel treatments have been widely used as an effective fire management tool to mitigate catastrophic wildland fire risk in forested landscapes. Fire research efforts of the last two decades have significantly advanced fire behavior modeling and fuel treatment effects analysis, but integrated fuel treatment planning and optimization models have yet to be extensively developed and used, mainly due to the complexity of the planning problem. This paper describes the problem complexity in terms of essential considerations when deciding where, when, and how to perform fuel treatments. Previous studies published in mainstream peer-reviewed journals are summarized and identified by their unique contributions, assumptions, and simplifications. Only a handful studies assessed fuel treatment effects in spatial and temporal contexts and incorporated them into the optimization framework. Most of these existing studies introduced optimization approaches as proof of concept with limited applications. It is hoped that future studies will build on these previous efforts and develop more efficient and integrated optimization approaches that can address multiple concerns simultaneously while producing effective fuel treatment plans for field implementation.
Woodam Chung. Optimizing Fuel Treatments to Reduce Wildland Fire Risk. Current Forestry Reports 2015, 1, 44 -51.
AMA StyleWoodam Chung. Optimizing Fuel Treatments to Reduce Wildland Fire Risk. Current Forestry Reports. 2015; 1 (1):44-51.
Chicago/Turabian StyleWoodam Chung. 2015. "Optimizing Fuel Treatments to Reduce Wildland Fire Risk." Current Forestry Reports 1, no. 1: 44-51.