Mauricio Acuna

As a part of the renewable energy cycle, forest biomass resources are considered to be important renewable materials and energy sources in many countries. It is evident from international and local research into forest biomass utilization that several challenges must be addressed to ensure logging waste can be transformed into material of commercial value. Several logistical and supply chain challenges have already been identified, including uncertainty about the nature, amount, and quality of forest residues. In this context, this paper presents a summary review of estimation methods and techniques for managing forest and woody residue along the timber supply chain. The review examines both the opportunities and the challenges evident in the international forest residue estimation methods within each supply chain for primary and secondary forest resources. The review also discusses techniques for supply chain and management planning and highlights the limitations of existing inform...

Effects of different stocking densities on harvesting of bluegum stands in Western Australia – Ayres 00 case study Authors: Mauricio Acuna, John Wiedemann Australian Forest Operations Research Alliance, University of the Sunshine Coast WAPRES Introduction This bulletin presents the results of a harvesting trial conducted near Greenbushes, Western Australia (WA) in December 2011. It corresponds to the second harvesting trial of this type conducted by AFORA in bluegum plantations, whose objective was to assess productivity and cost related to tree form and stocking density of 400, 550 and 1000 stems per ha (spha) created by removal of malformed, undersize and competing stems. The trial also forms part of a large-scale AFORA project focused on the comparison of WA blue gum harvesting systems designed to define the optimal harvesting system choice relative to local stand and site conditions.

In this first trial, an in-field chipping (cold-deck) operation was studied during the clearfell of a 10-yearold Eucalyptus globulus plantation. The study investigated the productivity and cost of an in-forest chipping operation and also used Multidat dataloggers to obtain delay information for each machine and for the system, to determine utilisation percentages and to identify bottlenecks and system imbalances. Harvesting machines studied

In-forest drying of roundwood and biomass (residues) can result in more efficient transport operations from an economical and environmental perspective. On the negative side, in-forest drying may result in dry matter losses (DML), impacting the quantity and quality of residues delivered to energy plants. This paper investigated the impact of roundwood and residues in-forest drying and DML on supply chain costs and Greenhouse Gas (GHG) emissions. For the assessment, a short-term optimization planning tool was applied to a supply chain located in Asturias, Spain, consisting of fourteen supply points and two demand points: A pulp mill (demanding roundwood) and a power plant (demanding residues). Four scenarios were included in the analysis comprising different combinations of DML for roundwood and residues resulting from in-forest drying. Our results indicate that in scenarios that include in-forest drying and DML, the negative economic effects are offset by the substantial reductions ...

Tree morphological characteristics, particularly straightness and lean, significantly influence the value of the commercial products that can be obtained. Despite this, they are not usually evaluated in timber field inventories because traditional techniques are labor-intensive and largely subjective, hence the use of these parameters is limited to research and genetic breeding programs. Here, a non-destructive, fully automated methodology is presented that estimates the parameters for describing straightness and lean using terrestrial laser scanning (TLS) data. It is based on splitting stems into evenly spaced sections and estimating their centers, which are then used to automatically calculate the maximum sagitta, sinuosity, and lean of each tree. The methodology was applied in a breeding trial plot of Pinus pinaster, and the results obtained were compared with field measurements of straightness and lean based on visual classification. The methodology is robust to errors in the es...

The transport of timber and biomass represents a significant proportion of the operational cost for the forest industry worldwide. This calls for optimization solutions so that companies can organize their transport operations and allocate resources efficiently, and reduce the impact of transport operations on the environment. This paper presents an extensive overview of the transport and biomass optimization problem in the forest industry. It provides a detailed description of mathematical solutions, including linear programming models and algorithms, to solve complex transportation planning problems involving annual, monthly and daily decisions. Also, the paper presents and describes two decision support tools, MCPLAN and FastTRUCK, which have been implemented to assist transport planners to optimize the flows of timber and biomass from the forest to mills and energy plants, and to schedule and route the trucks efficiently between these supply and demand points.

On an international comparison basis, Australia’s utilisation of forest residues remains very low. While there are numerous factors contributing to this low utilisation, this is greatly explained by the limited timely and accurate data on availability, quality, and location of residues generated during harvesting operations. This manuscript reports on the development and testing of a new freeware tool called FIELD (Forest Inventory Electronic Live Data), which supports the real-time monitoring and estimation of forestry harvesting residues. As inputs, FIELD uses StanForD pri files and geo-location data extracted from the harvester’s onboard computer in combination with locally developed species-specific allometric equations. Using a case study, this paper describes how FIELD works operationally and illustrates the range of support features that the tool can provide to decision-makers by producing real-time data on the availability, quality, and location of harvesting residues. In ad...

Under the Korean Emission Trading System in The Forestry Sector (KETSF) initiative, the Korean government has developed several greenhouse gas (GHG) emissions reduction programs that include forestry activities as cornerstones of the initiative. Forest management is deemed to be a major strategy to implement KETSF; this has been confirmed by most participants in the program, who have shown their preference for forest management projects as the most effective and encouraging strategy to participate in the KETSF program. For a successful implementation of KETSF projects, it is essential to explore methods that optimize the positive impacts of such strategies, thereby maximizing the economic returns and carbon stocks that result from the implementation of forest management activities. Thus, this study investigated the economic returns of several KETSF projects in Korea, which included simulated scenarios under two main forest management strategies, one based on an extension of the rota...

Forest harvesting operations worldwide are becoming increasingly mechanised. Advantages of mechanised felling include increased productivity compared with manual felling, the opportunity to bunch stems for more efficient extraction, and greater protection from physical harm for operators. Recent interest in Australia and New Zealand—and positive experiences elsewhere—in increasing mechanisation in steep terrain prompted this research trial to evaluate the potential of a self-levelling feller-buncher to improve the overall productivity and economics of a swing yarder. The main goal of the study was to determine the effect on productivity of the extraction by cable of bunched wood as opposed to unbunched wood.

Under the “Korean emission trading system in the forestry sector (KETSF)” initiative, the South Korean government has developed several greenhouse gas (GHG) emissions reduction programs that include forestry activities as the cornerstones of the initiative. Forest management is deemed to be a major strategy to implement KETSF; this has been confirmed by most participants in the program, who have shown their preference for forest management projects as the most effective and encouraging strategy to participate in the KETSF program. For a successful implementation of KETSF projects is essential to explore methods that optimize the positive impacts of such strategies, thereby maximizing the economic returns and carbon stocks that result from the implementation of forest management activities. Thus, this study investigated several value-added KETSF projects in South Korea, which included simulated scenarios under two main forest management strategies: one based on an extension of the ro...

In this study, the extraction operation of a RIMBAKA Timber Harvester R2020-A on steep terrain was investigated. A continuous time study was carried out to estimate the operational efficiency of the RIMBAKA timber harvester. Four dependent variables were observed to investigate their impacts on the extraction phases: skidding distance, hauling distance, volume and slope. A total of 48 working cycles were time studied. During the operation, RIMBAKA extracted 3.55 m3 of logs per cycle and had a machine utilization rate of 78%, with a corresponding productivity of 45.92 m3/PMH15. The unit cost of RIMBAKA was RM 4.64/m3. Meanwhile, hauling distance and log volume had a major effect on the productivity of the harvester during the extraction phase. Thus, a better understanding of the integrated effect on the productivity of the RIMBAKA extraction operation, in combination with the rest of machines of the harvesting system, will better help predicting the efficiency and productivity of the...

Traditionally forest products markets have required logs with particular external properties such as diameter, length and knot size. However, markets are now beginning to include requirements for new internal properties, such as basic density and stiffness. Although markets have responded to these new requirements with prices that afford only limited incentive for producers to meet such demands, the new characteristics are valued by these markets and are considered key for competitive forest companies to stay in business. This paper presents a general methodology to estimate relative log prices of Douglas-fir when logs of different wood density classes are processed and converted into end products (lumber and pulp). Three log density classes were evaluated. For the lowest basic density class (300-399 kg/m3), net returns for pulp were about 28 percent lower than the middle class (400-499 kg/m3). The upper class (500-600 kg/m3) net return was 32 percent higher than the middle class. F...

Mechanized timber harvesting is cost efficient and highly productive. However, mechanized harvesting operations are often associated with several environmental problems, including soil compaction and disturbance. Soil compaction impedes air circulation between the soil and atmosphere, which in turn results in increased concentrations of CO2 within soil pores. In this study, we investigated the impact of forest machine traffic on soil conditions to determine soil CO2 efflux (Fc), and soil CO2 concentrations (Sc). Field measurements included soil bulk density (BD), soil temperature (ST), soil water content (SWC), Fc, and Sc over a 3-year period at a specific thinning operation site (Hwacheon-gun) in the Gangwon Province of Korea. To assess the soil impacts associated with machine traffic, we established four machine-treatment plots (MT) characterized by different geographical and traffic conditions. The results revealed that BD, Sc, and SWC increased significantly on the disturbed tra...

Quantifying the impact of carbon (C) and timber prices on harvest scheduling and economic returns is essential to define strategies for the sustainable management of short-rotation plantations so that they can provide timber products and contribute to C sequestration. In this paper, we present a mixed-integer linear programming model that optimizes harvest scheduling at the forest level, C sequestration, and Net Present Value (NPV) over a planning period of up to 15 years. The model included revenue from the sale of timber (pulplogs) and credits from the net C sequestered during the life of the stands. In addition, plantation establishment, management, harvesting, and transportation costs were included in the analysis. The study area comprised 88 Eucalyptus grandis W. Hill and Eucalyptus dunnii Maiden stands located in Uruguay, totaling a forest area of nearly 1882 ha. The study investigated the impact of C and timber prices on NPV, harvest schedules, stands’ harvest age, timber flo...

The strong link between climate change and increased wildfire risk suggests a paradigm change on how humans must co-exist with fire and the environment. Different studies have demonstrated that human-induced fire ignitions can account for more than 90 % of forest fires, so human co-existence with wildfires requires informed decision making via preventive policies in order to minimize risk and adapt to new conditions. In this paper, we address the multidimensional effects of three groups of drivers (human activity, geographic and topographic, and land cover) that can be managed to assist in territorial planning under fire risk. We found critical factors of strong interactions with the potential to increase the likelihood of starting a fire. Our solution approach included the application of a Machine Learning method called Random Undersampling and Boosting (RUSBoost) to assess risk (fire occurrence probability), which was subsequently accompanied by a sensitivity analysis that revealed interactions of various levels of risk. The prediction performance of the proposed model was assessed using several statistical measures such as the Receiver Operating Characteristic curve (ROC) and the Area Under the Curve (AUC). The results confirmed the high accuracy of our model, with an AUC of 0.967 and an overall accuracy over test data of 93.01 % after applying a Bayesian approach for hyper-parameter optimization. The study area to test our solution approach comprised the entire geographical territory of central Chile.

For biomass energy systems to be cost-competitive, biomass must be delivered at the lowest possible costs. Truck transportation is not only the most common method used for supplying wood biomass, but it also constitutes a high proportion of the wood supply chain. Truck scheduling is part of the operational planning; the aim is to find a set of daily minimal cost routes for each truck in a fleet such that all customer demands are satisfied on time without exceeding the supplies available at the supply points.This chapter presents an approach for solving the log truck scheduling problem under Irish scenarios. The problem consisted of a heterogeneous fleet of 33 trucks based on 14 depots and carrying woodchips and logs. The problem consisted of 89 transportation tasks or deliveries to satisfy the energy demand from three peat power stations and the log demand of two panel board mills. The solution approach presented is based on a standard simulated annealing (SA) procedure. The problem was solved with a tool developed for the Microsoft Windows platform. It was programmed in Visual C++ using an object-oriented design. It includes the SA heuristics as an optimization engine in combination with a deterministic discrete event simulation to emulate the movement of trucks throughout the day.The model exported the results on a series of tables presenting the metrics of the truck performance and the daily schedule. A sensitivity analysis was conducted to determine the effect of truck configuration, driving route selection, and how the truck's payload is influenced by the biomass moisture content (MC) and loading and unloading times. Results showed that using five axle trucks reduced the total biomass supplied by 12% in comparison with 6-axled trucks, thus increasing the cost per ton delivered. Trucks choosing routes with the shortest distance decreased the overall transportation costs by 2.2%. However, these routes implied higher driving times (10.71%), which translated into 14.8% fewer deliveries and therefore the cost per ton increasing by 12.93%. The MC of wood did not affect the overall performance of how the trucks were scheduled, but it had an effect on the truck's productivity as it reduced the payloads and therefore the total tons supplied. The drier wood means higher energy content, increasing the payment per dry ton. Modeling the increase in loading times by 10% and 20% resulted in a reduction of the number of truckloads by 5.36% and 12.5%, respectively. In general, driving time and MC were the major factors affecting wood biomass delivery and the transportation costs per unit. © 2016 Elsevier Ltd. All rights reserved.

An integrated fire and forest management planning methodology is presented. It was applied to a forest unit in the boreal region of Canada and basically consists of a fire simulation model, a network model that identifies stands influencing the spread of fires across a landscape and a spatially explicit timber harvest scheduling model.

An important problem in forest operations is the daily transport of logs or chips from different coupes being harvested, with known supplies, to destinations with their daily demands. The basic objective is to satisfy the demand for different products at each destination and maximize the utilisation of the harvesting equipment at each origin, while minimising transportation transportations costs and waiting times within technical, policy and labour constraints. This paper presents the results of a trial of FastTRUCK, a truck scheduling system developed by the CRC for Forestry, to evaluate some of the factors that affect transport efficiency of Australian in-field chipping operations. The analysis focused on the effect of chipper productivity and utilisation, number of chipping operations accessible to each truck, truck loading and unloading time, net payload on daily transportation costs, number of trucks, and average truck utilisation. According to the results obtained payload and ...

Since wood represents an important proportion of the delivered cost, it is important to embrace and implement correct measurement procedures and technologies that provide better wood volume estimates of logs on trucks. Poor measurements not only impact the revenue obtained by haulage contractors and forest companies but also might affect their contractual business relationship. Although laser scanning has become a mature and more affordable technology in the forestry domain, it remains expensive to adopt and implement in real-life operating conditions. In this study, multi-view Structure from Motion (SfM) photogrammetry and commercial 3D image processing software were tested as an innovative and alternative method for automated volumetric measurement of truckloads. The images were collected with a small UAV, which was flown around logging trucks transporting Eucalyptus nitens pulplogs. Photogrammetric commercial software was used to process the images and generate 3D models of each ...

Uruguay has adopted cut-to-length (CTL) machines in forest harvesting operations, especially in large scale, fast-growing plantations. The majority of modern CTL machines have on-board computers that capture individual tree data and can be coupled with global navigation satellite systems (GNSS). This provides the opportunity to collect data for research purposes and to improve operations. In this study, we retrieved data (StanForD stm and drf files) from a GNSS-enabled harvester working in CTL operations in Eucalyptus spp. plantations in Uruguay. With two thirds of this data we fitted a mixed effects model to evaluate harvester productivity as a function of stem diameter at breast height (DBH), species, shift (day/night), slope, and operator. A slope surface derived from a digital terrain model was overlaid with GNSS stem records. Slope values were assigned to each stem using the Spatial Analyst toolbox in ArcGIS. The reserved third of the data were used to validate the model. DBH was the most influential variable in harvester productivity, showing a positive correlation and a R2 value of 0.73 in the validation model. Operator and species also had significant effects. There was no significant slope effect, whereby the study area only had flat and mildly sloping terrain. Shift did not have a significant effect, indicating there was no drop in night shift productivity. The model developed constitutes the first published harvester productivity model in South America based on data automatically collected by harvesters. In addition, the forestry company may benefit from using the model for operator management.

In this paper, we present a simulated annealing (SA) approach for solving the log-truck scheduling problem, which is an extension of the timber transport vehicle routing problem with time windows (TTVRPTW). The problem is characterised by a heterogeneous fleet of trucks that depart from their corresponding depots and must perform a number of daily transport tasks to move log products between wood pickup (harvest areas) locations and industrial customers, such as pulpmills and sawmills. Commencing at their depots, each truck must perform a number of successive transport tasks, each one charaterised by a trip between a designated harvest area and an industrial customer, until the number of daily working hours is completed (Karanta 2000, Audy et al. 2012). The objective of the model is to minimise total empty travel time for the whole fleet as well as waiting times at wood pickup locations. In addition, time windows and accessibility to harvest areas and customers, must be taken into account.

Forest management planners usually treat potential fire loss estimates as exogenous parameters in their timber production planning processes. When they do so, they do not account for the fact that forest access road construction, timber harvesting, and silvicultural activities can alter a landscape’s vegetation or fuel composition, and they ignore the possibility that such activities may influence future fire losses. We develop an integrated fire and forest management planning methodology that accounts for and exploits such interactions. Our methodology is based on fire occurrence, suppression, and spread models, a fire protection value model that identifies crucial stands, the harvesting of which can have a significant influence on the spread of fires across the landscape, and a spatially explicit timber harvest scheduling model. We illustrate its use by applying it to a forest management unit in the boreal forest region of the province of Alberta in western Canada. We found that f...

The transport of timber and biomass represents a significant proportion of the operational cost for the forest industry worldwide. This calls for optimization solutions so that companies can organize their transport operations and allocate resources efficiently, and reduce the impact of transport operations on the environment. This paper presents an extensive overview of the transport and biomass optimization problem in the forest industry. It provides a detailed description of mathematical solutions, including linear programming models and algorithms, to solve complex transportation planning problems involving annual, monthly and daily decisions. Also, the paper presents and describes two decision support tools, MCPLAN and FastTRUCK, which have been implemented to assist transport planners to optimize the flows of timber and biomass from the forest to mills and energy plants, and to schedule and route the trucks efficiently between these supply and demand points.

Australia’s large potential forest bioenergy resource is considerably underutilised, due largely to its high delivered costs. Drying forest biomass at the roadside can potentially reduce its delivered cost through weight reduction and increased net calorific value. There has been little research on the impact of roadside drying for Australian conditions and plantation species. This study compared delivered costs for three forest biomass types—Eucalyptus globulus plantation whole trees and logging residue (LR)-disaggregated (LR conventional) or aggregated (LR fuel-adapted)—and three roadside storage scenarios—no storage, ≤two-month storage and optimal storage—to supply a hypothetical thermal power plant in south-west Western Australia. The study was performed using a tactical linear programming tool (MCPlan). Roadside storage reduced delivered costs, with optimal storage (storage for up to 14 months) producing the lowest costs. Delivered costs were inversely related to forest biomass...

Nacrtak A research trial was conducted in Victoria, Australia, to evaluate a self-levelling feller-buncher on steep terrain and its potential to improve the overall productivity of steep terrain cable logging. The production study was conducted for a mechanized harvesting system using a Valmet 445 EXL self-levelling tracked feller-buncher and a Madill 124 swing yarder while operating in a clear fell plantation. This study quantified the equipment productivity of steep slope harvesting in a 33 year-old Pinus radiata D. Don (radiata pine) plantation. Mechanized felling was an integral part of this operation, although there were areas of motor manually felled trees due to terrain and stream restrictions. Thus the difference in productivity of the yarder for bunched and unbunched trees was quantified. For an average piece size of 0.8 m 3 , a productivity of 138 m 3 /PMH was predicted for the feller-buncher. Bunching substantially improved the productivity of the swing yarder. Mean volum...

Mallee plantations have been integrated into wheat farms in Western Australia as a large-scale and multi-purpose woody crop since the 1990s. Mallee describes the growing habit of certain eucalypt species that grow with multiple stems shooting from an underground crown root (lignotuber), usually to a height of up to 10 meters. These types of plantations could be a considerable source of biomass to produce renewable energy. In this project the supply chain of Mallee was modelled using BIOPLAN's linear programming model to investigate the im- pact of tree size, extraction distance and transport distance on supply chain costs. The harvest- ing system included a feller-buncher, front end loader, in-field chipper and truck. The mobile Bruks chipper was found to be more efficient than Peterson Pacific to chip Mallee trees. The results indicated that harvesting larger tree sizes can slightly diminish chipping cost. Extrac- tion cost was very sensitive to the extraction distance in this ...

... re-growth thinning research in the states of New South Wales and Victoria have described ... The authors are, respectively, Research Fellow (Mauricio.Acuna@ utas.edu.au), CRC for Forestry, University ... site 4) was larger than on moderately steep terrain (site 1), the ma-chine was ...

Internationally forest biomass is considered to be a valuable renewable energy feedstock. However, utilization of forest harvesting residues is challenging because they are highly varied, generally of low quality and usually widely distributed across timber harvesting sites. Factors related to the collection, processing and transport impose constraints on the economic viability of residue utilization operations and impact their supply from dispersed feedstock locations. To optimize decision-making about suitable locations for biomass energy plants intending to use forest residues, it is essential to factor in these supply chain considerations. This study conducted in Tasmania, Australia presents an investigation into the integration of Multi-criteria analysis (MCA) and Geographical Information systems (GIS) to identify optimal locations for prospective biomass power plants. The amount of forest harvesting biomass residues was estimated based on a non-industrial private native resour...