Oven-dry Tonnes Research Articles

Innovative wood use can enable carbon-beneficial forest management in California

Responsible stewardship of temperate forests can address key challenges posed by climate change through sequestering carbon, producing low-carbon products, and mitigating climate risks. Forest thinning and fuel reduction can mitigate climate-related risks like catastrophic wildfire. These treatments are often cost prohibitive, though, in part because of low demand for low-value wood "residues." Where treatment occurs, this low-value wood is often burned or left to decay, releasing carbon. In this study, we demonstrate that innovative use of low-value wood, with improved potential revenues and carbon benefits, can support economical, carbon-beneficial forest management outcomes in California. With increased demand for wood residues, forest health-oriented thinning could produce up to 7.3 million (M) oven-dry tonnes of forest residues per year, an eightfold increase over current levels. Increased management and wood use could yield net climate benefits between 6.4 and 16.9 million tonnes of carbon dioxide equivalent (M tCO2e) per year when considering impacts from management, wildfire, carbon storage in products, and displacement of fossil carbon-intensive alternatives over a 40-y period. We find that products with durable carbon storage confer the greatest benefits, as well as products that reduce emissions in hard-to-decarbonize sectors like industrial heat. Concurrently, treatment could reduce wildfire hazard on 4.9 M ha (12.1 M ac), a quarter of which could experience stand-replacing effects without treatment. Our results suggest that innovative wood use can support widespread fire hazard mitigation and reduce net CO2 emissions in California.

Utilization of forestry waste materials in British Columbia: Options and strategies

The Canadian province of British Columbia has large forestry resources and therefore provides an informative example of the potential role of bioenergy in mitigating GHG emissions. Even in biomass-rich British Columbia, forestry resources are only sufficient to meet part of the energy demand. This paper compares different energy conversion routes for forestry waste materials: via hydrothermal liquefaction, thermochemical methanol and bioethanol, renewable natural gas, cogeneration of heat and power, heat-only boilers, and power-only generation. The GHG savings, health impacts, minimum selling prices, and GHG abatement costs for each option are estimated by combining life cycle assessment with a discounted cash flow model. The input-based functional unit of 1 oven-dry tonne biomass provides a better basis for comparing possible uses of finite biomass supply than the commonly-used output-based functional unit of 1 GJ bioenergy. Heat-only boiler for district heating gives the highest GHG reduction of 960 kgCO2-eq per oven-dry tonne feedstock, while power-only generation delivers minimal GHG benefit in British Columbia. Heat-only boiler and cogeneration offer the lowest GHG abatement costs (<$-20/tCO2-eq), due to lower costs and higher energy conversion efficiencies, and are already economically viable, but will not use all the available resources because health impacts generated by biomass combustion limit their deployment, despite life cycle health benefits for avoiding hazardous emissions from slash burning of forestry waste materials. Refined biofuel options are much less cost-effective (>$50/tCO2-eq); further technology improvement and policy support are needed to offset the cost disadvantage.

Reed Canary Grass for Energy in Sweden: Yields, Land-Use Patterns, and Climatic Profile

Research Highlights: (1) Reed canary grass (RCG) is analysed in Sweden compared to willow and poplar for 2001–2020. (2) Each crop presents a different land-use and climatic profile. (3) Average yield records of RCG are similar to willow and poplar. (4) There are divergences between trial-based and commercial yields. (5) Existing land-use change patterns suggest meadow &gt; RCG and RCG &gt; cereal. (6) RCG land area is very sensitive to policy incentives. Background and objectives: RCG is an alternative crop for biomass-to-energy due to high yield and frost tolerance. We assess the cultivation in Sweden by using an extensive compilation of data, with emphasis on the extent of the cultivation, climatic profile, land-use patterns, and productivity. Material and methods: RCG plantations are analysed for 2001–2020. A geostatistical analysis is performed to characterize where it is cultivated and the land uses associated. Climatic, productivity, and yield profiles are compared to willow and poplar plantations from experiments and from commercial plantations. Results: The results show that the cultivation of RCG expanded after 2005, with a maximum of 800 ha in 2009, to then decrease to the current levels of about 550 ha. It is mainly grown in colder climatic areas, with lower agricultural productivity than willow and poplar. Mean yields from trials are 6 oven dry tonnes (odt) ha−1 year−1; commercial yields are 3.5 odt ha−1 year−1. RCG replaces meadow land and then is replaced by cereals when abandoned. Conclusions: RCG is an interesting alternative with similar yields (commercial and trials) as other energy crops, but its success is more sensitive to policy incentives.

Economic Modelling of Poplar Short Rotation Coppice Plantations in Hungary

No study has been previously completed on the range of sites, potential yield, and financial characteristics of poplar short rotation coppice plantations (SRC) in Hungary. This paper conducts a literature survey to reveal the biomass production potential of such plantations and presents a model that is used to analyze their financial performance. The results indicate that the break-even-point of production is between 6 and 8 oven-dry tons per hectare per year once a minimum cost level and wood chip price within a 10% range of the 2020 value are considered. The higher the wood chip price, the lower the break-even-point. Since the model excluded the administrative costs that depend on the type and size of the management organization, the break-even-points can be significantly higher in reality, which suggests that short rotation energy plantations can be a financially reasonable land-use option in above average or even superior poplar-growing sites. The rotation period of industrial poplar plantations that produce high quality veneer logs ranges from 12 to 25 years. Though such sites can provide higher returns on investment, short rotation plantations have the advantage of providing a more evenly distributed cash flow. To facilitate the wider application of poplar SRC, the related policies need to apply specific subsidies and allow the rotation cycle to be extended up to 20–25 years, which is currently limited to 15 years.

Potential Profitability Zones for Populus spp. Biomass Plantings in the Eastern United States

Short rotation woody crops (SRWCs) are key renewable feedstocks for the emerging bioeconomy. A critical step in developing a bioeconomy is defining suitable regions for commercial SRWC activities. The goal of this study was to estimate the obtainable yield in mean annual increment and economic returns on investment for Populus deltoides and Populus hybrids for the 33 eastern states using the 3PG model (Physiological Principles Predicting Growth). Yields ranged from 0.5 to 11.9 oven-dry tons (ODT) ac−1yr−1 with a mean of 3.9 ODT ac−1yr−1. Spatially, southern Illinois, Louisiana, Indiana, and central Missouri have the highest yield production. Kentucky, Tennessee, North Carolina, Oklahoma, Arkansas, and Virginia, as well as other southern regions of Georgia, Alabama, Mississippi, and South Carolina, have the lowest potential yield production. Land expectation values of P. deltoides ranged from –$1,369.12 to $1556.14/ac. The median internal rate of return (IRR) for the northern states was 2.0%, with a range of −13.9% to 14.6%. Spatially explicit potential profitability zones are useful as a coarse filter for evaluating sites for bioenergy projects that are under construction, in operation, proposed, or where due diligence is required.

Economic implications of grinding, transporting, and pretreating fresh versus aged forest residues for biofuel production

The moisture content in forest harvest residues is a key factor affecting the supply cost for bioenergy production. Fresh harvest residues tend to contain higher amounts of water, thus making transportation inefficient. Additionally, fresh harvest residues contain greater amounts of needles and bark that may reduce the polysaccharide content, thus affecting the production of liquid fuels derived from cellulosic components. In this study, we estimated the downstream economic effect in the supply chain of collecting, grinding, transporting and pretreating fresh versus aged residues. Specifically, we analyzed the effect of feedstock moisture content on grinder fuel consumption, bulk density, bark and needle content, and polysaccharide proportion. Fresh forest harvest residues were 60% moisture content (wet basis) and aged forest residues were 15% moisture content. The bark and needle proportion is 6.1% higher in fresh residue than in aged residue. Polysaccharides were 26% higher in aged residue than in fresh residue. On a dry-tonne basis, the cost of grinding fresh residues was about the same as that of aged residues. However, considering the difference in bulk density on transportation cost and the difference in polysaccharide yield, the value gain for in-field drying ranges from US$29.60 to US$74.90 per ovendry tonne.

Cradle-to-gate life cycle assessment of forest supply chains: Comparison of Canadian and Swedish case studies

This study took a Life Cycle Assessment (LCA) perspective to model a total of twenty forest supply chains, from seedling production to forest biomass delivery to industry. Four scenarios were analyzed, two in Sweden and two in Canada. Resource and energy consumption, and emissions to air, water and soil of conventional and biomass dedicated supply chains were evaluated and compared.The Swedish supply chains showed a better environmental profile, on average, per oven dry tonne (ODt) than the Canadian ones in the regions studied. In terms of climate change potential the Swedish biomass dedicated supply chains generated 48.8 kg CO2-eq, 13%, 30% and 38% lower than Swedish conventional, Canadian biomass dedicated and Canadian conventional supply chains, respectively. Sawlogs from final felling in the Swedish biomass dedicated supply chains generated 34.2 kg CO2-eq, the lowest emissions within the roundwood assortments. Concerning the forest fuel assortments in form of wood chips, pulpwood from final felling in the Swedish conventional supply chains, and stump core and long tops from final felling in the Swedish biomass dedicated supply chains generated the lowest emissions: 48.9 kg CO2-eq, 52.3 Kg CO2-eq and 57.8 kg CO2-eq respectively. Transport from forest to industry, harvesting, extraction, chipping, and crushing were identified as hotspots in the forest supply chains. Forwarding versus skidding, chipping and transportation were the processes that differed the most between countries.In both countries, when the supply chains were biomass dedicated the environmental impacts per ODt were lower than in the conventional supply chains. Therefore, integrating forest fuel supply with industrial wood harvesting has the potential to reduce emissions.

Forest biomass feedstock cost sensitivity to grinding parameters for bio-jet fuel production

Forest harvest residuals in the USA Pacific Northwest are a significant and largely underutilized source of renewable feedstock for “green” power. These forest harvest residuals are, however, not a uniform commodity and many choices can be made for source location, which tree parts to include in the harvest, how to comminute, transport, and process at a biofuels mill-site. Each of these many decisions can and should be informed by the overall impact on value chain costs, including all production costs and any impacts on the conversion process. The number of operational choices is large and the optimal solution not obvious. This paper explores the quantification of a number of the most likely significant operational choices in feedstock harvesting and preparation, and quantifies and ranks the main factors which can impact total value to the overall process of converting forest harvest residues to bio-jet fuel. Under the assumptions used here, total grinding costs are the largest cost impact factor, with a $26.12 per oven-dry tonne impact range. Higher bulk density (as long as moisture content is low enough) reduces hauling cost and is the second most powerful cost effect, having an impact range of $11.31 per oven-dry tonne.

Operational short rotation woody crop plantations: Manual or mechanised harvesting?

Harvesting is the most expensive, but the least investigated process in the cultivation of short rotation woody crops (SRWC). To get a better idea of the harvesting process (in terms of its performance, productivity, cost, soil compaction, cutting height and quality as well as biomass losses), we closely monitored the second harvest of a SRWC culture in Flanders (Belgium). We compared our results to the harvests of other, small European parcels. The trees at our site were harvested with both a manual and a mechanised (Stemster harvester) cut-and-store system, while the cut-and-chip system was analysed from an extensive literature survey. The production cost (to the edge of the field) at our site reached 426 (manual) and 94 (mechanised) € t−1, while the average values found in the literature are respectively 104 and 78 € t−1, versus 17 € t−1 for the cut-and-chip harvesting system. The productivity at our site reached 14 (manual) and 22 (mechanised) oven-dry tonnes per scheduled machine hour, while the average values found in the literature are respectively 15 and 23 t h−1. Based on the good performance (ha h−1) and productivity (t h−1) of the cut-and-chip system as well as its lower costs, this harvesting system is recommended for operational SRWC.

Forest harvest residue recovery in semi-mechanized hardwood selection operations

Semi-mechanized single-tree selection operations make important contributions to wood supply in parts of the northern hardwood forest region of northeastern North America. However, harvest residue recovery has not yet been integrated within this silvicultural system, due to low recovery rates, low mechanization, and small harvest blocks. As bioenergy policy incentives and markets continue to strengthen, there is a need to determine whether these partial harvest systems can contribute to local and regional energy wood supply. We assessed residue recovery and procurement costs during semi-mechanized single-tree selection operations in central Ontario, Canada. Logging contractors recovered 1.7–3.5 oven dry tonnes (ODt) of harvest residue per hectare by reducing the diameter at which trees were delimbed and topped. The time spent delimbing and topping increased by 10.8% but no extra time or machinery was required to recover the residue to roadside landings. Supply chain scenarios that included terminal chipping indicate that the harvest residue could be brought to market at a delivered cost <USD $75 per ODt for transport distances up to 150 km.

Determination of biomass accumulation in mixed belts of Salix, Corylus and Alnus species in combined food and energy production system

Given the energetic, demographic and the climatic challenges faced today, we designed a combined food and energy (CFE) production system integrating food, fodder and mixed belts of Salix, Alnus and Corylus sp. as bioenergy belts. The objective was to assess the shoot dry weight-stem diameter allometric relationship based on stem diameter at 10 (SD10) and 55 cm (SD55) from the shoot base in the mixed bioenergy belts. Allometric relations based on SD10 and SD55 explained 90–96% and 90–98% of the variation in shoot dry weights respectively with no differences between the destructive and the non-destructive methods. The individual stool yields varied widely among the species and within willow species with biomass yield range of 37.60–92.00 oven dry tons (ODT) ha−1 in 4-year growth cycle. The biomass yield of the bioenergy belt, predicted by allometric relations was 48.84 ODT ha−1 in 4-year growth cycle corresponding to 12.21 ODT ha−1 year−1. The relatively high biomass yield is attributed to the border effects and the ‘fertilizing effect’ of alder due to nitrogen fixation, benefitting other SWRC components. On termination of 4-year growth cycle, the bioenergy belts were harvested and the biomass yield recorded was 12.54 ODT ha−1 year−1, in close proximity to the biomass yield predicted by the allometric equations, lending confidence and robustness of the model for biomass yield determination in such integrated agro-ecosystem.

Metodologija za ocene potencialov lesa v Sloveniji

The information on wooden potentials from Slovenian forests is important for all stakeholders involved in the forest-wood chain (such as enterprises engaged in purchasing, processing or sales of roundwood, pulp industry, CHP plants ...). For these stakeholders, the actual amounts of wood appearing on the market are relevant. Thus the amount of wood consumed by forest owners for their own needs should be excluded. The Slovenian Forestry Institute has developed its own methodology for the evaluation of the actual and theoretical estimates of the quantities of timber. This article presents the potentials of both coniferous and deciduous roundwood as well as wood of lower quality. The actual potentials are based on the five-year averages (2009-2013) of wood that had previously been marked by district foresters for harvesting and at that time appeared on the market. The theoretical potentials, on the other hand, delineate the maximum amount of wood that can be harvested annually and sold on the market, while providing for sustainable forest management at the same time. The results are given in net cubic metres (m3 without bark) and oven-dry tons (ODT) when dealing with energy potential of lower-quality wood. The results show that in the case of spruce and fir trees the actual net quantity of roundwood on the market amounts to 1,239,000 m3. The assessment of theoretically marketable potentials of deciduous roundwood is 410,000 m3, while the actual amount of the deciduous roundwood on the market is 206,000 m3. In the case of lower-quality wood, the assessment of the total theoretically marketable potential is 1,443,000 ODT, while the assessment of the actual potentials on the market amounts to 468,000 ODT. The results indicate a low utilization rate of Slovenian forests, especially as far as privately owned forests are concerned. Still, we should be cautious in interpreting the results, as the analyses of the actual potential consider only the timber that was marked for harvesting by district forester, while in reality the harvested quantities are likely to be greater especially in privately owned forests.

Incorporating Uncertainty into a Life Cycle Assessment (LCA) Model of Short-Rotation Willow Biomass (Salix spp.) Crops

To estimate fossil fuel demand and greenhouse gas emissions associated with short-rotation willow (Salix spp.) crops in New York State, we constructed a life cycle assessment model capable of estimating point values and measures of variability for a number of key processes across eight management scenarios. The system used 445.0 to 1,052.4 MJ of fossil energy per oven-dry tonne (odt) of delivered willow biomass, resulting in a net energy balance of 18.3:1 to 43.4:1. The largest fraction of the energy demand across all scenarios was driven by the use of diesel fuels. The largest proportion of diesel fuel was associated with harvesting and delivery of willow chips seven times on 3-year rotations over the life of the crop. Similar patterns were found for greenhouse gas emissions across all scenarios, as fossil fuel use served as the biggest source of emissions in the system. Carbon sequestration in the belowground portion of the willow system provided a large carbon sink that more than compensated for carbon emissions across all scenarios, resulting in final greenhouse gas balances of −138.4 to −52.9 kg CO2 eq. per odt biomass. The subsequent uncertainty analyses revealed that variability associated with data on willow yield, litterfall, and belowground biomass eliminated some of the differences between the tested scenarios. Even with the inclusion of uncertainty analysis, the willow system was still a carbon sequestration system after a single crop cycle (seven 3-year rotations) in all eight scenarios. A better understanding and quantification of factors that drive the variability in the biological portions of the system is necessary to produce more precise estimates of the emissions and energy performance of short-rotation woody crops.

Productivity and cost of biomass harvesting for energy production in coppice natural stands of Quercus pyrenaica Willd. in central Spain

Biomass growing stocks, harvesting productivity and costs of energy production, were studied in thinnings of Quercus pyrenaica. Eleven forest sites were selected in coppices located in Castilla y León (Spain). Three systems were employed for harvesting: a mechanised whole tree harvesting (WTH) system, which included chipping at landing; a fully mechanised cut-to-length (CTL) harvesting system for firewood; and a semi-mechanised CTL system with manual felling and bunching. Three WTH trials had a hauling off 34.7–44.1 oven-dried tonnes (odt) ha−1. In contrast, only 11.6–30.0 odt ha−1 were obtained in the other eight CTL trials. Biomass weight equations for stems and whole trees were fitted. Worker operations were time-studied using software designed by the authors. The WTH system reached maximum productivity rates of 3.9 oven-dried tonnes per productive hour (odt h−1) for the felling and bunching operation and 6.9 odt h−1 for the forwarding operation. The mechanised CTL harvesting method achieved a productivity range of 1.3–0.5 odt h−1 for the harvesting operation. Furthermore, the average forwarding productivity was 7.3 odt h−1. Motor-manual felling and crosscutting in the CTL system accomplished a productivity range of 0.7–1.9 odt h−1. Manual bunching resulted in similar values. The lowest firewood unit cost for trees with 10 cm of diameter at breast height (DBH) was 62.0 € odt−1 using a semi-mechanised CTL system. Under similar conditions, this cost was 85.2 € odt−1 for the mechanised CTL system. Finally, the cost corresponding to chips at landing from WTH sites (average DBH = 10 cm) was 65.3 € odt−1.

Harvesting techniques for non-industrial biomass plantations

Two harvesting systems especially designed for non-industrial short-rotation forestry (SRF) plantations on farmland were evaluated. Both systems were based on versatile forest technology commonly used for conventional logging operations. They differed especially in where chipping was performed: in the field (terrain chipping) or at the field's edge (roadside chipping). Both systems were tested on two of the most common SRF poplar clones in Italy, namely: AF2 and Monviso. Results were encouraging: harvesting cost varied from 16.3 to 23.2 € t −1 , and was lower for terrain chipping and for the most productive clone (Monviso). Energy consumption varied between 147 and 212 MJ oven-dry tonne −1 , following the same trends as for harvesting cost. Resulting energy output–input ratios varied from 94 to 139. Life cycle impact assessment showed that the global warming potential (100 yr) was in the range of 2.4–3.4 kg CO 2 eq. oven-dry tonne −1 . Despite its higher cost, roadside chipping was preferred for its better terrain capability and for the superior storage quality of uncomminuted biomass. Both systems were suboptimal in their current configurations. They could offer a better performance with minor improvements. ► Two harvesting systems for non-industrial short-rotation forestry were tested. ► Harvesting cost varied from 16.3 to 23.2 € t −1 . ► Energy output–input ratios varied from 94 to 139. ► Global warming potential (100 yr) varied from 2.4 to 3.4 kg CO 2 eq. oven-dry tonne −1 . ► Terrain chipping was cheaper, but roadside chipping offered logistical advantages.

A new comminution device for high-quality chip production

The authors tested a chipper prototype adopting a new comminution device, designed to produce high quality chips when processing delimbed logs. The machine was fitted with innovative tubular blades, mounted on a flywheel. The prototype was powered by a 55kW farm tractor through the standard power take-off. The machine appeared as efficient as most conventional disc or drum chippers in the same size class, but offered a much better chip quality. Chips were free from any particles longer than 45mm, and with a very limited content of fine particles (max. 2.5%). Of course, this was achieved when using premium wood raw material, such as delimbed small logs. Performance varied with tree species: poplar was the softest and easiest to chip, whereas robinia was the hardest and required a much larger effort. Diesel fuel consumption varied between 3.4 and 4.3dm3 per oven-dry tonne.

Production Costs and Markets for Pellet Chips: Case Studies in Northern Sweden

Increasing use of woody fuels requires that nontraditional types of raw materials are exploited, including logging residues and small-diameter trees. Although medium-scale combustors often use pellets, they could conceivably use dried chips of sufficiently narrow size distribution (henceforth pellet chips). The influence of the following factors on the relative cost-effectiveness of producing pellets and pellet chips was investigated for three plant sites in northern Sweden: (1) harvesting and transporting of forest residues; (2) the potential of existing energy plants to supply drying heat in periods of capacity surplus; (3) the distance to potential end-users. Data from the national forest inventory were used to estimate raw material costs. The resulting production costs were 144–176 $ per oven-dry tonnes (OD t) for pellets (27.4–33.5 $ MWh−1) and 143–173 $ OD t−1(27.2–33.0 $ MWh−1) for pellet chips, with harvesting, forwarding, chipping, and transporting of logging residues to the sites amounting to 114–122 $ OD t−1(21.7–23.2 $ MWh−1) for both fuels. Even though the differences in production costs were minor, the production of pellet chips requires significantly less electricity input per OD t of produced fuel. For cost reductions improved methods for wood fuel procurement, compacting and transporting of chips, small-scale low-temperature drying and foliage and bark separation are needed.

Production and quality of biomass fuels from mechanized collection and processing of vineyard pruning residues

Vineyards cover about eight millions of hectares worldwide and their annual pruning generates a large amount of ligno-cellulosic biomass, potentially available for industrial and energy use. Commercial pruning residue harvesters are now available, which may allow cost-effective recovery. The study aimed at determining the quantity and the quality of pruning residues potentially derived from vineyard management. Data were obtained from 17 fields in Northern and Central Italy. Fields were harvested with seven different machines. The experimental design adapted to the necessities of field trials, but was adequate for testing the main sources of variability. Net residue yield varies around 1 oven dry tonne per hectare, with minor differences between grape varietals and harvesting technologies. Losses are still high, and are generally related to ineffective management techniques. Moisture content at harvest varies between 40% and 45%, whereas the higher heating value is slightly lower than that of forest fuels. Comminuted vineyard residues are unsuitable for firing residential boilers, due to the frequent presence of oversize and/or undersize particles. The application of pesticides does not result in any significant contamination with noxious chemicals, because these products are almost completely weathered before residues are recovered. In wine-producing regions, the recovery of vineyard pruning residue may represent a substantial source of industrial bio-fuel.

Performance of a mobile mechanical screen to improve the commercial quality of wood chips for energy

The study analyzed the performance of a mobile screening device for upgrading coarse wood chips to residential user standards, by removing oversize particles and fines. The machine was designed for transportation to forest landings, logistic terminals and plant chip yards. Average productivity was 1.9 oven-dry tons (odt) h−1, corresponding to a screening cost of 28.5€odt−1. This figure was lower than the price increase obtained by upgrading industrial chips to residential user standards. Hence, screening offered a profit of 4.7€odt−1, or 16% of the original screening cost. The screening process was capable of upgrading chips from industrial to residential specifications, by reducing the incidence of oversize particles below the 1% critical threshold. Screening also allowed a substantial reduction in the content of fines. A similar effect was not verified for crushed wood, which failed to meet the specifications for residential fuel.

Pine and spruce stump harvesting productivity and costs using a Pallari KH 160 stump-lifting tool

Even though stumpwood may become a significant part of the future fuel mix for combined heat and power plants in Sweden, the harvesting of stumps after regeneration felling is still only performed on a trial basis. Results from time studies on two, 23 tonne, excavators fitted for stump lifting, together with follow-up data on stump lifting and forwarding, are presented. Lifting, splitting, and piling the stumps accounted for 17, 32, and 32%, respectively, of the total productive work time. A predictive model was developed to estimate operational times and productivities when lifting pine and spruce stumps. Stump diameter, species, and terrain conditions contributed significantly to the fit of the model. The model predicts that productivity of stump lifting in spruce sites with easy terrain conditions and average stump diameters of 20 and 40 cm will be 1.23 and 4.19 oven-dry tonnes (ODT) per productive work hour, respectively. This is 43% higher than in pine sites with difficult terrain conditions and the same diameters. In the follow-up data, the productivity in stump lifting varied from 1.5 to 2.9 ODT per productive work hour while the cost for lifting and extraction to roadside varied from 37.8 to 59.4 €/ODT.