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Different abiotic and biotic disturbances are expected to become more common in the future due to a warming climate. Globally, post-disturbance salvage logging is becoming more predominant to recover economic value from timber in disturbed forests. This study collected comparative time-study data and analyzed the productivity of cutting for windfalls in clear cuttings and determined the cutting costs of windfalls. Furthermore, the logging (i.e., cutting and forwarding) costs of wind-damaged trees and those of undamaged standing Norway spruce (Picea abies (L.) Karst.) trees in clear cuts were calculated in Finland. The results revealed that the cutting productivity of windfalls was 19-33% lower than that of undamaged stems. The cutting costs of windthrown stems with a volume of 0.3-1.5 m 3 were 35-64% higher and the logging costs of windfalls were 10-30% higher than those of undamaged standing stems. The study provided new understanding regarding the productivity and costs of salvage logging operations under Finnish conditions. Even if the logging of windfalls is expensive and laborious, salvage logging operations are important for forest stands and their health to minimize post-disaster damage outbreaks in coniferous forests, such as the damage caused by bark beetles-mainly Ips typographus L.
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... Between 1950 and 2000, windthrows caused 53% of the total damage. It is expected that the frequency and severity of storms will continue to increase due to climate change in Europe [2]. ...
... Especially in the last ten years, there have been some studies carried out in order to better assess the efficiency and costs and support the planning of timber harvesting operations after windthrows [2,[11][12][13][14][15][16][17][18][19][20][21][22]. In this section, already developed productivity models are presented. ...
... Parameter average tree volume in m 3 average stand density in trees per hectare average breast height diameter in cm average load volume in m 3 average extraction distance in m average log volume in m 3 maximum terrain slope while driving in % slope of the machine during loading in % maximum terrain slope during loading in % number of logs per load average lateral yarding distance in m average slope of the terrain in degrees degree of damage to the thrown trees (1 is uprooted, 2 is uprooted and broken) Kärhä et al. [2] analyzed the productivity and costs of windthrow processing with harvesters (Ponsse Ergo, John Deere 1270D ECOIII, Logset 8H GT) in Finland and compared this data with the efficiency of timber harvest in undamaged stands. In both cases, stocking was done with the harvester without exception. ...
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Digitization can help the forest industry to improve cost efficiency and to reduce possible environmental impacts. In the context of this study, models were implemented using the example of windthrow processing, which enables a capacity planning for carrying out timber harvesting. For capacity planning, it is necessary to estimate the time required by the harvesting systems. For this purpose, existing productivity models were analyzed, the models were validated and adjusted, and the time required for each harvesting system and calamity area was calculated using stand and terrain parameters. Depending on the scenario and the preferred harvesting system, the time for harvesting the timber in an almost 200-hectare windthrow area in a case study region in Carinthia (Austria) varied. The harvesting with cable yarder and tractor takes about 26,000 machine hours and 86,000 man-hours. Harvesting operations with cable yarder and harvester-forwarder has proven to be the most productive with a duration of around 20,000 machine hours and 70,000 man-hours. Depending on the scenario, in windthrow areas, forest workers are needed for 28 to 42 min to fell, delimb, buck and extract 1 m3 of timber to the forest landing.
... Chaotic windthrow patterns (i.e., stems oriented in different directions), caused by whirlwinds, make harvest operations even more complicated and expensive than uniform patterns of windthrow (i.e., stems orientated approx. parallel), caused by straight-line winds [14,15]. The decision for a specific salvage harvesting and extraction system [16] should depend on the type and severity of the damage, the windthrow pattern and the spatial distribution of the felled trees [15]. ...
... The estimated stem lengths were systematically lower than the reference measures, showing a substantial bias of −60%, and even in the case where the problems in length estimation could be solved, trees were represented by lines and not by polygons such that no diameter estimation could be derived. In cases where the downed volume is the target variable, the proposed methodology may thus only be used as a first step, i.e., for stem detection, while other techniques (e.g., [14,30]) must be applied for volume estimation. ...
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Increased frequencies and windspeeds of storms may cause disproportionately highincreases in windthrow damage. Storm-felled trees provide a surplus of breeding material forbark beetles, often resulting in calamities in the subsequent years. Thus, the timely removal offallen trees is regarded as a good management practice that requires strategic planning of salvageharvesting. Precise information on the number of stems and their location and orientation are neededfor the efficient planning of strip roads and/or cable yarding lines. An accurate assessment of thesedata using conventional field-based methods is very difficult and time-consuming; remote sensingtechniques may be a cost-efficient alternative. In this research, a methodology for the automaticdetection of fallen stems from aerial RGB images is presented. The presented methodology was basedon a line segment detection algorithm and proved to be robust regarding image quality. It was shownthat the method can detect frequency, position, spatial distribution and orientation of fallen stemswith high accuracy, while stem lengths were systematically underestimated. The methodology canbe used for the optimized planning of salvage harvesting in the future and may thus help to reduceconsequential bark beetle calamities after storm events.
... As the average size of the stem increases, the hourly fuel consumption increases; however, the increase in productivity per cubic metre is greater and fuel consumption per cubic metre decreases (Rieppo and Örn 2003). Nevertheless, Kärhä et al. (2004Kärhä et al. ( , 2018, Ryynänen and Rönkkö (2001) and Visser and Spinelli (2012) reported that, when the stem size of the trees in the stand becomes sufficiently large, the productivity of harvesting machines begins to decrease. However, interestingly, this observation was not supported by the material in this study. ...
Article
To address the issue of climate change, the EU’s climate and energy framework has set targets to improve energy efficiency. Reducing greenhouse gas (GHG) emissions requires higher energy efficiency in the wood supply of forest industries. The aim of the study was to clarify the energy-efficiency baseline for wood-harvesting operations, define useful measures and follow up the total fuel consumption and resulting emissions. The results indicated that wood-harvesting entrepreneurs have a positive attitude towards energy efficiency. The fuel consumption of wood-harvesting machines was the lowest for the final fellings, while in first thinnings, the consumption was highest per cubic metre harvested. The average cubic metre-based fuel consumption and GHG emissions in respect of wood harvesting were more than double in the first thinning compared to the final felling. Better allocation of harvesting machines could reduce fuel consumption and GHG emissions while improving work efficiency. Hour-based fuel consumption is most affected by machines’ engine power and wood-harvesting conditions of forest stands. Fuel consumption per cut cubic metre is affected by wood-harvesting conditions and machine units. The calculated energy efficiency was highest in final fellings. A more significant factor than fuel consumption (input) is the amount of harvested wood (output) in the energy-efficiency equation. Energy efficiency can also be improved by operator education. Trucks which are used for harvesting-machine relocation have a significant impact on wood-harvesting operations' total fuel consumption and emissions. It is therefore essential to minimise the number of relocations and operational and resource planning should be developed. In the future, the examination of fuel consumption and GHG emissions should be extended to the entire wood-harvesting chain, including long-distance transportation and timber trade, and for example the effect of operator should be investigated in more detail.
... A combination of sanitation and salvage logging after storm events and outbreaks of I. typographus has been shown to reduce the number of trees killed by I. typographus (Karha et al., 2018;Stadelmann et al., 2013). One way to mimic this is to use trap logs, particularly to protect exposed forest edges after clear-cutting. ...
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Bark beetles can cause epidemic outbreaks and kill millions of cubic meters of economical and ecologically important forests around the world. It is well known what attracts and what repels different species of bark beetle, and these chemical cues can be used to protect trees and catch the beetles without using pesticides. Applying this knowledge, we investigated the use of push–pull strategies with trap logs along susceptible edges of a Swedish boreal spruce forest. The repellents (push) used were non-host volatiles (NHV) attached to tree trunks at the forest edge, and the attractants (pull) was a commercial aggregation pheromone attached to trap logs. The aim was to test whether the Ips typographus catch could be significantly increased by combining a push–pull system with traditional trap logs, thereby providing additional protection. The experiment was performed over two years and included the main flight period of I. typographus. The study sites were clear-cuts that had been harvested the preceding winter, and sun-exposed forest edges of mature spruce were targeted for protection. A full factorial setup was used comprising two treatments (repellent and attractant) and a control. Seven replicates of the trap logs were used, three during the first year and four during the second. The number of established I. typographus maternal galleries per square meter of log surface was used as the response variable. The trap logs captured large numbers of I. typographus, at an average density of 353 and 169 maternal galleries per m² during year 1 and year 2, respectively, over all treatments. Based on the catch data, with a sufficient number of trap logs, the risk of tree mortality at forest edges may be reduced and we recommend its general use. However, we did not see any significant effect of either the repellent or the attractant on the density of maternal galleries. Hence, we cannot recommend the addition of chemical cues to improve the efficiency of trap logs. Although trap logs are efficient in capturing bark beetles and hence may protect forest edges, it does not imply that they can provide protection on a larger scale. In line with other studies, we hence recommend that forest management to target nature-based solutions that strengthen the resilience of forest stands, by using mixed forest stands and resistant plant species, and nurture habitats for natural predators of I. typographus.
... The net income of forest owners is reduced after a storm event because parts of the trunks are broken and harvesting costs per cubic metre increase (Szewczyk et al. 2014;Kärhä et al. 2018). Storms also result in harvesting of trees at a non-optimal time, entailing economic losses (Pukkala et al. 2016). ...
Article
Resilient ecosystems provide natural insurance value, or resilience value, to the landowner and to society at large. In response to global calls for integrating biodiversity in sector policy and planning, we analysed the specified resilience value by simulating three storm regimes and five management scenarios: Business As Usual/BAU (spruce-dominance), Spruce Monoculture, More Broadleaves, Continuous Cover Forestry (CCF), and No Thinnings. The forest decision support system Heureka RegWise was used to simulate the effects of storms on forest dynamics and Net Present Value (NPV). No Thinnings, CCF and More Broadleaves were more resilient to storms (reduced damage cost) compared to BAU. BAU had the highest NPV only if storms are ignored, a common assumption in today’s forest planning. Given storms, No Thinnings maximises NPV on landscape level. On the 20% most vulnerable plots the NPV was much higher for No Thinnings and slightly higher for CCF and More Broadleaves, compared to BAU. CCF and More Broadleaves also provide nature-based solutions (co-benefits) including public goods. However, forestry adaptations to storms are slow in Sweden, in contrast to e.g. German state forestry which emphasises maximising tree growth and resilience to several stresses and disturbances rather than NPV optimisation.
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The interaction between wind loads and forest plantations has been fairly well understood. A large amount of valuable scientific and practical information has been obtained and published so far in this field. There are some known data on wind load damage to plantations, its effect on their growth, and the ability of forest plantations to reduce wind speed and force. Nevertheless, the issues of wind impact on both individual trees and forested areas remain relevant. Analysis of the literature and Internet resources showed that the research has left out the issue of the wind load impact on the grown wood quality. Multi-year observations and a wind rose created using these observations enable the determination of the prevailing wind strength and direction for each area. Knowing the features of the wind load impact on the quality of timber after logging, it is possible to predict the percentage of the yield of commercial and low-quality wood, and to purposefully influence this parameter in plantation forest growing by setting out the planting material in accordance with these data. The article shows the developed method for theoretical estimation of the probability of occurrence of critical bark deformations in the compressed zone, which appears when bending a growing tree due to wind load. Classical studies of the critical state of compressed rods on an elastic base were used as the theoretical basis of the method. A part of growing tree bark plays the role of a rod, while cambium and other living cells between the bark and the trunk wood play the role of the elastic base. A correlation simple enough for practical application is proposed in order to obtain quantitative estimates. Adequacy of the modeling results is confirmed by their consistency with the experimental data. The application of the developed methodology is shown on the examples.
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The aim of this study was to measure and model the fuel consumption of cut-to-length (CTL) logging machinery in cutting and forwarding under Nordic harvesting conditions, and to clarify which factors had the greatest effect on the fuel consumption. In addition, the total annual fuel consumption and CO 2 eq emissions were calculated for CTL logging operations in Finland in 2020. The data were collected during a long-term follow-up study on the fuel consumption of harvesters and forwarders conducted between March 2018 and April 2019. The fuel consumption data was obtained from a total of 16 harvesters and 13 forwarders equipped with digital flow meters featuring an accuracy of ± 1%. The engine power of the forest machines explained most of the hour-based fuel consumption. Correspondingly, the harvesting conditions of the forest stand best explained the cubic-metre-based fuel consumption. The fuel consumption of CTL logging operations (cutting and forwarding) averaged 1.4 L m − 3 in final felling, and 3.1 and 2.2 L m − 3 in first and later thinning, respectively. There was a large variation in the cubic-metre-based fuel consumption between individual machines, both for harvesters and forwarders. The total calculated fuel consumption in Finnish CTL operations in 2020 was 126.6 million L, with the calculated CO 2 eq emissions totalling 334,209 t (i.e. 5.7 kg m − 3 ). Several measures to accelerate fuel and energy efficiency and reduce CO 2 eq emissions in CTL logging operations are discussed in the paper.
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The wind is able to cause major damage to the forest in a very short time. The damage caused by the wind manifests itself in different ways. We distinguish windbreaks, windthrows, and bendings. This paper presents the research results on the productivity of the Komatsu 951G harvester in poplar stands (Populus x euramericana clone M-1), affected by windbreaks and windthrows. The share of the effective working time was represented by 79% of total time, while delays share was 21% of the total time of cutting and processing of assortments. The productivity of the harvester was expressed in m 3 per working hour of the machine, it was 24.48 m 3 /h. The research showed that the price of a harvester per one working hour is € 82.88, but the unit cost of the Komatsu 951G harvester is € 3.39/m 3 .
Chapter
Catastrophic wind disturbances under climatic changes are causing major economic impacts and ecological changes that can persist for decades. Bark beetle (Coleoptera: Curculionidae) population and community dynamics are often linked to such wind disturbances at several spatial and temporal scales ranging from damage to individual trees to large-scale windthrow that may prompt multiyear outbreaks on the landscape scale. In this chapter, we discuss how catastrophic wind disturbances and ensuing biological legacies enhance bark beetle populations, particularly in the context of climatic changes. The high level of variability at the tree, stand, and landscape levels created by windstorms generally has positive consequences for eruptive bark beetle species, particularly in Europe. Poststorm timber salvaging to alleviate pest burdens may push biotic elements, especially those dependent on coarse woody debris and forest gaps, into different successional pathways. Climate change is undoubtedly influencing the interactions between these two major disturbance agents by increasing their intensity and severity levels and altering landscape characteristics with feedback loops. In the Anthropocene, predictive modeling of network interactions between multiple abiotic and biotic disturbances and stressors will be critical for effective mitigation, forest restoration, and sustainable forestry practices in a rapidly changing world.
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Logging to "salvage" economic returns from forests affected by natural disturbances has become increasingly prevalent globally. Despite potential negative effects on biodiversity, salvage logging is often conducted, even in areas otherwise excluded from logging and reserved for nature conservation, inter alia because strategic priorities for post-disturbance management are widely lacking. A review of the existing literature revealed that most studies investigating the effects of salvage logging on biodiversity have been conducted less than 5 years following natural disturbances, and focused on non-saproxylic organisms. A meta-analysis across 24 species groups revealed that salvage logging significantly decreases numbers of species of eight taxonomic groups. Richness of dead wood dependent taxa (i.e. saproxylic organisms) decreased more strongly than richness of non-saproxylic taxa. In contrast, taxonomic groups typically associated with open habitats increased in the number of species after salvage logging. By analysing 134 original species abundance matrices, we demonstrate that salvage logging significantly alters community composition in 7 of 17 species groups, particularly affecting saproxylic assemblages. Synthesis and applications. Our results suggest that salvage logging is not consistent with the management objectives of protected areas. Substantial changes, such as the retention of dead wood in naturally disturbed forests, are needed to support biodiversity. Future research should investigate the amount and spatio-temporal distribution of retained dead wood needed to maintain all components of biodiversity.
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The mountain pine beetle (Dendroctonus ponderosae) has affected millions of acres of forests in the Rocky Mountain region in the United States. This study quantified the difficulty of harvesting beetle-killed stands caused by downed trees. A detailed time study was conducted on a whole-tree clearcut harvest using a ground-based system in western Montana in August 2015. Our study shows that the productivity of the feller-buncher was highly affected by the number of downed trees. The feller-buncher average cycle time per tree was 7.0 s when only standing trees were cut and bunched whereas it took 13.2 s per tree when the bunch included one or more downed trees. Our results also indicate that stand conditions with various levels of downed trees affect the unit production cost and productivity of the entire harvesting system by increasing operational delays in the combined felling, skidding, and delimbing operation. This research provides insight into how optimized system configurations may help cope with the increase in harvesting cost caused by beetle-killed stand conditions and helps quantify the potential financial impacts of delayed stand management decisions in the wake of high-mortality forest disturbances.
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It is well-known that machine operators vary in their performance when undertaking mechanized forestry harvesting operations. Nevertheless, the human factor is still largely disregarded in productivity calculations. In the present study, operator performance is evaluated by analysing archived production data collected automatically by computers on-board single grip harvesters driven by 32 operators working in 3,351 stands over a period of three years. The experimental conditions were all approximately the same. The effect of the operators is modelled by a multilinear regression analysis. Seventeen operators were found to have performance levels that differed significantly from the mean model. Together, ‘tree volume’ and ‘operator’ explained 84% of the overall variance. However, since 37.3% of the variance in productivity is explained by the operator, the influence of the operator on productivity is quite large. The minimum and maximum significant mean productivity values for all the operators differed by a factor of 2.2, which reduced to a factor of 1.8 if only data from experienced operators were analysed, although this still demonstrates that the best operators are nearly twice as productive as the worst. The operator, therefore, has an important influence on productivity and should be considered a key factor in productivity models.
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Natural disturbances such as windthrow and bark beetle Ips typographus L. outbreak often affect protected areas with non-intervention type of management located in close proximity to managed forest stands. This raises concerns about the migration of the beetle outbreak from non-intervention zones to adjacent managed forests. In this study we analyzed the spatiotemporal dynamics of large-scale disturbances by intervention and non-intervention type of management in the Tatra mountains (Central Europe). We collected a time series of Landsat images from 2003 to 2014, and applied maximum likelihood classification to map the extent of forest, windthrow, clear-cuts, beetle outbreak and fire. Our classified maps achieved high overall accuracies: 0.93 ± 0.03 ⩽ OA ⩽ 0.96 ± 0.03. The extent of forest declined over the study period. We found higher rate of beetle induced tree mortality in non-intervention versus intervention zone. Within two growing seasons after the windthrow, beetle infestation occurred in close proximity to uncleared windthrow (<∼250 m), which suggest the positive effect of salvage logging (removal of windthrown trees) on lowering the risk of beetle outbreak. The two times higher sum of disturbances in intervention then in non-intervention zone indicated the limited impact of sanitation felling (removal of standing beetle infested trees) to reduce beetle population. However, sanitation felling highly contributed to the decline of the forest cover. Overall, our results document the dynamics of windthrow, bark beetle and clear-cuts by type of management, and limited impact of logging activities in reducing beetle outbreak in neighboring areas with intervention and non-intervention type of management. download here: otherwise here: http://www.sciencedirect.com/science/article/pii/S0378112717300361 Or please contact me to share my author's copy of the manuscript + available data.