Articles containing the keyword 'harvest'

The objectives of this study were to record residual stand damage during harvesting operations and evaluate the influence of factors such as distance of the tree from the strip road, machine parts, operational phase, on the occurrence of tree wounds. The machine was a farm tractor equipped with a crane mounted on the front axle and a single grip harvester head. The study was carried out in two stands located in Southeast Sweden. Stand 1 was a 30-year-old Norway spruce (Picea abies (L.) H. Karst.) plantation on an afforested pasture while stand 2 was a 90-year-old mixed stand of Norway spruce, Scots pine (Pinus sylvestris L.), birch (Betula pendula Roth) and aspen (Populus tremula L.).

The mean damage percentage was 6.3% for the first stand and 6.5% for the second stand. Sixty-five percent of the wounds were less than 50 cm², with 91% of the damage occurring on the stem and 91% of the damage on or below the root collar. Sixty-six percent of the wounds produced by the stem under processing or by the harvesting head while only 10% of the wounds were produced by the tractor wheel. Damaged trees were distributed evenly in the crane reach zone. Significant differences were found between rut depths after one, two, four and six passes of the tractor in stand 1.

• Athanassiadis, E-mail: da@mm.unknown

In a silviculture experiment in east-central Maine, USA, natural regeneration was sampled to measure the effects of: (1) a range of partial harvest intensities, and (2) repeated partial harvest at one intensity. Under the first objective, five treatments were compared with residual basal areas ranging from 15 to 24 m² ha^-1 for trees ≥1.3 cm diameter at breast height. For the second objective, regeneration was evaluated after four harvests at 5-year intervals. Prior to harvests, the overstory of all the treated stands was dominated by Tsuga canadensis (L.) Carr., Picea spp. A Dietr., and Abies balsamea (L.) Mill. Eleven species or species groups were identified among the regeneration: A. balsamea, T. canadensis, Picea spp., Thuja occidentalis L., Pinus spp. L., Betula papyrifera Marsh., Acer rubrum L., Betula populifolia Marsh., Populus spp. L., Fagus grandifolia Ehrh. and Prunus serotina Ehrh. Regeneration abundance was measured as counts of seedlings or sprouts taller than 15 cm but with diameters less than 1.3 cm at breast height (1.37 m). Regardless of harvest treatment, total regeneration was profuse, ranging from over 25,000 to nearly 80,000 trees ha^-1. Regeneration was dominated by conifers with a total angiosperm component of 10 to 52 percent approximately 5 years after harvest and 11 to 33 percent after 10 years. Consequently, in forests of similar species composition, tree regeneration following partial harvests should be sufficiently abundant with an array of species to meet a variety of future management objectives.

• Brissette, E-mail: jb@mm.unknown

Time studies and an ergonomic assessment were carried out in logging operations for three logging machines based on backhoe loader chassis. The time studies were completed with a follow-up study of one backhoe loader-based single-grip harvester. The studies indicated a productivity at the same level as that of specialized Nordic logging machines. Ergonomics also proved to be good. Mean ground pressure exerted by the backhoe loader-based logging machines was little higher than for some of the conventional Nordic single-grip harvesters to which it was compared. The ability of the machines to operate in the terrain was also good, even in rough terrain.

These machines can also be used for other jobs, such as ditch digging, road building and road maintenance. The machines then function more as carriers for attachments rather than custom-built backhoe loaders. By more careful planning of operations, the machines can be used to a higher degree and more effectively. The relatively low investment cost compared to many custom-built Nordic logging machines also contributes to a reduction of operating costs.

• Johansson, E-mail: jj@mm.unknown

The paper discussed the definitions of different Finnish and English terms concerning timber harvesting, and suggests definitions and translations of the terms.

• Kantola, E-mail: mk@mm.unknown
• Harstela, E-mail: ph@mm.unknown

The area of stands studied by line plot survey was 594 ha. On the basis of the length of the inventory line the estimated proportion of harvesting strips was 14% and that of ditch openings 6% of the area. The calculated strip road spacing was 29 m. The option of the minimum diameter made it difficult to use the number of stems as criterion for thinning intensity. Thinning intensity evaluated according to the basal area had been stronger than recommended with low values of dominant height and milder with high values. The estimated removal according to stumps was 38 m³/ha on the average between the strips. The real removal has, however, been larger than that, as the strip road openings are made in connection with the first thinning.

The PDF includes an abstract in English.

• Rantonen, E-mail: hr@mm.unknown
• Päivänen, E-mail: jp@mm.unknown

Effects of varying rotation, thinning, fertilization and harvest intensity on the productivity and nitrogen cycle of Scots pine (Pinus sylvestris L.) stand were studied on the basis of computer simulation. The increasing intensity of management increased the loss of nitrogen in the cycle. Short rotation, associated with early thinning by means of the whole tree harvest, proved to be especially detrimental regarding the productivity of the forest ecosystem. Fertilization associated with thinnings is of great importance in maintaining the productivity of a forest ecosystem during an intensive timber harvest.

The PDF includes an abstract in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Seppälä, E-mail: ms@mm.unknown

Harvest index and number of associated traits were measured in a 16-year-old Scots pine (Pinus sylvestris L.) progeny test based on full-sib families. It was found that harvest index is a highly heritable trait and that a number of yield components are positively correlated with it. It is suggested that harvest index and tree ideotypes should be the basis of selection in cultivated trees. It is emphasized that an integrated approach to tree improvement including silviculture, soil science, industrial and economic constraints and tree breeding is a prerequisite for maximal response.

The PDF includes a summary in Finnish.

• Velling, E-mail: pv@mm.unknown
• Tigerstedt, E-mail: pt@mm.unknown

Using literature and a simulator experiment, an ordinary processor and a grapple loader processor were compared in conditions corresponding to thinning later than the first commercial thinning. Visual bucking only was employed in the simulator experiment. The strip road spacing was 30 m and there was no preliminary skidding of the trees. The simulator experiment confirmed the view reached in the literature that work productivity of the grappler loader processor is 20–40 % greater than that of an ordinary processor provided that the stem size is under 0.2–0.4 m3.

The PDF includes a summary in English.

• Harstela, E-mail: ph@mm.unknown
• Maukkonen, E-mail: am@mm.unknown

Questionnaires were sent out to determine the volume of wood harvested from peatlands during 1978 and the harvesting problems encountered. In total there were 110 responses which accounted for 8 million m3 of wood harvested, of which 1.0 million m3 (14%) was harvested from peatlands. The largest proportion of wood harvested from peatlands was during the winter. Most of the respondents reportet that they wait for the soil frost to set before harvesting is started on peatlands. Respondents indicated a total of 263 machines bogging down in to the soil or, for 1978, a total for Finland of 750 to 1,000 machines.
The PDF includes a summary in English.

The PDF includes a summary in English.

• Saarilahti, E-mail: ms@mm.unknown

The aim of the study was to find out the effect of the working place meetings on the increased cooperation between workers and supervisors, the improved work performance, the intensified use of machines and the improved job satisfaction. In the study loggers, forest machine operators and forement were interviewed. The results showed that the working place meeting is a useful means to realise the above-mentioned aims.

The PDF includes a summary in English.

• Kyttälä, E-mail: tk@mm.unknown

In the first part of the study the hindrance of the remaining trees when felling trees by machines working from the strip road in selective thinning was studied on the basis of the literature. In the second part there was geometrically studied the need of schematic thinning in some type stands when bundles are pre-skidded straight-lined to the strip road. In average only 0-1 trees per pre-skidding trail needs to be removed. It was concluded that trees removed from the pre-skidding trail do not significantly increase the need of schematic thinning. Remaining trees do not limit the length of machine booms if the pre-skidding trails are planned during the felling.

The PDF includes a summary in English.

• Harstela, E-mail: ph@mm.unknown

A theoretical nomogram was made for estimating the costs of fully mechanized thinning and the driving speed of the machine. Based on this nomogram and the previous studies three harvesting methods were compared; systematic fully mechanized harvesting, selective fully mechanized harvesting, and manual felling combined with whole-tree chipping.

The third method was cheaper than the fully mechanized methods in a pole-stage stand. The choice of the most advantageous chipping station depended on conditions, but the smaller tree size and possibly the reduced damage on the remaining stand favour chipping on the strip road rather than chipping on the intermediate landing or at the mill.

Mechanized systematic thinning was the cheapest method for harvesting in the sapling stand. The required driving speed were so low that ergonomic factors should not hinder its use. Factors related to the future production of the stand do, however, limit its use. Mechanized selective thinning does not seem to be an economic method for harvesting in a sapling or pole-stage stand.

The PDF includes a summary in English.

• Harstela, E-mail: ph@mm.unknown
• Tervo, E-mail: lt@mm.unknown

The amounts of harvestable logging residues and stump and root wood were examined in the area where 100,000 solid m³ of stemwood was cut in 1975. The cutting amounts of stemwood from work sites suitable for harvesting of logging residues was 35,000 m³, and suitable for harvesting of stump and root wood 38,000 m³. The increase in the yield of wood (without bark) from logging residues compared with the unbarked stemwood was 2.4%. The same percentage of wood from stump and root wood was 5.0–5.8% depending on the harvesting loss.

The PDF includes a summary in Finnish.

• Mäkelä, E-mail: mm@mm.unknown

This paper analyses the nutrient loses caused by whole-tree harvesting on the basis of the literature data. It has been considered that traditional stemwood harvesting does not lead to impoverishment of the soil because the nutrient content of the wood is quite low. The nutrient loss occurring in connection with heavy thinnings and whole-tree harvesting has been considered so great that it has to be compensated by fertilizer application. In comparison with harvesting unbarked stem timber, whole-tree harvesting has been found to increase the nutrient loss at the stage of final cutting as follows: N2 to 4 times, P 2 to 5 times, K 1.5 to 3.5 times and Ca 1.5 to 2.5 times. Depending on the conditions prevailing on the site, any one of these nutrients may be the limiting factor for tree growth during the next tree generation

The PDF includes a summary in Finnish.

• Mälkönen, E-mail: em@mm.unknown

The article reviews the position of the Department of Forest Technology in Finnish Forest Research Institute, among Finnish establishments in research on forest work. In addition, it describes the current research programmes of the departments both in wood harvesting studies and studies on silvicultural work. The equitable aims of the former are to increase productivity, lower the cost level, ease the work and improve job satisfaction, as well as to improve the utilization of wood raw material. The latter aims at e.g. improvement of the biological results.

Future prospects are surveyed from the point of view of the goals imposed by the State on the research and, on other hand, the appropriations earmarked for forest work science. A regrettable conflict has arisen between them.

The PDF includes a summary in English.

• Hakkila, E-mail: ph@mm.unknown

During the next decade there will be a marked increase in the allowable cut in drained peatlands. At the same time, the mechanization in logging proceeds, and in short-distance haulage the use of forwarders will increase. This study, based on literature and some observations, deals with logging conditions in drained peatlands with special reference to the suitability of heavy logging machines for use in such terrain. In addition, soil frost and the bearing capacity of the frozen peat soil were studied.

Freezing of the soil in a drained peatland area depends prevailingly on the weather conditions during early winter. The factors influencing soil freezing of a drained peatland are completely different from those regulating the freezing of natural peat soils. The frost penetrates in general deeper in the drained than virgin peatland. The topmost peat layer does not, however, freeze uniformly. Generally speaking, the bearing capacity of a drained peat soil is lower than that of undrained peat due to lower water content.

It is concluded that heavy logging machines are probably not fitted for use in drained areas on peatland even if the average soil frost values recorded would suggest it. Moreover, because of their extremely superficial root systems, peatland forests are exposed to damages by heavy machines in thinning operations.

The PDF includes a summary in English.

• Hannelius, E-mail: sh@mm.unknown

In this study a formula has been developed to describe the influence of the change of cost level on such a mechanization prognosis, where is assumed that wages and machine costs bear compound interest. In the study there are some numerical examples.

In the formula p1 = annual per cent increase of wages, p3 = annual per cent increase of machine costs, p2 = sudden and incident per cent increase of machine costs, and tv = delay in the profitability of mechanization.

The PDF includes a summary in English.

• Harstela, E-mail: ph@mm.unknown

The aim of the paper was to analyse, using a computer simulation technique, the moving distance of pulpwood bolts when direct felling of trees is used and the bolts are gathered alongside the strip road. According to the results, the average moving distance of bolts depends in a complicated way on the usable part of the stem and the spacing of strip road. As a rule, the differences between moving distances of two-meter bolts weighted and unweighted by bolt volume of various trees is 0–16% when the strip road spacing is 30 m the reason being the fact that the heaviest butt bolts are often more far away from the strip road than the top bolts.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

The material of 78 damaged Norway spruce (Picea abies (L.) H. Karst.) trees was gathered in Southern Finland in order to clarify the advance of decay. The harvesting which had caused the scars had been carried out 12 years earlier and at the moment of the investigation the growing stand was 110 years old. It was noticed that the variables used could explain only a few per cent of the variation of the advance of decay. It was concluded that the only important thing in practice is whether the injuries are in roots or in stems.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

The mobility of logging tractors was tested in the winter 1969 on difficult snow conditions to gather information for planning of logging operations and for logging machinery design. The tractors tested were Clark Ranger 666, Timberjack C, Valmet Terra, Ford Brunett 5000, Fiskars 510, BM-Volvo SM 660, BM Volvo SM 661, Ford Country 6, MF-Robur I and BM-Boxer T-350.

According to the results, there is a preference of tracked vehicles in difficult snow conditions compared to wheeled tractors. Ford Country with long and bearing full-tracks proved to have the best mobility. On downhill grades it was found significant differences between three-quarter-track-tractors and skidders, although the performance on level ground and uphill grades was relatively similar. The tracked vehicles can easier move on the packed snow layer and reach a higher speed.

The driving speed does not increase significantly until the density of snow has entirely changed through getting wet. Wet top layer of snow affects positively on driving, because it increases packing of the snow. Increasing density of the snow improves especially the mobility of broad-tired wheeled tractors. To be able to predict the driving speed of a tractor in winter working conditions one must know the depth of the snow layer and the density of the snow and the grade of the slope. In addition, the passages on the same route and the packing of the snow must be regarded.

The PDF includes a summary in English.

• Silvennoinen, E-mail: us@mm.unknown
• Haarlaa, E-mail: rh@mm.unknown

The goal of this study was to develop a mathematical model for determination of the optimal winching distance in different conditions as based on harvesting costs. In the thinned forest the strip roads are parallel and the winching routes perpendicularly to them. A directed felling of trees is used so that it is easy to make loads to be winched. The stems can also be prepared to timber assortments on the stump area and gathered to loads for skidding alongside the winching routes.

After winching the timber is transported using a forwarder mowing on the strip roads. If the stems have not been bucked in the forests, they are to be prepared to timber assortments before the following transportation, because the problem of turning whole stems in a thinned forest has not yet been solved.

In the mathematical model the formation of the costs was described using 18 variables of which 15 had an effect on the optimum winching distance. Some empirical values were estimated concerning these variables, and the corresponding optimum winching distance were computed. The optimum was mainly determined by the quantity of timber harvested per unit area, the size of the winching load, the regression coefficient of the times which were depended on the winching distance.

According to the model, the deviation from optimum winching distance does not cause a very great change in the analysed total costs. When the winching distance is longer, the increase of the costs is smaller than if it is shorter than optimum. In general, the increase of the costs was so small that in practice one obviously can be satisfied with rather approximate methods in determining the suitable winching distance.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

The most effective work organization will be used as a goal in minimizing of logging costs. Some type of problem approach is usually utilized. The concept of the ideal system offers a possibility to get guidance in this difficult task. The idea of an ideal system is based on the fact that an ideal system, even imagined, can be utilized for any purpose. There are checklists in handbooks to accomplish the four existing steps: define of function, design ideal, develop optimum and deliver results.

In this paper two special cases are taken up to illustrate the concept itself, and it’s use in design of forestry work organizations. There were found no such reasons which could limit or even prevent the use of this method for forest technological purposes. That is why the author believes the method to give better results than any other customary approach.

The PDF includes a summary in English.

• Haarlaa, E-mail: rh@mm.unknown

The purpose of this study was to explain whether it is possible to affect, in practical working site conditions, by means of logging waste on the strip road, the depth of the track which is formed in terrain transportation and the injuries of the growing stand. Five 20 m long investigation areas with logging waste and five similar areas without logging waste were arranged on one strip road at Teisko logging site in Southern Finland. The logging waste layer was mainly Norway spruce and 10–15 cm thick. A KL–836 B forwarder was used. The type of soil was loam.

The logging waste affected the depth of the track only by decreasing the wear of humus layer. Even decreasing effect of logging waste on the injuries in the growing stand was minor. At Kitee working site in Eastern Finland strip roads were studied. The type of soil was thick, rather mouldered peat. The thickness of logging waste was 3–4 times greater than in Teisko, mainly spruce. A Volvo Nalle SM 460 forwarder was used. The effect of the logging waste on the depth of the tracks was clearly to be noticed. On basis of the appearance of the tracks one could assume that the difference was due to different wear of the humus, and not so much due to the quantity of logging waste that improves the carrying capacity of terrain.

In some extent logging waste was also found to affect the amount and quality of tree injuries. In practical working conditions, the importance might be small, since in the experiments an unrealistically great amount of logging waste was used.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

The purpose of this study was to answer questions concerning the basic information in planning of timber harvesting, how this information has to be handled, and how the planning of logging has to be combined with other forest management planning.

A deductive research method was used. By analysing a logging plan, prepared for a certain forest area, general conclusions were reached. To prepare the logging plan in connection with the forest management plan, the following information was found to be necessary: boundaries of the area, extent and ownership of the planned area, maps including information of the location of the timber and the conditions for transportation, road network and a reliable picture of the difficulty of the forest terrain.

Based on the material of the present timber harvesting methods it will be possible to predict the logging methods which will be applicable in the near future. The object to be planned has to be divided to operation areas. The amount of manpower and equipment needed can be estimated for each phase of the timber harvesting chain on the basis of the information calculated in this manner. Investments to machines and basic improvement works have to be planned before the effect of planning can be calculated in the logging costs, which are to be minimized. Due to the rapid development of the field, the handling of the material in connection with a forest management plan has to be left partly unfinished since the development of future logging methods cannot be reliably predicted.

The PDF includes a summary in English.

• Haarlaa, E-mail: rh@mm.unknown

In 1957 the annual cuttings in Finland were 40.2 million m³ without bark. The aim of the study was to estimate the rate of mechanization of harvesting of timber in Finland, and make a prediction of the state of mechanization by 1972. According to the study, harvesting and transportation of the felling volume in 1957 would have required about 25.5 million working hours. Mechanization of forest work has decreased it only by 0.32 million working hours. The profitability of forest work has improved in 1950s, which is mainly due to changes in harvesting, such as shifting to longer lengths of pulpwood and props and cutting unbarked timber.
The study predicts that in 1972 it will take 14.8 million working hours to harvest and 5.4 million working hours to transport a corresponding felling volume as in 1957. However, a new way of producing timber or a working method of wood may change the picture completely. Reduction in harvesting expenses through mechanization may lead to diminishing the minimum diameter of logs, which affects profitability of work. It is also probable that mechanization of wood transportation will lead to working sites with longer distances of forest transportation. Also, industry using wood as raw material will also obviously expand.

The article includes a summary in English.

• Putkisto, E-mail: kp@mm.unknown

Silva Fennica Issue 92 includes presentations held in 1956 in the 8th professional development courses, arranged for forest officers working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

Fellings of valuable timber in the forests to be surrendered for settlement farms have been discussed widely in Finland. This presentation describes the effects of the new section in the Land Settlement Decree and new directions given by Central Forestry Association Tapio based on the decree. According to the directions, the fellings have to follow legislation concerning other fellings in private forests. The felling of all large, valuable timber, as has previously been the custom in settlement farm forests, does not follow this principle.

• Piepponen, E-mail: pp@mm.unknown

The wages of logging and haulage has been dependent on the decisions of foremen. The aim of this study was to provide better insight on how working conditions in a logging site affect productivity of the work. Six working sites operated by Forest Service, Veitsiluoto Oy and Kemi Oy in the communes of Salla, Muonio and Kolari in Lapland were studied. The forests in the area were mostly Scots pine (Pinus sylvestris L.).

The effect of average volume of the stems, the average daily haulage over distances of various lengths, density of the stand and shape of the stem on effectivity was calculated. The size of the team was of considerable importance to the felling and haulage result in the Northern Finland where the feller assists in loading of the logs. One of the aims of the study was to find out what size of team is most advantageous for each haulage distance. The results show the optimum distance of haulage for teams of different sizes.

The article includes a summary in English.

• Maliniemi, E-mail: em@mm.unknown

Silva Fennica Issue 64 includes presentations held in 1947 in the third professional development courses, arranged for foresters working in the public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. Two of the presentations were published in other publications than Silva Fennica. 

This presentation describes budgeting of costs of delivery loggings, which have been at times underestimated in the practical forestry in the state forests.

• Anttila, E-mail: aa@mm.unknown

Silva Fennica Issue 64 includes presentations held in 1947 in the third professional development courses, arranged for foresters working in the public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. Two of the presentations were published in other publications than Silva Fennica.

This presentation outlines the history of timber sales at delivered price made in state forests, and describes good practices to arrange timber harvesting locally.

• Sopanen, E-mail: es@mm.unknown

The aim of this treatise is to describe forests owned by timber companies, their area and position, the quality of forests, the condition of the forests, and fellings carried out during the World War II.

Area of the company-owned forest was 1,95 million hectares, 1,64 million hectares of which was productive and 0,31 hectares inferior forest soil, not including the areas lost after the war. Most of the forests were situated in remote regions. Average volume of the tree stands was slightly larger than in farm-owned forests. Fellings counted for 84% of the growth of the forests.

During the war  the state set felling quotas for both company, private and state forests. It was widely discussed how well they were met by the different owner groups. According to the statistics, the companies had followed relatively closely their cutting plans in peace years. Cuttings were highest in 1939, when the war begun. In the war years 1940-43, lack of workforce, horses and cars for transport complicated logging. The fellings increased again during truce after Winter War. Especially demand for small timber increased during the war. Felling of firewood increased in all the owner groups, in particular in the private forests that were situated near settlements. in general fellings were higher in forests that were easiest to reach.

During the war the companies acquired timber more from their own forests. The fellings from company forests were in war years 70% of those in peace years. The article concludes that companies fulfilled the requirements as well as it was possible in the circumstances.

The article includes an abstract in English.

• Lihtonen, E-mail: vl@mm.unknown

Silva Fennica issue 52 includes presentations held in professional development courses, arranged for foresters working in public administration in 1938. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes nature turism and recreation in Finland, how timber harvesting and nature conservation affect tourism and ways to adjust fellings to tourism.

• Heikinheimo, E-mail: oh@mm.unknown

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level.

This presentation describes how to make a document required in Metsähallitus (Forest Service) when a stand is marked for harvesting.

• Sopanen, E-mail: es@mm.unknown

Seasonal variation in the sawmill industry of Finland was studied in an investigation based on questionnaires answered by a random sample of sawmills concerning the time period of 1958-1960. The method is described in detail in a separate article in Acta Forestalia Fennica issue 75 no. 1.

The seasonal variations in purchase of roundwood was largest in big sawmills, which purchase the main part of the timber as standing sales and buy most of the wood from the State Forest auctions at the end of September. Also, they can afford to reserve their material earlier than the smaller companies. The saw logs are mainly felled in the winter in Finland because the climatic conditions and availability of labour are best at that time. Small sawmills begin fellings a little earlier than the larger ones.

In long-transport of timber the proportion of floating decreased from 47% in 1958 to 38% in 1960. At the same time, proportion of truck transport increased from 48% to 55%. Small sawmills use almost exclusively land transport. They received almost three-fourths of their logs between January and May, because the sawing is concentrated in the first half of the year. Therefore, floating does not suit for their transport method. The larger the sawmill, the later is the seasonal peak of log deliveries. The output of the big sawmills is distributed more evenly thoughout the year. The smaller the sawmill, the quicker is the turnover of raw material and the smaller the sawlog inventories.

The seasonal variation in output is sharper at small sawmills where sawing is concentrated in the first half of the year. The seasonal peak of the early spring is due to the aim at getting the sawn wood to dry early enough for shipments in the summer. Air drying takes an average of 4 ½ months. Kiln drying is more common at the larger sawmills, and gives them more flexibility. Due to the large seasonal variation in operation, the capacity of the small mills is poorly utilized. Domestic sales of sawn wood levels up the seasonality of the deliveries. Export sales are concentrated at the end and turn of the year. Also, the seasonal peak of expenditure occurs in the winter, but that of income in the summer.

The PDF includes a summary in English.

• Ervasti, E-mail: se@mm.unknown

The analysis of costs is the foundation for the efficient management of logging activities. However, there is little research on cost accounting of logging. This article is an overview on harvesting of timber and its cost accounting, concentrating on joint costs. Costs have to be divided on their structural elements and then regrouped according to different accounting needs to be investigated. This investigation bases the structural cost analysis on running booking of costs. Due to the variability of logging, the costs are divided in detail into categories. The costs of logging are classified by their origin into personnel cost, material costs, costs of services, compensation for use, unrequited costs, risks, depreciation and interest. Further, the costs are classified according to the subject and quality of performance, and by location.

The PDF includes a summary in English.

• Einola, E-mail: je@mm.unknown

Forest transport of timber in Finland has been arranged as horse haulage during winter time using horses vacant from farm work. Tractors have now begun to replace horses in agriculture, which will lead to shortage of horses for timber harvesting in future. The aim of this investigation was to find a method of mechanized forest transport suitable for Finnish conditions. The method should be provided by an agricultural wheel tractor that is shared with agriculture. It should also be applicable to timber transport of relatively small forest holdings.

A method for time studies of tractor driven timber harvesting was developed. The competitivity of tractor transport of timber against the traditional method was studied in four pulpwood harvesting sites. The results suggest that if the tractor forest transport method in question is to be applied in practice, conditions should first be chosen which favour it most. A tractor forest transport method evolved on the basis of experiments presupposes certain conditions to be successful. These include snow for the construction of the packed-snow driveway, frost to harden the driveway, the location of strip roads in relatively easy topography, and of the main haulage road that is gently sloping in the haulage-loaded direction. The optimal transport distance for this method are about 3-10 km.

The PDF includes a summary in English.

• Putkisto, E-mail: kp@mm.unknown

The article is a review on the costs of raw materials in the Finnish sawmill industry in 1920s based on statistics collected from the members of the Central Association of the Finnish Woodworking Industries (now Finnish Forest Industries). The article includes statistics about the average size of if the saw timber bought in standing sales from private forests and harvested from the industry’s own forests, stumpage price of the timber, and labour costs of the harvesting of the wood. The average size of the logs was greater in the northern part of Finland, where the sawmills could limit the purchases of smaller timber. In the southern part of the country, the size of the timber decreased in 1922‒1926 due to growing demand of the timber. The long transport distances in the north influenced the costs. The number of logs per tree increased during the period. The level of stumpage price varied considerably in different parts of the country, falling from the south-west to the east and north. Competition of raw material increased the stumpage prices in 1922a and 1926‒27. The international economic downturn influenced the industry in 1929‒1931.

The PDF includes a summary in German.

• Saari, E-mail: es@mm.unknown

The timber companies began acquiring forest land in 1890s which raised concerns about decrease of the number of private farms and agricultural land, as had happened in Sweden earlier. This was not considered to be a major problem in Finland, but the sale of homesteads on former state lands for sawmill companies was considered to be against their objective. One reason for the sale of farms was the farmers’ poor conception of the value of the land. In 1915 three decrees that restricted the right of companies that use timber to buy land were approved. The article discusses in detail the arguments that led to the legislation and compares it to the situation in Sweden.

A survey was commissioned to study the of landholdings of the companies, and to compare it with farming in private and company owned farms. The article includes a study about individual farms in the municipalities of Multia, Heinävesi, Sulkava, Ruokolahti and Luumäki, and about land use in the areas.

The PDF includes a summary in German.

• Renvall, E-mail: ar@mm.unknown
• Boman, E-mail: ab@mm.unknown

Two methods of pre-harvest inventory were designed and tested on three cutting sites containing a total of 197,500 m³ of wood. These sites were located on flat-ground boreal forest in north-western Quebec, Canada. Both methods studied involved scaling of trees harvested to clear the road path one year (or more) prior to harvest of adjacent cutblocks.

The first method (ROAD) considers the total road right-of-way volume divided by the total road area cleared. The resulting volume per hectare is then multiplied by the total cut-block area scheduled for harvest during the following year to obtain the total estimated cutting volume. The second method (STRATIFIED) also involves scaling of trees cleared from the road. A volume per hectare is calculated for each stretch of road that crosses a single forest stand. This volume per hectare is then multiplied by the remaining area of the same forest stand scheduled for harvest one year later. The sum of all resulting estimated volumes per stand gives the total estimated cutting-volume for all cut-blocks adjacent to the studied road. A third method (MNR) represent the actual existing technique for estimating cutting volume in the province of Quebec. It involves summing the cut volume for all forest stands. The cut volume is estimated by multiplying the area of each stand by its estimated volume per hectare obtained from standard stock tables.

When the resulting total estimated volume per cut-block for all three methods was compared with the actual measured cut-block volume (MEASURED), the analysis showed that MNR volume estimate was 30% higher than MEASURED. However, no significant difference from MEASURED was observed for volume estimates for ROAD and STRATIFIED methods, which respectively estimated cutting volumes 19% and 5% lower than MEASURED.

• Morasse, E-mail: jm@mm.unknown

Microcatchment water harvesting (MCWH) improved the survival and growth of planted trees on heavy soils in eastern Kenya five to six years after planting. In the best method, the cross-tied furrow microcatchment, the mean annual increment (MAI; based on the average biomass of living trees multiplied by tree density and survival) of the total and usable biomass of Prosopis juliflora (Sw.) DC. were 2,787 and 1,610 kg ha^-1 a^-1 respectively, when the initial tree density was 500 to 1,667 trees per hectare. Based on survival, the indigenous Acacia horrida Span., A. mellifera (Vahl) Benth. and A. zanzibarica (S. Moore) Taub. were the most suitable species for planting using MCWH. When both survival and the yield were considered, a local seed source of P. Juliflora was superior to all other species. The MAI in MCWH was at best distinctly higher than that in the natural vegetation (163–307 and 66–111 kg ha^-1 a^-1 for total and usable biomass respectively); this cannot satisfy the fuelwood demand of concentrated populations, such as towns or irrigation schemes.

The density of seeds of woody species in the topsoil was 40.1 seeds/m² in the Acacia-Commiphora bushland and 12.6 seeds/m² in the zone between the bushland and the Tana riverine forest. Rehabilitation of woody vegetation using the soil seed bank alone proved difficult due to the lack of seeds of desirable species.

The regeneration and dynamics of woody vegetation were also studied both in cleared and undisturbed bushland. A sub-type of Acacia-Commiphora bushland was identified as Acacia reficiens bushland, in which the dominant Commiphora species is C. campestris. Most of the woody species did not have even-aged population but cohort structures that were skewed towards young individuals. The woody vegetation and the status of soil nutrients were estimated to recover in 15–20 years on Vertic Natrargid soils after total removal of above-ground vegetation.

• Kaarakka, E-mail: vk@mm.unknown

Linear optimization model was used to calculate seven wood procurement scenarios for years 1990, 2000 and 2010. Productivity and cost functions for seven cutting, five terrain transport, three long distance transport and various work supervision and scaling methods were calculated from available work study reports. All methods are based on Nordic cut to length conditions. Finland was divided in three parts for description on harvesting conditions. Twenty imaginary wood processing points and their wood procurement areas were created for these areas. The procurement systems, which consists of the harvesting conditions and work productivity function, were described as a simulation model. In the LP-model the wood procurement system has to fulfil the volume and wood assortment requirements of processing points by minimizing the procurement cost. The model consists of 862 variables and 560 restrictions.

Results show that it is economical to increase the mechanical work in harvesting. Cost increment alternatives effect only little on profitability of manual work. The areas of later thinnings and seed tree- and shelterwood cuttings increase on cost of first thinnings. In mechanized work one method, 10-tonne one grip harvester and forwarder, is gaining advantage among other methods. Working hours of forwarder are decreasing opposite to the harverster. There is only little need to increase the number of harvesters and trucks or their drivers from today’s level. Quite large fluctuations in level of procurement and cost can be handled by constant number of machines, by alternating the number of season workers and by driving machines in two shifts. It is possible, if some environmental problems of large-scale summer time harvesting can be solved.

• Rummukainen, E-mail: ar@mm.unknown
• Alanne, E-mail: ha@mm.unknown
• Mikkonen, E-mail: em@mm.unknown

The paper is the final report of the Inter-Nordic Terrain-machine Project (1972–1975). It deals with the requirements for a terrain classification for forestry, its factors and classes, and presents a terrain classification.

The mechanization of hauling, which took place in the field of forestry in the 1950's, added to the need for a terrain classification. Different terrain classifications based on different terrain factors have been developed in many countries. In the meeting of IUFRO Section 32 held in Montreal in 1964, it was found that a general system was needed for measuring and describing those terrain conditions having a significant influence on forest operations. The requirements for such a classification system are given in the paper. Because some of the requirements are contradictory, the classification must be a compromise. The most important factors from the forestry point of view are presented in the article.

The terrain classification presented in this report consists of two stages. The first stage is a primary terrain classification, in which terrain factors are measured or described objectively. The second is a secondary descriptive classification. Only factors essential to the activity in question are taken into account. After this, in a secondary functional stage, the requirements of the employer of the system, e.g., working method, machines etc., are also taken into account.

The PDF includes a summary in Finnish.

• Eriksson, E-mail: te@mm.unknown
• Nilsson, E-mail: gn@mm.unknown
• Skråmo, E-mail: gs@mm.unknown

The study material was collected from 10 localities in South Finland in 1971–72. The material comprised 816 damaged Norway spruce (Picea abies (L.) H. Karst.) trees with a total of 978 injuries.

Decay (discoloration) spread upward from the damaged point was about three times as fast as downward. The mean rate of advance upward was 21 cm/year. The decay spreading at the quickest rate started from above-ground root collar injuries. The size of the damaged area (surface area, width and depth) correlated positively with the rate of increase in decay initiated by the injury. For the first 10 years the decay advanced at the same rate after which the advance became slower though not ceasing. Damage produced in the early summer caused a faster spread of decay than that produced in the late summer or winter. The rate of advance was the greater the larger the stem involved. When decay started from trunk damage its rate of advance was greater the faster the growth of the trees. With a better soil type, the rate of advance in decay increased. Fertilization increased the rate of advance.

The widest stem injuries reduced tree growth by about one-third, and severed roots by nearly half of the growth of trees where the width of the injuries was 0–4 cm. Fomes annosus (Heterobasidion annosum) infected spruce injuries especially in the southern coastal district. The farthest tips of discoloration proved in most cases to be sterile. The most common fungus isolated from these sites was Stereum sanguinolentum.

The PDF includes a summary in Finnish.

• Isomäki, E-mail: ai@mm.unknown
• Kallio, E-mail: tk@mm.unknown

• Wutzler, Max Planck Institute for Biogeochemistry, Jena, Germany E-mail: tm@nn.de
• Mund, Max Planck Institute for Biogeochemistry, Jena, Germany E-mail: mm@nn.de

• Kallio, Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, P.O.Box 5003, NO-1432 Ås, Norway https://orcid.org/0000-0002-5393-761X E-mail: maarit.kallio@nmbu.no
• Strîmbu, Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, P.O.Box 5003, NO-1432 Ås, Norway https://orcid.org/0000-0002-0588-2036 E-mail: victor.strimbu@nmbu.no
• Gobakken, Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, P.O.Box 5003, NO-1432 Ås, Norway E-mail: helle.ross.gobakken@nmbu.no
• Gobakken, Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, P.O.Box 5003, NO-1432 Ås, Norway https://orcid.org/0000-0001-5534-049X E-mail: terje.gobakken@nmbu.no

The EU’s influence on national forest policies is growing, and the implementation of forest-related policies proposed by the Commission will affect the practice of forestry in Europe. For instance, the Nature Restoration Law sets concrete areal goals for restoring forest ecosystems and for conservation, the Deforestation Regulation requires meticulous tracking of wood’s origin, and the renewed Renewable Energy Directive (RED III) sets new criteria to sustainable forest biomass procurement. So far there have been no studies that have looked into the impacts from the economic and operational point of view. In this study, structural systems analysis was first performed to discover the relevant variables (and their functioning) associated with the roundwood harvesting operations and the operating environment. A scenario approach was then applied to capture the potential levels of implementation of the EU’s forest-related policies. Finally, using different scenarios (low-, moderate- and high-impact) and a systems analysis framework, the impact of alternative levels of implementation was quantified in terms of harvesting costs, measured in € m^–3. The results indicate that with the low- and moderate-impact scenarios the harvesting costs would increase by less than 10% from the current levels in three different regions in Finland. Such an increase (less than 10%) could be tolerated over a period of a few years, but a sudden increase is likely to lead to challenges to the running of businesses. With the high-impact scenario the harvesting costs would increase by between 15% and 18%, depending on the region. This magnitude of increase (of approximately a sixth) corresponds to a severe change in the roundwood harvesting operations and operating environment.

• Ahtikoski, Natural Resources Institute Finland (Luke), Tekniikankatu 1, FI-33720 Tampere, Finland https://orcid.org/0000-0003-1658-3813 E-mail: anssi.ahtikoski@luke.fi
• Väätäinen, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0002-6886-0432 E-mail: kari.vaatainen@luke.fi
• Anttila, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland https://orcid.org/0000-0002-6131-392X E-mail: perttu.anttila@luke.fi
• Laitila, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland E-mail: juha.laitila@luke.fi
• Mutanen, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0003-0533-9356 E-mail: antti.mutanen@luke.fi
• Lindblad, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland https://orcid.org/0009-0003-6766-6587 E-mail: jari.lindblad@luke.fi
• Sikanen, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland E-mail: lauri.sikanen@luke.fi
• Routa, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0001-7225-1798 E-mail: johanna.routa@luke.fi

Uneven-aged forests set certain challenges for cut-to-length harvesting work. It is a challenge to cost-effectively remove larger trees while leaving a healthy understory for regrowth. The study’s aim was to evaluate productivity and costs of harvesting two-storied Silver birch (Betula pendula Roth) and Norway spruce (Picea abies (L.) H. Karst.) stands by creating time consumption models for cutting, and using existing models for forwarding. Damage to the remaining understory spruce was also examined. Four different harvesting methods were used: 1) all dominant birches were cut; 2) half of them thinned and understory was preserved; compared to 3) normal thinning of birch stand without understory; and 4) clear cutting of two-storied stand. Results showed the time needed for birch cutting was 26–30% lower when the understory was not preserved. Pulpwood harvesting of small sized spruces that prevent birch cutting was expensive, especially because of forwarding of small amounts with low timber density on the strip roads. Generally, when taking the cutting and forwarding into account, the unit cost at clear cuttings was lowest, due to lesser limitations on work. It was noted that with increasing removal from 100 to 300 m³ ha^–1, the relative share of initial undamaged spruces after the harvest decreased from 65 to 50% when the aim was to preserve them.  During summertime harvesting, the amount of stem damage was bigger than during winter. In conclusion, two-storied stands are possible to transit to spruce stands by accepting some losses in harvesting productivity and damages on remaining trees.

• Niemistö, Natural Resources Institute Finland (Luke), Natural resources, Kampusranta 9 C, FI-60320 Seinäjoki, Finland https://orcid.org/0000-0002-9152-2108 E-mail: ext.pentti.niemisto@luke.fi
• Korpunen, Norsk institutt for bioøkonomi (NIBIO), Division of Forest and Forest Resources, Department of Forest operations and digitalization, Divisjon for skog og utmark, Avdeling for Driftsteknikk og digitalisering, Høgskoleveien 8, 1433 Ås, Norway https://orcid.org/0000-0001-9749-5684 E-mail: heikki.korpunen@nibio.no
• Nuutinen, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6 B, FI-80100 Joensuu, Finland https://orcid.org/0000-0003-3360-4444 E-mail: yrjo.nuutinen@luke.fi

• Noordermeer, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway https://orcid.org/0000-0002-8840-0345 E-mail: lennart.noordermeer@nmbu.no
• Ørka, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway https://orcid.org/0000-0002-7492-8608 E-mail: hans-ole.orka@nmbu.no
• Gobakken, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway E-mail: terje.gobakken@nmbu.no

Forest buffers beside surface water can mitigate negative effects of logging. To gain more information on buffer implementation in operational forestry, forest buffers were inventoried during 2018 on 174 harvested and site-prepared compartments traversed by or bordering streams, ditches and lakes in three regions across Sweden 2–4 years after clearcutting. Most of the inventoried stream and ditch reaches were ≤5 m wide. The water reaches were categorized as lakes (n = 16), natural streams (n = 50), modified streams (n = 21) or ditches (n = 87). Forest buffers with 100% shoreline coverage were present along all lake reaches and 55% and 10% of the natural or modified stream and ditch reaches, respectively. Buffers were absent beside 14% of the natural or modified stream reaches and 61% of the ditch reaches. Lake reaches had significantly wider buffers on average than ditch reaches and natural or modified stream reaches. The mean (SE) buffer widths beside lakes, natural or modified stream reaches and ditch reaches across all three regions and shoreline coverage classes were 12 (1.1), 6.6 (0.6) and 1.5 (0.5) m, respectively. The character of the local stream networks (natural or modified streams or ditches) containing each inventoried reach, were assessed using map information and the reaches´ field classifications. This illustrated the difficulty of judging a streams´ character based solely on field inspections of individual reaches on forest land where historic drainage activities have been performed. We recommend that also upstream and downstream conditions should be considered when planning environmental measures to protect surface water bodies.

• Ring, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden https://orcid.org/0000-0002-8962-9811 E-mail: eva.ring@skogforsk.se
• Johansson, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden E-mail: fredrik.johansson@skogforsk.se
• von Brömssen, Department of energy and technology, Division of applied statistics and mathematics, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden https://orcid.org/0000-0002-1452-8696 E-mail: Claudia.von.Bromssen@slu.se
• Bergkvist, Mellanskog, Uppsala Science Park, Box 127, 751 04 Uppsala, Sweden E-mail: isabelle.bergkvist@mellanskog.se

Newly developed positioning systems in cut-to-length harvesters enable georeferencing of individual trees with submeter accuracy. Together with detailed tree measurements recorded during processing of the tree, georeferenced harvester data are emerging as a valuable tool for forest inventory. Previous studies have shown that harvester data can be linked to airborne laser scanner (ALS) data to estimate a range of forest attributes. However, there is little empirical evidence of the benefits of improved positioning accuracy of harvester data. The two objectives of this study were to (1) assess the accuracy of timber volume estimation using harvester data and ALS data acquired with different scanners over multiple years and (2) assess how harvester positioning errors affect merchantable timber volume predicted and estimated from ALS data. We used harvester data from 33 commercial logging operations, comprising 93 731 harvested stems georeferenced with sub-meter accuracy, as plot-level training data in an enhanced area-based inventory approach. By randomly altering the tree positions in Monte Carlo simulations, we assessed how prediction and estimation errors were influenced by different combinations of simulated positioning errors and grid cell sizes. We simulated positioning errors of 1, 2, …, 15 m and used grid cells of 100, 200, 300 and 400 m². Values of root mean square errors obtained for cell-level predictions of timber volume differed significantly for the different grid cell sizes. The use of larger grid cells resulted in a greater accuracy of timber volume predictions, which were also less affected by positioning errors. Accuracies of timber volume estimates at logging operation level decreased significantly with increasing levels of positioning error. The results highlight the benefit of accurate positioning of harvester data in forest inventory applications. Further, the results indicate that when estimating timber volume from ALS data and inaccurately positioned harvester data, larger grid cells are beneficial.

• Noordermeer, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, Norway E-mail: lennart.noordermeer@nmbu.no
• Næsset, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, Norway E-mail: erik.naesset@nmbu.no
• Gobakken, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, Norway E-mail: terje.gobakken@nmbu.no

The size of Finnish wood harvesting enterprises has grown, and entrepreneurs have become responsible for various additional tasks, resulting in networking with other harvesting enterprises of various sizes and suppliers of supporting services, but the profitability of the wood harvesting sector has remained low. In the present study, the financial performance of 83 wood harvesting companies in Eastern and Northern Finland was evaluated, based on public final account data from a five-year period between 2013 and 2017. The factors underlying economic success were identified based on 19 semi-structured entrepreneur interviews. The Business Model Canvas framework was applied in the analyses. In particular, the smallest companies (with an annual turnover of less than 600 000 €) struggled with profitability. They showed increasing indebtedness, suffered from poor power in negotiations, had typically short-term contracts, and faced difficulties in retaining skilled operators. Most of the small companies were subcontractors of larger wood-harvesting companies. The better economic success of larger companies was likely based on their capacity to provide wood harvesting services in large volumes and supply versatile services, power in negotiations, and more cost-effective operations. The future development of wood harvesting seems to be polarised: larger enterprises are likely to continue growing, while the size of smaller enterprises has stabilised. Enhancing business management skills and practices is required in enterprises of all size groups.

• Jylhä, Natural Resources Institute Finland (Luke), Production systems, Teknologiakatu 7, FI-67100 Kokkola, Finland E-mail: paula.jylha@luke.fi
• Rikkonen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Lönnrotinkatu 7, FI-50100 Mikkeli, Finland E-mail: pasi.rikkonen@luke.fi
• Hamunen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Yliopistokatu 6B, FI-80100 Joensuu, Finland E-mail: katri.hamunen@luke.fi

Considering the increasing use of wood biomass for energy and the related intensification of forest management, the impacts of different intensities of biomass harvesting on nutrient leaching risks must be better understood. Different nitrogen forms in the soil solution were monitored for 3 to 6 years after harvesting in hemiboreal forests in Latvia to evaluate the impacts of different biomass harvesting regimes on local nitrogen leaching risks, which potentially increase eutrophication in surface waters. In forestland dominated by Scots pine Pinus sylvestris L. or Norway spruce Picea abies L. (Karst.), the soil solution was sampled in: (i) stem-only harvesting (SOH), (ii) whole‐tree harvesting, with only slash removed (WTH), and (iii) whole‐tree harvesting, with both slash and stumps harvested (WTH + SB), subplots. In agricultural land, sampling was performed in an initially fertilised hybrid aspen (Populus tremula L.× P. tremuloides Michx.) short-rotation coppice (SRC), where above-ground biomass was harvested. In forestland, soil solution N (nitrogen) concentrations were highest in the second and third year after harvesting. Mean annual values in WTH subplots of medium to high fertility sites exceeded the mean values in SOH subplots and control subplots (mature stand where no harvesting was performed) for the entire study period; the opposite trend was observed for the low-fertility site. Biomass harvesting in the hybrid aspen SRC only slightly affected NO₃^–-N (nitrate nitrogen) and NH₄⁺-N (ammonium nitrogen) concentrations in the soil solution within 3 years after harvesting, but a significant decrease in the TN (total nitrogen) concentration in the soil solution was found in plots with additional N fertilisation performed once initially.

• Kļaviņš, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia; University of Latvia, Raiņa blvd 19-125, LV 1586, Riga, Latvia E-mail: ivars.klavins@silava.lv
• Bārdule, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia; University of Latvia, Raiņa blvd 19-125, LV 1586, Riga, Latvia E-mail: arta.bardule@silava.lv
• Lībiete, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia E-mail: zane.libiete@silava.lv
• Lazdiņa, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia E-mail: dagnija.lazdina@silava.lv
• Lazdiņš, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia E-mail: andis.lazdins@silava.lv

The effect of harvester operator tree selection or prior tree marking in thinning operations on satisfactory results and performance has been widely discussed. In harvester operator tree selection, the machine operator decides on the fly which trees are selected to remain or cut. The objective of the study was to analyze the effect of prior tree marking, thinning method and topping diameter on harvester performance in low-diameter thinning operations. The entire thinning operation was captured using video technology. Overall, 2.36 ha divided into 48 plots with 5202 trees were thinned with an average diameter at breast height (dbh) over bark for all plots of between 12.5 and 14.7 cm. In total, 3122 trees were harvested, resulting in 60% removal of stem number over all plots. The harvester achieved a mean productivity of 7.38 m³ PMH₀^–1 with 1.48 m³ PMH₀^–1 SEM, with stem volume having the major influence on harvesting productivity. Prior tree marking, topping and thinning method did not significantly affect productivity. Without prior tree marking by the foresters, harvesting removal was shifted toward lower diameters. Within the unmarked plots, 7.0% of the residual trees were damaged compared with 3.2% in marked plots.

• Holzleitner, University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan-Straße 82/3, A-1190 Vienna, Austria https://orcid.org/0000-0001-8489-3050 E-mail: franz.holzleitner@boku.ac.at
• Langmaier, University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Silviculture, Peter-Jordan-Straße 82/3, A-1190 Vienna, Austria; Austrian Research Centre for Forests, Department of Forest Growth and Silviculture, Seckendorff Gudent Weg 8, A-1130 Vienna, Austria E-mail: magdalena.langmaier@bfw.gv.at
• Hochbichler, University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Silviculture, Peter-Jordan-Straße 82/3, A-1190 Vienna, Austria E-mail: eduard.hochbichler@boku.ac.at
• Obermayer, University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan-Straße 82/3, A-1190 Vienna, Austria; Agricultural Technical School of Pyhra, Kyrnbergstraße 4, A-3143 Pyhra, Austria E-mail: bernhardt.obermayer@lfs-pyhra.ac.at
• Stampfer, University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan-Straße 82/3, A-1190 Vienna, Austria http://orcid.org/0000-0001-9350-2859 E-mail: karl.stampfer@boku.ac.at
• Kanzian, University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan-Straße 82/3, A-1190 Vienna, Austria http://orcid.org/0000-0002-1198-9788 E-mail: christian.kanzian@boku.ac.at

Accurately positioned single-tree data obtained from a cut-to-length harvester were used as training harvester plot data for k-nearest neighbor (k-nn) stem diameter distribution modelling applying airborne laser scanning (ALS) information as predictor variables. Part of the same harvester data were also used for stand-level validation where the validation units were stands including all the harvester plots on a systematic grid located within each individual stand. In the validation all harvester plots within a stand and also the neighboring stands located closer than 200 m were excluded from the training data when predicting for plots of a particular stand. We further compared different training harvester plot sizes, namely 200 m², 400 m², 900 m² and 1600 m². Due to this setup the number of considered stands and the areas within the stands varied between the different harvester plot sizes. Our data were from final fellings in Akershus County in Norway and consisted of altogether 47 stands dominated by Norway spruce. We also had ALS data from the area. We concentrated on estimating characteristics of Norway spruce but due to the k-nn approach, species-wise estimates and stand totals as a sum over species were considered as well. The results showed that in the most accurate cases stand-level merchantable total volume could be estimated with RMSE values smaller than 9% of the mean. This value can be considered as highly accurate. Also the fit of the stem diameter distribution assessed by a variant of Reynold’s error index showed values smaller than 0.2 which are superior to those found in the previous studies. The differences between harvester plot sizes were generally small, showing most accurate results for the training harvester plot sizes 200 m² and 400 m².

• Maltamo, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu E-mail: matti.maltamo@uef.fi
• Hauglin, Norwegian Institute of Bioeconomy Research, Division of Forest and Forest Resources, P.O. Box 115, 1431 Ås, Norway E-mail: marius.hauglin@nibio.no
• Naesset, Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, P.O. Box 5003, 1432 Ås, Norway E-mail: erik.naesset@nmbu.no
• Gobakken, Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, P.O. Box 5003, 1432 Ås, Norway E-mail: terje.gobakken@nmbu.no

Factors affecting soil disturbance caused by harvester and forwarder were studied on mid-grained soils in Finland. Sample plots were harvested using a one-grip harvester. The harvester operator processed the trees outside the strip roads, and the remaining residues were removed to exclude the covering effect of residues. Thereafter, a loaded forwarder made up to 5 passes over the sample plots. The average rut depth after four machine passes was positively correlated to the volumetric water content at a depth of 0–10 cm in mineral soil, as well as the thickness of the organic layer and the harvester rut depth, and negatively correlated with penetration resistance at depths of both 0–20 cm and 5–40 cm. We present 5 models to predict forwarder rut depth. Four include the cumulative mass driven over a measurement point and combinations of penetration resistance, water content and the depth of organic layer. The fifth model includes harvester rut depth and the cumulative overpassed mass and provided the best fit. Changes in the penetration resistance (PR) were highest at depths of 20–40 cm. Increase in BD and VWC decreased PR, which increased with total overdriven mass. After four to five machine passes PR values started to stabilize.

• Sirén, Natural Resources Institute Finland (Luke) c/o Aalto University, P.O. Box 15600, FI-00076 Aalto, Finland E-mail: matti.siren@luke.fi
• Ala-Ilomäki, Natural Resources Institute Finland (Luke) c/o Aalto University, P.O. Box 15600, FI-00076 Aalto, Finland http://orcid.org/0000-0002-6671-7624 E-mail: jari.ala-ilomaki@luke.fi
• Lindeman, Natural Resources Institute Finland (Luke), Korkeakoulunkatu 7, FI-33720 Tampere, Finland E-mail: harri.lindeman@luke.fi
• Uusitalo, Natural Resources Institute Finland (Luke), Korkeakoulunkatu 7, FI-33720 Tampere, Finland http://orcid.org/0000-0003-3793-1215 E-mail: jori.uusitalo@luke.fi
• Kiilo, Versowood, Teollisuuskatu 1, FI-11130 Riihimäki, Finland E-mail: kalle.kiilo@versowood.fi
• Salmivaara, Natural Resources Institute Finland (Luke), P.O. Box 2, FI-00791 Helsinki, Finland E-mail: aura.salmivaara@luke.fi
• Ryynänen, Natural Resources Institute Finland (Luke), Kaironiementie 15, FI-39700 Parkano, Finland E-mail: ari.ryynanen@luke.fi

Tree bucking, defined as the process in which a stem is segmented into shorter logs of varying lengths, has a significant effect on the value adding potential of a forest enterprise. Because of its importance in terms of correct product and length combinations, improper bucking can lead to financial losses. In this study, two treatments (OFF: quality bucking performed by the operator while using hot keys and ON: automatic bucking using the optimized suggestions from the harvester on-board computer; OBC) were tested in a Norway spruce (Picea abies [L.] Karst.) dominated stand located in Germany. Both treatments had the aim to maximize the value of a stem. The research took place in an 80-year old spruce and beech stand under a regenerative cutting. Fully-mechanized harvesting was performed with an 8-wheel Ponsse Bear single-grip harvester equipped with a H8 harvesting head. Results indicated that the product recovery of the two treatments differed by 4% in undamaged trees (no broken tree-tops or stems) to the benefit of manual bucking. However, the revenue of trees subjected to optimized bucking were up to 4% higher (in average 3%) than those of the manual bucking once expressed on a per cubic meter basis. Moreover, the harvesting productivity of the ON treatment was at the maximum 17% higher compared to the OFF treatment. Based on the results from this case study, the use of an optimization software in Norway spruce dominated stands with the aim to maximize the value of single stems showed promising results.

• Labelle, Assistant Professorship of Forest Operations, Department of Ecology and Ecosystem Management, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, D-85354 Freising, Germany E-mail: eric.labelle@tum.de
• Huß, Assistant Professorship of Forest Operations, Department of Ecology and Ecosystem Management, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, D-85354 Freising, Germany E-mail: linus.huss@gmx.de

Harvesting residues collected from the final cuttings of boreal forests are an important source of solid biofuel for energy production in Finland and Sweden. In the Finnish supply chain, the measurement of residues is performed by scales integrated in forwarders. The mass of residues is converted to volume by conversion factors. In this study, weather based models for defining the moisture content of residues were developed and validated. Models were also compared with the currently used fixed tables of conversion factors. The change of the moisture content of residues is complex, and an exact estimation was challenging. However, the model predicting moisture change for three hour periods was found to be the most accurate. The main improvement compared to fixed tables was the lack of a systematic error. It can be assumed that weather based models will give more reliable estimates for the moisture in varying climate conditions and the further development of models should be focused on obtaining more appropriate data from varying drying conditions in different geographical and microclimatological locations.

• Lindblad, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: jari.lindblad@luke.fi
• Routa, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: johanna.routa@luke.fi
• Ruotsalainen, Finnish Meteorological Institute, Aviation and Military Weather Services, P.O. Box 1627, FI-70211 Kuopio, Finland E-mail: johanna.ruotsalainen@fmi.fi
• Kolström, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: marja.kolstrom@uef.fi
• Isokangas, University of Oulu, Control Engineering, P.O. Box 8000, FI-90014 University of Oulu, Finland E-mail: ari.isokangas@oulu.fi
• Sikanen, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: lauri.sikanen@luke.fi

The purpose of this research is to establish time consumption and productivity when using Husqvarna 365 chainsaw for resinous tree felling in mountainous regions. The research was conducted in the Romanian Southern Carpathians, in two mixed spruce (Picea abies (L.) H. Karst.) and fir (Abies alba Mill.) tree stands (S1 and S2). Only one team of workers, made up of a feller and an assistant, was used in the felling operation. This was divided into nine specific stages for which work times were measured. Work time structure used here includes WP – workplace time (PW – productive work time; SW – supportive work time, NT – non-work time) and NW – non-workplace time. The results indicated a productivity of 10.138 m³ h^–1 (4.55 tree h^–1) in S1 and of 11.374 m³ h^–1 (4.33 tree h^–1) in S2. Work time structure was WP 88.61% (PW 19.59%; SW 33.88%; NT 35.14%) and NW 11.39% in S1 and WP 83.77% (PW 17.66%; SW 30.73%; NT 35.38%) and NW 16.23% in S2. The results obtained showed that the power function best describes the relationship between productivity expressed by tree h^–1 and breast height diameter (dbh) (R2 = 0.89 in S1 and R2 = 0.94 in S2). When productivity is expressed by m³ h^–1 the results obtained in the case of power, exponential and linear functions are comparable (R2 = 0.65 to 0.67 in S1 and R2 = 0.81 to 0.92 in S2). Productivity is also influenced by stump diameter and the distance between trees. Their influence on productivity was emphasized by linear regression equations.

• Campu, Transilvania University of Braşov, Faculty of Silviculture and Forest Engineering, Department of Forest Engineering, Forest Management Planning and Terrestrial Measurements, Şirul Beethoven no. 1, 500123, Braşov, Romania E-mail: vasile.campu@unitbv.ro
• Ciubotaru, Transilvania University of Braşov, Faculty of Silviculture and Forest Engineering, Department of Forest Engineering, Forest Management Planning and Terrestrial Measurements, Şirul Beethoven no. 1, 500123, Braşov, Romania E-mail: ciuboarc@unitbv.ro

Heuristic techniques have been increasingly used to address the complex forest planning problems over the last few decades. However, heuristics only can provide acceptable solutions to difficult problems, rather than guarantee that the optimal solution will be located. The strategies of neighborhood, hybrid and reversion search processes have been proved to be effective in improving the quality of heuristic results, as suggested recently in the literature. The overall aims of this paper were therefore to systematically evaluate the performances of these enhanced techniques when implemented with a simulated annealing algorithm. Five enhanced techniques were developed using different strategies for generating candidate solutions. These were then compared to the conventional search strategy that employed 1-opt moves (Strategy 1) alone. The five search strategies are classified into three categories: i) neighborhood search techniques that only used the change version of 2-opt moves (Strategy 2); ii) self-hybrid search techniques that oscillate between 1-opt moves and the change version of 2-opt moves (Strategy 3), or the exchange version of 2-opt moves (Strategy 4); iii) reversion search techniques that utilize 1-opt moves and the change version of 2-opt moves (Strategy 5) or the exchange version of 2-opt moves (Strategy 6). We found that the performances of all the enhanced search techniques of simulated annealing were systematic and often clear better than conventional search strategy, however the required computational time was significantly increased. For a minimization planning problem, Strategy 6 produced the lowest mean objective function values, which were less than 1% of the means developed using conventional search strategy. Although Strategy 6 performed very well, the other search strategies should not be neglected because they also have the potential to produce high-quality solutions.

• Dong, Department of Forest Management, College of Forestry, Northeast Forestry University, Harbin 150040, China E-mail: farrell0503@126.com
• Bettinger, Warnell School of Forestry and Natural Resources, University of Georgia, Athens 30602, GA, USA E-mail: pbettinger@warnell.uga.edu
• Liu, Department of Forest Management, College of Forestry, Northeast Forestry University, Harbin 150040, China E-mail: lzg19700602@163.com
• Qin, Department of Forestry Economic, College of Economic & Management, Northeast Forestry University, Harbin 150040, China E-mail: huiyanqin@hotmail.com
• Zhao, Department of Forest Management, College of Forestry, Northeast Forestry University, Harbin 150040, China E-mail: zyinghui0925@126.com

Recent developments in on-board technology have enabled automatic collection of follow-up data on forwarder work. The objective of this study was to exploit this possibility to obtain highly representative information on time consumption of specific work elements (including overlapping crane work and driving), with one load as unit of observation, for large forwarders in final felling operations. The data used were collected by the John Deere TimberLink system as nine operators forwarded 8868 loads, in total, at sites in mid-Sweden. Load-sizes were not available. For the average and median extraction distances (219 and 174 m, respectively), Loading, Unloading, Driving empty, Driving loaded and Other time effective work (PM) accounted for ca. 45, 19, 8.5, 7.5 and 14% of total forwarding time consumption, respectively. The average and median total time consumptions were 45.8 and 42.1 minutes/load, respectively. The developed models explained large proportions of the variation of time consumption for the work elements Driving empty and Driving loaded, but minor proportions for the work elements Loading and Unloading. Based on the means, the crane was used during 74.8% of Loading PM time, the driving speed was nonzero during 31.9% of the Loading PM time, and Simultaneous crane work and driving occurred during 6.7% of the Loading PM time. Time consumption per load was more strongly associated with Loading drive distance than with extraction distance, indicating that the relevance of extraction distance as a main indicator of forwarding productivity should be re-considered.

• Manner, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: jussi.manner@skogforsk.se
• Palmroth, John Deere Forestry, P.O. Box 472, FI-33101 Tampere, Finland E-mail: PalmrothLauri@JohnDeere.com
• Nordfjell, Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, SE-901 83 Umeå, Sweden E-mail: tomas.nordfjell@slu.se
• Lindroos, Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, SE-901 83 Umeå, Sweden E-mail: ola.lindroos@slu.se

Combining research into forest management stand conditions and wood supply chain processes has been missing from earlier forestry studies. There is a clear need to develop more cost-efficient small-diameter wood production, harvesting and transportation methods from first thinning, which could be used for either industrial or energy wood purposes. This study considers the total cost for small-diameter wood originating from young Scots pine (Pinus sylvestris L.) dominated stands. Pine pulpwood is the most harvested and most used roundwood assortment, use of which is expected to rise following new pulp-mill investments in Finland. In addition, utilisation of small-diameter trees directly for energy purposes has been increasing steadily in recent years. The aim of the study was to determine the cost-reduction potential of alternative forest management options and supply chains for small diameter-wood in the regional case of South Savo in eastern Finland. The total costs of three distinct scenarios were studied on the basis of forest management, first-thinning harvesting methods, and transportation: 1) industrial wood, 2) delimbed energy wood, and 3) whole trees for energy purposes. The cost-reduction potential for energy-wood supply chains from first thinning was compared to the industrial supply chain. Small-diameter delimbed wood delivered straight for energy purposes was found to be the most cost-efficient as far as the total cost of the supply chain is concerned. More cost-efficient small-diameter wood processes can be found by linking forest stand simulations with supply chain analysis.

• Karttunen, Lappeenranta University of Technology, LUT School of Energy Systems, Laboratory of Bioenergy, Lönnrotinkatu 7, FI-50100 Mikkeli, Finland E-mail: kalle.karttunen@lut.fi
• Laitila, Natural Resources Institute Finland (Luke), Bio-based business and industry, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: juha.laitila@luke.fi
• Ranta, Lappeenranta University of Technology, LUT School of Energy Systems, Laboratory of Bioenergy, Lönnrotinkatu 7, FI-50100 Mikkeli, Finland E-mail: tapio.ranta@lut.fi

Early thinnings are laborious and costly. Thus forest companies are searching for cost and time efficient ways to carry out this task. The study’s purpose was to determine the productivity of the EF28 accumulating energy wood harvesting head in harvesting small-diameter hornbeam (Carpinus betulus L.) undergrowth trees and evaluate the effect of its multi-tree handling (MTH) capacity on time consumption. The harvester was a wheeled, three-axle Komatsu 911. A time study of 7.1 hours on 19 plots, with a total area of 0.76 ha was conducted. On average, the harvested tree volume was 8 dm³ and the stand density was 2666 trees/ha. The productivity was modelled with MTH conduction, mean diameter at breast height and the number of trees handled per cycle as independent variables. On average, MTH took 27% longer per cycle, increased extracted volume per cycle by 33% and consequently increased productivity with 5.0%. In 71.9% of the cycles more than one tree was handled and if so, dimensions were smaller than in single-tree handling (5.8 cm vs. 12.0 cm). Maximum felling diameter of 23 cm was about 15% smaller than in softwood (according to the manufacturer’s specifications) and the driver didn’t exploit the EF28’s theoretical potential in terms of trees handled per cycle. It can be concluded that the head could significantly improve productivity in small-diameter wood procurement.

• Erber, Addresses University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan Straße 82/3, A-1190 Vienna, Austria E-mail: gernot.erber@boku.ac.at
• Holzleitner, Addresses University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan Straße 82/3, A-1190 Vienna, Austria E-mail: franz.holzleitner@boku.ac.at
• Kastner, Addresses University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan Straße 82/3, A-1190 Vienna, Austria E-mail: maximilian.kastner@boku.ac.at
• Stampfer, Addresses University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan Straße 82/3, A-1190 Vienna, Austria E-mail: karl.stampfer@boku.ac.at

Finnish wood harvesting contractors have been working in Russia since the 1990s and new entrepreneurs are still interested in starting operations there, even though Russia is not an easy business environment. This study identifies the most significant risks in contracting in Russia. Risks were identified through expert evaluation and a risk analysis was conducted by using a risk matrix. Possible preventative measures were assessed for the identified risks. Some risks were found to be common in Russia and Finland, for example a limited number of clients, dependency on a few clients, and weak negotiating positions. A stable amount of work, i.e. the availability of stands for harvesting, was also a challenge on the both sides of border. Typical problems in Russia were breaches of contract, especially disagreements on wood measurement and payment delays, potentially causing serious economic losses. Specific to Russia were problems related to machine service and spare parts, as well as security issues. The professional skills of machine operators, as well as changing work motivation were risks in Russia. Cultural differences lead to more challenging supervision and management of staff. Among the external factors, the most challenging in Russia were unhealthy competition in the marketplace and non-transparent and the unpredictable procedures of the authorities. In Russia problems caused by seasonality are amplified by the sparse road network and longer downtime. The revealed specific features of the Russian business environment can help Finnish wood harvesting companies to plan a risk management process for operations in Russia.

• Karvinen, Natural Resources Institute Finland (Luke), Economics and society, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: sari.karvinen@luke.fi
• Nummelin, Natural Resources Institute Finland (Luke), Green technology, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: tuomas.nummelin@luke.fi

Understanding the characteristics of unutilized biomass resources, such as small-diameter trees from biomass-dense thinning forests (BDTF) (non-commercially-thinned forests), can provide important information for developing a bio-based economy. The aim of this study was to describe the areal distribution, characteristics (biomass of growing stock, tree height, etc.) and harvesting potential of BDTF in Sweden. A national forest inventory plot dataset was imported into a geographical information system and plots containing BDTF were selected by applying increasingly stringent constraints. Results show that, depending on the constraints applied, BDTF covers 9–44% (2.1–9.8 M ha) of the productive forest land area, and contains 7–34% of the total growing stock (119–564 M OD t), with an average biomass density of 57 OD t ha^–1. Of the total BDTF area, 65% is located in northern Sweden and 2% corresponds to set-aside farmlands. Comparisons with a study from 2008 indicate that BDTF area has increased by at least 4% (about 102 000 ha), in line with general trends for Sweden and Europe. Analyses revealed that the technical harvesting potential of delimbed stemwood (over bark, including tops) from BDTF ranges from 3.0 to 6.1 M OD t yr^–1 (7.5 to 15.1 M m³ yr^–1), while the potential of whole-tree harvesting ranges from 4.3 to 8.7 M OD t yr^–1 (10.2 to 20.6 M m³ yr^–1) depending on the scenario considered. However, further technological developments of the harvest and supply systems are needed to utilize the full potential of BDTF.

• Fernandez-Lacruz, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden http://orcid.org/0000-0001-9284-8911 E-mail: raul.fernandez@slu.se
• Di Fulvio, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden; International Institute for Applied Systems Analysis (IIASA), Ecosystems Services and Management Program (ESM), Schlossplatz 1, A-2361 Laxenburg, Austria E-mail: Fulvio.di.Fulvio@slu.se
• Athanassiadis, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: Dimitris.Athanassiadis@slu.se
• Bergström, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: Dan.Bergstrom@slu.se
• Nordfjell, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: Tomas.Nordfjell@slu.se

Finding an optimal solution of forest management scheduling problems with even flow constraints while addressing spatial concerns is not an easy task. Solving these combinatorial problems exactly with mixed-integer programming (MIP) methods may be infeasible or else involve excessive computational costs. This has prompted the use of heuristics. In this paper we analyze the performance of different implementations of the Simulated Annealing (SA) heuristic algorithm for solving three typical harvest scheduling problems. Typically SA consists of searching a better solution by changing one decision choice in each iteration. In forest planning this means that one treatment schedule in a single stand is changed in each iteration (i.e. one-opt move). We present a comparison of the performance of the typical implementation of SA with the new implementation where up to three decision choices are changed simultaneously in each iteration (i.e. treatment schedules are changed in more than one stand). This may allow avoiding local optimal. In addition, the impact of SA - parameters (i.e. cooling schedule and initial temperature) are tested. We compare our heuristic results with a MIP formulation. The study case is tested in a real forest with 1000 stands and a total of 213116 decision choices. The study shows that when the combinatorial problem is very large, changing simultaneously the treatment schedule in more than one stand does not improve the performance of SA. Contrarily, if we reduce the size of the problem (i.e. reduce considerably the number of alternatives per stand) the two-opt moves approach performs better.

• Bachmatiuk, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal E-mail: jbachmatiuk@isa.ulisboa.pt
• Garcia-Gonzalo, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal E-mail: jordigarcia@isa.ulisboa.pt
• Borges, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal E-mail: joseborges@isa.ulisboa.pt

• Bettinger, School of Forestry and Natural Resources, 180 E. Green Street, University of Georgia, Athens, Georgia, USA 30602 E-mail: pbettinger@warnell.uga.edu
• Demirci, General Directorate of Forestry, Ministry of Forest and Water Affairs, Republic of Turkey E-mail: mehmetdemirci@yahoo.com
• Boston, Department of Forest Engineering, Resources and Management, College of Forestry, Oregon State University, USA E-mail: Kevin.Boston@oregonstate.edu

• Miranda, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade Lisboa, 1349-017 Lisboa, Portugal E-mail: Imiranda@isa.ulisboa.pt
• Gominho, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade Lisboa, 1349-017 Lisboa, Portugal E-mail: Jgominho@isa.utl.pt
• Pereira, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade Lisboa, 1349-017 Lisboa, Portugal E-mail: Hpereira@isa.utl.pt

• Szewczyk, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest and Wood Utilization, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: rlszewcz@cyf-kr.edu.pl
• Sowa, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest and Wood Utilization, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: rlsowa@cyf-kr.edu.pl
• Grzebieniowski, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest and Wood Utilization, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: wrzoswj@interia.pl
• Kormanek, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest Work Mechanisation, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: rlkorma@cyf-kr.edu.pl
• Kulak, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest and Wood Utilization, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: rlkulak@cyf-kr.edu.pl
• Stańczykiewicz, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest and Wood Utilization, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: rlstancz@cyf-kr.edu.pl

• Akujärvi, Finnish Environment Institute, Helsinki, Finland E-mail: anu.akujarvi@ymparisto.fi
• Hallikainen, Finnish Forest Research Institute, Northern Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: ville.hallikainen@metla.fi
• Hyppönen, Finnish Forest Research Institute, Northern Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: mikko.hypponen@metla.fi
• Mattila, Finnish Forest Research Institute, Northern Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: eero.mattila@metla.fi
• Mikkola, Finnish Forest Research Institute, Northern Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: kari.mikkola@metla.fi
• Rautio, Finnish Forest Research Institute, Northern Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: pasi.rautio@metla.fi

• Klockow, Department of Forest Resources, University of Minnesota, St. Paul, MN 55108, USA E-mail: klock039@umn.edu
• D'Amato, Department of Forest Resources, University of Minnesota, St. Paul, MN 55108, USA E-mail: damato@umn.edu
• Bradford, US Geological Survey, Southwest Biological Science Center, Flagstaff, AZ 86001, USA E-mail: jbradford@usgs.gov
• Fraver, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail: shawn.fraver@maine.edu

• Uusitalo, Finnish Forest Research Institute, Parkano Unit, Kaironiementie 15, FI-39700 Parkano, Finland E-mail: jori.uusitalo@metla.fi
• Ala-Ilomäki, Finnish Forest Research Institute, Vantaa Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: jari.ala-ilomaki@metla.fi

• Hedwall, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences (SLU), P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: per-ola.hedwall@slu.se
• Grip, Department of Forest Ecology and Management, SLU, SE-901 83 Umeå, Sweden E-mail: harald@grip2.se
• Linder, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences (SLU), P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: sune.linder@slu.se
• Lövdahl, Department of Forest Ecology and Management, SLU, SE-901 83 Umeå, Sweden E-mail: ll@nn.se
• Nilsson, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences (SLU), P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: urban.nilsson@slu.se
• Bergh, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences (SLU), P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: johan.bergh@slu.se

• Ezzati, Department of Forestry and Forest Engineering, Tarbiat Modares University, P.O. Box 64414-356, Iran E-mail: se@nn.ir
• Najafi, Department of Forestry and Forest Engineering, Tarbiat Modares University, P. Box 64414-356, Iran E-mail: a.najafi@modares.ac.ir
• Rab, Soil Physics Future Farming Systems Research Division, Department of Primary Industries, Victoria, Australia E-mail: mr@nn.ir
• Zenner, Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA, USA E-mail: eric.zenner@psu.edu

• Costa, CRA ING, Monterotondo Scalo (Roma), Italy E-mail: cc@nn.it
• Menesatti, CRA ING, Monterotondo Scalo (Roma), Italy E-mail: pm@nn.it
• Spinelli, CNR IVALSA, Sesto Fiorentino (FI), Italy E-mail: spinelli@ivalsa.cnr.it

• Holmgren, Swedish University of Agricultural Sciences, Forest Resource Management, Umeå, Sweden E-mail: johan.holmgren@slu.se
• Barth, The Forestry Research Institute of Sweden, Uppsala, Sweden E-mail: ab@nn.se
• Larsson, Swedish University of Agricultural Sciences, Forest Resource Management, Umeå, Sweden E-mail: hl@nn.se
• Olsson, Swedish University of Agricultural Sciences, Forest Resource Management, Umeå, Sweden E-mail: ho@nn.se

• Niemistö, Finnish Forest Research Institute, Parkano & Joensuu, Finland E-mail: pn@nn.fi
• Korpunen, Finnish Forest Research Institute, Parkano & Joensuu, Finland E-mail: hk@nn.fi
• Laurén, Finnish Forest Research Institute, Parkano & Joensuu, Finland E-mail: al@nn.fi
• Salomäki, Finnish Forest Research Institute, Parkano & Joensuu, Finland E-mail: ms@nn.fi
• Uusitalo, Finnish Forest Research Institute, Parkano & Joensuu, Finland E-mail: jori.uusitalo@metla.fi

• Laamanen, Metsähallitus, Vantaa, Finland E-mail: risto.laamanen@metsa.fi
• Kangas, Metsähallitus, Vantaa, Finland E-mail: ak@nn.fi

• Sullivan, Department of Forest Sciences, Faculty of Forestry, University of BC, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4 E-mail: tom.sullivan@ubc.ca
• Sullivan, Department of Forest Sciences, Faculty of Forestry, University of BC, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4 E-mail: dss@nn.ca
• Lindgren, Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, Canada V0H 1Z8 E-mail: pmfl@nn.ca
• Ransome, Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, Canada V0H 1Z8 E-mail: dbr@nn.ca

• Jylhä, Finnish Forest Research Institute, Kannus, Finland E-mail: paula.jylha@metla.fi
• Dahl, Aalto University School of Science and Technology, Department of Forest Products Technology, Espoo, Finland E-mail: od@nn.fi
• Laitila, Finnish Forest Research Institute, Joensuu, Finland E-mail: jl@nn.fi
• Kärhä, Metsäteho Oy, Helsinki, Finland E-mail: kk@nn.fi

• Lindroos, Department of Forest Resource Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: ola.lindroos@srh.slu.se
• Henningsson, Komatsu Forest AB, Box 7124, SE-907 04 Umeå, Sweden E-mail: mh@nn.se
• Athanassiadis, Department of Forest Resource Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: da@nn.se
• Nordfjell, Department of Forest Resource Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: tn@nn.se

• Belbo, Norwegian Forest and Landscape Institute, Box 115, 1431 Ås, Norway E-mail: helmer.belbo@skogoglandskap.no

• Laurila, Seinäjoki University of Applied Sciences, School of Agriculture and Forestry, FI-63700 Ähtäri, Finland E-mail: jussi.laurila@seamk.fi
• Lauhanen, Seinäjoki University of Applied Sciences, School of Agriculture and Forestry, FI-63700 Ähtäri, Finland E-mail: rl@nn.fi

• Eräjää, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: se@nn.fi
• Halme, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: panu.halme@jyu.fi
• Kotiaho, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: jsk@nn.fi
• Markkanen, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: am@nn.fi
• Toivanen, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: tt@nn.fi

• Öhman, SLU, Department of Forest Resource Management, SE-901 83 Umeå, Sweden E-mail: karin.ohman@srh.slu.se
• Eriksson, SLU, Department of Forest Resource Management, SE-901 83 Umeå, Sweden E-mail: loe@nn.se

• Pingoud, VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo, Finland E-mail: kim.pingoud@vtt.fi
• Pohjola, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: jp@nn.fi
• Valsta, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: lv@nn.fi

• Nuutinen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: yrjo.nuutinen@metla.fi
• Väätäinen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: kv@nn.fi
• Asikainen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: aa@nn.fi
• Prinz, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: rp@nn.fi
• Heinonen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: jh@nn.fi

• Rabinowitsch-Jokinen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301, Vantaa, Finland E-mail: rrj@nn.fi
• Vanha-Majamaa, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301, Vantaa, Finland E-mail: ilkka.vanha-majamaa@metla.fi

• Murphy, Forest Engineering, Resources and Management Department, Oregon State University, Corvallis, Oregon, USA E-mail: glen.murphy@oregonstate.edu
• Brownlie, Scion Research, Rotorua, New Zealand E-mail: rb@nn.nz
• Kimberley, Scion Research, Rotorua, New Zealand E-mail: mk@nn.nz
• Beets, Scion Research, Rotorua, New Zealand E-mail: pb@nn.nz

• Peuhkurinen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: jp@nn.fi
• Maltamo, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: mm@nn.fi
• Malinen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: jm@nn.fi

• Laitila, Finnish Forest Research Institute, Joensuu Research Unit, Joensuu, Finland E-mail: juha.laitila@metla.fi

• Koskela, University of Tampere, Dept of Mathematics, Statistics and Philosophy, FI-33014 University of Tampere, Finland E-mail: laura.koskela@uta.fi
• Sinha, Indian Statistical Institute, Kolkata, India E-mail: bks@nn.in
• Nummi, University of Tampere, Dept of Mathematics, Statistics and Philosophy, FI-33014 University of Tampere, Finland E-mail: tn@nn.fi

• Zhu, Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA E-mail: jz@nn.us
• Bettinger, Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA E-mail: pbettinger@warnell.uga.edu
• Li, Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA E-mail: rl@nn.us

• Zeng, University of Joensuu, Faculty of Forest Sciences, P. O. Box 111, FI-80101 Joensuu, Finland E-mail: hongcheng.zeng@joensuu.fi
• Pukkala, University of Joensuu, Faculty of Forest Sciences, P. O. Box 111, FI-80101 Joensuu, Finland E-mail: tp@nn.fi
• Peltola, University of Joensuu, Faculty of Forest Sciences, P. O. Box 111, FI-80101 Joensuu, Finland E-mail: hp@nn.fi
• Kellomäki, University of Joensuu, Faculty of Forest Sciences, P. O. Box 111, FI-80101 Joensuu, Finland E-mail: sk@nn.fi

• Uusitalo, The Finnish Forest Research Institute, Parkano unit, FI-39700 Parkano, Finland E-mail: jori.uusitalo@metla.fi
• Puustelli, University of Tampere, Department of Mathematics, Statistics and Philosophy, FI-33014 University of Tampere, Finland E-mail: ap@nn.fi
• Kivinen, University of Helsinki, Department of Forest Resource Management, Box 27, FI-00014 University of Helsinki, Finland E-mail: vpk@nn.fi
• Nummi, University of Tampere, Department of Mathematics, Statistics and Philosophy, FI-33014 University of Tampere, Finland E-mail: tn@nn.fi
• Sinha, Stat-Math Division, Indian Statistical Institute, 203 B.T. Road, Kolkata - 700 108, India E-mail: bks@nn.in

• Nurminen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: tuomo.nurminen@joensuu.fi
• Korpunen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: hk@nn.fi
• Uusitalo, Finnish Forest Research Institute, Parkano Research Unit, Kaironiementie 54, FI-39700 Parkano, Finland E-mail: ju@nn.fi

• Marshall, Ensis Forests, Private Bag 3020, Rotorua, New Zealand E-mail: hamish.marshall@ensisjv.com
• Murphy, Forest Engineering Department, Oregon State University, Corvallis, Oregon 97331, USA E-mail: gm@nn.us
• Boston, Forest Engineering Department, Oregon State University, Corvallis, Oregon 97331, USA E-mail: kb@nn.us

• Spinelli, CNR/IVALSA, Via Madonna del Piano - Palazzo F, I-50019 Sesto Fiorentino (FI), Italy E-mail: spinelli@ivalsa.cnr.it
• Nati, CNR/IVALSA, Via Madonna del Piano - Palazzo F, I-50019 Sesto Fiorentino (FI), Italy E-mail: cn@nn.it
• Magagnotti, CNR/IVALSA, Via Madonna del Piano - Palazzo F, I-50019 Sesto Fiorentino (FI), Italy E-mail: nm@nn.it

• Laukkanen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: sanna.laukkanen@joensuu.fi
• Palander, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: tp@nn.fi
• Kangas, UPM-Kymmene Forest, P.O. Box 32, FI-37601 Valkeakoski, Finland E-mail: jk@nn.fi
• Kangas, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: ak@nn.fi

• Ovaskainen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: heikki.ovaskainen@joensuu.fi

• Uusitalo, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: jori.uusitalo@joensuu.fi
• Kokko, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: sk@nn.fi
• Kivinen, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: vpk@nn.fi

• Murphy, Forest Engineering Department, Oregon State University, Corvallis, OR 97331, USA E-mail: glen.murphy@orst.edu
• Firth, Forest Research, Sala Street, Rotorua, New Zealand E-mail: jgf@nn.nz
• Skinner, Forest Research, Sala Street, Rotorua, New Zealand E-mail: mfs@nn.nz

• Andersson, Swedish University of Agricultural Sciences, Department of Silviculture, S-901 83 Umeå, Sweden E-mail: je@nn.se
• Eliasson, Swedish University of Agricultural Sciences, Department of Silviculture, S-901 83 Umeå, Sweden E-mail: lars.eliasson@ssko.slu.se

• Rosenberg, Skogforsk – The Forestry Research Institute of Sweden, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: olle.rosenberg@skogforsk.se
• Jacobson, Skogforsk – The Forestry Research Institute of Sweden, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: sj@nn.se

• Spinelli, CNR - Timber and Tree Institute, Via Madonna del Piano - Pal. F, 50019 Sesto Fiorentino, Italy; University College Dublin, Ireland E-mail: spinelli@ivalsa.cnr.it
• Owende, Dept. of Agricultural and Food Engineering, University College Dublin, Earlsfort Terrace, Dublin 2, Ireland E-mail: pmoo@nn.ie
• Ward, Dept. of Agricultural and Food Engineering, University College Dublin, Earlsfort Terrace, Dublin 2, Ireland E-mail: smw@nn.ie
• Tornero, Servicios Forestales SA, Ctra. SE-184 Km 0.63, E-41970 Santiponce, Sevilla, Spain E-mail: mt@nn.es

• Bettinger, Department of Forest Resources, Oregon State University, Corvallis, OR 97331 E-mail: pete.bettinger@orst.edu
• Graetz, Department of Forest Resources, Oregon State University, Corvallis, OR 97331 E-mail: dgw@nn.us
• Boston, Carter Holt Harvey Forest Fibre Solutions, Tokoroa, New Zealand E-mail: kb@nn.nz
• Sessions, Department of Forest Engineering, Oregon State University, Corvallis, OR 97331 E-mail: js@nn.us
• Chung, Department of Forest Engineering, Oregon State University, Corvallis, OR 97331 E-mail: wc@nn.us

• Nieuwenhuis, University College Dublin, Dept. of Forestry, Belfield, Dublin 4, Ireland E-mail: maarten.nieuwenhuis@ucd.ie

• Eid, Department of Forest Sciences, Agricultural University of Norway, P.O. Box 5044, N-1432 Ås, Norway E-mail: tron.eid@isf.nlh.no

• White, Canadian Forest Service, Pacific Forestry Centre, Natural Resources Canada, 506 West Burnside Road, Victoria, B.C., V8Z 1M5, Canada https://orcid.org/0000-0003-4674-0373 E-mail: joanne.white@nrcan-rncan.gc.ca