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Intensive management of boreal forests impairs forest biodiversity and species of old-growth forest. Effective measures to support biodiversity require detection of locations valuable for conservation. We applied species distribution models (SDMs) to a species of mature forest, the northern goshawk (Accipiter gentilis, goshawk), that is often associated with hotspots of forest biodiversity. We located optimal sites for the goshawk on a landscape scale, assessed their state under intensified logging operations and identified characteristics of goshawks' nesting sites in boreal forests. Optimal sites for the goshawk covered only 3.4% of the boreal landscape and were mostly located outside protected areas, which highlights the importance of conservation actions in privately-owned forests. Furthermore, optimal sites for the goshawk and associated biodiversity were under threat. Half of them were logged to some extent and 10% were already lost or notably deteriorated due to logging shortly after 2015 for which our models were calibrated. Habitat suitability for the goshawk increased with increasing volume of Norway spruce (Picea abies) peaking at 220 m(3) ha(-1), and with small quantities of birches (Betula spp.) and other broad-leaved trees. Threats to biodiversity of mature spruce forests are likely to accelerate in the future with increasing logging pressures and shorter rotation periods. Logging should be directed less to forests with high biodiversity. Continuous supply of mature spruce forests in the landscape should be secured with a denser network of protected areas and measures that aid in sparing large entities of mature forest on privately-owned land. peerReviewed

Forest planning at the landscape level has the potential to become a large intractable problem. In Finland, Metsähallitus (the state enterprise that manages federally owned land) creates strategic plans to determine the appropriate harvest level. While these plans are feasible, they are not implementable in practice as the harvests are scattered temporally and spatially. Requiring that harvests be organized both temporally and spatially for practical implementation can result in an intractable problem. Through a hierarchical approach, the problem can be organized into steps in which the intractable problem is broken down into smaller easily solvable parts. As an approximation technique, the hierarchical approach may not find a solution close to optimality. To meet this challenge, we combine the top hierarchical level problems with a limited selection of lower hierarchical level problems into a single optimization problem. An iterative process is then used to improve the link between the hierarchical levels. We evaluate the landscape-level management plans developed by the iterative approach with a solution to the complete problem. The iterative process dramatically improves the strategic solution, performing near the global optimum. This suggests that the process can be applied to more computationally challenging problems such as spatial planning and stochastic programming. peerReviewed

The boreal biome, representing approximately one-third of remaining global forests, provides a number of crucial ecosystem services. A particular challenge in forest ecosystems is to reconcile demand for an increased timber production with provisioning of other ecosystem services and biodiversity. However, there is still little knowledge about how forest management could help solve this challenge. Hence, studies that investigate how to manage forests to reduce trade-offs between ecosystem services and biodiversity are urgently needed to help forest owners and policy makers take informed decisions. We applied seven alternative forest management regimes using a forest growth simulator in a large boreal forest production landscape. First, we estimated the potential of the landscape to provide harvest revenues, store carbon and maintain biodiversity across a 50-year time period. Then, we applied multiobjective optimization to identify the trade-offs between these three objectives and to identify the optimal combination of forest management regimes to achieve these objectives. It was not possible to achieve high levels of either carbon storage or biodiversity if the objective of forest management was to maximize timber harvest revenues. Moreover, conflicts between biodiversity and carbon storage became stronger when simultaneously targeting high levels of timber revenues. However, with small reductions in timber revenues, it was possible to greatly increase the multifunctionality of the landscape, especially the biodiversity indicators. Forest management actions, alternative to business-as-usual management, such as reducing thinnings, extending the rotation period and increasing the amount of area set aside from forestry may be necessary to safeguard biodiversity and non-timber ecosystem services in Fennoscandia. Synthesis and applications. Our results show that no forest management regime alone is able to maximize timber revenues, carbon storage and biodiversity individually or simultaneously and that a combination of different regimes is needed to resolve the conflicts among these objectives. We conclude that it is possible to reduce the trade-offs between different objectives by applying diversified forest management planning at the boreal landscape level and that we need to give up the all-encompassing objective of very intensive timber production, which is prevailing particularly in Fennoscandian countries. peerReviewed

This paper includes some basic knowledge to be considered when discussing about the quality of work in harvesting wood and how to monitor it. This knowledge may aid to form an appropriate view on mechanised logging, environmental issues and trade of forest products. Many forest owners feel today, that leaving a good quality of work behind is the most important requirement set for logging machinery in the future. It is possible to present to the forest machine and equipment manufacturers some ideas on how to promote and influence the development of logging machines and equipment. This paper is partly based on a literature study, partly on theme interviews. Recent literature on productivity, machine and method studies on logging was examined from the quality of work point of view. Observations supporting an improvement in the quality of work were recorded. The idea was not to find out the level of the quality of work in practice as such, but to assess the relationships between the methods, machines and equipment used in respect to the quality of work. The interviews were conducted from May 22, 2000 to October 2, 2000 in Finland. The data consisted of six persons responsible for logging in a wood procurement district, six representatives of forest machine manufacturers and five logging contractors. A good quality of work in logging is characterised by doing it in an agreed way. Indicators for reaching the goals are evaluated by assessing the damages caused to the remaining trees, the rut formation, the strip road spacing and width, the way the thinning regimes are followed and the choice of trees to be cut. The target level is formed as a joint effect e.g. of efficiency in wood production, of credibility of mechanised operations, of considering the environment and of fluency in trade of forest products. Contributing factors to reach a good quality of work are the organisation of the logging, the forest machine operator as well as the machine and equipment technique. These factors may get a weighting value. However, the final result is a product of these factors, and all of them have to be considered. When looking at the situation today the human influence in logging, especially the role of the operator, is getting more emphasis. On the other hand, in the long run the possibilities to develop appropriate technologies are dominating, especially the use of new technologies. From the point of view of logging machinery the main factors affecting the work results, are the mobility of the vehicle, how to operate it and the work environment. In this paper, based on the development needs and possibilities, those aspects are looked at. An assessment of the present state is given and presents a basis for a more precise prediction of realistic targets. Based on a literature review and interviews conducted, it is possible to conclude, that there still is great potential to improve the quality of work in logging. Some direct technical improvements could promote the quality of work, but there are even some other actions, which indirectly through the operator would have a positive effect. An improved quality of work is often also improving the productivity in work. Furthermore it makes the organising of the logging operations easier and makes it possible to operate in a more demanding work environment even year around and 24 hours a day. The following is a list of research and development (R&D) needs concerning forest machinery, where inputs would be justified: • Better visibility (illumination, no dazzling, visibility) • Analysis of the CTI-system and eventual construction and testing of a test machine • The properties of tyres (width, diameter, tread, pressure) and their development • Control of the crane and its development (e.g. the automatic functions) • The role of a rotating cab on the operator, his productivity and the work result • Research into the role of levelling (seat, cabin, whole machine) • Steering of the machine (turning radius, “cutting” of corners) and possibilities to develop a vehicle with frame-steering and turning wheels • Research into the possibilities to utilise on-board weighing scales • Lighter machine construction • The role of tracks and comparison of different tracks • The role of a balanced boggie and its comparison with a single wheel • The role of the size of the harvester head on the operation control, work result and productivity • Possibilities to increase automation • Possibilities of work rotation and its effect on a normal logging system • The effect of a harwarder (harvester-forwarder) on the operator’s work

The objectives of this study was 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.) 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 9% 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.

Part II Biodiversity 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.

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 a 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 in operating costs.

A review of logging in Finland in relation to new logging technology developed in Nordic countries to meet their own specific requirements and constraints (high salaries, costs of social security, strict ergonomic standards, specific logging conditions, predominance of private ownership, and strong environmental and conservation concerns). Logging technology is based typically on the log-length method and load-carrying forwarders.

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.

Tutkimus kuuluu osana Harvennuspuun korjuun koneellistamistoimikunnan selvityksiin.

Metsänhoitajien jatkokurssit : 1956. 8.

Ensimmäinen painos ilmestynyt nimellä Metsän hoitohakkauksista (1931)