Category: Research article
article id 9918, category Research article
Modelling the effect of habitat composition and roads on the occurrence and number of moose damage at multiple scales. Silva Fennica vol. 53 no. 1 article id 9918. https://doi.org/10.14214/sf.9918
Highlights: The occurrence and number of moose damage were modelled with a zero-inflated count model; An admixture of mature forests within plantations increased the number of damage; Vicinity of inhabited areas and roads reduced damage; Plantations in landscapes with a large amount of pine-dominated thinning forests had less damage in Lapland; Damage risk assessment should include characteristics specific to each region.
We modelled the effect of habitat composition and roads on the number and occurrence of moose (Alces alces L.) damage in Ostrobothnia and Lapland using a zero-inflated count model. Models were developed for 1 km2, 25 km2 and 100 km2 landscapes consisting of equilateral rectangular grid cells. Count models predict the number of damage, i.e. the number of plantations and zero models the probability of a landscape being without damage for a given habitat composition. The number of moose damage in neighboring grid cells was a significant predictor in all models. The proportion of mature forest was the most frequent significant variable, and an increasing admixture of mature forests among plantations increased the number and occurrence of damage. The amount of all types of plantations was the second most common significant variable predicting increasing damage along with increasing amount of plantations. An increase in thinning forests as an admixture also increased damage in 1 km2 landscapes in both areas, whereas an increase in pine-dominated thinning forests in Lapland reduced the number of damage in 25 km2 landscapes. An increasing amount of inhabited areas in Ostrobothnia and the length of connecting roads in Lapland reduced the number of damage in 1 and 25 km2 landscapes. Differences in model variables between areas suggest that models of moose damage risk should be adjusted according to characteristics that are specific to the study area.
article id 1665, category Research article
Reliability of self-control method in the management of non-industrial private forests. Silva Fennica vol. 52 no. 1 article id 1665. https://doi.org/10.14214/sf.1665
Highlights: Self-control method was found reliable at the main stages of the forest regeneration process; Only slight overestimation was found in self-control results of soil preparation and planting and small underestimation in self-control of young stand management; Diverse utilizing of self-control data is possible in support of service providers operations.
This study seeks to determine the extent to which self-control data can be relied upon in the management of private forests. Self-control (SC) requires the forest workers to evaluate their own work quality to ensure the clients’ needs are met in terms of soil preparation, planting and young stand management. Self-control data were compared to an independent evaluation of the same worksites. Each dataset had a hierarchical structure (e.g., sample plot, regeneration area and contractor), and key quality indicators (i.e., number of prepared mounds, planted seedlings or crop trees) were measured for each plot. Self-control and independent-assessments (IA) were analyzed by fitting a multi-level multivariate model containing explanatory variables. No significant differences were observed in terms of soil preparation (number of mounds) or young stand management (number of crop trees) between self-control and independent-assessments. However, the self-control planting data included a slight but significant overestimation of the number of planted seedlings. Discrepancies are discussed in terms of sampling error and other explanatory factors. According to overall results, self-control methods are reliable at every stage of the forest regeneration process. As such, the diverse utilizing of self-control data is possible in support of service providers operations.
article id 1232, category Research article
Search reversion within s-metaheuristics: impacts illustrated with a forest planning problem. Silva Fennica vol. 49 no. 2 article id 1232. https://doi.org/10.14214/sf.1232
Highlights: The interruption of the sequence of events used to explore a solution space and develop a forest plan, and the re-initiation of the search process from a high-quality, known starting point (reversion) seems necessary for some s-metaheuristics; When using a s-metaheuristic, higher quality forest plans may be developed when the reversion interval is around six iterations of the model.
The use of a reversion technique during the search process of s-metaheuristics has received little attention with respect to forest management and planning problems. Reversion involves the interruption of the sequence of events that are used to explore the solution space and the re-initiation of the search process from a high-quality, known starting point. We explored four reversion rates when applied to three different types of s-metaheuristics that have previously shown promise for the forest planning problem explored, threshold accepting, tabu search, and the raindrop method. For two of the s-metaheuristics, we also explored three types of decision choices, a change to the harvest timing of a single management unit (1-opt move), the swapping of two management unit’s harvest timing (2-opt moves), and the swapping of three management unit’s harvest timing (3-opt moves). One hundred independent forest plans were developed for each of the metaheuristic / reversion rate combinations, all beginning with randomly-generated feasible starting solutions. We found that (a) reversion does improve the quality of the solutions generated, and (b) the rate of reversion is an important factor that can affect solution quality.
article id 1188, category Research article
Damage by the pine weevil Hylobius abietis to seedlings of two native and five introduced tree species in Sweden. Silva Fennica vol. 48 no. 4 article id 1188. https://doi.org/10.14214/sf.1188
Highlights: Both native and introduced confer species in Sweden can be highly susceptible to damage by the pine weevil; Douglas fir and Sitka spruce were generally the most damaged among six studied conifer species; The results highlight some of the risks in establishing exotic tree species for forest production.
There is increasing interest in using introduced species in Swedish forestry in response to climate change, but it is important to assess their resistance to native pests. Thus, we compared the extent of pine weevil feeding on two dominant native conifers, Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.), the non-host deciduous broadleaf hybrid aspen (Populus × wettsteinii Hämet-Ahti) and four introduced conifers: Douglas fir (Pseudotsuga menziesii (Mirb.) Franco), hybrid larch (Larix × marschlinsii Coaz), Sitka spruce (Picea sitchensis (Bong.) Carriére) and lodgepole pine (Pinus contorta Douglas ex Loudon). The extent of feeding damage on seedlings and its effect on their vitality were examined in a field study in south-central Sweden and a laboratory experiment, which gave largely consistent results. Generally, the species most heavily attacked by the pine weevil, in both experiments, were Douglas fir and Sitka spruce. In the field experiment pine weevils killed or severely damaged significantly higher proportions of Douglas fir and Sitka spruce seedlings (60%) than any other species except Norway spruce (49%). Among conifer seedlings the proportions of killed or severely damaged seedlings were lowest for Scots pine and hybrid larch (27%) and Lodgepole pine (36%). The results indicate that most conifer species planted on young clear-cuttings in Sweden need some kind of pine weevil protection, and the possibility that introducing new tree species might increase damage caused by pests must be considered. For instance, widespread use of hybrid aspen could reduce damage by pine weevils, but increase damage by other, untested pests or pathogens.
article id 937, category Research article
Stochastic simulation and optimization of mobile chipping economics in processing and transport of forest biomass from residues. Silva Fennica vol. 47 no. 5 article id 937. https://doi.org/10.14214/sf.937
Highlights: A stochastic simulation model is proposed to analyze forest biomass operations; The cost of chipper and truck waiting times was estimated in forest biomass recovery operations; The economic effect of truck-machine interactions under uncertainty was analyzed; Road characteristics and processing location have an economic impact in truck and chipper waiting times
We analyzed the economics of mobile chipping and transport of biomass from forest residues for energy purposes under uncertainty. A discrete-event simulation model was developed and utilized to quantify the impacts of controllable and environmental variables on productivity in order to determine the most cost effective transportation options under steep terrain conditions. Truck-chipper interactions were analyzed to show their effect on truck and chipper standing time. A costing model was developed to account for operating and standing time cost (for the chipper and trucks). The model used information from time studies of each activity in the productive cycle and spatial-temporal information obtained from geographic information system (GIS) devices, and tracking analysis of machine and truck movements. The model was validated in field operations, and proved to be accurate in providing the expected productivity. A cost distribution was elaborated to support operational decisions of forest managers, landowners and risk-averse contractors. Different scenarios were developed to illustrate the economic effects due to changes in road characteristics such as in-highway transport distance, in-forest internal road distance and pile to trailer chipper traveling distances.
article id 1046, category Research article
Evaluating continuous cover forestry based on the forest owner’s objectives by combining scenario analysis and multiple criteria decision analysis. Silva Fennica vol. 47 no. 4 article id 1046. https://doi.org/10.14214/sf.1046
Highlights: Scenario analysis and multiple criteria decision analysis were combined to evaluate alternative forest management strategies for Linköping municipality, Sweden; Continuous cover forestry (CCF) promoted ecological and social objectives better than even-aged forestry but was worse for economic objectives; Ecological and social objectives were important to the municipality and thus, in summary, CCF seemed to be a suitable strategy.
Forests are increasingly managed both to provide a sustainable yield of timber and for supplying a range of ecosystem services in line with the concept of sustainable forest management. Several incommensurable interests must then be considered, and it is necessary to strike a balance between different objectives. In evaluation of trade-offs to be made, both objective factors and subjective values need to be taken into account. In recent years, continuous cover forestry (CCF) has been put forward as an alternative to even-aged forestry. The aim of this study was to use scenario analysis in combination with multi criteria decision analysis (MCDA) to evaluate whether CCF is a suitable strategy based on the decision makers’ objectives and preferences for sustainable forest management in a specific landscape. This approach was applied to a planning case on the forest estate of the Linköping municipality in southwestern Sweden. The scenario analyses provided insights into relevant quantitative factors, while the MCDA evaluation helped in clarifying the objectives of the forest management and in assessing the relative importance of various objectives. The scenario analyses showed that in this case CCF is a good management strategy in ecological and social terms but yields worse economic outcomes than conventional even-aged forestry. In the Linköping case, there was a relatively strong emphasis on ecological and social aspects and thus, in summary, CCF seemed to be the most suitable option.
article id 922, category Research article
Forest planning in a Swedish company – a knowledge management analysis of forest information. Silva Fennica vol. 46 no. 5 article id 922. https://doi.org/10.14214/sf.922
Forest data and forest information are central to forest management planning. The knowledge a large forest-owning company possesses about its forests could potentially be a strategic capability. In this study, the forest-planning process of a large forest company is analyzed in terms of knowledge management (KM). The study was conducted as a case study of Sveaskog – the largest forest-owning company in Sweden. The study focuses on the long-term harvest strategy through medium-term planning until the stands are transferred to the tract bank and ready for operational planning. Interviews with key persons within the organization were conducted to assess how forest knowledge is used in this process. The results are presented for the four knowledge management processes: creation, storage-retrieving, transferring and applying. They show that the planning system relies to a great extent on codified knowledge realized by a push strategy.
article id 909, category Research article
Strengthening top-level guidance in geographically hierarchical large scale forest planning: experiences from the Finnish state forests. Silva Fennica vol. 46 no. 4 article id 909. https://doi.org/10.14214/sf.909
Different planning approaches conclude to different results. The top-down approach allocates resources efficiently from the top-level perspective, while the bottom-up approach provides optimal results for the lower levels. Integrated approach that combines the elements of these two basic approaches provides compromise solutions for decision makers. The aim of this study was to examine potential efficiency improvements in hierarchically structured large scale forest management through increased top-level guidance. The resulting effects on the acceptability of the plans on the lower level were also studied. Large scale planning typically considers forests owned by states, companies and municipalities. In the case study of the Finnish state forests, alternative country level solutions were generated by combining regional forest plans in different ways. The results showed that the currently applied bottom-up approach, which produces regionally optimal management strategies, did not result in the most efficient use of resources on the country level. However, the new country level solutions did not produce huge improvements in the country level objective values compared to the results of the current approach. Furthermore, if country level efficiency improvements were emphasized more, together with wide approval by regional stakeholders and local residents, new kind of interaction and participation between the planning levels and also between the regions would be needed.
article id 100, category Research article
Sensitivity of harvest decisions to errors in stand characteristics. Silva Fennica vol. 45 no. 4 article id 100. https://doi.org/10.14214/sf.100
In forest planning, the decision maker chooses for each stand a treatment schedule for a predefined planning period. The choice is based either on optimization calculations or on silvicultural guidelines. Schedules for individual stands are obtained using a growth simulator, where measured stand characteristics such as the basal area, mean diameter, site class and mean height are used as input variables. These characteristics include errors, however, which may lead to incorrect decisions. In this study, the aim is to study the sensitivity of harvest decisions to errors in a dataset of 157 stands. Correct schedules according to silvicultural guidelines were first determined using error-free data. Different amounts of errors were then generated to the stand-specific characteristics, and the treatment schedule was selected again using the erroneous data. The decision was defined as correct, if the type of harvest in these two schedules were similar, and if the timings deviated at maximum ±2 for thinning and ±3 years for clear-cut. The dependency of probability of correct decisions on stand characteristics and the degree of errors was then modelled. The proposed model can be used to determine the required level of measurement accuracy for each characteristics in different kinds of stands, with a given accuracy requirement for the timing of treatments. This information can further be utilized in selecting the most appropriate inventory method.
article id 178, category Research article
Effectiveness of sermon policy instruments: forest management planning practices applying the activity theory approach. Silva Fennica vol. 43 no. 5 article id 178. https://doi.org/10.14214/sf.178
Recent and ongoing societal changes have brought about a need to foster multiple-use forestry and to strengthen customer orientation in family forestry outreach. The study assesses how forest management planning in family forest holdings could be developed to tackle these challenges. The approach introduces a new way of evaluating the effectiveness of information- and communication-based policy instruments. Here, the cultural-historical activity theory is applied in studying the interwoven practices of present-day planning and the associated advisory services targeted at landowners. The data, comprising semi-structured in-depth interviews with 19 professional planners, were qualitatively examined, and a forest management planning activity model was constructed with the emphasis placed on the inherent contradictions of planning work. As the main contradiction, the forest and the forest owner compete as objects. The aims of making the forest productive and advising the landowners towards an increased activeness motivate forest management planning but the planners feel that they lack the opportunity to respond to the needs of the landowner. A wood-production-emphasizing interpretation of the benefits to the national economy frustrates the policy goal of genuinely promoting the goals of multiple-use forestry. The conclusion drawn is that the actors engaged in forest management planning can reveal the needs for change by discussing their opinions and practical innovations. This can be done with the aid of facilitation by e.g. researchers oriented to developmental work study.
article id 218, category Research article
Analyzing the effects of inventory errors on holding-level forest plans: the case of measurement error in the basal area of the dominated tree species. Silva Fennica vol. 43 no. 1 article id 218. https://doi.org/10.14214/sf.218
Accurate inventory data are required for ensuring optimal net return on investment from the forest. Erroneous data can lead to the formulation of a non-optimal plan that can cause inoptimality losses. Little is known of the effect of using erroneous stand inventory data in preparing holding-level forest plans. This study reports on an approach for analyzing such inoptimality losses. Furthermore, inoptimality losses caused by measurement errors in the basal area of the dominated tree species were investigated in a case study. Based on the inventory data including routine measurements by 67 measurers, four measurer groups were created with different measurement error profiles for the basal area of the dominated tree species. This was followed by measurement error simulations for each group and by adding these to the accurate control inventory data to create erroneous data of different error profiles. Three different forest plans were then constructed by using erroneous data of each group. The plans were then analyzed and compared with plans based on correct data. The effect of measurement errors on the net present value from the whole planning period, and on the amount of remaining growing stock at the end of planning period, were analyzed and utilized in calculating the inoptimality losses. It was concluded that even errors involving dominated tree species can cause significant changes in the holding-level forest plans.
article id 238, category Research article
Forest owners' decision support in voluntary biodiversity-protection projects. Silva Fennica vol. 42 no. 4 article id 238. https://doi.org/10.14214/sf.238
New forest-biodiversity-protection instruments based on temporary protection periods and non-industrial private forest owners’ voluntary participation have been recently introduced and tested in pilot areas located in Southern Finland. Thanks to their several benefits, the use of voluntary instruments is becoming more common in many other countries as well. Voluntary protection here means that forest owners voluntarily set aside tracts of forest to be protected and define their compensation fees. Depending on the objectives of the forest owners, the compensation fee reflects the forest owners’ (positive) attitude towards biodiversity, scenic beauty, recreational values and/or the existence of long-term cutting possibilities. When a forest owner decides to offer part of his/her forest holding to be temporarily protected, the owner faces a new decision problem related to definition of the compensation fee, which should be based on diverse information concerning stand- and holding-level opportunity costs as well as on the biodiversity value of the stand. This article introduces three decision-support elements for assisting forest owners in defining their compensation fees. The first element relates to the assessment of the potential stand-level loss of timber harvesting income that the temporary protection of the stand may cause. The second element sets the holding-level opportunity cost of protection by utilizing the forest owners’ holding level goals, the holdings’ production possibilities and optimization methods. The third element describes the biodiversity value of the stand by means of a multi-criteria expert model. Case study material collected from the area of Central Karelia Herb-rich Forests Network pilot project is used to illustrate the characteristics of the decision-support elements and to point out some development needs for the future use of these elements.
article id 276, category Research article
Additional insight into the performance of a new heuristic for solving spatially constrained forest planning problems. Silva Fennica vol. 41 no. 4 article id 276. https://doi.org/10.14214/sf.276
The raindrop method of searching a solution space for feasible and efficient forest management plans has been demonstrated as being useful under a limited set of circumstances, mainly where adjacency restrictions are accommodated using the unit restriction model. We expanded on this work and applied the model (in a modified form) to a problem that had both wood flow and area restriction adjacency constraints, then tested the problem formulation on six hypothetical forests of different sizes and age class distributions. Threshold accepting and tabu search were both applied to the problems as well. The modified raindrop method’s performance was best when applied to forests with normal age class distributions. 1-opt tabu search worked best on forests with young age class distributions. Threshold accepting and the raindrop method both performed well on forests with older age class distributions. On average, the raindrop method produced higher quality solutions for most of the problems, and in all but one case where it did not, the solutions generated were not significantly different than the heuristic that located a better solution. The advantage of the raindrop method is that it uses only two parameters and does not require extensive parameterization. The disadvantage is the amount of time it needs to solve problems with area restriction adjacency constraints. We suggest that it may be advantageous to use this heuristic on problems with relatively simple spatial forest planning constraints, and problems that do not involve young initial age class distributions. However, generalization of the performance of the raindrop method to other forest planning problems is problematic, and will require examination by those interested in pursuing this planning methodology. Given that our tests of the raindrop method are limited to a small set of URM and ARM formulations, one should view the combined set of work as additional insight into the potential performance of the method on problems of current interest to the forest planning community.
article id 418, category Research article
Testing a large-scale forestry scenario model by means of successive inventories on a forest property. Silva Fennica vol. 38 no. 3 article id 418. https://doi.org/10.14214/sf.418
Modellers of large-scale forestry scenario models face numerous challenges. Information and sub-models from different disciplines within forestry, along with statistical and mathematical methodology, have to be considered. The individual biological sub-models (i.e. models for recruitment, growth and mortality) applied in large-scale forestry scenario models are in general well documented and extensively evaluated. However, evaluations by means of full-scale comparisons of observed and predicted values for continuous forest areas, where the totality of the large-scale forestry scenario model including interactions between sub-models and other parts of the model, are considered, have rarely been seen. The aim of the present work was to test the totality of the Norwegian large-scale forestry scenario model AVVIRK-2000, and thereby evaluate the applicability of the model for use in management planning. The test was done by means of successive inventories and accurate recordings of treatments over a period of 30 years for a property comprising 78.5 ha forest-land. Seen in the perspective of management planning, the differences between observed and predicted values for potential harvest level, growing stock and growth were small, e.g. a difference between observed growing stock in year 2000 and growing stock in the same year predicted from 1970 of 2.6%. The model may therefore be applied for practical purposes without any fundamental changes or calibrations of the biological model basis. However, the present test should be seen as an example that failed to falsify the model, rather than a final validation. As long as the model is in practical use, further evaluations should continue and subsequent possible calibrations should be performed.
article id 545, category Research article
Eight heuristic planning techniques applied to three increasingly difficult wildlife planning problems. Silva Fennica vol. 36 no. 2 article id 545. https://doi.org/10.14214/sf.545
As both spatial and temporal characteristics of desired future conditions are becoming important measures of forest plan success, forest plans and forest planning goals are becoming complex. Heuristic techniques are becoming popular for developing alternative forest plans that include spatial constraints. Eight types of heuristic planning techniques were applied to three increasingly difficult forest planning problems where the objective function sought to maximize the amount of land in certain types of wildlife habitat. The goal of this research was to understand the relative challenges and opportunities each technique presents when more complex difficult goals are desired. The eight heuristic techniques were random search, simulated annealing, great deluge, threshold accepting, tabu search with 1-opt moves, tabu search with 1-opt and 2-opt moves, genetic algorithm, and a hybrid tabu search / genetic algorithm search process. While our results should not be viewed as universal truths, we determined that for the problems we examined, there were three classes of techniques: very good (simulated annealing, threshold accepting, great deluge, tabu search with 1-opt and 2-opt moves, and tabu search / genetic algorithm), adequate (tabu search with 1-opt moves, genetic algorithm), and less than adequate (random search). The relative advantages in terms of solution time and complexity of programming code are discussed and should provide planners and researchers a guide to help match the appropriate technique to their planning problem. The hypothetical landscape model used to evaluate the techniques can also be used by others to further compare their techniques to the ones described here.
article id 578, category Research article
Development of spatially feasible forest plans: a comparison of two modeling approaches. Silva Fennica vol. 35 no. 4 article id 578. https://doi.org/10.14214/sf.578
Spatial goals are becoming more frequent aspects of forest management plans as regulatory and organizational policies change in response to fisheries and wildlife concerns. The combination of green-up constraints (harvesting restrictions that prevent the cutting of adjacent units for a specified period of time) and habitat requirements for red-cockaded woodpeckers (RCW) in the southeastern U.S. suggests that spatially feasible forest plans be developed to guide management activities. We examined two modeling approaches aimed at developing management plans that had both harvest volume goals, RCW habitat, and green-up constraints. The first was a two-stage method that in one stage used linear programming to assign volume goals, and in a second stage used a tabu search – genetic algorithm heuristic technique to minimize the deviations from the volume goals while maximizing the present net revenue and addressing the RCW and green-up constraints. The second approach was a one-stage procedure where the entire management plan was developed with the tabu search – genetic algorithm heuristic technique, thus it did not use the guidance for timber volume levels provided by the LP solution. The goal was to test two modeling approaches to solving a realistic spatial harvest scheduling problem. One is where to volume goals are calculated prior to developing the spatially feasible forest plan, while the other approach simultaneously addresses the volume goals while developing the spatially feasible forest plan. The resulting forest plan from the two-stage approach was superior to that produced from the one-stage approach in terms of net present value. The main point from this analysis is that heuristic techniques may benefit from guidance provided by relaxed LP solutions in their effort to develop efficient forest management plans, particularly when both commodity production and complex spatial wildlife habitat goals are considered. Differences in the production of forest products were apparent between the two modeling approaches, which could have a significant effect on the selection of wood processing equipment and facilities.
article id 606, category Research article
Modelling future timber price development by using expert judgments and time series analysis. Silva Fennica vol. 35 no. 1 article id 606. https://doi.org/10.14214/sf.606
Timber prices belong to the most important variables affecting the optimality of forest management. On the other hand, forecasting of timber prices is very uncertain. One difficulty when using past time series data in forecasting future timber price development is the possibility of changes in the markets and in the society at large. Expert knowledge can be applied in forecasting of timber prices as information additional to that provided by time series modelling. This paper presents an approach utilising both time series data and expert judgments in modelling future timber prices. A time series model is used as the basis for the approach. Parameters describing future timber price trends, variation in future timber prices, and the probabilities of price peaks taking place in the future are estimated with expert judgments as the basis. A case study involving 12 experts was carried out in Finland, and models were estimated for all the six major timber assortments in the country. The model produced can be utilised in the optimisation calculations of forest planning.
article id 651, category Research article
Optimization bias in forest management planning solutions due to errors in forest variables. Silva Fennica vol. 33 no. 4 article id 651. https://doi.org/10.14214/sf.651
The yield of various forest variables is predicted by means of a simulation system to provide information for forest management planning. These predictions contain many kinds of uncertainty, for example, prediction and measurement errors. Inevitably, this has an effect on forest management planning. It is well known that uncertainty in the forest yields causes optimistic bias in the observed values of the objective function. This bias increases with the error variances. The amount of bias, however, also depends on the error structure and the relations between the objective variables. In this paper, the effect of uncertainty in forest yields on optimization is studied by simulation. The effect of two different sources of error, the correlation structure of these errors and relations among the objective variables are considered, as well as the effect of two different optimization approaches. The relations between the objective variables and the error structure had a notable effect on the optimization results.
article id 677, category Research article
Analysing uncertainties of interval judgment data in multiple-criteria evaluation of forest plans. Silva Fennica vol. 32 no. 4 article id 677. https://doi.org/10.14214/sf.677
The use of interval judgments instead of accurate pairwise comparisons has been proposed as a solution to facilitate the analysis of uncertainties in the widely applied pairwise comparisons technique. A method is presented for deriving probability distributions for the pairwise comparisons and for utilizing the distributions in the analysis of uncertainties in the evaluation process. The first step is that the expert or the decision-maker is queried as to the best guess of the priority ratio of the attributes compared. This is followed by an adjusting query concerning the uncertainty in the comparison: what is the probability of the priority ratio being between the best guess ± 1 unit of the pairwise comparison scale? An application of the method is presented in the form of multiple-criteria evaluation of alternative management plans for a forest area.
Category: Discussion article
article id 527, category Discussion article
Socioecological landscape planning: an approach to multi-functional forest management. Silva Fennica vol. 36 no. 4 article id 527. https://doi.org/10.14214/sf.527
article id 7378, category Article
Tutkimuksia metsän puuston muodostumisesta : tuottohakkauslaskelma. Acta Forestalia Fennica vol. 51 no. 2 article id 7378. https://doi.org/10.14214/aff.7378
English title: (1943). Studies on development of growing stock: calculation of cutting budget.
The aim of the study was to develop a method for calculating a cutting budget that is adapted to the present forest management practices. The cutting budget determines the volume of annual cuttings for a forest holding in a certain period of time. Effect of fellings on the cutting budget depends on the cutting methods used. The study aimed at proving that growth of the forest can be estimated based on growing stock and structure of the forests for a certain time period. Accordingly, adequate drain can be defined in advance. The cutting budget is based on age-class distribution of the forest holding, which is most applicable for even-aged forestry. Calculation is based on area of the forest land and estimated volume of the growing stock. Also, the quality of the forest soil can be taken into account when age-class distribution is used. A suitable period for estimating a cutting budget is suggested to be 20 years, which is divided in two 10-year periods. The cutting budget it is included in a forestry plan. An example of a cutting plan based on the method is presented.
The PDF includes a summary in German.
article id 5594, category Article
Economic impacts of carbon sequestration in reforestation: examples from boreal and moist tropical conditions. Silva Fennica vol. 30 no. 2–3 article id 5594. https://doi.org/10.14214/sf.a9239
The impact of carbon sequestration on the financial profitability of four tree plantation cases in Finland and the Philippines were examined. On the basis of stem wood growth; the accumulation of carbon in forest biomass, the formation and decomposition of litter, and the carbon flow in wood-based products were assessed for each reforestation case representing boreal (Finland) and moist tropical conditions (the Philippines). Using different unit values for carbon sequestration the profitability of reforestation was estimated for a fixed 100-year period on a per hectare basis. The financial profitability of reforestation increased notably when the sequestered carbon had high positive values. For example, when the value of carbon sequestration was set to be Twenty-five United States Dollar per megagram of carbon (25 USO/Mg C), the internal rate of return (IRR) of a reforestation investment with Norway spruce (Picea abies (L.) H. Karst.) in Finland increased from 3.2% to 4.1 %. Equally, the IRR of reforestation with mahogany (Swietenia macrophylla King) in the Philippines increased from 12.8% to 15.5%. The present value of carbon sequestration ranged from 39–48% and from 77–101% of the present value of the reforestation cost in Finland and the Philippines, respectively when a 25 USO/Mg C shadow price and a 5% discount rate were applied. Sequestration of one mg of carbon in reforestation in Finland and the Philippines was estimated to cost from 10.5–20.0 and from 4.0–13.6 USO, respectively.
article id 5492, category Article
Use of computer graphics for predicting the amenity of forest trails. Silva Fennica vol. 26 no. 4 article id 5492. https://doi.org/10.14214/sf.a15653
Ten trails, one kilometre each, were evaluated by 15 persons for scenic beauty, recreational value and variety. All trails passed through commercially managed forests dominated by conifers. The trails were first evaluated by viewing computer simulations based on a series of graphical illustrations of forest landscapes, then from a slide show, and finally in the field. In the computer simulation and slide show, landscape pictures along the trail at an interval of 35–40 m were presented for 3–4 seconds. The ranks between slide show and field were slightly more similar than those between simulation and field. The mean correlation of 12 persons between the field ranking and assessment of either computer simulations or slide shows or graphics than scenic beauty or recreational value. Spearman’s rank correlations computed from median scores of a group of 12 peers were clearly better than the average of individual persons varying from 0.6 to 0.9.
The PDF includes an abstract in Finnish
article id 5484, category Article
A decision theoretic approach applied to goal programming of forest management. Silva Fennica vol. 26 no. 3 article id 5484. https://doi.org/10.14214/sf.a15645
An alternative approach to formulating a forestry goal programming problem is presented. First, single objective optima levels are solved. The Analytical Hierarchy Process is applied in the estimation of a priori weights of deviations from the goal target levels. The ratios of the weights can be interpreted as relative importance of the goals, respectively. The sum of the weighted deviations from all single optima levels associated with the management goals is minimized. Instead of absolute deviations, relative ones are used. A case study problem of forest management planning with several objectives, measured in different units, is analysed.
The PDF includes an abstract in Finnish.
article id 5191, category Article
Metsänuudistamisen vaatiman ajan merkitys uudistamispäätöksissä. Silva Fennica vol. 17 no. 3 article id 5191. https://doi.org/10.14214/sf.a15174
English title: (1983). Elevation of the time factor in reforestation decisions.
Length of the regeneration period is a criterion commonly used for comparing different reforestation methods. The time factor should be evaluated using a realistic system for long-term planning. In this paper the preliminary evaluation is made by simplified calculations based on the development series. The slow regeneration method is assumed to be otherwise equal to the rapid one but it has a 5- or 10-years delay at the beginning, and the rotation is thus the final cutting age plus 5- or 10-years delay. Cost of the time delay is taken to be the difference in reforestation costs that makes the rapid and the slow methods equivalent. Calculations are made using zero costs for the slow method; but if the cost of the slow method increases, the critical cost difference decreases very slowly. The final cutting age and the regeneration method must be decided simultaneously. Therefore, the cost of the time delay is presented as a function of final cutting age. By maximizing the average annual revenue, rotation can be even increased if more rapid but more expensive regeneration method is used.
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article id 4918, category Article
Metsätalousyksikön puuntuotannon suunnittelu lineaarista ohjelmointia käyttäen. Silva Fennica vol. 9 no. 2 article id 4918. https://doi.org/10.14214/sf.a14762
English title: (1975). Linear programming in the planning of timber production in a forestry unit.
The planning of timber production in a forestry unit is divisible into two phases. In the first phase, planning provides the decision-maker with a number of possible timber production policies; these policies define the production possibility boundary. After the decision-maker has chosen one of these policies, planning moves to the second phase, in which a detailed programme is prepared with a view to meeting the requirements of the timber production policy accepted. The paper indicates one possibility of solving these two tasks simultaneously. In the first phase, the solution of the primal linear programming problem is employed and in the second phase the respective dual or shadow price solution.
The PDF includes a summary in English.
article id 7513, category Article
A participatory approach to tactical forest planning. Acta Forestalia Fennica no. 251 article id 7513. https://doi.org/10.14214/aff.7513
The paper examines the needs, premises and criteria for effective public participation in tactical forest planning. A method for participatory forest planning utilizing the techniques of preference analysis, professional expertise and heuristic optimization is introduced. The techniques do not cover the whole process of participatory planning, but are applied as a tool constituting the numerical core for decision support. The complexity of multi-resource management is addressed by hierarchical decision analysis which assesses the public values, preferences and decision criteria toward the planning situation. An optimal management plan is sought using heuristic optimization. The plan can further be improved through mutual negotiations, if necessary. The use of the approach is demonstrated with an illustrative example. Its merits and challenges for participatory forest planning and decision making are discussed and a model for applying it in general forest planning context is depicted. By using the approach, valuable information can be obtained about public preferences and the effects of taking them into consideration on the choice of the combination of standwise treatment proposals for a forest area. Participatory forest planning calculations, carried out by the approach presented in the paper, can be utilized in conflict management and in developing compromises between competing interests.
article id 7659, category Article
Hoidettujen talvilaitumien vaikutus hirvituhoihin mäntytaimikoissa. Acta Forestalia Fennica no. 212 article id 7659. https://doi.org/10.14214/aff.7659
English title: (1990). Effect of winter feeding on moose damage to young Scots pine stands.
The establishment of moose (Alces alces L.) winter feeding sites, their utilization and their effect on damage to young Scots pine (Pinus sylvestris L.) plantations was studied in Ruokolahti-Imatra area in Eastern Finland in 1987–89. During the period, the density in the area was about 3–5 moose/ 1,000 ha.
Six feeding sites were established by fertilization, offering mineral lics and the tops of aspen and Scot pine and by salting the tops of pine. The moose preferred the feeding site to control areas during both summer and winter. In winter browsing was very heavy, especially in those areas located in or close to traditional wintering areas. In winter no moose were seen in the summer habitats.
The extent of, and fluctuations in moose damage were studied in 47 Scots pine plantations in the immediate surroundings of the feeding sites (29 plantations), control areas (18 plantations) and also 68 randomly selected pine plantations. Before the experiment began in 1987 four plantations had been seriously damaged. During the study period only one plantation was seriously damaged. However, it could not be conclusively proved that damage to the pine plantations had been reduced as a result of the feeding sites. The results of the study can be put into practice elsewhere to create better living conditions for moose in their winter habitats. However, the food offered at the feeding site should be in the right proportion to the number of animals wintering in the area, so that the risk of damage to nearby plantations would be kept as small as possible.
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article id 4719, category Article
Metoder og muligheter for langsiktige prognoser i skoglig planlegging. Silva Fennica no. 115 article id 4719. https://doi.org/10.14214/sf.a14278
English title: (1963). Methods and possibilities of long-term forecasts in forest management planning.
This paper describes different methods of long-term forecasts in forest management planning with a special attention on intention forecasts for a total forest property or district. Methods for calculating the sustained yield on the basis of the actual increment or the yearly area cut are discussed. It is concluded that a better estimate of the sustained yield is obtainable by the application of a long-term forecast technique. Forecasts for 100 years should not be viewed as plans, but as a background for making short-term decisions. Some of the long-term-type programmes, such as the programme of maximum profit, sustained yield in volume and in money are discussed briefly.
It is pointed out that there is often present a conflict between the various elements of the policy formulated by a forest owner. This leads to the conclusion that the calculations of the profitability of single projects may be misleading.
The precision of a long-term forecast is discussed, and how under certain assumptions the error of the allowable cut is influenced by errors in area, volume, age etc. It is shown that the precision in area and volume is more important in this connection than, say, the precision in increment. In conclusion, existing knowledge, methods and equipment for calculations constitute a basis for long-term forecasts which make them an important instrument in forest management planning.
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article id 4584, category Article
Metsätaloudelliset näkökohdat ja keskitetyt hakkuut. Silva Fennica no. 64 article id 4584. https://doi.org/10.14214/sf.a13986
English title: (1948). Forest management and centralized loggings.
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 issue 64.
This presentation discusses different ways of organizing felling cycle, forest management practices used in the forests of Finnish forest research institute, and how good practices developed in the institue could be applied in state forests.