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Silva Fennica 1926-1997
Acta Forestalia Fennica

Silva Fennica vol. 36 no. 2 | 2002

Category : Research article

article id 545, category Research article
Pete Bettinger, David Graetz, Kevin Boston, John Sessions, Woodam Chung. (2002). Eight heuristic planning techniques applied to three increasingly difficult wildlife planning problems. Silva Fennica vol. 36 no. 2 article id 545.
Keywords: forest planning; spatial harvest scheduling; adjacency constraints
Abstract | View details | Full text in PDF | Author Info
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.
  • Bettinger, Department of Forest Resources, Oregon State University, Corvallis, OR 97331 E-mail: (email)
  • Graetz, Department of Forest Resources, Oregon State University, Corvallis, OR 97331 E-mail:
  • Boston, Carter Holt Harvey Forest Fibre Solutions, Tokoroa, New Zealand E-mail:
  • Sessions, Department of Forest Engineering, Oregon State University, Corvallis, OR 97331 E-mail:
  • Chung, Department of Forest Engineering, Oregon State University, Corvallis, OR 97331 E-mail:
article id 544, category Research article
Perttu Anttila. (2002). Updating stand level inventory data applying growth models and visual interpretation of aerial photographs. Silva Fennica vol. 36 no. 2 article id 544.
Keywords: aerial photographs; stand level inventory; MELA; updating of inventory data; visual interpretation
Abstract | View details | Full text in PDF | Author Info
In this study two procedures for updating stand level inventory data were developed and tested. The development of the growing stock of 62 stands over 12 years was simulated in the MELA stand simulator with no prior information of rapid changes, such as clear-cuttings. The acceptability of the simulation was decided standwise with visual interpretation of aerial false-colour photographs. If the simulated data were not accepted, new stand attributes were assessed with photo interpretation in procedure 1. In procedure 2, on the other hand, it was possible to utilise old management proposals. In case a cutting or other operation had been proposed and it looked like the operation had been realised, the interpreters accepted the proposal. Otherwise the last implemented operation and implementation year were interpreted. In case no operation had been carried out during the updating period but the growth model updated data were not acceptable, the same stand characteristics were estimated as in procedure 1. Stands where a proposal had been accepted or an operation interpreted were later updated again in MELA so that the program simulated the operations. The Root Mean Squared Errors of stem volume were 62 and 57 m3 per ha (34 and 30%) with procedures 1 and 2. With procedure 2 the accuracy of updating was comparable with a stand level field inventory carried out in the study area. The productivity of the photo interpretation procedures was 57 and 84 ha per h, respectively, whereas the productivity of a field inventory has been 3.3–5 ha per h.
  • Anttila, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: (email)
article id 543, category Research article
Maarten Nieuwenhuis. (2002). The development and validation of pre-harvest inventory methodologies for timber procurement in Ireland. Silva Fennica vol. 36 no. 2 article id 543.
Keywords: pre-harvest inventory; simulation; dynamic programming; value maximisation; optimal crosscutting
Abstract | View details | Full text in PDF | Author Info
This article describes the development and validation of a decision-support system for sawmill wood procurement, dealing specifically with the integration of the pre-harvest inventory procedures, site-specific dbh/height models and a generic taper equation, with a crosscutting simulator. The crosscutting simulation program faithfully mimics the process of cut-to-length harvesting and provides detailed information on the potential volume, logs count and diameter distributions for different log assortment specifications. Four data sets, consisting of a total of 4153 diameter and height measurements, were used in the validation process. The sites included two Sitka spruce clearfells, a Sitka spruce thinning and a Norway spruce clearfell. The evaluation process has shown that the developed decision-support system produced accurate results for a wide range of stand types, as long as sufficient large data sets were used, and that it provides the wood procurement manager of a sawmill with an efficient means of gaining a comprehensive insight into the yield potential of standing timber lots and, as such, represents a valuable aid to timber procurement and production planning.
  • Nieuwenhuis, University College Dublin, Dept. of Forestry, Belfield, Dublin 4, Ireland E-mail: (email)
article id 542, category Research article
Håkan Lindström. (2002). Intra-tree models of juvenile wood in Norway spruce as an input to simulation software. Silva Fennica vol. 36 no. 2 article id 542.
Keywords: Picea abies; image analysis; juvenile wood; growth conditions
Abstract | View details | Full text in PDF | Author Info
Juvenile wood found in the first 5–25 growth rings of a conifer has a structure and properties that differ from mature wood. Juvenile wood is therefore said to influence processing and the end-use of sawn products. Consequently, models describing the juvenile wood content, within and between trees, could be useful in improving the utilisation and value of wood as an industrial raw material. The objective of the present study was to develop juvenile wood models, based on Norway spruce trees, which could be used within a model system for conversion simulation studies. Nineteen stands of Norway spruce (Picea abies [L.] Karst.) were selected throughout Sweden. Based on DBH, two small, two medium, and two large diameter timber trees were taken from each stand. DBH varied between 180–470 mm, tree height between 17–34 m, and total age between 51–152 years. Each selected tree was cross-cut into logs; discs were prepared from the large end of each log and from the top end of the top log. Image analysis was used to determine growth ring development on sampled discs. Using tree and growth variables, the juvenile core radius and the logarithmic value of juvenile wood percentage were modelled. The two models had an R2Adj of 0.71 and 0.88 respectively.
  • Lindström, University of Canterbury, School of Forestry, Private Bag 4800, Christchurch, New Zealand E-mail: (email)
article id 541, category Research article
Azim U. Mallik, F. Wayne Bell, Yanli Gong. (2002). Effectiveness of delayed brush cutting and herbicide treatments for vegetation control in a seven-year-old jack pine plantation in northwestern Ontario, Canada. Silva Fennica vol. 36 no. 2 article id 541.
Keywords: species richness; Pinus banksiana; species diversity; conifer release treatments; glyphosate; brushsaw; competition index
Abstract | View details | Full text in PDF | Author Info
Efficacy of three conifer release treatments, i) single application of glyphosate (Vision™) herbicide, ii) multiple application of glyphosate herbicide, and iii) motor-manual brush cutting for controlling competing plants, particularly trembling aspen (Populus tremuloides), pin cherry (Prunus pensylvanica), green alder (Alnus viridis spp. crispa), and beaked hazel (Corylus cornuta spp. cornuta), was studied in a seven-year-old jack pine (Pinus banksiana) plantation in northwestern Ontario, Canada. The single and multiple glyphosate applications were equally effective in controlling trembling aspen and pin cherry, causing over 90% stem mortality. The brushsaw treatment caused an initial decrease followed by an increase in stem density of these two species. A high degree of stem thinning by natural mortality in the untreated control plots was observed in trembling aspen (23–46%) and pin cherry (41–69%) over four years. As with trembling aspen and pin cherry, stem density of green alder and beaked hazel initially decreased and then increased following the brushsaw treatment, mainly due to resprouting. Stem mortality in green alder and beaked hazel was 45% and 97%, respectively, two years after the operational glyphosate treatment. Competition index (CI) was low (mean CI = 52, ranging from 18 to 115) in all the plots including the untreated control. There was a significant increase in basal diameter of jack pine in the brushsaw and herbicide-treated plots compared to the control three years after the treatments. Jack pine seedlings in the brushsaw and glyphosate treated plots were taller compared to that of control but differences were not significant. Lower species richness and diversity were recorded in the herbicide-treated plots compared to the brushsaw and control plots in the third growing season following treatment.
  • Mallik, Department of Biology, Lakehead University, Thunder Bay, Ontario, Canada P7B 5E1 E-mail: (email)
  • Bell, Ontario Forest Research Institute, Ontario Ministry of Natural Resources, Sault Ste. Marie, Ontario, Canada P6A 2E5 E-mail:
  • Gong, Department of Biology, Lakehead University, Thunder Bay, Ontario, Canada P7B 5E1 E-mail:
article id 540, category Research article
Finn H. Brække, Nagwa Salih. (2002). Reliability of foliar analyses of Norway spruce stands in a Nordic gradient. Silva Fennica vol. 36 no. 2 article id 540.
Keywords: Norway spruce; Picea abies; needle analyses; diagnostic methods; nutrient status; imbalanced nutrition; fertilisation; volume growth
Abstract | View details | Full text in PDF | Author Info
Norway spruce stands at eleven sites in Finland, Norway and Sweden have been studied under various climates, atmospheric deposition of N and S and fertilisation regimes. Nitrogen was growth restricting at eight inland sites, while P was growth restricting at three coastal sites. Liming and N fertilisation caused serious B deficiency on some of the inland sites. It is likely that liming affects uptake of B, whereas N fertilisation causes a dilution due to increased growth. Application of S combined with N probably caused K deficiency at one of the sites. The reliability of foliar analyses as a method to diagnose nutrient status and the likely changes after nutrient input to spruce forests in the Nordic countries, are discussed. The CR- and the DOP-method are evaluated for diagnostic purposes. Both methods seem to give reliable conclusions even if the CR-method often produces more specific results. Interpretation based on both current and one year old foliage improved the diagnostic prognoses. The accuracy of diagnosis also relies on knowledge and ability of the interpreter. Based on the results it is reason to be cautious about recommendations of single element fertilisations, e.g. with N alone, because the demand of other elements beyond available pools frequently occurs. Forest trees in the boreal region are probably well adapted to N deficiency, which means that they can handle the physiological consequences rather well, while deficiencies of other elements usually are more detrimental to growth vigour and stress related diseases.
  • Brække, Department of Forest Sciences, Agricultural University of Norway (AUN), P.O. Box 5044, N-1432 Ås, Norway E-mail: (email)
  • Salih, Department of Ecology and Environmental Research, Swedish University of Agricultural Sciences (SLU), P.O. Box 7072, S-750 07 Uppsala, Sweden E-mail:
article id 539, category Research article
Martti Venäläinen, Seppo Ruotsalainen. (2002). Procedure for managing large-scale progeny test data: a case study of Scots pine in Finland. Silva Fennica vol. 36 no. 2 article id 539.
Keywords: Pinus sylvestris; selection; progeny testing; performance level; reliability coefficient
Abstract | View details | Full text in PDF | Author Info
Large progeny test networks are typical for conventional forest tree breeding programmes. The individual progeny tests differ with respect to age, composition and ability to screen the breeding values of the parent trees. Several approaches have been introduced to manage the unbalanced and diverse nature of the data generated by progeny tests. This report presents a procedure for ranking breeding material on the basis of ‘messy’ data. Plot means were used as input values and missing plots were estimated from least squares. The differences between test means and variances were standardised by the performance level method. The different precision of the tests was quantified through the reliability coefficient. In order to facilitate the selection of plus trees for different purposes, all the available test results were combined into a single variable that was used for ranking. Three different kinds of ranking variable were calculated and each of them proved to be more useful for the selection of plus trees than an arithmetic or weighted mean. One of them, WMEAN, relied on the reliability and number of the progeny tests, while the others, WCONF0.50 and WCONF0.10, relied on the standard error of the plus tree mean, thus emphasising the precision of the values obtained. The analyses were carried out with SAS® procedures, which require only moderate skills in statistics, programming and data processing technology. The procedure has functioned well throughout an eight-year development phase. Nearly three thousand Scots pine (Pinus sylvestris) plus trees have been ranked for various characters, and the results have been used for roguing the seed orchards, to establish new ones, and to select plus trees for breeding populations.
  • Venäläinen, Finnish Forest Research Institute, Punkaharju Research Station, FIN-58450 Punkaharju, Finland E-mail: (email)
  • Ruotsalainen, Finnish Forest Research Institute, Punkaharju Research Station, FIN-58450 Punkaharju, Finland E-mail:
article id 538, category Research article
Seppo Nevalainen. (2002). The incidence of Gremmeniella abietina in relation to topography in southern Finland. Silva Fennica vol. 36 no. 2 article id 538.
Keywords: Pinus sylvestris; forest inventory; Gremmeniella abietina; topography; digital elevation models
Abstract | View details | Full text in PDF | Author Info
Field data of the 8th National Forest Inventory (NFI) from southern Finland and digital elevation models (DEMs) were used in this study. Damage due to Gremmeniella abietina increased slightly with an increase in absolute elevation in mineral soils. Severe damage increased almost linearly with an increase in elevation in mineral soil plots. The mean elevation in the tract area (the 7 km x 8 km area surrounding the plot) was more strongly correlated with the disease than the elevation of individual plots. The relative altitude of the plot was important: the disease was most severe in the plots situated lower than the mean elevation of the tract area, especially in the peatland plots. In this group, the damage increased linearly with an increase in absolute elevation. According to detailed DEMs in the most diseased areas, steepness of the slope was negatively correlated with the disease. The aspect of the slope had a weak influence. On mineral soils, the disease was most common in south-facing slopes. The microtopography was not as important for the disease occurrence as the relative elevation of the plot. The disease frequencies were very similarly related to the three most common types of surface features (channels, ridges and planar regions) within the 50-m scale. At the cell size of 100 metres, the disease was more common in channels than in ridges, except in mineral soil plots. Topographic variables only partly explained the regional patterns in the occurrence of this disease. The disease was frequent on upland areas, but, on the other hand, it was also common on lowland areas. The most diseased areas studied in detail differed very much from each other with respect to topography and the disease incidence.
  • Nevalainen, Finnish Forest Research Institute, Joensuu Research Centre, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: (email)
article id 537, category Research article
Timo Kurkela. (2002). Crown condition as an indicator of the incidence of root rot caused by Heterobasidion annosum in Scots pine stands. Silva Fennica vol. 36 no. 2 article id 537.
Keywords: Pinus sylvestris; Heterobasidion annosum; root rot; symptoms; disease incidence
Abstract | View details | Full text in PDF | Author Info
Trees in three Scots pine stands seriously infected by Heterobasidion annosum were classified according to their crown condition into four classes, from healthy to dead trees. After cutting the stands, the classification was compared with the symptoms of annosum root rot on stump surfaces (pitched area) and with the extension of decay in the roots of excavated stumps. When dead trees were included, the average crown condition on the survey plots correlated with disease incidence. Without dead trees the correlation was not significant. Slightly infected trees could not be distinguished from healthy trees on the basis of crown condition. It was concluded that only the proportion of dead and dying trees in a stand is a reliable indication of the disease incidence for making decisions about the future management.
  • Kurkela, Finnish Forest Research Institute, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: (email)

Category : Review article

article id 546, category Review article
Teijo Palander, Mari Toivonen, Sanna Laukkanen. (2002). GroupWare and group decision support systems for wood procurement organisation. A review. Silva Fennica vol. 36 no. 2 article id 546.
Keywords: collaboration; teamwork-based organisation; group decision-making; communication
Abstract | View details | Full text in PDF | Author Info
Many kinds of decision support systems (DSSs) have been suggested for use of wood procurement organisations, but few meet the real needs of team managers in group decision-making process. Therefore, it has been concluded that the important features of group decision support systems (GDSSs) should be developed for teamwork-based organisations. Electronic meeting systems (EMSs), Computer-aided Visualisations (CAVs) and heuristics as well as other numerical approaches as combined with optimisation seem to be some of the most promising elements of GroupWare, because decisions are made in distributed groups and they deal with human behaviour. Relations between GDSSs and spontaneous decision conferencing (SDC) for modern organisations are also discussed, and suggestions for future research of management approaches are also given.
  • Palander, University of Joensuu, Faculty of Forestry, Box 111, FIN-80101 Joensuu, Finland E-mail: (email)
  • Toivonen, University of Joensuu, Faculty of Forestry, Box 111, FIN-80101 Joensuu, Finland E-mail:
  • Laukkanen, University of Joensuu, Faculty of Forestry, Box 111, FIN-80101 Joensuu, Finland E-mail:

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