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Articles by Kalle Kärhä

Category: Research article

article id 1323, category Research article
Tiina Laine, Kalle Kärhä, Antti Hynönen. (2016). A survey of the Finnish mechanized tree-planting industry in 2013 and its success factors. Silva Fennica vol. 50 no. 2 article id 1323. https://doi.org/10.14214/sf.1323
Highlights: In 2013, 31 planting machines were operated by 22 businesses and planted 4.7 million seedlings on 2663 hectares in Finland; Critical success factors included expertise of planting machine operators, high quality planting, adequate amount of work, stoniness, and removal of slash; Growth of the industry will depend on improved cost-efficiency, appropriate worksites, marketing, development of planting machines.

The aim of the study was to update the information pertaining to mechanized tree-planting activity in Finland in 2013 and its success factors. All businesses providing a mechanized tree-planting service were interviewed and asked to describe their equipment and activities, identify critical success factors (CSFs), and suggest areas for improvement. In 2013, 31 planting machines (18 Bracke P11.a, 11 M-Planter and 2 Risutec) operated by 22 businesses planted approximately 4.7 million seedlings on 2663 hectares. CSFs included expertise of planting machine operators, high quality planting, adequate amount of work, stoniness, and removal of slash. Based on the survey, some recommendations for improving mechanized planting work can be made. Firstly, improving the cost-efficiency of mechanized planting is necessary to enhance businesses’ profitability. Secondly, worksite selection is crucial as stoniness, stumps and slash debris diminish productivity. Lastly, the popularity of mechanized planting in the future will benefit from more marketing. Many businesses were unwilling to increase the area of service, invest in new equipment, or increase the volume of planting work but they believed that mechanized planting will become more popular in the near future.

  • Laine, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: tiina.laine@luke.fi (email)
  • Kärhä, Stora Enso Wood Supply Finland, P.O. Box 309, FI-00101 Helsinki, Finland ORCID ID:E-mail: kalle.karha@storaenso.com
  • Hynönen, University of Eastern Finland, Faculty of Science and Forestry, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: hynonena@gmail.com
article id 454, category Research article
Paula Jylhä, Olli Dahl, Juha Laitila, Kalle Kärhä. (2010). The effect of supply system on the wood paying capability of a kraft pulp mill using Scots pine harvested from first thinnings. Silva Fennica vol. 44 no. 4 article id 454. https://doi.org/10.14214/sf.454
The efficiencies of wood supply systems based on cut-to-length (CTL) harvesting, the harvesting of loose whole trees, and whole-tree bundling were compared using the relative wood paying capabilities (WPC) of a kraft pulp mill as decisive criteria. The WPCs from mill to stump were calculated for three first-thinning stands of Scots pine (Pinus sylvestris L.) with mean breast-height diameter of the removal of 6, 8, and 12 cm. Pulp price had a strong effect on the WPC, and the CTL system resulted in the highest WPC per m3 at stump. The savings in procurement costs and gains in energy generation from additional raw material acquired with the harvesting of loose whole trees did not compensate the losses in pulp production. Considering removal per hectare, loose whole trees gave the highest WPCs at stump in the two stands with the smallest trees and the highest proportion of additional raw material. Decrease in pulp price and increase in energy price improved the competitiveness of the whole-tree systems. In the case of whole-tree bundling, savings in transportation costs did not balance the high cutting and compaction costs, and the bundling system was the least competitive alternative.
  • Jylhä, Finnish Forest Research Institute, Kannus, Finland ORCID ID:E-mail: paula.jylha@metla.fi (email)
  • Dahl, Aalto University School of Science and Technology, Department of Forest Products Technology, Espoo, Finland ORCID ID:E-mail:
  • Laitila, Finnish Forest Research Institute, Joensuu, Finland ORCID ID:E-mail:
  • Kärhä, Metsäteho Oy, Helsinki, Finland ORCID ID:E-mail:
article id 144, category Research article
Markku Oikari, Kalle Kärhä, Teijo Palander, Heikki Pajuoja, Heikki Ovaskainen. (2010). Analyzing the views of wood harvesting professionals related to the approaches for increasing the cost-efficiency of wood harvesting from young stands. Silva Fennica vol. 44 no. 3 article id 144. https://doi.org/10.14214/sf.144
A lot of viable guidelines are currently available for more cost-effective harvesting of energy wood and industrial roundwood (i.e. pulpwood) from young stands. The study ranked the proposed potential approaches for increasing the cost-efficiency of small-diameter (d1.3 < 10 cm) energy wood and industrial roundwood harvesting from early thinnings. Research data, based on a total of 40 personal interviews, was collected in early 2008. The interviewees were divided into four wood harvesting professional groups: 1) Managers in wood procurement organizations, 2) Forest machine contractors, 3) Forest machine manufacturers and vendors, and 4) Wood harvesting researchers. In the opinion of the respondents, there is great potential to increase the cost-efficiency of wood harvesting through improving harvesting conditions (i.e. effective tending of seedling stands, delaying harvesting operations, and pre-clearance of dense undergrowth). The interviewees also underlined that harvesting methods can be rationalized, e.g. multiple-tree handling in industrial roundwood cuttings, crane scale measurement, integrated wood harvesting, and careful selection of stands for harvesting. The strong message given by the interviewees was that the education of forest machine operators must be made more effective in the future. There would be significant possibilities for cost savings in young stands, if methods and techniques with the most potential were utilized completely in wood harvesting.
  • Oikari, Karelwood, Kontiolahti, Finland ORCID ID:E-mail: markku.oikari@karelwood.com (email)
  • Kärhä, Metsäteho Oy, Helsinki, Finland ORCID ID:E-mail:
  • Palander, University of Eastern Finland, Faculty of Science and Forestry, Joensuu, Finland ORCID ID:E-mail:
  • Pajuoja, Metsäteho Oy, Helsinki, Finland ORCID ID:E-mail:
  • Ovaskainen, University of Eastern Finland, Faculty of Science and Forestry, Joensuu, Finland ORCID ID:E-mail:
article id 698, category Research article
Kalle Kärhä, Sami Oinas. (1998). Satisfaction and company loyalty as expressed by non-industrial private forest owners towards timber procurement organizations in Finland. Silva Fennica vol. 32 no. 1 article id 698. https://doi.org/10.14214/sf.698
The satisfaction and company loyalty as expressed by non-industrial, private forest (NIPF) owners towards timber procurement organizations were clarified via a mail questionnaire. The results denoted that there is a positive correlation between the levels of forest owners’ expectations (EXP) and perceived performance (PERF). In addition, the lower EXP and the higher PERF were, the greater was the overall satisfaction index (SAT). About two thirds of forest owners were characterized by a negative SAT value or then they were dissatisfied with the performance of the procurement organization in their last timber-sales transaction. Furthermore, the results obtained indicated that the SAT index significantly influences the company loyalty expressed by NIPF owners – their willingness to give favourable reports of the company to the others, and their willingness to engage in future timber-sales transactions with the same company. Nonetheless, the SAT index did not affect the market share of a particular company, and this could be partly accounted for by the similar level of performance among the companies and the lack of competition in the timber trade. Finally, the results revealed several dimensions of timber procurement, and some seller segments to which companies could pay more attention to in order to be able to achieve better satisfaction levels and the loyalty of NIPF owners in the future. One approach to successfully addressing these challenges could be the adopting of a satisfaction decision support system (SatDSS).
  • Kärhä, Faculty of Forestry, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland ORCID ID:E-mail: karha@forest.joensuu.fi (email)
  • Oinas, Faculty of Forestry, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland ORCID ID:E-mail:

Category: Research note

article id 915, category Research note
Kalle Kärhä. (2012). Comparison of two stump-lifting heads in final felling Norway spruce stand. Silva Fennica vol. 46 no. 4 article id 915. https://doi.org/10.14214/sf.915
The use of stump and root wood chips has increased very rapidly in the 21st century in Finland: in the year 2000, the total consumption of stump wood chips for energy generation was 10 GWh, while in 2010 it was approximately 2 TWh. Metsäteho Oy and TTS Research evaluated two stump-lifting devices for the lifting of Norway spruce (Picea abies) stumps. The productivity and costs of stump lifting were determined. There was one base machine with one operator in the time study. When lifting stumps with a diameter of 30 cm, the effective hour productivity of stump lifting was 11.2 m3 solid over bark (sob)/E0 (4.8 tonD/E0) without site preparation using a Väkevä Stump Processor, and when lifting spruce stumps with a diameter of 40 cm, the productivity was 14.9 m3 sob/E0 (6.5 tonD/E0). When the site preparation (mounding) was integrated into lifting work, the stump-lifting productivity decreased 21–27%. The stump-lifting productivity of the other lifting head (Järvinen) was lower than that of the Väkevä Stump Processor. Some development suggestions for the Järvinen lifting head were presented and discussed. The cost calculations showed that stump-lifting costs are extremely high when stump diameter is less than 20 cm. Therefore, the study recommended a change in the current stump-harvesting guidelines of Finland: The study suggested that all the stumps with a diameter less than 20 cm should be left on the harvesting site.
  • Kärhä, Stora Enso Wood Supply Finland, Talvikkitie 40 C, FI-01300 Vantaa, Finland ORCID ID:E-mail: kalle.karha@storaenso.com (email)

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