Assessing the Guidelines for Pre-Harvest Clearing Operations of Understory in First Thinnings: Preliminary Results from Stora Enso in Finland

Year 2020, , 14 - 22, 26.06.2020

Kalle Kärhä Dan Bergström

https://doi.org/10.33904/ejfe.645639

Cited By: 3

Abstract

The objective of this study was to analyze forest industry professionals’ opinions of the utility of pre-clearance work prior to the first-thinning operations. A total of 153 interviews were conducted with three groups of professionals (forest machine entrepreneurs, harvester operators and logging officers) with a response rate of 80%. In general, the respondents agreed that the occurrence of understory would hinder the cutting work if the softwood tree understory density exceeded 1,152 trees/ha and a height of 1.42 m. The corresponding values for broadleaved trees were 1,669 trees/ha and a height of 1.86 m. The respondents stated that trees eligible for logging should be pre-cleared within a circular area with a mean radius of 1.24 m, and the stump height of cleared trees should not exceed 10.8 cm. In intermediate areas (i.e., outside of the circular areas) understory trees exceeding a height of 1.96 m should be pre-cleared. Pre-harvest clearing should be conducted, on average, 9.2 months prior to the logging operation. The results indicated significant differences between the opinions of the respondents concerning the understory density, the height that would hinder cutting and the most convenient pre-harvest clearing method. As a result of this research, pre-clearance guidelines, based on the best-practice knowledge of the professionals, was launched at Stora Enso company in Finland. Because the study results were based on subjective knowledge, they should be validated by long-term empirical data collection and continuing analysis of the effect of understory trees on the efficiency of a forest machine operator.

Keywords

Undergrowth, Pre-clearance, Logging, Cutting, Interview survey

References

• Äijälä, O., Koistinen, A., Sved, J., Vanhatalo, K., Väisänen, P. (Eds.), 2019. Metsänhoidon suositukset (Recommendations of good silviculture). Tapion julkaisuja. 252 p.
• Bergström, D., Di Fulvio, F., Nuutinen, Y., 2016. Effect of Forest Structure on Operational Efficiency of a Bundle-Harvester System in Early Thinnings. Croatian Journal of Forest Engineering, 37(1):37-49.
• Dehlén, J., 2010. Mindre studie av en ny gallringsmetod i stamtät förstagallring av gran i södra Sverige (A brief study of a new thinning method in dense first-thinning of spruce in southern Sweden). Sveriges lantbruksuniversitet, Skogshushållning, Examens-arbete 12. 49 p.
• Eriksson, A., Lindberg, A., 2010. Förröjning i förstagallring - vad kostar det och följer utförarna instruktionerna (Cleaning understorey trees in first thinning - what is the cost and do the contractors follow their directive)? Sveriges lantbruksuniversitet, Skogshushållning, Examensarbete 18. 45 p.
• Finnish Forest Centre. 2019. Korjuujäljen tarkastusten tulokset vuodelta 2018 (Harvesting quality in thinning stands in Finland, 2018). https://www.metsakeskus.fi/sites/default/files/tiedote-liite-korjuujalki-tarkastukset.pdf (Accessed: 21 September 2019).
• Frank, N., 2006. Underröjning i förstagallring (Cleaning of understorey trees before thinning). Sveriges lantbruksuniversitet, Institutionen för skogens produkter och marknader, Examensarbeten 64. 9 p.
• Haavikko, H., Kärhä, K., Hourula, M., Palander, T., 2019. Attitudes of Small and Medium-Sized Enterprises towards Energy Efficiency in Wood Procurement: A Case Study of Stora Enso in Finland. Croatian Journal of Forest Engineering, 40(1):107-123.
• Hakkuukonetyömaan ennakkoraivaus (Pre-clearance of mechanized harvesting site). 2001. Metsätehon opas. 7 p.
• Heikkinen, A., 2012. Ennakkoraivaustarpeiden määrittä-minen ensiharvennuskohteilla Metsähallituksen Kuh-mon metsätiimissä (Determining of pre-clearing needs at first thinning sites in Metsähallitus forestry team of Kuhmo). Bachelor’s Thesis. North Karelia University of Applied Sciences. 45 p.
• Hjelmqvist, R., 2016. Jämförelse av produktivitet och kostnader för drivningsarbetet vid två olika förröjningsnivåer i första gallring av konfliktbestånd (Comparison of productivity and costs for harvesting and forwarding at two different preclearance levels in first thinning of conflict stands). Sveriges lantbruks-universitet, Institutionen för Skogens Biomaterial och Teknologi, Arbetsrapport 17. 37 p.
• Jonsson, F., 2015. Hur påverkar avlövad underväxt kvaliteten och drivningskostnaden i gallring (How does leafless undergrowth affect quality and logging costs in thinning)? Sveriges lantbruksuniversitet, Institutionen för skogliga biomaterial och teknologi, Arbetsrapport 8. 46 p.
• Kärhä, K., 2006. Effect of undergrowth on the harvesting of first-thinning wood. Forestry Studies, 45:101-117.
• Kärhä, K., 2015. Towards better pre-clearance guideline of undergrowth in first thinnings: Case study of Stora Enso Wood Supply Finland. In: Kanzian, C., Erber, G., Kühmaier, M. (Eds.), Forest Engineering: “Making a positive contribution”. Abstracts and Proceedings of the 48th Symposium on Forest Mechanization, Linz, Austria 2015:63-67.
• Kärhä, K., Keskinen, S., 2011. Ensiharvennukset metsäteollisuuden raaka-ainelähteenä 2000-luvulla (First thinnings as a raw material source of Finnish forest industries in the 21st century). Metsätehon Tuloskalvosarja 2/2011. 29 p.
• Kärhä, K., Rönkkö, E., Gumse, S.-I., 2004. Productivity and cutting costs of thinning harvesters. International Journal of Forest Engineering, 15(2):43-56.
• Kärhä, K., Keskinen, S., Liikkanen, R., Kallio, T., Lindroos, J., 2006. Ennakkoraivaus osana ensihar-vennuspuun korjuuta (Undergrowth pre-clearance as a part of first-thinning wood harvesting). Metsätehon Raportti, 187. 77 p.
• Korhonen, K.T., Ihalainen, A., Ahola, A., Heikkinen, J., Henttonen, H.M., Hotanen, J.-P., Nevalainen, S., Pitkänen, J., Strandström. M., Viiri, H., 2017. Suomen metsät 2009–2013 ja niiden kehitys 1921–2013 (Finnish forests 2009–2013 and their development in 1921–2013). Natural Resources Institute Finland, Natural resources and bioeconomy studies 59/2017. 86 p.
• Lankinen, T., 2012. Uuden ennakkoraivausohjeen ja työvaikeusluokittelun käyttöönotto Metsä Groupin harvennuskohteilla (The new pre-clearance methods and the working difficulty guides introduced in Metsä Group thinnings). Bachelor’s Thesis. HAMK University of Applied Sciences. 52 p.
• Ministry of Agriculture and Forestry. 2014. Forest Act, 1093/1996, amendments up to 567/2014 included. https://www.finlex.fi/fi/laki/kaannokset/1996/en19961093.pdf (Accessed: 21 September 2019).
• Ministry of Agriculture and Forestry. 2015. National Forest Strategy 2025. Government Resolution of 12 February 2015. Publications of the Ministry of Agriculture and Forestry 6b/2015. 56 p.
• Natural Resources Institute Finland. 2019a. Hakkuu-kertymä ja puuston poistuma, Hakkuukertymä metsäkeskusalueittain (Roundwood removals and drain, Removals by forest center area). http://statdb.luke.fi/PXWeb/pxweb/fi/LUKE/LUKE__04%20Metsa__02%20Rakenne%20ja%20tuotanto__10%20Hakkuukertyma%20ja %20puuston%20poistuma/01_Hakkuukertyma.px/table/tableViewLayout1/?rxid=001bc7da-70f4-47c4-a6c2-c9100d8b50db (Accessed: 21 September 2019).
• Natural Resources Institute Finland. 2019b. Metsän-hoito- ja metsänparannustyöt, Hakkuupinta-alat (Silvicultural and forest improvement works, Cutting areas). http://statdb.luke.fi/PXWeb/pxweb/fi/LUKE/LUKE__04%20Metsa__02%20Rakenne%20ja%20tuotanto__12%20Metsanhoito%20ja %20metsanparannustyot/07_Hakkuupintaalat_mk.px/table/tableViewLayout1/?rxid=31895822-9689-4415-bacb-d9dd7dbdfb51 (Accessed: 21 September 2019).
• Natural Resources Institute Finland. 2019c. Metsän-hoito- ja metsänparannustyöt (Silvicultural and forest improvement works). http://statdb.luke.fi/PXWeb/pxweb/fi/LUKE/LUKE__04%20Metsa__02%20Rakenne%20ja%20tuotanto__12%20Metsanhoito%20ja %20metsanparannustyot/05_Metsanhoitojametsanparannustyot.px/table/tableViewLayout1/?rxid=001bc7da-70f4-47c4-a6c2-c9100d8b50db (Accessed: 21 September 2019).
• Niemistö, P., Korpunen, H., Laurén, A., Salomäki, M., Uusitalo, J., 2012. Impact and productivity of harvesting while retaining young understory spruces in final cutting of downy birch. Silva Fennica, 46(1):81-97.
• Oikari, M., Kärhä, K., Palander, T., Pajuoja, H., Ovaskainen, H., 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, 44(3):481-495.
• Pålsson, M., 2013. Behovsgrad av förröjning i förstagallring av konfliktbestånd, avverkad med flerträdshantering (Required level of pre-commercial thinning in conflict stands, thinned with multi-stemming aggregate). Sveriges lantbruksuniversitet, Institutionen för sydsvensk skogsvetenskap, Examensarbete 206. 38 p.
• Sanz, B., Malinen, J., Hujala, T., Tokola, T., 2019. ALS-based estimation of vegetation hindering cut‐to-length harvesting operations. In: Berg, S., Talbot, B. (Eds.), Forest Operations in Response to Environmental Challenges. Proceedings of the Nordic-Baltic Conference on Operational Research (NB-NORD), June 3-5, 2019, Honne, Norway. NIBIO Book, 5(6):48.
• Sjöqvist, M., Olofsson, V., 2018. Förröjningens påverkan på avverkning med förstagallringsskördare (Precleanings effects on first-thinning). Sveriges lantbruksuniversitet, Skogshushållning, Examensarbete 19. 27 p.
• Skogelid, O., 2019. Underväxtens påverkan på produktiviteten och gallringskvalitén hos två gallringsskördare (The impact of undergrowth on productivity and thinning quality for two thinning harvesters). Sveriges lantbruksuniversitet, Skogshus-hållning, Examensarbete 2. 32 p.
• Strandström, M., 2018a. Timber harvesting and long-distance transportation of roundwood 2017. Metsä-tehon Tuloskalvosarja 7b/2018. 31 p.
• Strandström, M., 2018b. Average harvesting conditions in Finland in 2017. Metsäteho Ltd, Unpublished statistics.
• Thunell, A., 2008. Kvalitet och ekonomi i utförandet av förstagallring baserat på olika gallrings- och underväxtröjningsprogram (Quality and economy in first thinning based on different thinning and preclearance programs). Sveriges lantbruks-universitet, Institutionen för skoglig resurshus-hållning, Arbetsrapport 218. 38 p.