Reference product: pulpwood, hardwood, measured as solid wood under bark [m3]
Location: RoW - Rest-of-World
This dataset covers the production and harvesting of 1 m3 of stemwood, birch, solid, under bark, plus the relative share of enery wood from slash from sustainable forest management as the prevailing management practices in Sweden.
For Sweden forestry processes for the 3 main tree species are modelled:• hardwood: birch
• softwood: spruce
• softwood: pine
Table 1-1 lists the parameters of the inventoried tree species and their sources:
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The inventories are based on several literature sources, mainly Kilpeläinen et al. (2011), Berg & Lindholm (2004), Berg & Karjalainen (2003) and Yrjölä 2002. Some process data for stand establishment and maintenance was taken from Albrecht et al. (2009).
The datasets cover in particular:
• stand establishment with planting and/or natural regeneration, depending on the tree species, based on Kallio & Leinonen (2005) (as for Finland). For seedling production in heated and unheated greenhouses, data from Aldentun (2002) is used. The ratio between seedlings from heated and unheated greenhouses as calculated to meet the energy consumption for seedling production as reported by Kilpeläinen et al. (2011). Planting is modelled according to Albrecht et al. (2008);
• site preparation, including soil scarification with harrows or similar equipment as well as ditch cleaning (Kilpeläinen et al. 2011);
• tending, young growth tending, and cleaning have been inventoried based on Albrecht et al. (2009); for birch, the scenario for beech by Albrecht et al. (2009) has been assumed;
• maintenance construction of forest road according to information from Svaeskog (personal communication,2007);
• thinning and final harvest, whereas it has been assumed that 98% of the harvesting from thinning und final harvest are done in a fully mechanised way with harvester and forwarder, and 2% of the harvesting are done in a motor-manual way with power saw and forest tractor (based on Klvac & Skoupy 2009).
Table 1-2 compiles the parameters used for the inventorying of the stand establishment and maintenance over one rotation period for each tree species:
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Within the scope of the datasets, eventual fertilization, redistribution of wood ash or the extraction of stumps for energetic purposes has not been considered.
The total harvest and assortments have been assumed for the inventoried tree species over one rotation period. Total harvesting over one rotation period has been estimated from the following sources and from the rotation periods as listed in Table 1-2:
• birch: yield estimated based on Hynenen et al. (2008), who assume a total harvest of between 360 and 560 m3 /ha, plus 8.1% of the commercial volume as „GROT“ for energy purposes (Skogsstyrelsen 2012);
• spruce: yield estimate based on (1995, 2004) quoted after (Kallio & Leinonen 2005), whereas 75% of the theoretically available biomass are extracted for energy purposes (Kallio & Leinonen 2005);
• pine: yield estimated from the ratio of the yield estimates for spruce and pine as documented in Table 1-3.
Table 1-3 compiles the total harvest over one rotation period and its relative distribution in main assortments, in m3 solid under bark (sub), based on own calculations.
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In Sweden thinnings and final harvests are done fully mechanised in the so-called „cut-to-length“ system. Klvac & Skoupy (2009) estimate that 98% of the total harvest of stemwood are harvested with harvesters and forwarders in a fully mechanised system whereas only 2% are harvested motor-manually with a power saw and a forest tractor.
Tops and branches are either chipped in the stand or forwarded as loose material or as bundles that have been produced with an energy wood harvester.
In Table 1-4 the effort is estimated for the harvesting of an average m3 of stemwood from thinnings and harvesting over one rotation period. In the final step at the bottom of the table, the PMH/m3 as documented in literature for Swedish conditions have been adapted to be consistent with the fuel consumption inventoried in the ecoinvent datasets on forest machinery and as reported for Swedish forestry operations. These adaptations are due to the average size of harvesters and forwarders used in Sweden, which deviates from the size of the forest machinery inventoried in the respective dataset (see Kärhä 2011, Skogforsk 2006).
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For the chipping in the stand a productivity of 25 m3bulked/PMH is assumed (based on Cremer & Velazquesz 2007, referring to Lechner et al. 2007)); for the bundling of slash, an energy wood harvester is inventoried with a productivity of 9 m3 solid/PMH for spruce, 6.5 m3 solid/PMH for pine and 8.3 88m3 solid/PMH for birch (Kallio & Leinonen 2005).
For the forwarding, a productivity of 25 bundles/PMH is assumed for Swedish condition, while an average length of 3 m and an average diameter of 0.75 m diameter is assumed for a bundle (Eriksson 2008, Kallio & Leinonen 2005). This adds up to a productivity of 88 m3bulked/PMH for the forwarding of bundles with a diesel consumption of 9.5 l/h of the forwarder (Gustavsson 2011).
For wood chips chipped in the stand a productivity of the forwarding of 70 Sm3 bulked/PMH with a diesel consumption of 9.5 l/h of the forwarder is assumed.
Losses of biomass during the production chain are disregarded due to the relatively rough estimates within the production chain of wood chips and bundles (see Erikkson & Gustavsson 2008 for more information).
Due to the available data, it has not been possible to distinguish productivities for the individual tree species.
Harvesting of all assortments for the reference year 2011 has been taken from the Statistical Yearbook 2012 (Skogsstyrelsen 2012); total harvest consists of the harvested stemwood plus the harvested tops and branches (GROT) for energetic purposes. The distribution of the total harvest in the harvests of each tree species have been made based on information from Svaeskog and the values on percentages in Table 1-3.
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Due to the prevailing practice of clear-cutting in final harvest and due to the sketched practices for site preparation, the area of productive forestry in Sweden has been classified as „forest, intensive“ according to the CORINE classification of land covers.
The production volumes for the assortments of energy wood are converted to kg dry mass within the dataset for ecoinvent 3.
The global production volumes of the newly inventoried tree species birch as well as the amount of bundles of energy wood are extrapolated via the Gross Domestic Product of Sweden and the world respectively (GDP Welt 70‘210‘920 Mio. US $ / GDP Sweden 539‘387 Mio. US $= 130) . This estimate is not really meaningful; the corresponding global dataset is, however, required as a technical precondition of the ecoinvent 3 software.
Albrecht, S., S. Rüter, J. Welling, M. Knauf, U. Mantau, A. Braune, M. Baitz, H. Weimar, S. Sörgel, J. Kreissig, J. Deimling and S. Hellwig (2009): ÖkoPot - Ökologische Potenziale durch Holznutzung gezielt fördern. Abschlussbericht zum BMBF-Projekt FKZ 0330545. Universität Stuttgart, Universität Hamburg, Hamburg.
Berg, S. and T. Karjalainen (2003): Comparison of greenhouse gas emissions from forest operations in Finand and Sweden. Forestry, 76(3): 271-284.
Berg, S. and E.-L. Lindholm (2004): Energy use and environmental impacts of forest operations in Sweden. Journal of Cleaner Production, 13(1): 33-42.
Eriksson, L. N. (2008): Comparative analyses of forest fuels in a life cycle perspective with a focus on transport systems. Resources, Conservation and Recycling, 52(2008): 1190–1197.
Eriksson, L. N. and L. Gustavsson (2008): Biofuels from stumps and small roundwood - costs and CO2 benefits. Biomass and Bioenergy, 32: 897-902.
Hakkila, P. (1995): Procurement of Timber for th efinnish Forest Industries. The Finnisch Forest Research Institute, Helsinki.
Hakkila, P. (2004): Developoing technology for large-scale production of forest chips. Technology Programme Report 6/2004, Tekes, Helsinki.
Hynyne, J., P. Niemistö, A. Viherä-Aarnio, A. Brunner, S. Hein and P. Velling (2009): Silviculture of birch (Betula pendula Roth and Betula pubescens Ehrh.) in northern Europe. Forestry, 83(1): 103-119.
Kallio, M. and A. Leinonen (2005): Production technology of forest chips in Finland. VTT, Jyväskyla.
Kärhä, K. (2011): Industrial supply chains and production machinery of forest chips in Finland. Biomass and Bioenergy, 35: 3404-3413.
Kilpeläinen, A., A. Alam, H. Strandman and S. Kellomäki (2011): Life cycle assessment tool for estimating net CO2 exchange of forest production. GCM Bionenergy: 1-11.
Klvac, R. and A. Skoupy (2009): Characteristic fuel consumption and exhaust emissions in fully mechanized logging operations. Journal of Forest Research, 14(6): 328-334: referring to Freitas 2004.
Lindholm, E.-L. (2010): Energy use and environmental impact of roundwood and forest fuel production in Sweden; doctoral thesis. Swedish University of Agricultural Sciences, Uppsala.
Schweinle, J. (2000): Analyse und Bewertung der forstlichen Produktion als Grundlage für weiterführende forst- und holzwirtschaftliche Produktlinien-Analysen. Mitteilungen der Bundesforschungsanstalt für Forst- und Holzwirtschaft Hamburg, Komissionsverl. Max Wiedebusch, Hamburg.
Schweinle, J. and C. Thoroe (2001): Vergleichende Ökobilanzierung der Rohholzproduktion in verschiedenen Forstbetrieben. Mitteilungen der Bundesforschungsanstalt für Forst- und Holzwirtschaft Nr. 204, Kommissionsverlag Max Wiedebusch, Hamburg.
Skogforsk (2006): Fuel consumption in forestry continues to fall. Results from Skogforsk, Skogforsk, Uppsala.
Skogsstyrelsen (2012): Swedish Statistical Yearbook of Forestry 2012. Skogsstyrelsen/Swedish Forst Agency, Jönköping.
Yrjölä, T. (2002): Forest management guidelines and practices in Finland, Sweden and Norway. Interal Report No. 11, European Forest Institute, Joensuu.
[This dataset has been generated using the system model “Allocation at the point of substitution" (APOS). A system model describes how activity datasets are linked to form product systems. The APOS model subdivides multi-output activities by physical properties, economic, mass or other properties allocation. By-products of treatment processes are considered to be part of the waste-producing system and are allocated together. Markets in this model include all activities in proportion to their current production volume.
Version 3 of the ecoinvent database offers three system models to choose from. For more information, please visit: https://www.ecoinvent.org/database/system-models-in-ecoinvent-3/system-models-in-ecoinvent-3.html)]