Reference product: cleft timber, measured as dry mass [kg]
Location: DE - Germany
This dataset covers the production and harvesting of 1 m3 of stemwood, beech, solid, under bark, plus the relative share of enery wood from slash from sustainable forest management as the prevailing management practices in Germany.
For Germany forestry processes for the 4 main tree species are modelled:
• hardwood: beech
• hardwood: oak
• softwood: spruce
• softwood: pine
Table 1-1 lists the parameters of the inventoried tree species and their sources:
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The inventories largely rely on data from Albrecht et al. (2009); however, they have been modeled as multi-output unlinked Unit Process, according to the ecoinvent Data Quality Guidelines. Therefore, it was not possible to implement some of the methodological settings in Albrecht et al. (2009), particularly those related to the co-product allocation of some sub-processes.The datasets cover in particular (for details, see Albrecht et al., 2009):
• stand establishment with planting, including the use of a planting device mounted on a tractor and – in a separate dataset - the production of seedlings in an unheated greenhouse according to Aldentun (2002). The number of seedlings required varies between 3000 seedlings/ha for spruce up to 10‘000 seedlings/ha for oak (see Table5-2);
• tending, including the use of a brush cutters in one intervention for all tree species;
• young growth tending, including the use of a brush cutters in two interventions for beech and oak, and in one intervention for pine;
• cleaning, including one intervention as selective cleaning with a small power saw and one systematic cleaning with a mulching device or similar for all tree species;

• maintenance of forest road, whereas – deviating from Albrecht et al. (2009) – the distribution of a new gravel layer every ten years has been inventoried.
• thinning, whereas it has been assumed that all thinning are made as mechanical thinnings with a harvester and a forwarder. The range for the use of harvesters is assumed to lay between 10 and 32 cm of average DBH of the exiting stand. For spruce and pine, the development of the average diameters of the exiting stand allows the use of harvesters up to the years ‘rotation period minus 30 years’. In the case of beech and oak harvesters can only be used up to the ages of 110 and 105 years respectively, due to the increasing DBH in older stands.
• final harvest, whereas motor-manual wood harvesting and skidding has been inventoried for the final harvesting as the predominant harvesting method for large-sized timber in Germany.
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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The total harvesting over one rotation period have been derived from the following yield tables over the assumed rotation periods as listed in Table 1-2:
• beech: Wiedemann "yield class II.0“, plus 20% of the commercial volume as wood chips (Wittkopf 2005)
• oak: Jüttner "yield class II.0", plus 22% of the commercial volume as wood chips (Wittkopf 2005)
• spruce: Assmann/Franz. "dominant height site index 36", plus 13% of the commercial volume as wood chips (Wittkopf 2005)
• pine: Wiedemann "yield class II.0", plus 19% of the commercial volume as wood chips (Wittkopf 2005)
The relative distribution of the total harvest corresponds to the situation of wood harvesting in 2011 (see Table 1-5) and has been derived from the sources listed there (Table 1-3).
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As mentioned above, it has been assumed as a simplification that all wood from thinnings is harvested with a harvester and a forwarder; wood from final harvest is harvested motor-manually with a power saw and skidded with a forest tractor. In Table 1-4 the harvesting effort for an average m3 harvested over one rotation period from thinnings and final harvest is derived, taking into account the different productivities of the two harvesting methods:
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For the chipping in the stand a productivity of 25 m3 bulked/PMH is assumed (based on Cremer & Velazquesz 2007, referring to Lechner et al. 2007)). 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).
The data on harvesting in the reference year 2011 has been taken from the German Statistical Yearbook (Anonymous 2012) . The assortment „industrial wood/energy wood“ has been split into industrial wood and energy wood respectively according to the Statistical Yearbook for Nutrition, Agriculture and Forestry of the Federal Republic Germany (Anonymous 2010) based on the situation in 2009. Due to the lack of data on federal level, the share of wood chips and cleft timber as energy wood has been approximated based on a survey of forest owners in Bavaria, which has been published by the Bavarian Institute for Forests and Forestry.
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Due to a lack of information, it has been assumed that no bundles of energy wood are produced in Germany.
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 inventoried tree species are extrapolated via the Gross Domestic Product of Germany and the world respectively (GDP global 70210920 Mio. US $ / GDP Germany 3,604,061 Mio. US $= 19.48) . This estimate is not really meaningful; the corresponding dataset is, however, required as a technical precondition of the ecoinvent 3 software.
References:
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.
Anonymous (2010): Statistisches Jahrbuch über Ernährung, Landwirtschaft und Forsten der Bundesrepublick Deutschland. 54. Jahrgang, Wirtschaftsverlag NW GmbH, Bremerhaven.
Anonymous (2013): 19 Land- und Forstwirtschaft. In: Statistisches Jahrbuch 2012, Statistisches Bundesamt, Berlin, 471-500.
Cremer, T. and B. Velazques-Marti (2007): Evaluation of two harvesting systems for the supply of wood-chips in Norway spurce forest affected by bark beetle. Croation Journal of Forest Engineering, 28(2): 145-155.
Eriksson, L. N. and L. Gustavsson (2008): Biofuels from stumps and small roundwood - costs and CO2 benefits. Biomass and Bioenergy, 32: 897-902.
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.
Werner, F., T. Künniger, H.-J. Althaus and K. Richter (2007): Life cycle inventories of wood as fuel and construction material, Duebendorf, November 2002. Centre for life cycle inventories in the ETH domain, Duebendorf.
Wittkopf, S. (2005): Bereitstellung von Hackgut zur thermischen Verwertung durch Forstbetriebe in Bayern; Dissertation. Technische Universität München, München.

[This dataset has been generated using the system model "Allocation, cut-off by classification". A system model describes how activity datasets are linked to form product systems. The allocation cut-off system model subdivides multi-product activities by allocation, based on a physical properties, economic, mass or other properties. By-products of waste treatment processes are cut-off, as are all by-products classified as recyclable. 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-…)]