How environmental friendly is timber production in Germany?
Life cycle assessment of forest production including forest biomass for energetic use
We assess the environmental burdens of forest operations in order to analyze and quantify potential ecological benefits of wood products compared to their alternative non-wood products.
Background and Objective
We analyse environmental impacts caused by forest management activities by assessing relevant material and energy flows of timber production in Germany. Product life cycle assessments are now available for timber products (logs, pulpwood, fuelwood and wood chips) of main tree species (beech, oak, spruce and pine).
The methodology for life cycle assessments are regulated by the standards 14040 and 14044 of the International Organization for Standardization. We assess the material and energy flows of timber production in Germany. This provides a life-cycle inventory database of forest production. By evaluating the inventory data the environmental impacts of forest production (for example: Global Warming Potential) can be identified. Furthermore, life cycle inventory data sets for goods with wood in their production process is created.
Data and Methods
We use the forest growth simulator SILVA 2.2 to calculate the natural production of forest stands. Technical production in the forest module is based on literature (example: diesel consumption of harvester). We use the life cycle database / software GaBi 4.4 for upstream processes like diesel production and to aggregate data to life cycle inventories and life cycle impact asessments.
The majority of environmental impacts are not caused by preparatory measures (for example planting, pre-commercial thinning, liming or forest road construction) but by logging and skidding activities. Less than 1 % of the carbon dioxide and energy stored in the wood is released or consumed by means of timber production.
The expansion of the product system to the gate of the saw mill, the pulping plant or the panel manufacturer reveals that the environmental impacts of timber production are multiplied by the transportation of logs and pulpwood. Example: Global Warming Potential of logs and pulpwood increases by a factor of 3 to 7. The environmental impacts increase depending on tree species, assortment and impact category. Given the impact of the transportation module, alternative allocation methods or different modelling approaches for the growth simulation in the forest module have a much smaller influence on the results.
Janzen N (2012) Ökobilanzielle Analyse der forstlichen Produktion. In: Moog M (ed) Wald, Umwelt, Energie : FowiTa - Forstwissenschaftliche Tagung 2012 ; Tagungsband zur 12. Forstwissenschaftlichen Tagung an der Technischen Universität München vom 19. bis 22. September 2012 . Bad Orb: Sauerländer, p 101