Assessing the net atmospheric impacts of wood production and utilization.

The main objective of the study was to calculate net atmospheric impacts for wood production and utilization in Finnish boreal forest conditions. Net atmospheric impacts were calculated by comparing net CO exchanges of the wood production and utilization to the reference management regime. Net CO exchanges were simulated with a life cycle assessment (LCA) tool for a Scots pine ( Pinus sylvestris L.) stand (MT, Myrtillys-type) in central Finland (Joensuu region, 62°39 N, 29°37 E) over two consecutive rotation periods (100 + 100 years/200 years). Net atmospheric impacts were calculated both for sawn timber and pulpwood, and expressed in kgCOm. According to the results, the production of pulp and sawn timber produced emissions of 0.20 and 0.59 kgCOm over the 200-year period, respectively, when the unmanagement regime was used as the reference management regime. When 50 % of the processing waste of timber was accounted as an instant emission to the atmosphere, the atmospheric impact increased to 0.55 kgCOm in pulpwood and to 1.27 kgCOm in sawn timber over the 200 year period. When turnover rates of sawn timber in the technosystem were decreased by 30 % and the share of energy use was decreased to 30 %, the atmospheric impact decreased by 17 % and 4 % for pulpwood and sawn timber, respectively, compared to the default wood degradation and energy use of 50 %. The utilized LCA approach provided an effective tool for approaching net atmospheric impacts originating from the ecosystem carbon (C) flows and variable wood utilization. Taking the ecosystem production and utilization of wood (i.e. degradation of technosystem C stock) into account, in terms of net CO exchange, the mitigation possibilities of wood compared to other products can be accounted for more precisely in the future and C sequestration credited more specifically for a certain wood product. [ABSTRACT FROM AUTHOR]