Potential of forest biomass production and utilization for mitigation of climate change in boreal conditions

Abstract

The aim of this work was to study the potential of forest biomass production and utilization for mitigating climate change in boreal conditions, based on integrated use of forest ecosystem model (SIMA) simulations and life cycle assessment (LCA). More specifically, it was studied how forest management (e.g. thinning regime, nitrogen fertilization, rotation length), harvesting intensity (timber, logging residues, stumps and coarse roots in the final felling) and gradually changing climate affect in Finnish conditions forest biomass production (timber and energy biomass) (Papers I, III, IV), carbon neutrality (Paper I) and net climate impacts of forest biomass production and utilization in substituting fossilintensive materials and fuels (Paper III, IV). Furthermore, it was studied the need to adapt the cultivation of the main Finnish tree species under the gradually changing climate (Paper II). This work showed that by modifying the business-as-usual (baseline) management and by increasing the harvesting intensity, we may increase simultaneously forest biomass production, carbon sequestration and stocks of forests, and climate benefits of forest biomass production and utilization. This could be done by maintaining higher stocking over a rotation (of 60 to 80 years) compared to the baseline management and using nitrogen fertilization, and harvesting in addition to timber, also logging residues, stumps and coarse roots for energy in the final felling. However, some trade-offs exist between the economic profitability of forest biomass production and climate impacts of forest biomass production and utilization. The impacts will also vary over time depending on the prevailing environmental conditions, forest structure and forest biomass assortments used in substitution. To conclude, gradual adaptation of forest management and utilization is needed in the future, taking into account the prevailing environmental conditions (climate, site) and uncertainties related to the climate change, to fully utilize the positive effects of climate change and reduce the negative ones.