Carbon Balance Implications Of Forest Biomass Production Potential

Forests in boreal and temperate forest-ecosystems have an important function since they sequester atmospheric carbon by uptake of carbon-dioxide in photosynthesis, and transfer and store carbon in the forest ecosystem. Forest material can be used for bio-fuel purposes and substitute fossil fuels, and supply wood products, which can replace carbon- and energy-intensive materials. Therefore it is vital to consider the role of forests regarding today´s aim to mitigate climate change. This thesis assess (i) how climate change affects future forest carbon balance, (ii) the importance of different strategies for forest management systems, and biomass production for the carbon balance, (iii) how the use of forest production affect the total carbon balance in a lifecycle perspective, and (iv) how the Swedish carbon balance is affected from the standpoint of both the actual use of forest raw material within Sweden and what Swedish forestry exports. The analysis was made mainly in a long-term perspective (60-300 year) to illustrate the importance of temporal and also the spatial perspective, as the analysis includes stand level, landscape level, and national level. In this thesis, forestry was considered a system. All activities, from forest regeneration to end use of forest products, were entities of this system. In the evaluation, made from a systems perspective, we used life-cycle analysis to estimate carbon stock in different system flows. Different forest management systems and forest production were integrated in the analyses. Different forest management scenarios were designed for the Swedish forest management in combination with the effect of future climate change; (i) intensive forest practice aiming at increased growth, (ii) increased forest set-aside areas, changes in forest management systems for biomass production, and (iii) how the use of forest production affect the total carbon balance (construction material, bioenergy and other domestic use). The results showed that future climate changes and intensive forest management with increased production could increase the biomass production and the potential use of forest raw material. This has a positive effect on carbon storage for the forest carbon stock, litter production and carbon storage in the ground etc. and help mitigating carbon-dioxide. Increased forest set-aside areas can increase the short-term carbon stock in forest ecosystems, but will reduce the total long-term carbon balance. The net carbon balance for clear-cut forestry did not differ significantly from continuous-cover forestry, but was rather a question of level of growth. Most important, in the long term, was according to our analysis, how forest raw material is used. Present Swedish forestry and use of forest raw material, both within Sweden and abroad, reduce carbon-dioxide emissions and mitigate climate change. The positive effect for the total carbon balance and climate benefit take place mostly abroad, due to the Swedish high level of export of wood products and the higher substitution effects achieved outside Swedish borders. One strategy is to increase production, harvest and change the use of Swedish forest raw material to replace more carbon intensive material, which can contribute to significant emission reduction. Carbon-dioxide mitigation, as a result of present Swedish forestry, was shown to be almost of the same level as the total yearly emission of greenhouse gases. The total carbon benefit would increase if the biomass production and felling increased and if Swedish wood products replaced carbon intensive materials.This thesis shows also that, by changing forest management, increase the growth and the use of forest raw material and export of forest material we can contribute to even larger climate benefits. In a long-term perspective, the substitution effects and replacement of carbon- and energy-intensive materials are of greater significance than carbon storage effects in forests. A more production oriented forestry needs to make balances and increase the prerequisite for biological diversity, improve recreation possibilities, and protect sensitive land areas and watersheds.Climate benefits, from Swedish forestry, are highly dependent on policy decision-making and how that can steer the direction for the Swedish forestry