A forest optimisation model including carbon flows: Application to a forest in Norway

We analyse which management to choose in order to increase the carbon benefit from the 1.342 million ha forest area in Hedmark County, Norway, and the cost of doing this compared to traditional profit maximising behaviour. The model used in the analysis is a dynamic forest management optimisation model which includes the main carbon flows and benefits from the forest area: tree growth and mortality, litter accumulation, decomposition of dead wood and harvest residues, soil processes, end-use of wood products, and saved greenhouse gas emissions from using wood products instead of more energy intensive materials and fossil fuels. The overall harvest from the region is restricted to the present level, in order to see which carbon benefits can be achieved while keeping a steady supply of timber to the forest industry. Under this restriction, maximising carbon benefit decreases the net present value of timber revenue from the region by 21%. There is more planting and less thinning compared to when timber revenue is maximised. If substitution effects, i.e. saved greenhouse gas emissions from use of wood products, are included in the analysis, it is optimal with more planting and thinning, although the changes are small in this case study because harvest level is held constant. On the other hand, net present value of carbon benefit (in ton CO2-equivalent) is increased by 1.4–1.6 times when substitution effects are included. Changing forest management is a cost effective mitigation option. For a cost of € 0–10 per ton discounted CO2-equivalent, the net present value of carbon benefit from the area can be increased with 0.2–0.3milliontonnes CO2-equivalents on average in every year of the 120 years long planning horizon taking discounting into account (annuity).