Climate Change Mitigation Potential in Boreal Forests: Impacts of Management, Harvest Intensity and Use of Forest Biomass to Substitute Fossil Resources

The impacts of alternative forest management scenarios and harvest intensities on climate change mitigation potential of forest biomass production, utilization and economic profitability of biomass production were studied in three boreal sub-regions in Finland over a 40-year period. Ecosystem modelling and life cycle assessment tools were used to calculate the mitigation potential in substituting fossil materials and energy, expressed as the net CO2 exchange. Currently recommended management targeting to timber production acted as a baseline management. Alternative management included maintaining 20% higher or lower stocking in forests and final felling made at lower breast height diameter than used in the baseline. In alternative management scenarios, logging residues and logging residues with coarse roots and stumps were harvested in final felling in addition to timber. The net CO2 exchange in the southern and eastern sub-regions was higher compared to the western one due to higher net ecosystem CO2 exchange (NEE) over the study period. Maintaining higher stocking with earlier final felling and intensified biomass harvest appeared to be the best option to increase both climate benefits and economic returns. Trade-offs between the highest net CO2 exchange and economic profitability of biomass production existed. The use of alternative displacement factors largely affected the mitigation potential of forest biomass.