Integrated simulation of forest dynamics and bioenergy utilization for GHG mitigation: A case study of Hyogo prefecture, Japan

This study developed a dynamic simulation framework integrating forest growth, forest management, biomass supply, and energy utilization to jointly assess the supply potential and greenhouse gas (GHG) emissions of woody biomass energy, using Hyogo Prefecture, Japan, as a case study. Under conventional carbon-neutral accounting, GHG emissions from forest harvesting and forest residue utilization were 0.168 and 0.094 kg-CO 2eq /kWh, respectively. When biogenic CO 2 from combustion was included without subsequent forest uptake, these values increased to 2.660 and 2.586 kg-CO 2eq /kWh. At the forest-system level, both woody biomass supply and the GHG balance were strongly influenced by forest age structure and harvesting regime. Under the baseline S3-a scenario, annual woody biomass harvest declined from approximately 84,000 BDT/yr in 2020 to 14,000 BDT/yr by 2050 and remained relatively stable thereafter, while cumulative net GHG emissions reached −60.492 million t-CO 2eq by 2100. Increasing final felling enhanced woody biomass supply but weakened the long-term GHG balance. Among the scenarios examined, 10 km 2 /yr represented the highest final-felling level and approached the long-term forest-stock constraint, whereas 5 km 2 /yr maintained a substantially more favorable cumulative GHG balance than 10 km 2 /yr. These results demonstrate that maintaining forest growing stock and achieving a favorable GHG balance represent distinct management criteria, highlighting the importance of dynamically considering forest age structure, harvesting, regeneration, and subsequent growth when evaluating woody biomass energy utilization.