Tradeoffs and synergies of optimized management for maximizing carbon sequestration across complex landscapes and diverse ecosystem services

Forest natural climate solutions such as improved forest management and reforestation have been identified as a cost-effective way to mitigate climate change. Several US states have GHG reduction policies, often citing forests as a key to meeting mitigation targets despite not knowing how specific practices impact carbon and other forest ecosystem services at the regional level. In response, we link a regional forest landscape model (LANDIS -II) with economic and policy data to assess how shifting forest management in Maine, USA, impacts the region's future carbon sequestration, timber supply, biodiversity, and landowner returns. Scenario analysis results show consistent tradeoffs between carbon sequestration and timber supply, with impacts diminished when managers shift to a land-sparing and balanced management approach consisting of permanent set -asides and intensive clearcut with planting regimes. We also estimate that carbon sequestration can increase by 15-25% over the reference case while still maintaining harvest levels by shifting to a broader mix of intensive and extensive practices. Further, we estimate that harvests could grow by 20% above the baseline and still positively affect forest carbon. In all cases, shifts in practices had a mixed impact on biodiversity due to the diverse habitat indicators evaluated for this study. Overall, we find that changes in forest management can lead to improved outcomes for both carbon and other forest ecosystem services of interest, provided managers are given the policy, economic, and social incentives to do so.