Plot level comparative Global Warming Mitigation Potential analysis of Red Alder Wood & Douglas fir in the Pacific Northwest

Abstract

Working forests help remove CO2 from the atmosphere, and when the trees from these forests getharvested, some of that sequestered carbon pass on to harvested wood products. Wood products produced from sustainably harvested forests (where average annual harvests are lower than the annual biomass accumulation) could help decrease atmospheric greenhouse gas (GHG) since they store the biogenic carbon removed from the atmosphere. Such processes that help reduce atmospheric GHGs are measured by their global warming mitigation potential (GWMP). Red Alder (RA) is a species of particular interest as it is known for rapid growth at its early stage compared to conifers. Utilizing Red Alder wood products is expected as one of the natural climate solutions for global warming. Using a temporally dynamic LCA modeling, this study estimates the GWMP of RA wood products over a 100-year (GWMP100) and 25-year (GWMP25) time horizons and compares those with the corresponding GWMPs of the Douglas-Fir. The research also factors in the actual DF and RA site class indices (SIs) of all forestland in Washington. The GHG calculations and corresponding GWMP estimates factor in a cradle-to-grave analysis of wood products’ emissions and storage documentation, starting from plantation to the disposal of wood products. In addition, this research also calculates net present values (NPV) of the first cycle of plantations to understand preferable harvesting ages (HA) to balance economic profitability and contribution to mitigating global warming. The study result shows that the area where DF produces more GWMP is more extensive than RA under the rotation with industrial-preferred harvesting ages in PNW. The optimal harvesting age to balance NPV and GWMP is 25 years for RA, 50 years for DF, respectively.