The impact of forest disturbances on residual biomass supply: A long-term forest level analysis

Abstract

Residual forest biomass is an attractive feedstock for bioenergy production due to its abundance and renewability. However, natural forest disturbances such as wildfire and insect infestation cause unpredictable fluctuations in supply, disrupting long-term procurement plans for delivering feedstock to biorefineries. This study proposes a method to assess the impact of disturbances on long-term supply of residual forest biomass. The method was integrated within a framework of forest management planning for timber production, reflecting current reality of commercially-managed forests. The method was implemented to a case study in eastern Canada focusing on the two most prevalent forest disturbances, wildfire and spruce budworm (Choristoneura fumiferana [Clemen]) infestation. Nine scenarios were considered, with disturbance rates ranging from 0 to 1.6% yr−1 (predicted maximum). Residual biomass considered in this study were (i) logging residue, (ii) salvage biomass, and (iii) sawmill residue. The results show that, as the disturbance rate increases, the area available for timber harvest decreases, leading to a reduction in logging and sawmill residues. In the highest disturbance rate scenario, logging and sawmill residue decreases by almost 40%. Collection of salvage biomass can make up for the reduction, redeeming approximately 20% of the loss. Our method complements the conventional timber production planning process, allowing quantification of residual biomass supply in the face of uncertain natural disturbances due to climate change. The proposed method should support managers in their effort to maintain robust supply chains, while facilitating the adoption of the principles of circular economy.