(380d) Life-Cycle Assessments of Forest Biomass Supply in Michigan

In this study, we developed measures of the environmental footprint for primary forest products supply chain activities (harvesting and hauling wood) within the state of Michigan. A life-cycle assessment procedure is described, relying on a combination of peer-reviewed literature, national databases, and primary data collected from loggers and truckers within the Michigan study area. Several different equipment configurations and operating scenarios for roundwood harvesting have been considered, with greenhouse gas emissions and fossil energy demand per unit of delivered wood utilized as ultimate environmental indicators. Results indicated that a full processor / forwarder is the best choice of harvesting equipment configuration due to relatively low inputs and high reported productivity, although the burdens of harvesting depend strongly on the intensity of harvest being conducted. Multimodal truck + rail transport had roughly 2X lower environmental burdens than typical log truck transport, which was directly related to the increased fuel efficiency of rail transport.  Aggregated results for roundwood supply within the state of Michigan are comparable to similar studies in other regions, although the mechanization of the harvesting industry and large size of MI log trucks are factors in the relatively smaller environmental burden.