Sustainability assessments and biomass inventories often neglect the operational challenges involved in the harvesting of forest biomass for bioenergy. Thus, concerns that increasing demands for biomass will lead to greater environmental impacts, particularly on soil productivity, need to be considered from an operations perspective that takes into consideration the technical and cost limitations to biomass recovery. We examine operational forest biomass recovery potential of harvest residue (slash) for three sites located north of Kapuskasing, Ontario. The sites are in the Northern Claybelt, which is in the boreal forest and is comprised primarily of lowland black spruce and upland mixedwoods. Supply flows of harvest residues estimated using the Biomass Opportunity Supply Model (BiOS), developed by FPInnovations – Feric Division are compared to validation data collected from the sites. Costs for the supply flows were also estimated using BiOS. After harvesting limitations and planned retentions (such as wildlife trees) were taken into consideration, 41% (41.2 ovendry tonnes/ha) and 59% (99.1 odt/ha) of total above-ground biomass were estimated to remain on site in two mixedwood blocks, and 25% (25.3 odt/ha) in a black spruce block. Thus, considerable biomass was left on the forest floor, contrary to popular perceptions that bioenergy harvesting will result in a “clearing” or potential “vacuuming” of the forest floor. The delivered cost was $53/odt ($2.86/GJ energy equivalent) and $58/odt ($3.14/GJ) for the two upland sites and $59/odt ($3.19/GJ) for the lowland black spruce site. This is higher than conventional hog fuel costs. Although operational and cost considerations thus limit harvest residue recovery, and although there are a number of operational factors that can minimize environmental impacts on soils and biodiversity, sustainable biomass removal guidelines still need to be implemented on sites sensitive to soil damage and nutrient removal. Key words: biomass, bioenergy, harvest, operations, cost, supply chain, sustainable management, soil nutrients, forest residues, BiOS model, Ontario
Pattern of forest biomass recovery and biodiversity loss after reduced impact logging in East Kalimantan
