RESEARCH ARTICLE Regional GIS-based evaluation of the potential and supply costs of forest biomass in Sweden Dimitris ATHANASSIADIS (✉), Tomas NORDFJELL Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, SE-90183 Umeå, Sweden Abstract The potential for harvestable forest fuel (logging residues and stumps from regeneration fellings and small diameter trees from early thinnings) in Sweden, divided in five regions, is provided. Marginal cost curves for logging residues and stumps are calculated through a GIS-based method based on forest inventory plots and locations of selected terminals, and heat and combined heat and power facilities. Four supply chains for logging residues and two for stumpwood were compared. Fixed and variable costs of harvesting equipment and transport vehicles were used for determining the costs of each of the supply systems under consideration. A list with the GPS coordinates of all facilities and terminals was made based on their geographical location. The distance from the center of each forest inventory plot to the nearest receiving point within the region, either facility or terminal, was estimated. There were large differences in the estimated potential of harvestable forest fuel between the regions. The overall annual potential for each of the five regions ranged from 0.97 to 2.73 million oven dry tonnes and the total potential amounted to 9.39 Mt (oven dry). One of the northernmost regions (R1) had the steepest slope in its marginal cost curve. For the other regions, the slope of their cost curves was less dramatic. Information on the economic availability of logging residues and stumps in each region is important for forest fuel suppliers and receiving facilities. Keywords GIS, logging residues, heat and-power faci- lities, stumpwood 1 Introduction Public awareness of climate change, international obliga- tions to decrease greenhouse gas emissions and the scarcity of fossil fuels have increased the interest in renewable energy sources. By 2020, the European Union aims to decrease the emissions of global warming gases by 20% (compared with the 1990 emission levels) while increasing the amount of energy coming from renewable resources to 20% of total energy production (2008: about 8.5%) [1] . As a consequence, the demand for wood as raw material for heat and power generation has increased considerably in Europe and globally. The Nordic countries have been active for more than 30 years and generally have well established renewable energy markets and supply chains for servicing these markets. In Sweden, the use of bioenergy has increased by an average of 3.3 TWh$yr –1 over the past 20 years. In 2013, it represented 35% (130 TWh) of the total energy consump- tion [2] . From 2003 to 2007, 44 new biofuel fired facilities were built in Sweden (mainly large scale combined heat and power facilities). This expansion has mainly been made possible through an increased use of forest industry by-products. Today and in the future, a further expansion requires an increased use of forest biomass [3] . Potential forecasts and marginal cost curves for logging residues (branches and tops) and stumps from regeneration fellings for the period 2010–2019 for the whole of Sweden were reported by Athanassiadis et al. [4] . The forecasts were based on data from the Swedish National Inventory collected from 2002 to 2006 and specific assumptions on future forest management and regeneration fellings [5,6] . The forecasted annual potential assumes that Swedish silvicultural practices will not change and annual fellings will still be at a level that is regarded as sustainable, that environmental legislation will not change and that climate change will be light. Three potential levels were estimated depending on a number of ecological and environmental, technical and economical restrictions. For Level 1 the only restriction was that areas of nature protection were excluded from the extraction of logging residues and stumps. For Level 2, and in addition to Level 1 restriction, a number of ecological restrictions were applied: wet areas, areas with peat soils with low bearing capacity, and areas located within 25 m of Received April 7, 2017; accepted October 24, 2017 Correspondence: Dimitris.Athanassiadis@slu.se Front. Agr. Sci. Eng. 2017, 4(4): 493–501 https://doi.org/10.15302/J-FASE-2017179 Available online at http://engineering.cae.cn © The Author(s) 2017. Published by Higher Education Press. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0)