Evaluation of forest logging residues availability for energy generation: a multicriteria geographic information system (GIS) approach

In the context of the current climate change, energy (heat and/or electricity) generation represents an interesting solution to exploit forest logging residues, since the combustion of wood does not cause – compared to fossil fuels – additional carbon dioxide (CO2) emissions into the atmosphere. In Italy, the quantification of harvestable logging residues for energy purposes is one of the main problems in planning forest-wood-energy chain since Forest Management Plans (FMP) generally provide information only about the harvested gross cormometric volume. Moreover, studies on this topic are generally performed at the District/Regional level, without considering site-specific primary data collected in the FMPs. The aim of this work is to quantify the mass of harvestable logging residues (mHR; t∙ha-1∙yr-1 dry matter, DM) for energy generation at the forest stand level. mHR is computed by applying to the mass of producible logging residues (mPR; t∙ha-1∙yr-1 DM) a “Stand Utilization Index” (UI; -), which is calculated through a multicriteria Geographic Information System (GIS) approach, by combining information provided by FMPs (forest function, form of management, forest typology) with information on: (i) landscape topography (stand accessibility, forest road conditions), (ii) harvesting method and (iii) wood market demand. A first application of this approach concerned 2019 forest stands (3.7∙104 ha) of Valle Camonica District (Northern Italy) recorded in 45 FMPs. Assuming that mHR is prepared into woodchips to feed cogeneration plants, heat and electricity (GJ∙yr-1), as well as avoidable fossil fuels and CO2 emissions into the atmosphere due to the contribution of each stand are also computed.