Constraints on the provision of bio-energy from forest biomass in Austria

Limited access to gas has stimulated a new interest in domestically available sources of renewable energy. Currently, about 13% of the Austrian national energy demand (1453.9 PJ) is met from forest biomass and residues from wood product manufactoring. The share of renewable sources of energy is 29.8% (432.9 PJ). Efforts to increase the bioenergy production are in stark contrast to European policies to prevent an icrease of the direct energetic use of primary forest biomass. Austria has a highly efficient timber processing sector and is globally the second largest importer of timber. After a cascade of timber utilization for sawnwood, particle boards and pulp & paper about 50% of the resource is used for energy production. It partially supplies energy for timber processing, and is partially used in biomass power plants. Primary wood that goes directly from the forest into energy production comprises assortments and tree parts that presently cannot be turned into wood products. Yet, particularly in rural areas small-holder foresters extract timber for their regional energy needs. The growing demand for pellets cannot be fully met from the residues of timber processing and relies partially on imported pellets. A further increase of the provision of energy is possible, if (i) the market demands more wood products, and/or (ii) the harvesting rate is increased. Simulations have shown that Austrian forests can sustain several decades of increased harvesting rates, merely because the harvesting rate has been lower than the annual growth, as shown by rising biomass stocks since at least 60 years. Many forests are overdue for thinning because the operational  costs are not covered. Sustainability issues are raised. A slight increase in the production of bioenergy is feasible. Strong increases would deplete resources within only a few decades, and potentially lead to undesired side effects such as nutrient depletion.