Potential alternatives for Norway spruce wood: a selection based on defect-free wood properties

Key message The application of material selection principles uncovered eight possible alternative tree species (two deciduous and six coniferous species) to substitute Norway spruce ( Picea abies (L.) H. Karst.) and potentially prevent economic loss in European forest. Context Climate change is a major challenge for the Central European forest and timber industry. Increasing biotic (e.g. beetle damage) and abiotic (e.g. drought) calamities have led to major losses in forest value, especially on Norway spruce ( Picea abies (L.) H. Karst.) stands. Therefore, a transition to climate change adapted forest management is necessary. Concurrently, neophytes (e.g. tree of heaven ( Ailanthus altissima (Mill.) Swingle), Douglas fir ( Pseudotsuga menziesii (Mirbel) Franco), grand fir ( Abies grandis (Douglas ex D. Don) Lindl.) and Paulownia ( Paulownia tomentosa (Thunb.) Steud.)) are increasing their dominance in forest communities and causing additional adaption of the forest ecosystem. Both factors will lead to significant changes in wood species distributions in Central European forests, mainly at the expanse of Norway spruce, over the next decades. Aims Choosing the “right” tree species for afforestation will become ever more complex and will require a holistic approach that combines forestry and technological aspects alike. Therefore, this review presents a selection approach based on available wood material data from literature and the material selection principles proposed by M. Ashby with the aim to identify suitable alternatives for Norway spruce ( Picea abies (L.) H. Karst.) and further concisely assess their silvicultural relevance. Methods For this wood species comparison and selection process, dry and raw density, bending strength and modulus of elasticity were chosen as key properties. Beam- and plate-like components subjected to a bending load were chosen as representative use cases. Results European birch ( Betula spp.), grand fir ( Abies grandis (Douglas ex D. Don) Lindl.) and silver fir ( Abies alba Mill.) were identified as suitable alternatives for Norway spruce ( Picea abies (L.) H. Karst.) from a technological as well as silvicultural point of view. In addition, Paulownia ( Paulownia tomentosa (Thunb.) Steud.), Sitka spruce ( Picea sitchensis (Bong.) Carrière), yellow pine ( Pinus strobus L.), western red cedar ( Thuja plicata Donn ex D. Don in Lambert) and loblolly pine ( Pinus taeda L.) offer a technological advantage but currently lack relevance in the forest sector. Conclusion The proposed selection process offers an evaluation of technical performance, and in combination with an assessment of the silvicultural relevance, it will be possible to optimize the wood-supply chain and prevent future economic loss of Central European forests.