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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2025

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Abstract

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Abstract

Data from the Norwegian national forest inventory spanning from 1994 to 2022 were analyzed to explore the growth dynamics of pure and mixed stands of Norway spruce and Scots pine. The derived large dataset enabled the development of models designed to assess how stand characteristics and drought interactively affect volume increment at the stand and individual tree level. The analysis revealed that pine-dominated stands outperform spruce-dominated stands at lower site qualities, while the opposite was true at higher site qualities. Mixed stands exhibited overyielding, with productivity exceeding the expected combined pure stand productivity of the individual species components. Based on model predictions, relative overyielding increased with stand age and declined with increasing site quality. Transgressive overyielding, where mixed stands outperform pure stands of either species, was predicted for medium site qualities. Drought-induced productivity losses increased with spruce proportion, especially at lower site qualities, and with stand density. The presence of pine in mixed stands mitigated the negative effects of drought on spruce. The findings of this study suggest that pure spruce stands should be avoided on lower-quality sites while mixed stands with appropriate thinning interventions should be promoted to maintain productivity under changing climatic conditions.

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Abstract

The rising impact of the spruce bark beetle (Ips typographus L.) on Europe's forests is becoming a major concern, with climate change intensifying the problem. This situation has sparked discussion across Europe about adopting new, adaptive forest management strategies to mitigate the economic impacts on the forestry sector. Despite this, some regions have yet to fully embrace long-term strategies against bark beetle outbreaks from a climate change perspective. In our study, we examined the effects of integrating bark beetle risk into forest management strategies, considering both current and future climate change scenarios. Our findings indicate that reducing rotation length of low density stands with a high proportion of Norway Spruce situated in more productive sites yields substantial economic advantages. Particularly, regions with a history of bark beetle outbreaks, like Vestfold in Norway, stand to gain significantly from early harvesting. The economic gain from harvesting earlier in this region is projected to increase nearly tenfold over the next 50 years under climate change scenarios. Additionally, we recommend considering the use of mixed tree species within forests as another adaptation strategy, to enhance forest resilience against bark beetle infestations and other natural disturbances.