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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.

2024

Abstract

There is currently no quality sorting of harvested hardwood timber in Norway on a national scale. Medium- and high-quality logs including those from birch (Betula pubescens Ehrh., B. pendula Roth) are thus not utilized according to their potential monetary value. Increased domestic utilization of quality birch timber requires that the quality of harvested logs be properly assessed for potential end uses. A preferred sorting procedure would use visually detectable external log defects to grade roundwood timber. Knots are an important feature of inner log quality. Thus, the aim of this study was to evaluate whether correlations between branch scar size and knot features could be found in Norwegian birch. Using 168 knots from seven unpruned birch trees, external bark attributes often showed strong correlations with internal wood quality. Both length of the mustache and length of the seal performed well as predictors of stem radius at the time of knot occlusion. The presence of a broken off branch stub as part of an occluded knot significantly increased the knot-effected stem radius, proving that the practice of removing branches and branch stubs along the lower trunk is a crucial measure if quality timber production is the primary management goal.

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Abstract

Forest grazing by free-roaming livestock is a common practice in many countries. The forestry sector sees the practice as unfortunate owing to several reasons, such as damages inflicted by grazing in young plantations. Concerning Norway spruce forests, a tree species known to develop wood decay with high frequency followed from stem bark damage, there is a strong perception among foresters that the trampling damage caused by livestock on the superficial root system of this tree leads to decay. Because of the very limited scientific documentation available on this topic, we pursued a clarification by investigating three 38- to 56-year-old Norway spruce forests used for silvopasture. Two types of injuries were observed on exposed roots: bark cracks characterized by resin exudation, and injuries involving localized bark peeling and exposure of the underlying wood. These injuries occurred up to 250 cm away from the root collar, with the sector 50–150 cm away from the root collar showing the highest incidence of injuries. In two of the forest stands, wood within the injured root areas was primarily colonized by the wound parasite Corinectria fuckeliana or species of the order Helotiales, fungi that do not cause wood decay. Wood colonization of injured roots by Heterobasidion species, the most frequent wood decay fungi of Norway spruce, was common in the third stand, but only in a few cases it was possible to deduce that the colonization had probably initiated via trampling injuries on roots. In a few cases, an injury was located at stem base at the root collar height along paths used by animals, and in such cases, it was obvious that stem colonization by Heterobasidion species had initiated via the wound. The relatively small amount of data warrants caution when drawing conclusions. Considering the high establishment frequency of decay via stem bark wounds of Norway spruce observed in previous studies, our data would suggest that roots are generally better equipped to defend themselves upon infliction of superficial wounds than stem of this tree species. The likelihood of trampling injuries leading to decay may vary considerably between different stands, this presumably depending on the level of local propagule pressure by pathogenic wood decay fungi and the frequency of damages close to root collar.

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Abstract

Creatively integrating synthetic materials (semiconductors and electrodes) and microorganisms, the semi-artificial photosynthetic system (SAPS) couples the advantages of natural photosystems (high catalytic reaction selectivity) and artificial photosystems (excellent light-harvesting performance). This combination effectively overcomes the shortcomings of poor selectivity in artificial photosystems, bringing new opportunities for developing photosynthetic systems. It also provides a promising strategy for addressing the current energy crisis and environmental pollution. The design and selection of synthetic materials play a crucial role in this system, aiming to achieve efficient photon capture and electron transfer. This review begins by exploring the fundamental principles of SAPS, emphasizing the integration of materials and microorganisms and the factors that influence their interactions. It provides a critical analysis of the diverse compositional arrangements and systematically elucidates the foundational research methodologies employed in the investigation of SAPS. Grounded in their distinctive redox characteristics, it comprehensively surveys their recent applications in environmental remediation and sustainable energy production over the past years. Finally, reflections on future research are proposed, beginning with the challenges that limit the application of SAPS. Building on previous studies, the present review identifies the factors that limit SAPS and suggests potential avenues for future research. Additionally, this review delves into the environmental and economic policies and practical implications. In conclusion, by critically assessing the existing research landscape, delineating challenges, and charting future research directions, the present review aims to provide valuable insights for researchers and practitioners, guiding efforts toward advancing SAPS for enhanced environmental sustainability and economic feasibility.

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Abstract

This article aims to increase the knowledge of the roles and functions of public health institutes (PHIs) by exploring and comparing the Scandinavian PHIs, their roots, and developments over time. The research questions are the following: What was the history behind these public institutions? How have they changed over time? Have they followed divergent or parallel paths of change? How, if at all, have they been influenced by public sector reforms? Comparing the three Scandinavian countries based on an institutionalist approach, the article seeks to increase the understanding of the role of PHIs in governing public health. The article is based on documents from parliaments and governments from the public health institutes, supplemented by institution narratives and relevant public health and public administration literature. The Scandinavian PHIs have common roots from the early 1900s, have followed different routes, and have different institutional characteristics and different roles as public health institutions. However, after more than 100 years, the Scandinavian PHIs belong to the international PHI organization. They are responsible for knowledge dissemination, surveillance, and preparedness for the handling of epidemics and pandemics. The article argues for more comparative research on institutions related to public health authorities, such as the PHIs.