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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

Abstract

Based on data from 58 stands located in three different regions within Norway, this study presents new models for quantifying growth characteristics of young, planted trees of Norway spruce (Picea abies (L.) Karst), a species that forms the backbone of the Norwegian forestry sector. The study focused on well-established, sufficiently stocked plantations to capture their inherent growth patterns. The presented models predict total tree height and the number of years required to reach a diameter at breast height of 5 cm for dominant and average-sized individuals, using common tree- and stand-level metrics. The study’s findings indicate enhanced growth of young spruce stands compared to growth dynamics observed in the 1960–1970s, likely due to improved growing conditions. The models presented here are an improvement over existing similar models and can be used in future forest growth and yield simulations. The study also aimed to provide a means to predict diameter distributions of young spruce plantations. While the results suggested significant differences between observed and predicted distributions, this still represents progress as there are currently no tools to estimate diameter distributions of young spruce plantations in Norway. Further research is recommended to corroborate the findings across a larger number of sites and to consider larger sample plots for potentially more accurate diameter distribution predictions.

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Abstract

Aim: This study sets out to understand the variability in larval traits of dispersive life stages of a famous invader, the European shore crab Carcinus maenas, in its native distribution range. Location: North East Atlantic coast from the Norwegian Arctic to the southern European distribution limit of C. maenas in Southern Spain. Taxon: European shore crab Carcinus maenas (Crustacea, Decapoda). Methods: We quantified latitudinal patterns in larval body mass, elemental composition (C and N content), and thermal tolerance of the first larval stage. We collected crabs from four populations spanning 25° of latitude (Vigo in Northern Spain; Bergen, Trondheim, and Bodø in Norway) and reanalysed published and unpublished data of body mass and elemental composition of additional populations from Germany, Wales, France, and Southern Spain. Furthermore, we used two laboratory experiments to test the thermal tolerance limits of the first larval stage from Vigo and the Norwegian populations. In the first experiment, we reared larvae from hatching to Zoea II at seven temperatures (9°C–27°C) and from hatching to LT50 at 6°C. In the second experiment, we exposed freshly hatched larvae acutely to increasing or decreasing temperatures (up to 40°C and down to 3°C). Results: Across the entire European range, we found a substantial increase in dry mass and carbon and nitrogen content of freshly hatched larvae with latitude. Norwegian populations exhibited higher survival at 9°C than the Vigo population. Furthermore, LT50 at 6°C increased from South to North. All populations showed high survival in the range 12°C–24°C but low survival at 27°C.

Abstract

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Abstract

The solute exclusion technique (SET) is often used to characterise the nano-porous structure of water-swollen cell walls. SET is based on the immersion of water-saturated wood samples in solutions of probe molecules of known size. Based on determined concentration differences in the solution before and after immersion, the accessible water within the wood is determined for each probe. However, this assumes that the concentration of probe molecules is the same in the pores of the material as in the surrounding bulk solution, but the concentration in narrow pores is actually lower than in the bulk solution. This study investigated the nano-porous structure of water-swollen wood cell walls by incorporating these known effects of concentration differences in narrow pores into the analysis. Based on solute exclusion measurements on both untreated and hydrothermally treated Norway spruce wood, the study explored the effect of modification on the nano-porous cell wall structure as well as potential sources of uncertainties such as soaking time, osmotic effects and probe molecule adsorption. The results suggested that the water-swollen, nano-porous structure of untreated and hydrothermally treated Norway spruce was dominated by one characteristic pore size which increased by hydrothermal treatment. The exact size depended on the assumed geometry of the pores.