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.
2026
Abstract
Neural Radiance Fields (NeRF) have been widely adopted for reconstructing high-quality 3D scenes from 2D RGB images. However, achieving accurate 3D object segmentation within these reconstructed scenes remains challenging. Existing NeRF-based segmentation methods either rely on post-processing (SA3D), which produces noisy point clouds due to the absence of density field optimization, or employ joint training with additional segmentation heads (FruitNeRF), which can lead to suboptimal performance due to conflicting learning objectives. In this work, we propose InvNeRF-Seg (Input-substitution NeRF for Segmentation), a two-stage fine-tuning strategy for 3D object segmentation that preserves the original NeRF architecture and loss function entirely. We first train a standard NeRF on RGB images and then fine-tune it using 2D segmentation masks formatted as RGB-like inputs, without introducing any architectural modifications or additional loss functions. This input-substitution approach reshapes the density field to align with object regions while suppressing background density. We validate InvNeRF-Seg through comprehensive ablation studies examining the roles of density and color MLPs, loss function choices, and training strategies. Field density analysis reveals consistent semantic refinement: densities of object regions increase while background densities are suppressed. Experiments on synthetic fruit datasets and real-world soybean imagery demonstrate that InvNeRF-Seg produces cleaner 3D segmented point clouds compared to both SA3D and FruitNeRF, enabling more accurate downstream object counting. The method is further validated on a self-collected soybean dataset to demonstrate its applicability in real-world agricultural scenarios.
Abstract
In Norway, agroclimatic zones (ACZs) are a valuable tool for national analyses in subject areas concerning the optimized management of agricultural land resources. However, current Norwegian ACZs have been criticized for having an outdated standard climate normal (1931–1960), a limited representation of the local climatic variation, a lack of important model parameters, and weak methodological documentation. Therefore, this paper presents new ACZs for Norway that address these weaknesses. The most significant methodological updates are the use of the standard climate normal of 1991–2020, additional weather data variables, the downscaling of weather data to 250 m hexagons, and the incorporation of phenological crop models for spring wheat, spring barley, and forage grass. The grass model was calibrated with the number of grass harvests at research stations, while the grain models were calibrated with subsidy claim data. The modeled zones for the three crops were combined into the general ACZs. Example maps of the crop zones and new ACZs for the selected regions and the whole country are presented. The new ACZs are more robust, agronomically relevant, and better aligned with the current climatic conditions in Norway. The deliberate exclusion of factors other than climate ensures the new ACZs’ national comparability and their applicability in policy development, land-use planning, climate adaptation, and agronomic assessments at the national scale.
Abstract
This paper describes from a methodological point of view a recent attempt to test how Historic Landscape Characterisation (HLC) as developed with respect to the British landscape can be adapted and applied to the different and distinctive landscapes of a Norwegian upland territory, on the edges of the Hardangervidda plateau. This is an area characterised by mobility, close nature-culture interactions, and practices such as summer farming and short-distance transhumant practices. The research was carried out by two Norwegian agencies – NIKU and NIBIO – as part of a larger project known as PARKAS designed in the context of green transitions to promote better-integrated and publicly-responsible management and safeguarding of protected areas. We briefly describe the origins and principles of HLC in Britain, and then at greater length assess the suitability of HLC in Hardangervidda and key ways by which the approach would require modification and adaptation. A concrete method for a Hardangervidda HLC – and a suitable high-level classification – is identified and discussed.
Abstract
Semi‐natural grasslands are valuable habitat for bumblebees ( Bombus spp.) in Fennoscandia. These grasslands are often maintained by livestock such as free‐ranging sheep, but it is unclear if sheep grazing impacts bumblebee communities, and if so, which grazing intensity is best. We compared bumblebee species richness and abundance on semi‐natural grasslands in southeastern Norway at varying levels of disturbance by sheep (0–1680 initially released). We used Bayesian hierarchical models to test the intermediate disturbance hypothesis, that the highest bumblebee abundance and richness would occur at moderate grazing intensity, while considering other important habitat variables: distance to forest, meadow size, sward height, and availability of flowers, litter, and bare soil. We found no support for the intermediate disturbance hypothesis but rather a negative relationship between the number of sheep released and measures of bumblebee species richness and abundance from targeted netting. Effects varied among the most common species. B. pratorum and B. wurflenii were more sensitive to the number of sheep released than were B. jonellus . Bumblebee abundance estimated by two capture methods (blue vane trapping and targeted netting) was only weakly correlated and bumblebee species richness estimated from traps was unrelated to any of our predictor variables. Practical implication . Our results suggest a weak negative influence of any amount of sheep grazing on bumblebee abundance and richness. Targeted netting was a more reliable method than blue vane traps to assess effects on the bumblebee community.
Authors
Geir Wæhler Gustavsen Philip Bester Van Niekerk Jonas Niklewski Christian Brischke Gry AlfredsenAbstract
This cross-country study examineed perceptions of maintenance for coated wooden cladding in residential buildings across Norway, Sweden, and Germany. As timber cladding gains popularity in European homes, understanding expectations around cleaning, recoating, and replacement intervals becomes increasingly important. An online survey gathered responses from over 3,000 participants aged 18–89, randomly selected from representative regional panels in each country. The survey focused on the perception of maintenance practices and intervals, while also collecting data on personality traits, risk aversion, and socioeconomic background. Perceived maintenance practices for coated timber cladding differed across countries, but individual characteristics were generally more influential than national context. Most respondents accepted longer cleaning intervals than recommended, while their preferences more closely aligned with guidelines for recoating. Acceptance of replacement intervals varied markedly by country. Longer acceptable maintenance intervals were associated with a higher preference for uncoated cladding, particularly in Germany and Sweden. Younger age, urban residence, limited experience, and selected demographic and personality traits were linked to more intensive maintenance preferences.
Authors
Theresa Weigl Jorunn Børve Emily Follett Ingunn Øvsthus Carl Gunnar Fossdal Hanne Larsen Siv Fagertun RembergAbstract
The mid-early-ripening cultivar ‘Summerred’ is popular among consumers and widely grown in Norway. However, ‘Summerred’ fruit is prone to rapid softening and development of senescence-related disorders, especially senescent breakdown. Calcium can have a significant role in maintaining firmness and delaying senescence of fruits. In a two-year study, foliar application of calcium chloride (CaCl2) was conducted six times, with varying weather conditions between the growing seasons. Fruit was harvested at optimal commercial maturity and stored at 4°C for either 6 or 9 weeks, followed by simulated shelf-life conditions at 20°C. Ethylene levels were monitored during storage to detect ripening discrepancies. At harvest, CaCl2-treated fruit exhibited significantly lower ethylene production compared to untreated fruit, although no differences were observed at the end of the storage period. Senescent breakdown showed significant variability between the two seasons, with an incidence of up to 15% in the first season and nearly no incidence in the second. Senescent breakdown increased with storage duration but was unaffected by foliar CaCl2 application. Real-time PCR analysis of fruit flesh samples revealed increased expression of polygalacturonase and β-galactosidases genes after storage, indicating their involvement in apple softening. Notably, there were no differences in gene expression between CaCl2-treated and untreated fruit after storage. Expression patterns of genes involved in ethylene biosynthesis at harvest were different between the two seasons. Higher expression was observed in the year with greater disorder development, indicating greater maturity at harvest. There were no significant differences in the Streif index between the two years.
Authors
Pia BorgAbstract
We compared written guidance on date marking on the websites of Norwegian Food Safety Authority, Swedish Food Agency, and the Danish Agriculture and Fisheries Agency. We also compared what the three authorities write about guidance as a tool .
Authors
Edward H. Cabezas-Garcia Yang Li Daniel Korir Jesse K. Gakige Stefan Muetzel César S. Pinares-Patiño Vibeke Lind Mutian Niu Claudia ArndtAbstract
No abstract has been registered
Authors
Anaïs Zimmer Adrienne Grêt-Regamey Ignacio Palomo Carolina Adler Meryem Aakairi Marie Anière Fabien Anthelme Chloe Baruffa Bolette Bele Vincent Ralph Clark Aida Cuni-Sanchez Sebastian Eiter Richard Field WariNkwi Flores Katherine Hanly Jan Hartmann Amina Maharjan Sara Manuelli Dominic Andreas Martin Nelly Nambande Masayi Paula Mayer Graham McDowell Holly Moulton Anne Nolin Lydia Olaka Binaya Pasakhala Jorge Recharte Neema Robert Kinabo Luciana Rojas Hanne Sickel Lobzang Stanzen Peter John Taylor Irene Teixidor-Toneu Catherine Tucker Sabarnee Tuladhar Robert MarchantAbstract
No abstract has been registered
Authors
Alexander Jueterbock Anne Margrete Leiros Nilsen Niko Steiner Clément Gauci Leo Minini Ralf Rautenberger Christian Guido Bruckner Nikolai Buer Inka BartschAbstract
Mariculture has emerged as a sustainable solution to address growing global demands for food and high-value products, with kelp cultivation playing a central role due to its diverse applications and ecological benefits. While advances in kelp farming have focused on optimizing either hatchery or grow-out phases, the long-term effects of early gametophyte treatments on sporophyte performance remain underexplored. Although the transition from gametophyte culture to harvestable sporophytes is routine in commercial kelp farming, no published, integrated framework exists that is purpose-built for researchers and R&D practitioners who need to document the effect of specific early-stage treatments applied under replicated, controlled conditions on measurable differences in sporophyte performance. Here, we present a detailed methodology for conducting experimental mariculture trials that bridge controlled laboratory experiments and field-scale applications. Our approach integrates controlled gametophyte treatments, seeding, hatchery cultivation, and field deployment, providing a replicable experimental framework for studying the influence of early-stage conditions on the growth, resilience, and productivity of mature sporophytes. This adaptable methodology enables researchers to address, in collaboration with kelp farmers, the impact of experimental conditions during gametophyte cultivation on the growth and performance of the kelp sporophytes in a factorial replicated design.