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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.

2026

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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.

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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.

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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.

Sammendrag

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 .

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No abstract has been registered

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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.

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Green roofs are increasingly recognized as nature-based solutions that enhance urban resilience by supporting biodiversity, regulating microclimates, and mitigating stormwater runoff. However, their performance—particularly in extensive, lightweight systems—is often constrained by drought stress, which limits plant survival and ecosystem functioning under climate change. While substrate composition has been widely investigated in this context, the role of wind as a co-driver of drought impacts remains poorly understood. In this study, we examined how moderate wind interacts with substrate properties to shape drought responses in green roof vegetation. Using three non-succulent species (Plantago maritima, Pilosella officinarum, and Festuca rubra), we quantified substrate and plant water balance, physiological performance, wilting dynamics, and survival under prolonged drought conditions. Our results demonstrate that wind significantly accelerates drought effects—regardless of species or substrate—by intensifying substrate desiccation, with critical moisture thresholds reached at 6–8%. While wind alone did not impair plant performance under well-watered conditions, its interaction with drought markedly reduced survival time and increased physiological stress. Although general response patterns were consistent across species, subtle interspecific differences indicate that plant selection for green roofs should account for combined drought and wind exposure. These findings highlight wind as an overlooked but critical factor in the design and evaluation of resilient green roof systems and potentially contribute to a more comprehensive understanding of vegetation performance in urban nature-based solutions under climate stress.

Sammendrag

In high-latitude arable systems (63.9°N), short growing seasons and cold climates often constrain regenerative practices. This study investigates how cover crop (CC) diversity influences the synergy among root development, carbon (C) persistence, and nutrient (N and P) dynamics within a barley (Hordeum vulgare L.)-oat (Avena sativa) rotation. Over three years, we evaluated a gradient of CC intercropping complexity using a randomized complete block design. Treatments were: (1) Control (barley/oat without NPK), (2) Biochar-Fertilizer (barley/oat + NPK + 1.8 Mg ha-1 year-1 biochar), (3) Monocrop (barley/oat), (4) Ryegrass (barley + ryegrass), (5) Clover (barley + ryegrass + white/red clover), and (6) Chicory (barley + ryegrass + red clover + chicory + bird’s-foot trefoil). We quantified root biomass, soil organic matter (SOM) fractions, specifically Mineral-Associated Organic Matter (MAOM) and Particulate Organic Matter (POM), aggregate stability, nutrient stocks, and microbial abundance via qPCR. The CCs sown shortly after barley were successfully established, with an average biomass of 1525 kg/ha, without compromising cereal yields, thereby confirming their viability in Nordic climates. A central finding was that root development served as the primary driver of organo-mineral associations. Ryegrass- and Clover-based systems produced significantly higher root biomass, which correlated strongly (p < 0.01) with MAOM stocks and total P acquisition. These systems stored 12 Mg/ha more MAOM-C and 1.1 Mg/ha more MAOM-N than the control at 0-20 cm depth. The inclusion of diverse functional traits in the complex five-species mixture significantly improved soil physical structure, yielding higher aggregate stability and lower bulk density. While CCs accumulated approximately 7 kg P/ha, the diverse mix optimized nutrient availability, whereas simpler mixtures showed higher C:P ratios, suggesting potential microbial P immobilization. Microbial abundance was consistently higher in multi-species treatments, indicating a more active biological environment. Ongoing analysis integrates cereal physiological data, focusing on the photosynthetic efficiency of oats in response to cultivation? regimes. Our findings bridge the gap between root morphology, plant physiology, and long-term SOM persistence, providing a strategic framework for using functional crop traits to enhance soil resilience and nutrient efficiency in cold-climate regions.

Sammendrag

High-latitude regions pose challenges for soil organic matter (SOM) sequestration and for improving soil fertility due to low temperatures, which shorten growing seasons and promote off-season nutrient leaching. Even long-term experiments on conservation practices have shown only modest increases in C storage. Nonetheless, persistent SOM fractions, such as mineral-associated organic matter (MAOM), have been shown to improve relatively quickly through conservation practices in temperate regions, which could be key in high-latitude regions. MAOM is an important SOM fraction not only for promoting carbon (C) storage but also for providing an available form of nitrogen (N) for plant nutrition. In this study, we show that, in Norwegian agriculture (63.9°N), MAOM (C and N) stocks improved only after three years of implementing cover crop systems that combined 1 to 4 cover crops with cereals (barley or oats) intercropped simultaneously (12 Mg ha-1 for C and 1.1 Mg ha-1 for N in the 0-20 cm layer more compared to unfertilized Control plots). Cover crops containing red and white clover and ryegrass efficiently increased the MAOM fraction in soil. An increase in root biomass and changes in root morphology were the primary factors linking cover crops to MAOM improvements in this field. In addition to benefits for SOM stocks, we recorded improvements in microbial abundance, soil structure, nutrient cycling, and cereal physiology. Our findings help to reframe MAOM as a bioavailable nutrient pool essential for soil health and nutrient cycling, which can be improved in the relatively short term through root development.