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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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Abstract

Abstract This study investigated the incorporation of various waste materials including wastepaper, Tetra Pak, wood chips and scrap tire fluff into flue gas desulfurization (FGD) gypsum and cement mortar matrices to produce sustainable composite materials. Four distinct composite types based on the waste materials were developed and evaluated for selected properties including thermal and acoustic insulation. The proportion of the waste materials was varied between 10 and 40 vol% of the base matrix. The compressive strength of the filled gypsum composites was in the range of 4.17–10.39 N/mm² while the pure gypsum was 11.38 N/mm². The addition of the wastes in gypsum composites reduced compressive strength by about 10% for the best recipe and as large as 60% for the worst combination. However, the measured strength still exceeds the strength of typical gypsum wallboard with a compressive strength of about 3–4 N/mm² for whole-board crushing tests and it is much lower for point loads. The normal-incidence sound absorption coefficient indicated that the waste-filled samples absorbed around 80% of the incident sound energy between 2000 and 3000 Hz, comparable to some commercial acoustic foams. The results highlight the potential of utilising these waste-based composites in environmentally friendly construction applications. Depending on the waste type and matrix used, the results revealed trade-offs between multi-functional performance and sustainability benefits.

Abstract

Potato field management in Europe is already optimized for high production and tuber quality; however, numerous environmental challenges remain if the industry is to achieve “green economy” targets, such as less resources utilized, and less nitrate leached to the environment. Strategic co-scheduling irrigation and nitrogen (N) fertilization might increase resource use efficiency while minimizing reactive losses such as nitrate leaching. This study aimed to quantify the combined effect of irrigation and N fertilization on potato production, growth, and resource use efficiencies. A field experiment was conducted from 2017 to 2019 on a coarse sandy soil in Denmark, with a drought event occurring in 2018. Full (Ifull, maximized), deficit (Idef, 70–80 % of Ifull) and low irrigation treatments (Ilow, minimized amount to keep crop survival), each under full (Nfull, maximized) and variable (Nvar, variable amount according to the crops’ needs) N fertilization were applied. The analyses results show that Ilow limited potato growth under a drought-heat event; otherwise, potato growth was comparable between Ifull and Idef treatments, with 31–32 % higher irrigation efficiency (IE) under Idef than under Ifull. Nitrate leaching was variable and not significantly different among the treatments, being in general 9–13 % lower under Idef in absolute terms than under Ifull. Unexpectedly, outcomes from Nvar were statistically lower compared to those from Nfull. Radiation use efficiencies (RUEs) from Ilow and Nvar were significantly lower than from Ifull and Idef (14–19 %), and from Nfull (9–11 %). N use efficiencies (NUE) were comparable between N fertilization treatments but significantly different among different irrigation treatments. Overall, this study confirms that Idef is the best irrigation strategy. Future efforts should focus on developing improved approaches for detecting in-season crop N status and further quantifying N requirements, as well as promoting the co-scheduled management of irrigation and N fertilization. Remote sensing approaches have great potential to assist with this.

2025

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Abstract

Pollinator conservation schemes typically focus on conserving existing, restoring degraded, or creating new wild bee habitats. Their effectiveness depends on dispersal corridors enabling habitat colonization by bees. However, the role of seminatural linear landscape structures (LLS) in connecting pollinator communities across intensively managed landscapes remains poorly understood. We analyzed 953 occurrences of wild bees comprising 79 nonparasitic species sampled at 68 study sites across a Norwegian and a Danish landscape. We first tested whether bee species richness was positively associated with the lengths of seminatural LLS in bee foraging ranges of study sites while controlling for local plant species richness. We then combined maps identifying seminatural LLS with least‐cost path (LCP) analysis to determine whether bee species compositional similarity, a proxy for connectivity, decreased as LCP length increased. The length of seminatural LLS, such as forest edges, was positively correlated with bee species richness and habitat connectivity. Specifically, wild bee species richness sampled along roadsides increased as the length of seminatural LLS increased in 1.5 km circles around the study sites, and increased as local plant species richness increased. The most likely dispersal routes between our bee communities tracked forest edges. The length of LCPs provided better models of bee species compositional similarity than geographic distance, suggesting that seminatural LLS, particularly forest edges, act as dispersal corridors in intensively managed landscapes. However, bee species compositional similarity among communities depended on site‐specific plant species richness and similarity in plant community composition, which highlights the importance of improving the habitat quality of seminatural LLS if they are to function as dispersal corridors. Our findings suggest that maps of LCPs can be used to identify important dispersal corridors between bee habitats and to direct wild bee habitat management actions along seminatural LLS to facilitate the dispersal of bees in intensively managed landscapes.

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Abstract

Hyperspectral imaging (HSI) captures rich spectral data across hundreds of contiguous bands for diverse applications. Dimension reduction (DR) techniques are commonly used to map the first three reduced dimensions to the red, green, and blue channels for RGB visualization of HSI data. In this study, we propose a novel approach, HSBDR-H, which defines pixel colors by first mapping the two reduced dimensions to hue and saturation gradients and then calculating per-pixel brightness based on band entropy so that pixels with high intensities in informative bands appear brighter. HSBDR-H can be applied on top of any DR technique, improving image visualization while preserving low computational cost and ease of implementation. Across all tested methods, HSBDR-H consistently outperformed standard RGB mappings in image contrast, structural detail, and informativeness, especially on highly detailed urban datasets. These results suggest that HSBDR-H can complement existing DR-based visualization techniques and enhance the interpretation of complex hyperspectral data in practical applications. Tested in remote sensing applications involving urban and agricultural datasets, the method shows potential for broader use in other disciplines requiring high-dimensional data visualization.

Abstract

Food self-sufficiency and local food production are increasingly important in the context of global supply chain uncertainty. In Northern Norway, sustaining agricultural activity is central to national food preparedness, yet vegetable production in Arctic municipalities remains limited. In this study, we examine how vegetable production can be enhanced in Nordreisa municipality by exploring barriers, opportunities, and stakeholder perspectives. Using a qualitative single-case study design, we investigate local realities that shape the current lack of vegetable production through semi-structure interviews with diverse stakeholders across the regional food system and a local interest in vegetable production survey. We found that systemic barriers such as limited infrastructure, fragmented markets, and governance gaps constrain immediate growth. At the same time, motivated producers, consumer interest in local food, and a shared desire for self-sufficiency indicate a latent potential for development. This study suggests that increasing local vegetable production requires a dual approach: grassroots initiatives that mobilize local actors and supportive governance that enables implementation. Practical measures include the establishment of local storage and distribution facility, fostering collaboration between producers and consumers, and aligning municipal and national policies with local capacities. Through the enhancement of social networks and institutional support, municipalities like Nordreisa can take concrete steps towards strengthened local vegetable production.

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Abstract

A controlled peatland rewetting experiment was conducted on two adjacent drained peatland sites in southeastern Norway. Eddy covariance monitoring of CO 2 and CH 4 fluxes at both sites began in 2019. In 2021, the Treatment Site was rewetted while the Control Site remained drained. Using nine environmental variables and the processed flux data as training data, Bayesian Additive Regression Tree (BART) models were used to generate annual flux balances for CO 2 and CH 4 . The 4-year mean annual flux at the Control Site was 17.3 ± 10 g CO 2 -C m − 2 yr − 1 and 4.6 ± 0.1 g CH 4 -C m − 2 yr − 1 . At the Treatment Site, the 2-year mean annual flux before the rewetting was 12.2  ±  3.8 g CO 2 -C m − 2 yr − 1 and 1.8  ±  0.04 g CH 4 -C m − 2 yr − 1 . In the first year after rewetting the annual flux was 53.3  ±  13 g CO 2 -C m − 2 yr − 1 and 3.8  ±  0.3 g CH 4 -C m − 2 yr − 1 , and in the second year after rewetting the annual flux was 41.2  ±  18 g CO 2 -C m − 2 yr − 1 and 3.4  ±  0.4 g CH 4 -C m − 2 yr − 1 . BART counterfactual modeling was able to estimate the effect of the rewetting on CO 2 and CH 4 fluxes. Two years after the rewetting, the BART counterfactual modeling estimated that the cumulative fluxes had increased by 80.3 ± 49 g CO 2 -C m − 2 and 3.4 ± 0.47 g CH 4 -C m − 2 because of the rewetting. Carbon flux monitoring of both sites is ongoing as the Control Site remains drained and the soil and vegetation at the Treatment Site continues to adjust to the altered hydrological regime after rewetting.