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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.

2023

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Abstract

Nature-based solutions are promising for climate adaptation and environmental management in urban areas, but urban conditions are stressful for vegetation. In particular, the interaction of drought and high temperatures may be detrimental. Guiding plant selection for urban greening with native species requires a far better knowledge of plant adaptations and stress acclimation. We tested the physiological responses of four candidate calcareous grassland species for green roofs and walls to the combined effects of drought and high temperatures under controlled conditions. The tested species proved relatively resistant to stress despite different strategies to protect the photosynthetic apparatus, maintain water balance, and repair damages. Based on the physiological responses, we rank the species in descending order of resistance to the stress factors tested: Trifolium medium > Festuca ovina > Carex flacca > Potentilla reptans, but all four can serve as potential candidates for green walls and roofs. Physiological stress screening of plant species for use on green roofs and walls supplements the habitat template approach to provide a stronger and wider base for prioritizations.

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Abstract

The benefits of individual vessel quota (IVQ) management in terms of improved harvest strategy and profitability are well recognized, but there is less focus on how different components of a quota portfolio can influence decisions underlying the effort allocation and profit-maximizing behaviour of fishers. Variations in the components of the quota portfolio may create economic incentives that alter the optimal harvest strategy and profitability. Thus, we study the potential impact of different components of quota portfolio on the intra-annual harvest strategy and profitability in two segments of the Norwegian bottom trawl fleet. By developing a vessel-based spatio-temporal bioeconomic framework, we demonstrate and compare adopted harvest strategies and accrued profits for small and large trawl vessels under three scenarios regarding restrictive quotas in codfish fishery. Our analysis confirms that alternations in the components of the quota portfolio influence the spatio-temporal dynamics of the fishing effort for small and large trawl vessels in different ways, probably due to the differences in vessel-specific characteristics. We also demonstrate that the differences in profit between small and large vessels in part depend on the overall size of the quota portfolio. The economies of scale in the trawl industry are being eroded as the shares of higher-priced species in the quota portfolio decreases. The benefits of economies of scale cannot be reaped as trawlers respond to the reduction in profit by redirecting effort from offshore areas of the Arctic to nearshore waters or staying ashore. Likewise, having small quotas of high-priced species reduces the effectiveness of the IVQ system in meeting management objectives, and could in some cases undermine sustainability outcomes. Our results also demonstrate that both the intensity with which fishers react to the fluctuations in market price levels and fishers’ perceptions of location attractiveness are influenced by the components of the quota portfolio.

Abstract

Constructed wetlands (CWs) are a widely recognised measure for reducing pollution loads and improving the quality of surface waters. The removal efficiency of CWs varies considerably depending on system type and design as well as residence time, hydraulic load, particles and nutrient loading rates. Therefore, there is a need to closely monitor the efficiency of existing measures, look at their efficiency in practice and be able to foresee potential implications for their efficiency in light of climate change and land management intensification. This study presents 18 years of data from a typical Norwegian small CW established in the Skuterud catchment. The main objective of this study was to look at the impact of hydraulic load, particles and nutrient loads (depending on climatic factors such as temperature and precipitation) on CW effectiveness. The results showed an average of 39 % and 22 % annual removal efficiency for sediment and phosphorus, respectively. It appears that good CW effectiveness coincides with a combination of high sediment or phosphorus loads to the CW and a stable runoff of low to moderate intensity. At the seasonal level, the highest sediment and phosphorus removal efficiency is observed in the summer seasons (47% for sediment and 29% for phosphorus), when the sediment and phosphorus loads and runoff are at their lowest, and the lowest in autumn (23% for sediment) and in winter (4% for phosphorus). The relationship between removal efficiency and loads to the CW is not that straightforward, as other seasonal differences, such as erosion patterns, vegetation development, also become important. The conclusion based on the results presented is that establishing CWs can be a good supplement to best management practice in erosion-prone catchments with sensitive recipients.

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Abstract

Productive and stable forage yields are essential for the sustainability of ruminal livestock production. Grassland seed mixtures composed of species of diverse functional groups have previously been demonstrated to increase yield performance and stability compared to monocultures. In this study we conducted field trials with five grass and two legume species either grown in monocultures or a range of mixtures from two-species to seven-species mixtures sown in a simplex design. The species represented different functional groups regarding ability to fixate atmospheric nitrogen (N), rate of establishment and temporal persistence.The experiments were established with the same cultivars of species at five locations in Norway with climatically contrasting environments – from mild humid, mountainous continental to sub-arctic. The experimental plots were harvested for three years at four of the sites and two years at one of the sites, and they were fertilised according to normal practise in intensive silage grass production in the respective regions (regular N). At three of the sites, a treatment with low mineral N supply rate was also included.We found that crops sown as mixtures returned higher yields and contained less weeds than the average of monoculture crops, and these effects were consistent over all sites and study years. The grass-legume mixtures managed at low N supply rate performed equally well or better than monocultures or grass-only mixtures managed at regular N supply. We found no effects of the functional groups categorised as temporal persistence or rate of establishment on the yield performance, and there were no apparent benefits of increasing the number of species beyond the species P. pratense, F. pratensis and T. pratense over the three production years the experiments lasted.The results suggest that by using grass-clover mixtures, farmers can reduce N fertiliser rates, without compromising productivity of temporary grassland under northern conditions over the first three years of production.

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The Governing Missions and Mission-Oriented Research and Innovation in the European Union guidelines promoted by the European Commission (EC) are helpful as a starting place for creating the enabling environment for BioCities which follow the principles of natural ecosystems to promote life (Mazzucato 2018, 2019). The strength of mission-oriented policies, defined as systemic public policies that draw on frontier knowledge to attain specific goals, is the empowerment of emergent solutions achieved by: (1) being bold and inspirational with wide social relevance; (2) having a clear direction with targeted, measurable, and time-bound metrics; (3) being ambitious but realistic; (4) being cross-disciplinary and cross-sectoral; and (5) driving multiple bottom-up solutions (Ergas 1987).

Abstract

The world's burgeoning billions have been kept fed thanks to the "Green Revolution" of the 20th century, which featured new hybridized crops with enhanced yields. Often deemed a miracle of science, it was also made possible by energy-intensive industrial fertilizers. Fritz Haber and Carl Bosch were each awarded the Nobel Prize for their contributions to the widely used processes for synthesizing ammonia from nitrogen taken from ambient air and hydrogen derived from fossil fuels. These ammonia-based nitrogen fertilizers, along with mined fertilizers, today help to feed the world, something Thomas Robert Malthus never envisioned in his 18th century writings warning of overpopulation. Today we are concerned with another green revolution that seeks to end the use of fossil fuels, which when burned create emissions that are dangerously warming the atmosphere and creating the need for a second agricultural revolution to ensure the world's billions can still be fed in the face of drastic climatic extremes. So as we look to decarbonize the world's economy and phase out the use of fossil fuels, what is the fertilizer industry doing to green its highly fossil fuel-dependent industrial and mining processes? We talk with Alzbeta Klein, CEO of the International Fertilizer Association, freshly returned from COP28 in Dubai, where for the first time the world's nations agreed to the need to phase out fossil fuels to temper the runaway climate change we are experiencing. "Food is energy, and we need to understand that connection," Klein says. "We need to understand the transition for the energy markets, and we need to understand the transition for the food market because the two go hand-in-hand." We also hear from Hiro Iwanaga of Talus Renewables, a nitrogen fertilizer startup at the forefront of using photovoltaics to crack hydrogen from water, rather than fossil fuels. Also freshly returned from Dubai, Iwanaga talks about his company's demonstration project now under way in Kenya, and the company's next projects here in the United States. "The green hydrogen tax credit that was passed as part of the Inflation Reduction Act makes our product cost-competitive," he explains. Also, Brandon Kail of Rocky Mountain BioAg speaks to his company's approach employing soil microbes as the foundation of a non-fossil fuel-based approach to plant nutrition, and Divina Gracia P. Rodriguez of the Norwegian Institute of Bioeconomy Research tells us about an EU-funded project in Ethiopia she is spearheading that seeks to address barriers to the adoption of human urine-based fertilizers.

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Abstract

The gut microbiota plays an important role in host health and disease. Our understanding of the fish microbiota lags far behind our knowledge of that of humans and other mammals. Nevertheless, research has highlighted the importance of the microbiota in the health, performance, and various physiological functions of fish. The microbiota has been studied in various fish species, including model animals, economic fish, and wild fish species. The composition of the fish microbiota depends on host selection, diet, and environmental factors. The intestinal microbiota affects the nutritional metabolism, immunity, and disease resistance of the fish host, while the host regulates the intestinal microbiota in a reciprocal way through both immune and non-immune factors. Improved and novel gnotobiotic fish models have been developed, which are important for the mechanistic study of host-microbiota interactions in fish. In this review, we discuss recent progress in fish microbiota research. We describe various aspects of this research, including both studies on fish microbiota variations and fundamental research extending our knowledge of host–microbiota interaction in fish. Perspectives on how fish microbiota research may benefit fish health and industrial sustainability are also discussed.

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Abstract

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17–34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling.