Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2020
Forfattere
Alexander Melvold Engebretsen Johanna Skrutvold Frøydis Meen WærstedSammendrag
I forbindelse med vegutbyggingen av Rv 4 på strekningen Gran-Jaren har NIBIO på oppdrag fra Statens vegvesen Region øst gjort etterundersøkelser av vannkjemi i berørte resipienter og i grunnvannsbrønner tilknyttet et masselager med svartskifer. Det har i anleggsfasen og i driftsfasen blitt oppdaget at det forekommer utslipp av naturlig forekommende uran og Direktoratet for Stråling og Atomsikkerhet har kommet med en tilsynsrapport der det påpekes at disse utslippene etter all sannsynlighet krever utslippstillatelse. I grunnvannsbrønner som ligger på masselageret er det registrert urankonsentrasjoner på opptil 933 μg/l mens det i utslippspunktet til resipient har blitt registrert urankonsentrasjoner på mellom 65 og 140 μg/l og spesifikk aktivitet for naturlig radioaktivt kalium (K-40) på mellom 0,3 (9,6 mg/l) og 0,5 (16 mg/l) Bq/l. Urankonsentrasjonene i grunnvannsbrønnene på masselageret har stabilisert seg på et lavere nivå de siste årene, men konsentrasjonene er fortsatt relativt høye. Det har blitt beregnet at total aktivitet for tilførsel av naturlige radionuklider til resipienten Vigga ligger på mellom 40 og 546 MBq for U-238 og på mellom 1924 og 3211 MBq for K-40, beregnet årlig for årene 2014-2020.
Forfattere
Anastasia Georgantzopoulou Julia Farkas Kuria Ndungu Claire Coutris Patricia Almeida Carvalho Andy M Booth Ailbhe MackenSammendrag
In this study, the effects of aged Ag and TiO2 nanoparticles (NPs), individually and as a mixture, in wastewater relative to their pristine counterparts on the development of the copepod nauplii (Tisbe battagliai) were investigated. NP behavior in synthetic wastewater and seawater was characterized during aging and exposure. A delayed development and subsequent mortality were observed after 6 days of exposure to aged Ag NPs, with a twofold decrease in EC50 (316 μg/L) compared to pristine NPs (EC50 640 μg/L) despite the similar dissolved Ag concentrations measured for aged and pristine Ag NPs (441 and 378 μg/L, respectively). In coexposures with TiO2 NPs, higher dissolved Ag levels were measured for aged NPs (238.3 μg/L) relative to pristine NPs (98.57 μg/L). Coexposure resulted in a slight decrease (15%) in the Ag NP EC50 (270 μg/L) with a 1.9-fold increase in the Ag NP retained within the organisms after depuration (2.82% retention) compared to Ag NP single exposures as measured with sp-ICP− MS, suggesting that the particles are still bioavailable despite the heteroaggregation observed between Ag, Ti NPs, and wastewater components. This study shows that the presence of TiO2 NPs can affect the stability and toxicity of Ag NPs in complex media that cannot be predicted solely based on ionic, total, or nanoparticulate concentrations, and the need for studying NP interactions in more complex matrices is highlighted.
Forfattere
Isabella Righini Bram Vanthoor Michel Verheul Muhammad Naseer Henk Maessen Tomas Persson Cecilia StanghelliniSammendrag
A greenhouse climate-crop yield model was adapted to include additional climate modification techniques suitable for enabling sustainable greenhouse management at high latitudes. Additions to the model were supplementary lighting, secondary heating and heat harvesting technologies. The model: 1) included the impact of different light sources on greenhouse air temperature and tomato production 2) included a secondary heating system 3) calculated the amount of harvested heat whilst lighting was used. The crop yield model was not modified but it was validated for growing tomato in a semi-closed greenhouse equipped with HPS lamps (top-lights) and LED (inter-lights) in Norway. The combined climate-yield model was validated with data from a commercial greenhouse in Norway. The results showed that the model was able to predict the air temperature with sufficient accuracy during the validation periods with Relative Root Mean Square Error <10%. Tomato yield was accurately simulated in the cases under investigation, yielding a final production difference between 0.7% and 4.3%. Lack of suitable data prevented validation of the heat harvest sub-model, but a scenario is presented calculating the maximum harvestable heat in an illuminated greenhouse. Given the cumulative energy used for heating, the total amount of heating pipe energy which could be fulfilled with the heat harvestable from the greenhouse air was around 50%. Given the overall results, the greenhouse climate(-crop yield) model modified and presented in this study is considered accurate enough to support decisions about investments at farm level and/or evaluate beforehand the possible consequences of environmental policies.
Forfattere
Hella Ellen Ahrends Stefan Siebert Ehsan Eyshi Rezaei Sabine Julia Seidel Hubert Hüging Ewert Frank Thomas Döring Victor Rueda-Ayala Werner Eugster Thomas GaiserSammendrag
Yield stability is important for food security and a sustainable crop production, especially under changing climatic conditions. It is well known that the variability of yields is linked to changes in meteorological conditions. However, little is known about the long-term effects of agronomic management strategies, such as the supply of important nutrients. We analysed the stability of four major European crops grown between 1955 and 2008 at a long-term fertilization experiment located in Germany. Six fertilizer treatments ranged from no fertilization over the omission of individual macronutrients to complete mineral fertilization with all major macronutrients (nitrogen, phosphorus, potassium and calcium). Yield stability was estimated for each crop x treatment combination using the relative yield deviation in each year from the corresponding (nonlinear) trend value (relative yield anomalies). Stability was lowest for potato, followed by sugar beet and winter wheat and highest for winter rye. Stability was highest when soils had received all nutrients with the standard deviation of relative yield anomalies being two to three times lower than for unfertilized plots. The omission of nitrogen and potassium was associated with a decrease in yield stability and a decrease in the number of simultaneous positive and negative yield anomalies among treatments. Especially in root crops nutrient supply strongly influenced both annual yield anomalies and changes in anomalies over time. During the second half of the observation period yield stability decreased for sugar beet and increased for winter wheat. Potato yields were more stable during the second period, but only under complete nutrient supply. The critical role of potassium supply for yield stability suggests potential links to changes in the water balance during the last decades. Results demonstrate the need to explicitly consider the response of crops to long-term nutrient supply for understanding and predicting changes in yield stability.
Sammendrag
Blue light (BL) affects different growth parameters, but information about the physiological effects of BL on conifer seedlings is limited. In northern areas, conifer seedlings are commonly produced in heated nursery greenhouses. Compared with Norway spruce, subalpine fir seedlings commonly show poor growth in nurseries due to early growth cessation. This study aimed to examine the effect of the BL proportion on the growth and development of such conifer seedlings in growth chambers, using similar photosynthetic active radiation, with 5% or 30% BL (400–500 nm) from high pressure sodium (HPS) lamps (300 μmol m−2 s−1) or a combination of HPS (225 μmol m−2 s−1) and BL-emitting diodes (75 μmol m−2 s−1), respectively. Additional BL increased transpiration and improved the growth of the Norway spruce seedlings, which developed thicker stems, more branches, and a higher dry matter (DM) of roots and needles, with an increased DM percentage in the roots compared with the shoots. In contrast, under additional BL, subalpine fir showed reduced transpiration and an increased terminal bud formation and lower DM in the stems and needles but no change in the DM distribution. Since these conifers respond differently to BL, the proportion of BL during the day should be considered when designing light spectra for tree seedling production.
Sammendrag
The open landscapes produced over centuries by small-scale farming in Norwegian coastal and fjord areas are threatened by agricultural abandonment, raising public concern for maintenance of the species-rich and valuable coastal grasslands. Semi-natural grasslands, traditionally grazed in the spring and fall and mown in summer, are most affected. Two linear programming models, one for small-scale sheep and one for small-scale mixed dairy and meat farms, both described in a separate method article, were developed. In the models is studied effects on production, grazing and land utilization, of altering government financial support among leys on arable land, enclosed farm pasture, grazing animals, and altering the (regulated) prices farmers pay for concentrate feed at the farm level. Sheep grazing can be expanded by intensification through increased fertilization and purchase of concentrate feed. Raising steers instead of bulls on dairy and beef farms with a milk quota would result in more mixed grazing by both sheep and steers, which is advantageous for the landscape. Steers are currently quite rare in Norway and their numbers can be increased with more subsidies for grazing, (Grazing Support (GS)) or by increasing the Regional Environmental Support (RES), a policy instrument targeting local projects for more grazing in specific areas. The current Agriculture and Cultural Landscape (ACL) subsidy payment places a higher value on arable land compared to the more biodiverse farm pastures, resulting in weaker incentives for keeping farm pasture in production. Raising the rate for farm pasture relative to that of arable land in the ACL scheme would result in stronger incentives for keeping such farm pasture in production, and likely increase biodiversity and landscape values. Increased GS for sheep might lead to more purchase of concentrate to keep more animals through the winter and eventually needs to be counteracted with higher prices for concentrated feedstuffs.
Sammendrag
An understanding of the relationship between volume increment and stand density (basal area, stand density index, etc.) is of utmost importance for properly managing stand density to achieve specific management objectives. There are two main approaches to analyse growth–density relationships. The first relates volume increment to stand density through a basic relationship, which can vary with site productivity, age, and potentially incorporates treatment effects. The second is to relate the volume increment and density of thinned experimental plots relative to that of an unthinned experimental plot on the same site. Using a dataset of 229 thinned and unthinned experimental plots of Norway spruce, a growth model is developed describing the relationship between gross or net volume increment and basal area. The models indicate that gross volume increases with increasing basal area up to 50 m2 and thereafter becomes constant out to the maximum basal area. Alternatively, net volume increment was maximized at a basal area of 43 m2 and decreased with further increases in basal area. However, the models indicated a wide range where net volume increment was essentially constant, varying by less than 1 m3 ha−1 year−1. An analysis of different thinning scenarios indicated that the relative relationship between volume increment and stand density was dynamic and changed over the course of a rotation.
Forfattere
Min Lin Melanie Stadlmeier Volker Mohler Kar-Chun Tan Andrea Ficke James Cockram Morten LillemoSammendrag
Key message We identifed allelic variation at two major loci, QSnb.nmbu-2A.1 and QSnb.nmbu-5A.1, showing consistent and additive efects on SNB feld resistance. Validation of QSnb.nmbu-2A.1 across genetic backgrounds further highlights its usefulness for marker-assisted selection. Abstract Septoria nodorum blotch (SNB) is a disease of wheat (Triticum aestivum and T. durum) caused by the necrotrophic fungal pathogen Parastagonospora nodorum. SNB resistance is a typical quantitative trait, controlled by multiple quantitative trait loci (QTL) of minor efect. To achieve increased plant resistance, selection for resistance alleles and/or selection against susceptibility alleles must be undertaken. Here, we performed genetic analysis of SNB resistance using an eight-founder German Multiparent Advanced Generation Inter-Cross (MAGIC) population, termed BMWpop. Field trials and greenhouse testing were conducted over three seasons in Norway, with genetic analysis identifying ten SNB resistance QTL. Of these, two QTL were identifed over two seasons: QSnb.nmbu-2A.1 on chromosome 2A and QSnb.nmbu-5A.1 on chromosome 5A. The chromosome 2A BMWpop QTL co-located with a robust SNB resistance QTL recently identifed in an independent eightfounder MAGIC population constructed using varieties released in the United Kingdom (UK). The validation of this SNB resistance QTL in two independent multi-founder mapping populations, regardless of the diferences in genetic background and agricultural environment, highlights the value of this locus in SNB resistance breeding. The second robust QTL identifed in the BMWpop, QSnb.nmbu-5A.1, was not identifed in the UK MAGIC population. Combining resistance alleles at both loci resulted in additive efects on SNB resistance. Therefore, using marker assisted selection to combine resistance alleles is a promising strategy for improving SNB resistance in wheat breeding. Indeed, the multi-locus haplotypes determined in this study provide markers for efcient tracking of these benefcial alleles in future wheat genetics and breeding activities.
Forfattere
Hye-Seon Kim Jessica M. Lohmar Mark Busman Daren W. Brown Todd A. Naumann Hege Hvattum Divon Erik Lysøe Silvio Uhlig Robert H. ProctorSammendrag
Background Sphingolipids are structural components and signaling molecules in eukaryotic membranes, and many organisms produce compounds that inhibit sphingolipid metabolism. Some of the inhibitors are structurally similar to the sphingolipid biosynthetic intermediate sphinganine and are referred to as sphinganine-analog metabolites (SAMs). The mycotoxins fumonisins, which are frequent contaminants in maize, are one family of SAMs. Due to food and feed safety concerns, fumonisin biosynthesis has been investigated extensively, including characterization of the fumonisin biosynthetic gene cluster in the agriculturally important fungi Aspergillus and Fusarium. Production of several other SAMs has also been reported in fungi, but there is almost no information on their biosynthesis. There is also little information on how widely SAM production occurs in fungi or on the extent of structural variation of fungal SAMs. Results Using fumonisin biosynthesis as a model, we predicted that SAM biosynthetic gene clusters in fungi should include a polyketide synthase (PKS), an aminotransferase and a dehydrogenase gene. Surveys of genome sequences identified five putative clusters with this three-gene combination in 92 of 186 Fusarium species examined. Collectively, the putative SAM clusters were distributed widely but discontinuously among the species. We propose that the SAM5 cluster confers production of a previously reported Fusarium SAM, 2-amino-14,16-dimethyloctadecan-3-ol (AOD), based on the occurrence of AOD production only in species with the cluster and on deletion analysis of the SAM5 cluster PKS gene. We also identified SAM clusters in 24 species of other fungal genera, and propose that one of the clusters confers production of sphingofungin, a previously reported Aspergillus SAM. Conclusion Our results provide a genomics approach to identify novel SAM biosynthetic gene clusters in fungi, which should in turn contribute to identification of novel SAMs with applications in medicine and other fields. Information about novel SAMs could also provide insights into the role of SAMs in the ecology of fungi. Such insights have potential to contribute to strategies to reduce fumonisin contamination in crops and to control crop diseases caused by SAM-producing fungi.
Sammendrag
Laser scanning data from unmanned aerial vehicles (UAV-LS) offer new opportunities to estimate forest growing stock volume ( V ) exclusively based on the UAV-LS data. We propose a method to measure tree attributes and using these measurements to estimate V without the use of field data for calibration. The method consists of five steps: i) Using UAV-LS data, tree crowns are automatically identified and segmented wall-to-wall. ii) From all detected tree crowns, a sample is taken where diameter at breast height (DBH) can be recorded reliably as determined by visual assessment in the UAV-LS data. iii) Another sample of crowns is taken where tree species were identifiable from UAV image data. iv) DBH and tree species models are fit using the samples and applied to all detected tree crowns. v) Single tree volumes are predicted with existing allometric models using predicted species and DBH, and height directly obtained from UAV-LS. The method was applied to a Riegl-VUX data set with an average density of 1130 points m−2 and 3 cm orthomosaic acquired over an 8.8 ha managed boreal forest. The volumes of the identified trees were aggregated to estimate plot-, stand-, and forest-level volumes which were validated using 58 independently measured field plots. The root-mean-square deviance ( RMSD% ) decreased when increasing the spatial scale from the plot (32.2%) to stand (27.1%) and forest level (3.5%). The accuracy of the UAV-LS estimates varied given forest structure and was highest in open pine stands and lowest in dense birch or spruce stands. On the forest level, the estimates based on UAV-LS data were well within the 95% confidence interval of the intense field survey estimate, and both estimates had a similar precision. While the results are encouraging for further use of UAV-LS in the context of fully airborne forest inventories, future studies should confirm our findings in a variety of forest types and conditions.