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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.

2021

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Slorene i Gjersjøen er et delta- og våtmarksområde med et svært rikt fugleliv og utvalgte naturtyper av stor verdi. Det har vært stor interesse for området, og i 2005 ble området regulert til spesialområde for naturvern av Ski, Ås og Oppegård kommuner (i dag Nordre Follo og Ås kommuner). Det har siden 2002 blitt utarbeidet flere rapporter som omhandler Slorene våtmarksområde. Forslag til skjøtselsplan har blitt utarbeidet av Jordforsk (2002), Ski, Ås og Oppegård kommuner (2011) og Biofokus (2018). Sweco gjorde også en hydraulisk undersøkelse av området i 2019. Grunneiere og interesseorganisasjoner har kommet med innspill til tiltak for området ved høringsuttalelse i 2012. Denne rapporten bygger på undersøkelsene gjort av Jordforsk, Biofokus og Sweco og NIBIOs erfaringer fra tidligere restaureringsarbeider. Det er foreslått ny målsetting for våtmarksområdet: Reguleringens målsetning er å ivareta et kulturbetinget våtmarksdelta med tilhørende skogområder i et aktivt elvedelta med intakte hydrologiske og geologiske prosesser. Det legges vekt på å bevare og utvikle tilhørende naturtyper, og områdets funksjon som leveområde for et rikt artsmangfold av naturlig forekommende planter og dyr. Slorene er delt inn i 5 skjøtselssoner, som bygger på Biofokus sin metode fra 2018. I sone 1 og 2 foreslås det et restaureringsregime over en treårs periode for å restaurere det åpne kulturpåvirkede slåttemarkspreget. Det er videre foreslått for sone 1 og 2 en skjøtselsplan med slått, beite og regelmessig rydding for å vedlikeholde og ivareta naturverdiene i våtmarksområdet. For sone 3 og 4 er det tenkt en naturlig utvikling av urørt skogmiljø med tilhørende naturlig biologisk mangfold. Det er forslått hydrauliske tiltak for å sikre og ivareta kulturminnet Steinhvelvsbrua, da denne ikke er dimensjonert for store vannmengder. Rapporten inneholder også forslag til ferdselsrestriksjoner og kanalisering av ferdsel for å skåne fugleliv og vegetasjon mens man samtidig åpner for naturopplevelser i Slorene.

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Eradication of alien invasive species in the soil with steam as an alternative to chemical fumigation may allow contaminated soil to be reused. We have investigated steam disinfestation of soil to combat invasive plant species in three experiments including different temperatures and exposure durations using a prototype stationary soil-steaming device. The experiments included effects on seed germination of bigleaf lupine (Lupinus polyphyllus Lindl.), ornamental jewelweed (Impatiens glandulifera Royle), and wild oat (Avena fatua L.; one population from Poland and one from Norway), as well as effects on sprouting rhizome fragments of Canada goldenrod (Solidago canadensis L.) and Bohemian knotweed (Reynoutria x bohemica Chrtek & Chrtková). In Experiment 1, we tested four different soil temperatures of 64, 75, 79, and 98 C with an exposure duration of 90 s. In Experiments 2 and 3, we tested exposure durations of 30, 90, and 180 s and 90, 180, and 540 s, respectively, at 98 C. Seed pretreatment of 14 d cooling for L. polyphyllus and I. glandulifera, no seed pretreatment and 12-h moistening for A. fatua populations, and 5- and 10-cm cutting size for R. x bohemica were applied. Our results showed germination/sprouting was inhibited at 75 C for I. glandulifera (for 90 s) and 98 C for the other species; however, longer exposure duration was needed for L. polyphyllus. While 30 s at 98 C was enough to kill A. fatua seeds and S. canadensis and R. x bohemica rhizome fragments, 180-s exposure duration was needed to kill L. polyphyllus seeds. The results showed promising control levels of invasive plant propagules in contaminated soil by steaming, supporting the steam treatment method as a potential way of disinfecting soil to prevent dispersal of invasive species.

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Key words: VKM, risk assessment, Norwegian Scientific Committee for Food and Environment, Norwegian Food Safety Authority, biological control, Nematodes, Phasmarhabditis californica, Moraxella osloensis. Parasitic nematodes and associated bacteria are increasingly being used for biocontrol of molluscs. Functionally, it is the bacteria that kill and thus control the targeted pests, but the function of the bacteria is dependent on the nematodes, which should be regarded as vectors of biocontrol. Although the nematodes and the bacteria have a symbiotic relationship within such biocontrol formulations, it should be noted that they are not dependent on each other in the wild, but can establish separate populations which can be free-living or hosted by other organisms. The biocontrol product Nemaslug 2.0 contains the nematode Phasmarhabditis californica (strain P19D) and the bacterial symbiont Moraxella osloensis (unknown strain). The nematode was first described in 2016 and has never been reported in Norway. The lack of reports suggests that it is absent from Norway, but this conclusion comes with a high degree of uncertainty since there have been limited search efforts. The climatic thresholds of the nematode are not known, but its current distribution, spanning widely varying climates, suggests that it could survive and establish in Norway. Natural spread from currently known areas of establishment to natural habitats in Norway is ruled out due to the nematode’s limited dispersal capacity. However, human-assisted spread (e.g. via the use of biocontrol products) and establishment would be likely if Nemaslug 2.0 is allowed for use in open fields in Norway. Use of Nemaslug 2.0 in greenhouses and other enclosed areas is not likely to facilitate spread to natural habitats in Norway provided that residues are properly handled. However, deposition of product residues from greenhouses to outdoor areas may result in local establishment of the nematode in the vicinity of the deposition. Phasmarhabditis californica has a broad host range and may parasitize both rare/endangered and common mollusc species. However, there is no scientific evidence suggesting that the nematode can affect natural populations of molluscs in wild habitats, or otherwise have negative effects on biodiversity. The nematodes’ association with the bacteria Moraxella osloensis is most likely lost, or at least weakened, in natural habitats, suggesting that the nematode becomes less capable of killing its hosts in the wild. Phasmarhabditis californica is not capable of harming or infecting humans. The bacterial species Moraxella osloensis is already present in Norway in a few locations and at a low abundance, and it may be native to Norway. Little is known regarding its distribution in natural environments, but the literature shows that it can infect humans and other mammals. In humans with immunodeficiency or other comorbidities, M. osloensis can cause meningitis, vaginitis, sinusitis, bacteremia, endocarditis, and septic arthritis. The risk of infection in people handling Nemaslug 2.0 can probably be substantially reduced by protective clothing and appropriate handling. We are not aware of any reported health issues arising from use of the previous version of Nemaslug, which also contains M. osloensis. Different strains of M. osloensis are known to vary in their sensitivity to antibiotics, and likely in other traits too. Thus, the lack of information provided about the strain identity and specific characteristics of the strain used in Nemaslug 2.0 generates a high degree of uncertainty regarding its pathogenicity, climate tolerance, sensitivity to antibiotics etc.

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Simple Summary: Horses with free faecal liquid defecate in one solid and one liquid phase, and the liquid phase can be a concern for the horse owner and veterinarians. The causes of free faecal liquid are unknown, but previous studies have indicated that feed ration composition may play an important role in the occurrence of the condition. A study comparing feed rations, feeding practices and management factors for horses with and without free faecal liquid was performed. Horses without free faecal liquid were reported to have a lower daily intake of starch and sugar and a higher daily intake of protein and fibre compared to horses with free faecal liquid. Horses with and without free faecal liquid were fed similar amounts of wrapped forages and were subject to the same management practices. The reported differences may be of importance for the condition, but further studies are required to establish if its occurrence is due to specific feeding regimens. Abstract: Free faecal liquid (FFL) in horses is characterised by the excretion of faeces in two phases (one solid and one liquid), which may cause dermatitis on the hindlegs. The causes of FFL are not known. Results from previous studies have indicated that feed ration composition and management factors may play important roles in the occurrence of FFL. A case–control study was therefore performed in which data on feed rations, feeding practices and management factors were compared between horses with (case) and without (control) FFL on 50 private farms in Sweden and Norway. The comparisons show that case and control horses were reported to be fed similar average amounts of wrapped forage (p = 0.97) and to be subject to similar management practices, but case horses were fed higher proportions of concentrates in their diet (p < 0.001) and lower average amounts of straw and lucerne (p < 0.05) compared to control horses. Case horses were reported to be fed twice as much concentrate per 100 kg BW and day as control horses and a higher daily intake of starch and water-soluble carbohydrates (p < 0.05). Case horses also had a lower daily intake of digestible crude protein and neutral detergent fibre compared to control horses (p < 0.05). These differences were small but are of interest for further studies of factors causing FFL.

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Continuous light (CL) or a predominant nitrogen supply as ammonium (NH4+) can induce leaf chlorosis and inhibit plant growth. The similarity in injuries caused by CL and NH4+ suggests involvement of overlapping mechanisms in plant responses to these conditions; however, these mechanisms are poorly understood. We addressed this topic by conducting full factorial experiments with tomato plants to investigate the effects of NO3− or NH4+ supply under diurnal light (DL) or CL. We used plants at ages of 26 and 15 days after sowing to initiate the treatments, and we modulated the intensity of the stress induced by CL and an exclusive NH4+ supply from mild to strong. Under DL, we also studied the effect of nitrogen (N) deficiency and mixed application of NO3− and NH4+. Under strong stress, CL and exclusive NH4+ supply synergistically inhibited plant growth and reduced chlorophyll content. Under mild stress, when no synergetic effect between CL and NH4+ was apparent on plant growth and chlorophyll content, we found a synergetic effect of CL and NH4+ on the accumulation of several plant stress hormones, with an especially strong effect for jasmonic acid (JA) and 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of ethylene, in xylem sap. This modulation of the hormonal composition suggests a potential role for these plant hormones in plant growth responses to the combined application of CL and NH4+. No synergetic effect was observed between CL and NH4+ for the accumulation of soluble carbohydrates or of mineral ions, indicating that these plant traits are less sensitive than the modulation of hormonal composition in xylem sap to the combined CL and NH4+ application. Under diurnal light, NH4+ did not affect the hormonal composition of xylem sap; however, N deficiency strongly increased the concentrations of phaseic acid (PA), JA, and salicylic acid (SA), indicating that decreased N concentration rather than the presence of NO3− or NH4+ in the nutrient solution drives the hormone composition of the xylem sap. In conclusion, N deficiency or a combined application of CL and NH4+ induced the accumulation of JA in xylem sap. This accumulation, in combination with other plant hormones, defines the specific plant response to stress conditions.

Sammendrag

Occasionally, high mycotoxin levels are observed in Norwegian oat grain lots. The development of oat varieties with improved resistance to Fusarium and mycotoxins is therefore highly valued in order to increase the share of high quality grain into the food and feed industry. The Norwegian project “SafeOats” (2016-2020) aimed to develop resistance-screening methods to facilitate the phase-out of Fusarium-susceptible oat germplasm, as well as to give new insight into the biology of Fusarium langsethiae and HT2+T2 accumulation in oats. In naturally infested as well as in inoculated field trials, the relative ranking of oat varieties according to Fusarium graminearum/DON content did not resemble the ranking according to F. langsethiae/HT2+T2 content. One variety regarded as moderate resistant to Fusarium according to studies of DON content, was susceptible to F. langsethiae and thus at high risk for HT2+T2 contamination. Screening of resistance to F. langsethiae/HT2-T2 should therefore be routinely applied in breeding programs in addition to the already established screening of resistance to F. graminearum/DON. The incidence of F. langsethiae in a selection of oat seed lots used for commercial sowing showed a similar ranking of varieties as in the field trials. On average, the fungus was observed on 5% of the kernels in 168 seed lots tested during 2016-2018. No indication of transmission of F. langsethiae from germinating seed to seedling was found in a study with germination of naturally infected seeds. We investigated whether removing of small kernels by size sorting could be a method to reduce the content of mycotoxins in oat grain. For several of the mycotoxins including HT2+T2, the concentrations were considerably higher in the small kernel fraction compared to unsorted grain. Our results demonstrate that the level of mycotoxins in unprocessed oat grain can be reduced by removing small kernels. The results from SafeOats will benefit consumers nationally and internationally by providing tools to increase the share of high quality grain into the food and feed industry. The project was financed by The Agriculture and Food Industry Research Funds /Research Council of Norway with support from the industry partners Graminor, Lantmännen, Felleskjøpet Agri, Felleskjøpet Rogaland & Agder, Fiskå Mølle Moss, Norgesmøllene, Strand Unikorn/Norgesfôr and Kimen Seed Laboratory.

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Key words: Risk assessment, Crayfish, Shrimps, Crabs, Climate change, Aphanomyces astaci, White spot syndrome, Alien species, Biological invasion Introduction The Norwegian Scientific Committee for Food and Environment (VKM) was requested by the Norwegian Environment Agency to assess the risk of negative impacts to biodiversity in Norway resulting from import of crustacean decapods for keeping in freshwater aquariums. VKM was asked to 1) list species of crayfish, crabs and shrimps that are currently kept in freshwater aquaria in Norway, and species that are likely to be kept in freshwater aquaria in Norway within the next 10 years, 2) assess the ability of the species to survive under Norwegian conditions and cause impacts on ecosystems and other species, and 3) state the potential negative effects on the biological diversity of diseases caused by pathogens, regulated under the Norwegian Food Act. Methods The risk assessment, without focus on pathogens, was performed in two steps. First, we used a pre-screening toolkit to identify species of crayfish, crabs and shrimps with potential to become invasive in freshwater habitats in Norway. Each species was given an invasiveness score based on 55 questions on biogeography, ecology, and climate change. In a second step, a full risk assessment, including the potential impacts of pathogens, was conducted on those species receiving the highest invasiveness score. This assessment included questions on the organism’s probability of entry and pathways of entry, establishment and spread, potential impacts on biodiversity, and how climate change scenarios might affect the assessment. Likelyhood and confidence was assessed for each question. In conclusion, each species was designated as either low-, moderate-, or high risk. Many crustacean decapod species are confirmed or suspected carriers of pathogens that can cause mass mortality among native crustaceans. The risk posed by crustaceans as carriers of pathogens may be independent of the environmental risk that they pose through ecological interactions. Therefore, the four crustacean disease pathogens that are regulated under the Norwegian Food Act, were assessed separately. These include Aphanomyces astaci causing crayfish plague, white spot syndrome virus (WSSV) causing white spot disease, Taura syndrome virus (TSV) causing Taura syndrome, and yellow head virus genotype 1 (YHV1) causing yellow head disease. The assessments comprised questions on the pathogen’s probability of entry (as a hitchhiker organism with imported crustaceans), pathways of entry, establishment and spread, and potential impact on crustacean biodiversity. Likelihood and confidence were assessed for each question. In conclusion, each pathogen was designated as either low-, moderate-, or high risk. In a third step, we categorized the likelihood that a crustacean species introduces a pathogen associated with a high- or moderate risk into: I) known chronic carriers, II) suspected chronic carriers, III) suspected situational carrier, IV) possible pathogen transmitters, and V) no direct or circumstantial evidence for carrier status or pathogen transmission in the genus. Results Based on information from the Norwegian Pet Trade Association, the project group listed 112 taxa (mainly species and some genera) of freshwater crayfish, crabs and shrimps that are relevant for trade in Norway. These included 38 crayfish taxa, 28 crab taxa, and 45 shrimp taxa. In addition, one marine crab was included. Sixteen species of crayfish, four species of shrimps, and two species of crabs underwent a full ecological risk assessment. The probabilities of entry both into the aquarium trade in Norway, and potentially further into Norwegian nature, were based on the prevalence of the species in the aquarium trade in Norway. We assumed that all species were equally likely to escape captivity or to be .........

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Soft rot Pectobacteriaceae (SRP) are ubiquitous on earth as there are records of findings from all continents where host plants are grown. This chapter describes information on soft rot diseases on these continents. For some countries, detailed information is provided by local experts on the SRP present, their economic damage, and the management strategies applied for their control. The focus of the chapter is mainly on SRP as causative agents of potato blackleg, although in specific cases details are provided on SRP in other host plants. In Europe, the SRP cause important economic losses mainly on potato, with most species described in the literature being found. In Latin America significant losses are also reported due to potato diseases caused by various Dickeya and Pectobacterium species, while in Australia and Oceania, recent outbreaks of D. dianthicola in potato have resulted in high economic losses. In Asia, however, SRP cause economic losses mainly in vegetable crops other than potato, while in North America SRP cause diseases on a wide range of crops (including potato and ornamental plants) in both field and storage. In Africa SRP are only known to occur in 17 of the 54 African countries but where it is known, potato is the most affected crop.

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In agricultural catchments, hydrological processes are highly linked to particle and nutrient loss and can lead to a degradation of the ecological status of the water. Global warming and land use changes influence the hydrological regime. This effect is especially strong in cold regions. In this study, we used long-term hydrological monitoring data (22–26 years) from small agricultural catchments in Norway. We applied a Mann–Kendall trend and wavelet coherence analysis to detect annual and seasonal changes and to evaluate the coupling between runoff, climate, and water sources. The trend analysis showed a significant increase in the annual and seasonal mean air temperature. In all sites, hydrological changes were more difficult to detect. Discharge increased in autumn and winter, but this trend did not hold for all catchments. We found a strong coherence between discharge and precipitation, between discharge and snow water equivalent and discharge and soil water storage capacity. We detected different hydrological regimes of rain and snow-dominated catchments. The catchments responded differently to changes due to their location and inherent characteristics. Our results highlight the importance of studying local annual and seasonal changes in hydrological regimes to understand the effect of climate and the importance for site-specific management plans.